Injection Moulding Plastics: How to Improve Flow Lines 

Injection Moulding Plastics: How to Improve Flow Lines 

Injection moulding plastics is a widely used manufacturing process for creating high-quality plastic parts. However, like any process, it is not without its challenges. One common issue that arises during injection moulding is the occurrence of flow lines. Flow lines are wavy patterns or streaks that appear on the surface of moulded parts, resulting from uneven material flow and cooling. While flow lines may 

not affect the functionality of the part, they can impact its aesthetic appeal. In this article, we will explore the causes of flow lines in injection moulding and discuss strategies to prevent and minimise their occurrence. 

Injection Moulding Plastics

Understanding Flow Lines in Injection Moulding Plastics

Flow lines are visual defects that manifest as circles, lines, or patterns on the surface of a moulded part, predominantly near the gate where the material enters the mould cavity. These lines are an indication of non-uniformity in the flow pattern of the molten plastic within the mould. When the molten material reaches a cooled area of the mould, it solidifies, while the material in the inner area continues to flow. This temperature difference between the flowing and solidified material results in a ripple-like effect, causing flow lines to appear. 

While flow lines can provide insights into the material flow and fill behaviour within the mould, they are generally considered undesirable. Customers and manufacturers prefer visually flawless parts with high aesthetic standards. Flow lines can be particularly problematic for parts that require a smooth surface, such as gears. Therefore, it is cruc

ial to address flow lines through proper process and mould design to ensure the production of high-quality plastic parts. 

Causes of Flow Lines in Injection Moulding Plastics

Flow lines can occur due to various factors, including material properties, machine settings, and mould design. Understanding these causes is essential for implementing preventive measures. Let’s explore some common causes of flow lines: 

Material Temperature 

The melt temperature of the plastic material plays a significant role in controlling its viscosity and flow characteristics. If the melt temperature is too low, the material may not flow uniformly, leading to flow lines. It is important to heat the plastic to an optimal temperature that allows for proper deformation and flow. However, caution must be exercised to avoid exceeding the degradation temperature of the material. Monitoring temperature at different points in the injection moulding process using temperature sensors and employing control systems and alarms can help prevent flow lines. 

Mould Temperature 

The temperature within the mould can also contribute to the formation of flow lines. If the mould temperature is too low, premature cooling may occur when the molten material enters the mould cavity. This can result in uneven flow and the appearance of flow lines. Adjusting the mould temperature to ensure proper heat transfer and preventing premature cooling can help minimise flow lines. 

Injection Speed and Pressure 

The speed and pressure at which the molten material is injected into the mould also affect the occurrence of flow lines. Insufficient injection speed or pressure can cause slower flow, resulting in parts of the material solidifying before others. This temperature difference in the flow pattern leads to the formation of flow lines. Increasing the injection speed and pressure

Injection Moulding Plastics

 can help maintain uniform flow and minimise flow lines. 

Runner and Gate Design 

The design of the runner and gate in the mould can significantly impact material flow and the occurrence of flow lines. A narrow runner or gate restricts flow, slowing down the material and exposing it to increased temperature loss. This can result in non-uniform cooling and the appearance of flow lines. It is important to ensure that the runner and gate dimensions are appropriately sized to allow for smooth and even flow throughout the mould cavity. 

Preventing Flow Lines in Injection Moulding 

Preventing flow lines requires a combination of careful mould design and proper adjustment of process parameters. Here are some strategies to consider: 

Optimise Mould Design 

A well-designed mould is essential for minimising flow lines. Maintaining uniform wall thickness throughout the moulded part is crucial to ensure consistent cooling and prevent temperature variations that lead to flow lines. Avoiding sharp corners and incorporating smooth bends in the design can promote even material flow and reduce the occurrence of flow lines. Additionally, proper gate placement and type selection can help distribute material evenly, reducing the likelihood of flow lines. 

Control Process Parameters 

Controlling process parameters during injection moulding is vital for preventing flow lines. It is important to ensure that the melt temperature is within the recommended range for the chosen material. Adjusting the mould and nozzle temperature to maintain optimal heat transfer and prevent premature cooling can also minimise flow lines. Increasing injection speed and pressure can help maintain uniform flow and prevent temperature variations that lead to flow lines. Furthermore, ensuring proper venting in the mould can help eliminate trapped air and promote even material flow. 

Post-Processing Treatments 

In some cases, even with careful mould design and process optimisation, flow lines may still appear on the surface of the moulded parts. In such situations, post-processing treatments can be employed to minimise their appearance. Texturing the mould surface can help hide flow lines, as they are more visible on smooth surfaces. However, it is important to consider the functional requirements of the part before applying texturing treatments. Painting and pad printing techniques can also be used to mask flow lines and improve the aesthetic appeal of the parts. 


Injection Moulding Plastics: How to Improve Flow Lines

Flow lines are a common defect in plastic injection moulding that can impact the visual appeal of moulded parts. Understanding the causes of flow lines and implementing preventive measures through proper mould design and process optimisation is crucial for producing high-quality plastic parts. By optimising material and mould temperatures, adjusting injection speed and pressure, and ensuring proper venting and gate design, manufacturers can minimise the occurrence of flow lines. Additionally, post-processing treatments such as mould texturing, painting, and pad printing can help mask flow lines and enhance the aesthetic quality of the parts. By addressing flow lines, manufacturers can meet the demands of customers for visually flawless plastic products.


Plastic Injection Moulding Near Me : Tips on Maintaining the Quality of High Gloss Injection Moulded Parts.

Design Optimisation in Plastics Injection Moulding: Embracing the Simultaneous Engineering Principle

Design Optimisation in Plastics Injection Moulding: Embracing the Simultaneous Engineering Principle

  • Introduction
  • Understanding the Simultaneous Engineering Principle (SEP) Effect
  • Advantages of SEP in Injection Mould Design
  • Incorporating SEP Principles in Mould Flow Analysis
  • Material Selection and the SEP Effect
  • Optimising Cooling Systems with SEP
  • Reducing Cycle Times through SEP
  • The SEP Effect in Multi-Cavity Moulds
  • Conclusion


Plastics injection moulding is a widely used manufacturing process known for its precision and efficiency in producing high-quality plastic components. One crucial aspect of achieving optimal results in injection moulding is the design of the mould itself. Design optimisation plays a vital role in ensuring better performance, reduced costs, and faster production cycles. In recent years, the concept of the Simultaneous Engineering Principle (SEP) Effect has emerged as a groundbreaking approach in the field of injection mould design. By integrating design, analysis, and manufacturing processes right from the initial stages of product development, designers can anticipate potential issues, optimise the mould design, and minimise the need for costly modifications later in the manufacturing process.

In this article, we will explore various aspects of the SEP Effect and its application in enhancing the performance of injection moulds. We will delve into the advantages of incorporating SEP principles in mould design, the role of mould flow analysis in optimising designs, the impact of material selection, the optimisation of cooling systems, strategies to reduce cycle times, and the application of the SEP Effect in multi-cavity moulds.

