Plastic product design for manufacture

This is the transition from product design concept to product manufacturing design and process optimisation for plastic injection moulding.

30th November 2020

Plastic product design for manufacture through injection moulding

The complexities of engineering moulded plastic parts for volume injection moulded plastic parts means understanding the methodologies essential for creating a highly efficient production process. There are six key steps that tool and process engineers take to ensure consistent and repeatable manufacturability of flawless moulded parts. Which is why the Tex Plastics ‘design for manufacture’ team of qualified product designers guide you through every step of the design process. Helping you transform your product design concepts into design for manufacture in any material.

Process optimised plastic injection moulding 

Process optimised plastic injection moulding is where the design for manufacture team critically exam the process to create the most efficient, value-driven manufacturing process possible. Designing for manufacturing (DFM) is the focus on ease of manufacture. It’s a principle used in a wide range of industries, from the selection of materials to the complexity and design of the product. This mentality can often result in an increase in both productivity and profit, and can be applied to a wide range of components, from cable management solutions to flange protection solutions.

The six key principles of DFM and Process optimised plastic injection moulding

Simplify – Use the smallest number of components possible. The more joins, hinges or connections that a component possesses, the more opportunities exist for defects and component failure. The more simplistic a component is, the less chance it has of going wrong. Assembly will be more efficient and have fewer issues with inventory management. If in doubt, keep it simple.

Process – the manufacturing process chosen must be the correct one for the part or product. In determining the manufacturing process, DFM takes into consideration the quantity of parts being manufactured, the material being used, the complexity of the surfaces, the tolerances required and whether there are any secondary processes required. In injection moulding, a complex design typically requires a complex mould tool, and a complex mould tool is more expensive to design and manufacture.

Design – design is an essential element of DFM. The actual drawing of the part or product has to conform to good manufacturing principles for the chosen manufacturing process. With plastic injection moulding the following design principles apply:

  • constant wall thickness, to allow for consistent and quick cooling
  • simple transitions from thick to thin features
  • wall thickness not too small – this increases injection pressure
  • no undercuts or features that require side action
  • specify tolerances that enable a good product to be manufactured
  • ideally as few sharp corners or edges as possible, as these provide stress points (weaknesses) on the product.

Material – material properties to consider during DFM include:

  • mechanical properties – how strong does the material need to be
  • thermal properties – is resistance to heat required
  • colour – is a specific colour is required
  • optical properties – does the material need to be reflective or transparent
  • electrical properties – is the material an insulator or a conductor
  • flammability – what level of flame resistance is required

Waste is also an important consideration, especially in environmentally conscious times. Ideally product sections and walls should be as thin as possible without affecting product performance and strength. This also reduce costs in two ways, firstly by reducing material content, and secondly by allowing