Understanding the Simultaneous Engineering Principle (SEP) Effect

The Simultaneous Engineering Principle (SEP) emphasises the integration of design, analysis, and manufacturing processes right from the initial stages of product development. By adopting this approach, designers can anticipate potential issues, optimise the mould design, and reduce the need for costly modifications later in the manufacturing process. The SEP Effect in injection mould design involves separating the filling, packing, and cooling stages of the injection moulding process, allowing for better control and optimisation of each stage. This approach leads to shortened product development cycles, improved product quality, increased manufacturing efficiency, and reduced overall costs.

Advantages of SEP in Injection Mould Design

The adoption of the SEP Effect in injection mould design offers numerous advantages. By incorporating SEP principles, designers can significantly shorten product development cycles. This is achieved by addressing potential issues early in the design process, minimising the need for costly modifications during manufacturing. Additionally, the SEP Effect allows for improved product quality. By optimising each stage of the injection moulding process, designers can ensure greater consistency and accuracy in the final product. This, in turn, leads to increased customer satisfaction and reduced rejection rates.

The SEP Effect also contributes to increased manufacturing efficiency. By integrating design, analysis, and manufacturing processes, designers can identify opportunities for optimisation, such as reducing cycle times and streamlining production. This results in higher productivity and lower costs for manufacturers. Overall, the SEP Effect enables companies to deliver high-quality products to the market faster and at a lower cost, giving them a competitive edge in the industry.

Incorporating SEP Principles in Mould Flow Analysis

Mould flow analysis is an essential tool in the design optimisation process for injection moulds. By simulating the injection moulding process, designers can identify potential defects, optimise cooling channels, and predict part warpage. The integration of the SEP Effect into mould flow analysis takes this analysis to a new level of accuracy and insight. By considering the simultaneous engineering principles during the analysis, designers can make more informed decisions regarding the design of the mould. This includes optimising gate placement, identifying potential flow imbalances, and predicting the cooling characteristics of the mould. By incorporating SEP principles in mould flow analysis, designers can achieve more accurate predictions, better insights, and enhanced mould designs.

Material Selection and the SEP Effect

The choice of materials used in injection moulds is a critical factor in their performance and longevity. The SEP Effect can assist designers in selecting the most suitable materials for their specific applications. By considering factors such as part complexity, expected production volume, and environmental conditions, designers can choose materials that offer the best combination of strength, durability, and cost-effectiveness. The SEP Effect also takes into account the compatibility of the selected materials with the injection moulding process, ensuring optimal performance and minimal issues during manufacturing. By incorporating SEP principles in material selection, designers can maximise the overall efficiency and effectiveness of their injection moulds.

Optimising Cooling Systems with SEP

Efficient cooling is crucial for achieving high-quality parts and reducing cycle times in injection moulding. The SEP Effect can be applied to optimise cooling systems within the mould. This includes designing conformal cooling channels that follow the contours of the part, allowing for more uniform cooling and reduced cycle times. Proper baffle design can also be implemented to control the flow of cooling media and improve heat transfer. Additionally, the use of advanced cooling materials, such as thermally conductive alloys, can further enhance the cooling efficiency and reduce cycle times. By optimising cooling systems with SEP principles, designers can achieve improved part quality, reduced production costs, and increased overall productivity.

Reducing Cycle Times through SEP

Cycle time directly impacts production efficiency and costs in injection moulding. By utilising the SEP Effect, designers can identify opportunities to reduce cycle times without compromising part quality. This includes strategies such as optimising part design to minimise material flow distance and reduce cooling time. Gate placement can also be optimised to ensure efficient filling and packing of the mould cavity. Furthermore, selecting the appropriate mould material can contribute to faster cycle times by improving heat transfer and reducing cooling time. By applying SEP principles to reduce cycle times, manufacturers can increase their production output, lower costs, and improve overall efficiency.

The SEP Effect in Multi-Cavity Moulds

Multi-cavity moulds offer increased productivity but present challenges related to cavity balance and consistent part quality. The SEP Effect can be applied to address these challenges and ensure uniformity across multiple cavities. By optimising the mould design, gate placement, and cooling system for multi-cavity moulds, designers can achieve balanced filling and packing, resulting in consistent part dimensions and quality. The SEP Effect allows for better control and optimisation of each cavity, reducing variations and improving overall productivity. By embracing SEP principles in multi-cavity moulds, manufacturers can maximise their production efficiency and deliver high-quality parts consistently.


The Simultaneous Engineering Principle (SEP) Effect has revolutionised the field of injection mould design, providing designers with powerful tools to optimise designs, enhance performance, and reduce costs. By integrating SEP principles into various aspects of injection mould design, manufacturers can achieve greater efficiency, faster production cycles, and higher-quality plastic components. Embracing the SEP Effect is essential for staying competitive in the fast-paced world of injection moulding and delivering superior products to the market. By considering the advantages of SEP in mould design, incorporating SEP principles in mould flow analysis, optimising cooling systems, reducing cycle times, and applying the SEP Effect to multi-cavity moulds, manufacturers can unlock the full potential of injection moulding and drive success in their operations.

With the adoption of the Simultaneous Engineering Principle (SEP) Effect, designers can optimise injection mould designs, reduce costs, and enhance performance. By integrating design, analysis, and manufacturing processes from the initial stages, the SEP Effect allows for faster product development, improved quality, and increased manufacturing efficiency. By incorporating SEP principles into mould flow analysis, designers can make more informed decisions and achieve better insights. Material selection and optimisation of cooling systems can further enhance performance and reduce cycle times. The SEP Effect can also be applied to multi-cavity moulds to ensure consistent part quality. Embracing the SEP Effect is crucial for staying competitive in the world of injection moulding and delivering high-quality plastic components.

Injection Moulding

Plastic Moulders UK Article | Demystifying Part Warp: Analysing Pressure Gradients, Polymer Temperature, and Their Effects

Plastic Moulders UK Article | Demystifying Part Warp: Analysing Pressure Gradients, Polymer Temperature, and Their Effects on Residual Shear Stress and Shear Rate


The following article is from Ledwell Plastics, Plastic Moulders UK

When it comes to the manufacturing of plastic parts, one of the most common challenges faced is part warp. The phenomenon of part warp can be frustrating and costly, often resulting in rejections, rework, and even production delays. However, by understanding the underlying factors that contribute to part warp, such as pressure gradients and polymer temperature, manufacturers can take proactive measures to prevent or minimise this issue. In this blog post, we will delve into the intricate details of part warp, exploring its causes and effects on residual shear stress and shear rate. By demystifying these complex concepts and providing practical insights, we aim to equip manufacturers with the knowledge and tools necessary to effectively address part warp and ensure the production of high-quality plastic parts.

1. Understanding part warp: Causes and consequences

Understanding part warp is crucial in the manufacturing process, as it can have significant consequences on the final product’s quality and performance. Part warp refers to the distortion or deformation that occurs in a plastic component during the cooling process after moulding. It is a commonly encountered issue that can lead to dimensional inaccuracies, poor aesthetics, and even functional problems. Several factors can contribute to part warp, with pressure gradients and polymer temperature being two key influencers. Pressure gradients occur when there is an uneven distribution of pressure within the mould cavity during the injection moulding process. This can result from variations in material flow, gate design, or the filling pattern. High-pressure areas can lead to increased material flow, resulting in excess poly

plastic moulders uk

mer filling certain regions of the mould cavity faster than others. Conversely, low-pressure regions can cause insufficient filling, leaving voids or thin sections. These imbalances in material distribution can lead to uneven cooling rates, which ultimately result in part warp. Polymer temperature also plays a crucial role in part warp. During the cooling phase, the polymer undergoes thermal contraction, which can cause distortion if not uniformly controlled. If sections of the part cool faster than others, thermal stresses build up and can cause warping. Factors such as material composition, mould design, and cooling mechanisms can influence polymer temperature distribution. The consequences of part warp can vary depending on the specific application and requirements of the component. It can result in dimensional variations, making the part incompatible with assembly or causing functional issues. Aesthetically, part warp can lead to visible deformities, surface defects, or even part failure. Understanding the causes and consequences of part warp is essential for manufacturers to implement effective mitigation strategies. This involves careful design considerations, including gate placement, mould design optimisation, and material selection. Additionally, controlling process parameters such as injection pressure, melt temperature, and cooling rate can help minimise the occurrence of part warp. By addressing pressure gradients and polymer temperature distribution, manufacturers can strive to produce high-quality components with minimal distortion and ensure optimal performance and customer satisfaction.

2. Pressure gradients: A key factor in part warp

When it comes to part warp in the manufacturing of plastic components, pressure gradients play a crucial role. Understanding and analysing pressure gradients can help demystify the causes behind part warp and provide insights into effective mitigation strategies. Pressure gradients refer to the variation in pressure experienced across different sections of a mould during the injection moulding process.

These variations can arise from a multitude of factors, including variations in polymer temperature, flow rate, and the design of the mould itself. The uneven distribution of pressure within a mould can lead to uneven cooling and solidification of the molten polymer, resulting in part warp. The variations in pressure can cause different rates of cooling and shrinkage across the part, leading to distortions and deformations. Analysing and managing pressure gradients is essential to minimise part warp. One effective approach is to optimise the design of the mould by incorporating features that promote uniform pressure distribution. This can include the strategic placement of cooling channels, the use of venting systems to release trapped air, and the implementation of proper gate design. Furthermore, careful monitoring and control of polymer temperature during the injection moulding process can help mitigate pressure gradients and minimise part warp. Maintaining consistent temperature throughout the mould cavity ensures uniform cooling and reduces the likelihood of uneven shrinkage. It is also important to consider the shear stress and shear rate experienced by the polymer during the injection moulding process, as they can influence pressure gradients and subsequently affect part warp. High shear stresses and rapid shear rates can result in non-uniform polymer flow, leading to uneven pressure distribution and subsequent part distortions. By understanding the correlation between pressure gradients, polymer temperature, residual shear stress, and shear rate, manufacturers can take proactive measures to mitigate part warp and enhance the overall quality of their plastic components. In conclusion, pressure gradients are a key factor contributing to part warp in the injection moulding process. Analysing and managing these gradients, along with considerations of polymer temperature, shear stress, and shear rate, can help manufacturers effectively address and minimise part warp issues, leading to improved product consistency and customer satisfaction.

3. Polymer temperature: Its impact on part warp

Polymer temperature plays a crucial role in the phenomenon of part warp. Understanding how it impacts the warping of plastic parts is key to achieving high-quality, dimensionally stable products. When a polymer is heated, it undergoes thermal expansion, causing it to expand in size. As the polymer cools down, it contracts, returning to its original dimensions. However, if the cooling process is not uniform or controlled properly, residual stresses can accumulate within the material, leading to part warp. The temperature at which the polymer is processed and cooled significantly affects the degree of part warp. If the cooling rate is too rapid, temperature gradients can form within the material, causing uneven contraction and resulting in warping. On the other hand, if the cooling rate is too slow,

Plastic components

the polymer may remain at elevated temperatures for an extended period, leading to excessive relaxation and potential warping as well. To mitigate part warp caused by improper temperature control, it is crucial to monitor and control the cooling process carefully. This can be achieved through techniques such as adjusting cooling rates, using cooling fixtures, or employing cooling media to facilitate uniform temperature distribution. Additionally, optimising the mould design and incorporating cooling channels can help regulate the polymer’s temperature and minimise temperature gradients. Furthermore, it is important to consider the polymer’s specific thermal properties during the processing stage. Different polymers have their own unique thermal behaviours, including their coefficient of thermal expansion and glass transition temperature. Understanding these properties and adjusting the processing conditions accordingly can help minimise part warp. In conclusion, the temperature at which a polymer is processed and cooled plays a significant role in part warp. By carefully controlling and monitoring the cooling process, selecting appropriate materials, and optimising mould design, manufacturers can minimise the effects of temperature gradients, reduce residual stresses, and achieve high-quality, dimensionally stable plastic parts.

4. Analysing residual shear stress and shear rate

When it comes to understanding part warp in manufacturing processes, analysing residual shear stress and shear rate is crucial. Residual shear stress refers to the internal stress that remains within a material after it has undergone deformation. Shear rate, on the other hand, measures the rate at which adjacent layers of a material slide past each other. Analysing residual shear stress and shear rate can provide valuable insights into the underlying causes of part warp. High residual shear stress indicates that there is excessive internal stress within the material, which can lead to deformation and warping. By identifying and addressing the factors contributing to high residual shear stress, manufacturers can mitigate part warp issues. Similarly, studying shear rate helps in understanding the speed and intensity at which material layers are moving relative to each other. A high shear rate can result in uneven material flow and increased internal friction, both of which can contribute to part warp. By analysing shear rate, manufacturers can identify areas of the manufacturing process where adjustments may be needed to minimise shear-induced warping.

injection moulding quality

To analyse residual shear stress and shear rate, various techniques can be employed, such as numerical simulations, experimental testing, and rheological studies. Numerical simulations involve using advanced software to model and simulate the behaviour of materials under different conditions, allowing for the prediction of residual shear stress and shear rate. Experimental testing involves subjecting materials to controlled conditions and measuring the resulting residual shear stress and shear rate. This can be done through techniques like mechanical testing, thermal analysis, or microscopy. Rheological studies involve analysing the flow behaviour of materials, particularly their viscosity and elasticity, which are directly related to shear stress and shear rate. Rheological measurements can provide valuable data on how a material responds to different levels of stress, temperature, and deformation, aiding in the understanding of part warp mechanisms. By analysing residual shear stress and shear rate, manufacturers can gain a deeper understanding of the factors contributing to part warp and develop targeted strategies to minimise its occurrence. This knowledge can lead to more efficient manufacturing processes, improved product quality, and reduced waste, ultimately benefiting both manufacturers and customers.

We hope you have enjoyed our Plastic Moulders UK Article.

To find out more about injection moulding services please contact Benn Simms, Managing Director of Ledwell.


Injection Moulding

Injection Moulding Process – The Vital Role of Mould Temperature

Injection Moulding Process and Mould Temperature

Plastics Injection Mould Tool

Injection moulding is a popular technique in manufacturing, enabling the production of a vast array of components with intricate designs and diverse materials. Given the efficiency of the injection moulding process and its adaptability, it is used across numerous sectors, including automotive, electronics, and healthcare.

One of the most important aspects of injection moulding is mould temperature, this factor can significantly impact the quality of the production and the parts that are being produced. Effective temperature control is critical for preventing quality issues such as shrinkage, stresses and warping from developing in the plastic. It is important that a balance between temperature of the cooling fluid and the rate of mould cooling is controlled.

This article delves into the importance of mould temperature in the injection moulding process, exploring its influence on the various stages and the resulting outcomes.

Defining Mould Temperature

Mould temperature refers to the temperature of the mould surface itself. It is a crucial factor during the injection moulding process as it determines how the product heats up and cools down. This temperature fluctuation significantly affects the final look, feel, and quality of the product.

Importance of Mould Temperature Control

The precision of mould temperature control is a vital aspect of the injection moulding process. The goal is to maintain the mould surface temperature within a specific range to ensure optimal conditions for the plastic material to flow, fill the mould cavity, and solidify into the desired shape.

The mould temperature is typically controlled using cooling or heating channels within the mould. These channels carry a coolant, often water, that regulates the mould’s temperature by either removing or adding heat. The design of these channels, including their diameter, number, location, and distance from the mould’s surface, is crucial to the performance of the moulded part.

Mould Temperature and Material Behaviour

The mould temperature plays a significant role in determining the behaviour of the plastic during the injection moulding process. For instance, in amorphous polymers like Acrylonitrile Butadiene Styrene (ABS) and polycarbonate, higher mould temperatures result in lower levels of moulded-in stress. Consequently, the final product has better impact resistance, stress-crack resistance, and fatigue performance.

On the other hand, in semi-crystalline plastics, the mould temperature is a key factor in determining the degree of crystallinity in the polymer. The degree of crystallinity influences many performance parameters, including creep resistance, fatigue resistance, wear resistance, and dimensional stability at elevated temperatures.

Mould Temperature and Injection Pressure

The mould temperature also impacts the injection pressure required during the injection moulding process. The injection pressure is the force that propels the plastic to flow, and it varies depending on the mould temperature. A higher mould temperature reduces the viscosity of the molten plastic, making it easier to flow and fill the mould. Conversely, a lower mould temperature increases the plastic’s viscosity, requiring a higher injection pressure to fill the mould.

Mould Temperature and Injection Time

Another critical parameter influenced by mould temperature is the injection time, which refers to the time taken for the plastic melt to fill the cavity. The injection time must be carefully adjusted according to the mould temperature to ensure that the mould is completely filled before the plastic solidifies. This precision in setting the injection time is crucial for improving the surface quality of the products and reducing dimensional variance.

Importance of Mould Locking Pressure

To resist the injection pressure, it is necessary to use mould locking pressure. The objective is to calculate a suitable value considering the projected area. The projected area of injection moulded parts is the maximum area seen from the direction of the clamping force. The appropriate mould locking pressure helps to maintain the integrity of the mould and ensure that the moulded part accurately represents the design.

Back Pressure and Its Role

Back pressure refers to the pressure that must be produced and exceeded before the screw retreats. Although a high back pressure is beneficial for pigment dispersion and plastic melting, it prolongs the screw’s return time, reduces the length of the fibre in the filled plastic, and increases the stress on the injection moulding machine. Therefore, the back pressure should be as low as possible, generally not exceeding 20% of the injection pressure.

Mould Temperature and the Cooling Process

A significant phase of the injection moulding process influenced by mould temperature is the cooling process. The objective of the cooling process is to lower the temperature of the moulded plastic to the point where it solidifies. Once the plastic solidifies, it can be demoulded. The cooling process needs to be carefully controlled to minimise warpage, twisting, or other shrinkage-related problems.

Mould Temperature and Its Impact on Final Products

The mould temperature significantly affects the final properties of a moulded product. A product cooled too quickly could become brittle and crack under pressure or force. On the other hand, slow cooling could result in a part with lower stress resistance and a higher propensity for warping or distortion. Hence, the mould temperature should be carefully regulated to balance these factors and produce a high-quality moulded part.

Key Takeaways

In conclusion, mould temperature plays a pivotal role in the injection moulding process. It influences the behaviour and transformation of the material, the injection pressure and time, the cooling process, and the final properties of the moulded part. By carefully controlling the mould temperature, manufacturers can optimise the injection moulding process to produce high-quality, durable, and precise moulded parts. Therefore, understanding and managing mould temperature is a critical aspect of successful injection moulding production.

To find out more about the injection moulding process, mould temperature control and mould tool design please contact Benn Simms Managing Director of Ledwell

Injection Moulding


Injection moulding quality | Control of material flow in a runner system to optimise injection moulding quality.

Injection moulding quality

Injection moulding quality and the optimisation of the runner system’s design.

Injection moulding is a widely used manufacturing process to produce high-quality plastic components with excellent dimensional accuracy and surface finish. However, the process is highly complex, and any deviation in the material flow can significantly affect the consistency and quality of the final product. Therefore, it is crucial to optimise the runner system’s design and control the material flow to ensure uniform filling and minimise defects. In this article, we will discuss the control of material flow in a runner system to optimise injection moulding quality. This guide is intended for engineers, product designers, mould designers, toolmakers, and mould makers seeking to improve their injection moulding processes and achieve consistent, high-quality results.

1. Importance of Runner System Design

The runner system is a crucial component in the injection moulding process and the injection moulding quality. A well-designed runner system can ensure consistent material flow and minimise defects. It is essential to consider factors such as gate types, gate locations, and runner size when designing the runner system. A small gate can lead to high injection pressure and poor part quality but does allow for a faster cycle time and the potential for self-trimming gates such as sub gates which reduce part cost. A large gate can increase cycle time and slow down production and will also need a separate trimming operation. Therefore, selecting the right gate type and location is critical for achieving optimal injection moulding quality.

2. The Role of Material Properties

Another essential factor that can affect material flow is the material properties. It is crucial to understand the viscosity and flow rate of the material being injected to optimise the runner system design. The material’s viscosity can impact the gate size, while a low flow rate can increase dwell time and affect the melt’s temperature. Therefore, it is essential to choose the right material and adjust the runner system design accordingly to achieve optimal injection moulding quality. The type of material is also a consideration a Crystaline or semi-crystalline material will behave very differently to an amorphous material, and this will often impact the gate and runner design and type chosen for the application.

3. Simulation Software

Simulation software can aid in designing a runner system by predicting the flow of the material within the mould. It allows designers to simulate various scenarios and optimise design parameters before creating the final mould. By simulating the injection moulding process, designers can predict potential issues such as weld lines, air traps, and flow hesitation. This approach helps in reducing the iterations required during the mould design process and optimising the runner system design for optimum injection moulding quality.

4. Sustainable Runner System Design

In recent years, there has been a growing interest in sustainable manufacturing practices and reducing waste in the injection moulding process. Runner systems can contribute to material waste, as they are often discarded after each cycle. One solution is to design a cold runner system, where the runners are not ejected with the part and can be re-processed and fed back into the machine to use in subsequent cycles. Another option is to create a hot runner system, where the runner material is kept melted and reused in the next cycle, reducing waste and energy consumption. Sustainable runner system design not only benefits the environment but can also lead to cost savings and increased efficiency.

5. Runner Balancing

Balancing the runner system is crucial for achieving consistent material flow and preventing defects in the final product. This stage is often overlooked by toolmakers and imbalanced runners can lead to variations in filling time and pressure, causing issues such as short shots, sink and warpage. Balancing the runner system involves adjusting the runner length, diameter, and placement to ensure equal pressure and material flow to each cavity. This process can be time-consuming but is essential for achieving optimal injection moulding quality.

6. Design for Manufacturability

Design for manufacturability (DFM) is a concept that involves designing parts and moulds that are optimised for the injection moulding process. By considering DFM principles, designers can ensure that the part is mouldable, with appropriate wall thickness, draft angles, and gating locations. These factors can impact the runner system design and ultimately affect the part’s quality. Designing for manufacturability can reduce lead times, decrease costs, and improve quality control in the injection moulding process.

In summary, controlling material flow in a runner system is crucial to achieving optimal injection moulding quality. A well-designed runner system, consideration of material properties, simulation software and using well-established practices to ensure the runner is designed properly, can significantly impact the final product’s consistency and quality. Optimising the injection moulding process requires a thorough understanding of the runner system and its role in the overall process. By following these guidelines, engineers, product designers, mould designers, toolmakers, and mould makers can improve their injection moulding processes and achieve consistent, high-quality results.

In conclusion, there are various factors to consider when designing a runner system for injection moulding. optimising the runner system design can result in consistent material flow, reduced defects, and improved product quality. Using simulation software and designing for sustainability and manufacturability can also improve the injection moulding process’s efficiency and reduce waste. Balancing of the runner system is also crucial for ensuring optimal quality and preventing downtime. By following these guidelines, manufacturers can achieve consistent, high-quality results in their injection moulding processes.

For more information about runner system design and injection moulding quality, please contact Benn Simms, Managing Director of Ledwell

Injection Moulding

Injection moulding services company Ledwell goes for growth

Injection moulding services company Ledwell purchases new factory to enable growth


plastic injection moulding company

As Ledwell’s business continues to grow, we are excited to announce that we have acquired a new factory site to better serve you. This expansion will help us to meet the increasing demand for our injection moulding services and allow us to provide even better quality and faster turnaround times. Our new factory site will allow us to increase our production capacity and improve our efficiency. We are proud to be able to continue to innovate and expand, and we look forward to the new opportunities this will bring for our customers.

Our goal has always been to provide high-quality products and services to our customers, and with the new factory site, we can now do so even more efficiently and effectively. This expansion will allow us to streamline our operations, which will ultimately benefit our customers. We are thrilled to embark on this new journey and look forward to the exciting opportunities that lie ahead.

Our previous site was operating at maximum capacity and we were finding it increasingly difficult to keep up with demand. Commenting on the new site, Benn Simms, Managing Director of Ledwell said “We found ourselves a victim of our own success.  Our business grew substantially despite the challenging economic climate.  It was soon realised that space was paramount to the continued success of Ledwell Plastics. After evaluating several properties near to our existing factories a suitable facility was found.  We now have an efficient storage facility that is meeting our current needs and gives us capacity in line with our goals and strategy. I’m incredibly proud of our team and their achievements to adapt and continue to build on our 55 years”.

To find out more about Ledwell’s injection moulding services please contact Benn Simms Managing Director of Ledwell.


Plastic Moulding Company Ledwell invests in In-Touch | Cutting-Edge IT Production Systems

Plastic Moulding Company Ledwell invests in In-Touch | Cutting-Edge IT Production Systems

Plastic Moulding Company Ledwell invests in In-Touch

Plastic moulding company Ledwell has been a leader in the plastic injection moulding industry for many years.  To maintain our quality and drive our production efficiencies we have recently introduced, In-Touch, a new IT production system that has taken our production efficiency to the next level.

These new systems allow us to monitor all our machines in real-time, which gives us a better understanding of how operations are running. By monitoring our machines in this way, we can identify areas where improvements can be made. This has ultimately led to greater efficiency and increased productivity.

In today’s dynamic business environment, the ability to monitor and optimise production processes in real-time is crucial for manufacturers. With the increasing demand for higher-quality products and shorter lead times, companies need to adopt effective monitoring solutions that can help them identify potential problems early on and reduce downtime.

Intouch Monitoring is a cutting-edge software tool that provides real-time production monitoring for engineers, product designers, and engineering designers. Since investing in this powerful tool Ledwell has realised greater efficiency and improved product quality.

Improved Efficiency:

Intouch Monitoring provides us with real-time data on production processes, which helps us identify where the bottlenecks are and where improvements could be made. By having access to this information in real-time, Ledwell’s team can make adjustments as needed, and streamline production. This reduces the amount of waste produced, minimising downtime and increasing overall production efficiency.

Enhanced Collaboration:

Intouch Monitoring helps us identify issues quickly, leading to faster solutions and reduced downtime. By pooling resources and knowledge, our teams can work together more effectively and make better decisions that improve product quality and overall production efficiency.

Job Planning

The use of Intouch’s unique built-in planning software allows for greater flexibility and adaptability. Machine setters have full access to the current plan in real-time rather than having to wait for a message and revised documentation.

Real-time quality data

Having access to real-time scrap data is essential for consistent product delivery, to our customers. This enables us to understand any potential issues with moulding or tooling and rectify them early on before they become costly and detrimental to the delivery schedule. Our operators log the scrap as it happens, so we have the data immediately at our fingertips.

To find out more about the advantages of In-Touch and how it will improve production lead times and quality please contact Benn Simms Managing Director of plastic moulding company Ledwell

Plastic Moulded Products | Ledwell Implements New dedicated assembly lines to support our clients’ requirements.

Ledwell | Plastic Moulders Make Major Investment in Injection Moulding Machines & Robots

Ledwell | Plastic Moulders Make Major Investment in Injection Moulding Machines & Robots

To maintain our growth, offer clients more scope and improve production efficiencies plastic moulders are investing in new injection moulding machines and robots.

Benn Simms, Managing Director of Ledwell said, “We are a leading injection moulding company in the UK.  To maintain our position and offer clients the solutions they need, we are continually investing in new technologies”.

How Plastic Moulders are Improving Production Efficiency in Injection Moulding with Robotic Automation

In today’s fast-paced injection moulding industry, companies are constantly seeking ways to improve production efficiency and gain a competitive edge. With the advent of robotic automation, injection moulding companies can now streamline their operations, enhance product quality, and increase overall productivity. In this article, we will explore the various ways in which robots can and have improved the production efficiency of injection moulding, at Ledwell, along with the benefits they bring to the table.

The Rise of Robotics in Injection Moulding

The demand for more flexible solutions in the plastics industry has led to the extensive use of industrial robots in injection moulding operations. These robots can automate the entire injection moulding process, from loading plastic parts into the machine to placing the finished products onto a conveyor belt. By replacing human-operated injection moulding with robots, companies can ensure the consistent production of high-quality products that are accurately formed.

Advantages of Robotic Automation

The utilisation of robotics in injection moulding offers several advantages for manufacturers. Firstly, it provides them with a competitive advantage by increasing both productivity and the quality of the produced parts. Robots can work faster and more efficiently than humans, leading to higher output and reduced cycle times. Additionally, robots can perform highly repetitive tasks 24/7 without the need for breaks or rest, maximising the utilisation of injection moulding equipment and increasing overall efficiency.

Another significant advantage of robotic automation is the improvement in product quality. Robots can perform precise and repeatable tasks, ensuring consistent quality and reducing the risk of errors or defects. They can also handle parts in a controlled and consistent manner, reducing the risk of contamination and improving the overall quality of the final product. By incorporating robots into the injection moulding process, manufacturers can reduce waste, minimise the need for rework or scrap, and deliver products that meet the required specifications.

Application of Robotics in Injection Moulding

Robots have a wide range of applications in different stages of the injection moulding process. One common application is machine tending, where robots are used to unload finished parts from the injection moulding machine and deliver them to downstream processes such as packaging. By automating this task, manufacturers can improve product consistency, reduce the risk of injuries to labourers, and increase production capacity.

Another important application is insert moulding, which involves enclosing inserts such as pins or threaded rods in moulded plastic. Robots, such as SCARA robots, can add inserts to mouldings and load them into machines to continue the process. They can also work in collaboration with pick-and-place robots to complete the manufacturing process.

Automation can also be applied to over-moulding, where a moulded object is removed from one injection moulding machine and placed into another with the help of a robot. This automated process ensures a more efficient and accurate arrangement of parts, reducing labour and assembly expenses while ensuring the quality and integrity of the final product.

In-mould labelling is another popular application for automation in injection moulding. Robots can feed pre-printed labels or decorated film directly into the open plastic injection mould, ensuring precise and stable positioning of labels. This process enhances the visual appeal of the final product and eliminates the need for secondary processing or shipping parts to and from warehouses.

Post-processing tasks, such as inspection, testing, and trimming of plastic moulded parts, can also be automated using robots. Robotic trimming cells provide superior repeatability compared to manual trimming, resulting in higher precision, accuracy, and cycle times. Robots can minimise waste and improve production efficiency by reducing errors and defects.

The Future of Robotic Technology in Injection Moulding

The future of robotic technology in injection moulding looks promising, with ongoing advancements aimed at simplifying operations and maximising overall equipment effectiveness. Companies like Sepro Group are breaking new ground in the area of robot and automation control. Their work focuses on simplifying robot programming with the use of artificial intelligence (AI) and creating highly integrated control systems that communicate with all equipment in a production cell.

Plastic moulders can overcome the technical complexities associated with robot programming by implementing “no-code” programming and AI-driven robot controllers. This enables easier retrofitting of code or hardware to evolving business and market needs, making robotic automation more accessible and user-friendly. As a result, even relatively new employees with limited training can set up basic moulding processes, further reducing the need for skilled technicians.

In conclusion, robotic automation offers immense potential for improving production efficiency in injection moulding. Manufacturers can increase productivity, enhance product quality, and reduce costs by utilising robots in various stages of the process. Robots’ flexibility, precision, and efficiency contribute to the overall competitiveness of injection moulding companies. As technology advances, the future of robotic automation in injection moulding looks promising, paving the way for further innovations and improvements in the industry.


Injection Moulded Parts | Advantages and Disadvantages

Plastic Moulded Products | Ledwell Implements New dedicated assembly lines to support our clients’ requirements.

Streamlining Production of Plastic Moulded Products: How Dedicated Assembly Lines Benefit Ledwell and Our Clients

Ledwell has invested in new dedicated assembly lines to give our clients the solutions they need.

Commenting on the new assembly lines at Ledwell, Matt Aucott, Production Director of Ledwell said, “In today’s fast-paced business world, it’s crucial to find ways to increase efficiency and reduce costs of plastic moulded products. One of the most effective ways to achieve these goals is through the use of dedicated assembly lines. Ledwell’s production lines are designed to streamline the assembly of plastic moulded products and post-moulding production processes by breaking tasks down into smaller, more manageable steps. By doing so, they minimise the amount of time workers spend moving parts and materials around, and maximise the time spent actually assembling products”.

Matt explained further. “Ledwell’s assembly lines divide the production process into smaller, simpler steps, and assign each step to a specific worker or machine. The plastic moulded products moves along a conveyor belt or other system, with each step of the process performed at a different station along the line.

By streamlining the production process into smaller, simpler steps, workers can become experts in their specific area, leading to increased efficiency and higher-quality products. Additionally, assembly lines can be designed to maximise the use of space and materials, reducing waste and lowering costs. They can also be easily scaled up or down to meet our changing production demands”.

Matt went on, “One key aspect of assembly lines is the use of automation and machinery to perform repetitive tasks. This not only speeds up production, but also reduces the risk of human error. However, it’s important to note that assembly lines still require skilled workers to oversee the process, troubleshoot any issues and perform more complex tasks that can’t be automated.

By implementing dedicated assembly lines in our production process, we have brought numerous benefits to our business. First and foremost, we have significantly increased our production efficiency. By having dedicated assembly lines, each worker can focus on a particular task which they become highly skilled at performing. This results in faster production times and fewer errors or defects, leading to an overall increase in productivity and quality of output”.

Other benefits we have identified include:

  • improved safety
  • better inventory and supply chain management
  • reduced lead times and faster turnaround
Commenting on the benefits to Ledwell, Matt said, “One of the greatest benefits of implementing dedicated assembly lines was reduced lead times and faster turnaround. With each assembly line dedicated to a specific set of tasks, the production process becomes more streamlined and efficient. This enables us to produce more products in less time, resulting in a quicker turnaround time for our customers”.

“Dedicated assembly lines have been a game-changer for Ledwell”, Matt concluded.

To find out more about Ledwell’s dedicated assembly lines and how they may help your production requirements, please contact Matt Aucott , Production Director of Ledwell.


Ledwell | Plastic Moulders Make Major Investment in Injection Moulding Machines & Robots

Plastic Injection Moulding Near Me : Tips on Maintaining the Quality of High Gloss Injection Moulded Parts.

Plastic Injection Moulding Near Me: Tips for maintaining a high gloss finish. There is an art to keeping your high gloss in top condition

Plastic Injection Moulding Near Me | High gloss injection moulded parts are becoming increasingly popular for their sleek and modern look. However, maintaining the quality and shine of these parts can be a daunting task. Scratches, dust, and other damage can quickly diminish their appearance. In this article, we will provide you with tips and tricks on how to maintain the quality of these parts so that they stay looking as good as new for years to come. From cleaning and polishing techniques to proper storage and handling, you’ll learn everything you need to know to keep them looking their best.


1.0 What are high gloss injection moulded parts?

High gloss injection moulded parts are a popular choice for manufacturing a variety of products today. These parts are made by injecting molten plastic into a mould and then allowing it to cool and solidify into a specific shape and size. The result is a product that has a smooth, glossy finish that is both durable and aesthetically pleasing to the eye. These parts are used in everything from automotive interiors to consumer electronics to medical devices. They are particularly popular in industries where appearance and durability are crucial, such as the automotive and home appliance industries. High gloss parts are known for their excellent quality and have become widely used for manufacturing products that require a strong and attractive finish.

2.0 How to clean and polish high gloss injection moulded parts

High gloss parts and products are chosen by designers as they add a sleek and polished look. However, maintaining the quality of these parts requires a little extra effort and care. When it comes to cleaning and polishing these parts, there are a few things to keep in mind. First, you should always use mild soap and lukewarm water to clean the surface. Avoid using harsh chemicals or scrubbing brushes as they can scratch or damage the surface. Once you have thoroughly cleaned the surface, it’s time to polish it. There are several ways to polish the parts, but one of the most effective methods is to use a high-quality polish that is specifically designed for plastic surfaces. Apply the polish to a soft cloth and gently buff the surface in a circular motion. This will help to remove any minor scratches or blemishes and leave the surface looking shiny and new. It is important to remember that regular maintenance is key to keeping them looking their best. With a little extra care and attention, you can ensure that your products always shine on.

3.0 Proper storage and handling of high gloss injection moulded parts

Proper storage and handling of high gloss parts and products is essential to maintain their quality. It’s crucial to ensure that these parts are stored in a clean, dry, and dust-free environment. Any dirt or dust particles can scratch the surface of the parts, which can mar their high gloss finish. You should also avoid touching the high gloss surface directly with any sharp or abrasive objects as this can cause scratches or damage to the finish. When it comes to storing, you should use protective packaging or covers to avoid any contact with other objects that may scratch or damage the surface. If the parts are large and require stacking, you should use protective materials such as foam to prevent any damage from the pressure of the parts’ weight. It’s also important to store high gloss parts away from heat sources or direct sunlight. The heat can cause the parts to warp, and the sunlight can cause fading or discolouration over time. By following these proper storage and handling procedures, you can help maintain the quality and high gloss finish of your injection moulded parts, ensuring they look and perform their best for years to come.

4.0 Conclusion.

Maintaining the quality of your parts and products requires consistent effort and attention to detail. However, it is well worth the investment, as these parts can add a beautiful and polished look to any product. By using the right cleaning tools and techniques, avoiding harsh chemicals, and protecting the parts from scratches and damage, you can keep your products and parts looking like new for years to come. Whether you are a manufacturer or a consumer, these tips can help you get the most out of your parts and products. With a little bit of care and attention, you can keep your parts looking shiny and new for a long time.


For more information on the storage and upkeep of your high gloss injection moulded component and products, please contact Benn Simms, Managing Director of Ledwell – Plastic Injection Moulding Near Me

Injection Moulding

Injection Moulded Parts | Advantages and Disadvantages

Injection Moulded Parts | Advantages and Disadvantages

Injection Moulded Parts | As engineers, we know that choosing the best manufacturing process for a particular product is crucial for its success in the market. Injection moulding is a widely used manufacturing process for producing plastic parts due to its high efficiency, repeatability, and ability to produce complex shapes. However, like any manufacturing process, it has its advantages and disadvantages that need to be carefully considered before implementation. In this article, we will analyse the advantages and disadvantages of injection moulding, providing a comprehensive understanding of this process for engineers seeking to make informed decisions for their projects.

Advantages of Injection Moulded Parts:


1.0 High Efficiency:

One of the biggest advantages of injection moulding is its high efficiency in producing plastic parts. The process involves feeding raw plastic material into a heated barrel, which is then melted and injected into a moulding cavity. The entire process takes just a few seconds, during which time multiple parts are moulded.  With good mould tool design and under the right circumstances different parts can be produced simultaneously. As a result, injection moulding is highly efficient and reduces the cost per part.


2.0 Repeatability:

Another advantage of injection moulding is its ability to produce identical parts with high repeatability. This is due to the computer-controlled IM machinery, giving a consistent and repeatable process.  This results in consistently shaped parts. As a result, the parts produced through injection moulding can be easily assembled with high levels of interchangeability, in various applications.


3.0 Production of complex shapes:

Injection moulding enables the creation of complex and intricate shapes that may be challenging to produce through other manufacturing techniques. The ability to produce parts with such complex geometries opens up exciting opportunities in various industries, including automotive, medical, and consumer electronics.


Disadvantages of Injection Moulded Parts:


1.0 Start-up Costs:

The biggest disadvantage of injection moulding is the start-up costs associated with the machinery, moulds, and equipment required. The cost of creating the moulding tools and setting up the initial process can be high, making it challenging for manufacturers looking for low-volume production runs. There are options to help with tooling cost reduction including the “Ledwell Plastics Rapid Tooling System”.  However, due to the nature and requirements of the process, this cost does still need to be overcome.


2.0 Limited Material Compatibility:

An additional disadvantage of injection moulding is that it is limited to material compatibility. Certain materials cannot be easily processed through injection moulding.  The design of components and parts needs to be considered carefully to make sure it is possible to produce them in the desired polymer. The choice of the wrong materials for components and parts that work together within an assembly may result in certain parts not functioning as they should. Careful consideration of the materials used needs to be addressed at the design and prototype stage to ensure cross-compatibility and correct product operation. Temperature is a part of this too.  Although there are polymers that can withstand high temperatures they can often limit the design of the part due to the difficulty in processing them. Manufacturers must carefully consider the material selection before opting to use injection moulding.


3.0 Design Limitations:

Finally, injection moulding has design limitations that need to be considered when developing components. Often with thought and by working with an injection moulding company workarounds or design tweaks can overcome these limitations. Simply put the injection moulded parts must be designed with the moulding process in mind, and this can limit what designers can achieve creatively. Additionally, parts produced by injection moulding may require additional post-production processing, which may increase the overall cost.



Injection moulding has many advantages, but these need to be weighed against the associated costs and limitations. Engineers must carefully consider their design requirements and materials, but working with an injection moulding company with sound knowledge of the process and limitations can often resolve such issues.  By fully understanding the advantages and disadvantages of injection moulding, engineers can make informed decisions for their projects, both in terms of design and cost-efficiency.


To find out more about the advantages and disadvantages of injection moulding your products please contact Benn Simms Managing Director of Ledwell


Injection Moulding

Ledwell Expands Quality Control | Meet Paige

Quality Control in the Field of Injection Moulding: An In-Depth Guide

**Paige Otter, Ledwell’s Quality Control Supervisor

Injection moulding, a cornerstone manufacturing process, has been the backbone of the plastic industry for decades. It’s a complex procedure that requires precision, expertise, and strict quality control measures. This post delves into the quality control aspect of injection moulding, highlighting its importance, the procedures involved, and the benefits it offers.

The Art of Injection Moulding

Before diving into quality control, let’s understand the process of injection moulding. It’s a technique where molten plastic or composites are forced into a mould to create a part, a product or component. There is a wide range of different plastics to choose from as well as composites and biodegradable materials. The process begins with the material being heated until it becomes molten. It’s then injected into a mould under pressure, cooled to solidify, and eventually removed from the mould. The result is a solid part fashioned and engineered from your chosen material.

Injection moulding technology came into existence in the early 1870s, initially used to manufacture billiard balls. Fast forward to today, and injection moulding has become a versatile method to create a plethora of products – from drink tumblers and automotive parts to musical instruments and medical devices.

The Vital Role of Quality Control in Injection Moulding

In the world of injection moulding, quality control is crucial. It’s a systematic process that ensures the final products meet the set specifications and consumer expectations. Several factors, including dimensional stability, colour, gloss, and moulding defects, define how well the product aligns with the intended design and overall quality.

Quality control is not just a term used to boost brand image or a buzzword thrown around casually. It’s a rigorous process that involves meticulous planning, design, development, assembly, production, and packaging. Quality control measures are integral to the success of a business, reducing production costs and boosting customer satisfaction.

Dimensional Stability and Quality

Dimensional stability is an important aspect of quality control. If the product is an individual piece that doesn’t connect to anything, the dimensions might not matter. However, for components that fit together to form an assembled product, having the correct dimensions is crucial.

Each component must conform to specific dimensions to fit with other parts correctly. This includes being neither too large nor too small and maintaining the right shape to fit, perfectly with other components. If the components don’t fit together, the entire assembly might not function as intended, resulting in halted manufacturing lines or dissatisfied customers.

The Impact of Colour in Injection Moulding Quality Control

Colour is another critical factor that can affect the overall quality of the product. Changing process parameters, such as increasing or decreasing temperature and pressure, can affect the end colour of the product. There are different ways to colour the plastic, including pre-coloured plastic from a plastics manufacturer or a blended plastic created at the moulding factory.

Colour harmony is crucial to ensure each component meets the specification, meaning each part aligns with the intended colour within a few shades. It’s important to show uniformity and consistency of colour between all components, meeting the design intent.

The Role of Gloss in Product Quality

Gloss, though a small detail, can significantly influence the perceived quality of the product. The right gloss level can enhance your product’s visual appeal, influencing your consumer’s perception. The process parameters during moulding can influence gloss to a certain degree. For instance, high temperature may increase gloss, while the time in the mould could decrease the gloss level of your product.

Common Moulding Defects and Quality Control

Moulding defects can affect the quality of your product. The five most common defects that may occur include flow/weld lines, sink marks, short shots, burn marks, and flashing. Each of these defects can compromise the overall quality of the product, deterring customers from purchasing it.

However, not all defects warrant discarding the product. For instance, some defects might be acceptable on an internal component that isn’t visible after assembly. The product specification should outline if a defect is acceptable, its acceptable location, and the degree of defectiveness allowed.

Benefits of Quality Control in Injection Moulding

Quality control in injection moulding comes with numerous benefits. It encourages a quality-conscious approach among the workers, leading to higher product quality. It also reduces production costs by minimising waste and inefficiencies. Companies can ensure the utilisation of resources, improve employee morale, and satisfy customers by maintaining stringent quality control measures. Additionally, quality control helps identify and fix problems early, reducing returns and failures.

Quality Control Trends: AI and Advanced Quality Assurance Tools

Quality control in injection moulding has seen significant advancements with the emergence of artificial intelligence (AI) and advanced quality assurance tools. AI enables complex and reliable quality control systems, ensuring consistency in mass production. The integration of AI with quality control systems allows automatic adjustments to the moulding cycle, improving the overall production process.

In addition to AI, advanced quality assurance tools like IdentiPol QA2 have revolutionised quality control in injection moulding. It enables efficient quality assurance tests, ensuring consistency and quality across the production line. It’s a user-friendly tool that grades plastics based on a pass or fail basis, bridging the gap between simple testing and complex lab analysis.

To find out more about Ledwell’s quality control procedures please contact Paige Otter Ledwell’s quality control supervisor.

Ledwell Plastics excels at injection mould design, toolmaking, plastics injection moulding, assembly, and just in time production.  We offer a turnkey solution that can organise a new product launch from concept to consumer.  We have a complete turn-key solution to bring your product to market, and we are ISO9001:2015 certified

Peter Has Taken on Technical Sales and Marketing at Ledwell

New Technical Sales and Marketing Manager at Ledwell

Ledwell Plastics are delighted to announce that Peter Wilkinson has joined the team as Sales and Marketing Manager.


Marketing Manager at Ledwell | Peter brings with him a great depth and breadth of experience, built on over 40 years of marketing technical and engineering products. His knowledge across the board will benefit our team at this exciting time of growth. Peter is here to help Ledwell’s clients with technical sales enquiries.  From a mould making, casting and injection moulding background, Peter will ensure the best solutions are presented for your needs.

Benn Simms, Managing Director, commented; “I am looking forward to working with Peter and I am confident that the broad experience that he brings to the role will help to accelerate Ledwell to the next stage of our growth, whilst ensuring that we further develop strong systems and customer satisfaction levels”.

Peter added; “I’m delighted to join Ledwell at this exciting time of development across the business. I’m looking forward to a bright future with the company and working collaboratively with all our teams internally.”

To contact Peter for technical or sales enquiries please email or call Peter on 07930330125



You don’t need to take our word for it. Here’s what our customers have to say.

  • We have worked with Ledwell for many years, always a great service!

    Charlotte Smith Avatar Charlotte Smith

    Great company! We have been working with Ledwell for many years and have always found them to be friendly and helpful. Matt and Shirley in particular provide an excellent service.

    Peter Smith Avatar Peter Smith

    Been here for years, something must be right.

    adie seare Avatar adie seare

    We are only a small customer to them but always feel valued, would not hesitate to recommend them.

    Andy McCaughan Avatar Andy McCaughan
  • Great injection moulding company! High-quality services and friendly and helpful staff. Highly recommended!

    Aditi Dharmesh Avatar Aditi Dharmesh

    Great people, true British manufacturing thoroughbred

    Peter Wilkinson Avatar Peter Wilkinson

    Great place to work with likeminded brilliant people.

    Benn Simms Avatar Benn Simms

    Great blokes on Goods in.

  • Manufacturers of High Quality Injection Moulded Plastic Products #InjectionMolding #Toolmakers #Moulders

    Balu Nandigam Avatar Balu Nandigam

    10/10 would go again

    72gaming 72gaming Avatar 72gaming 72gaming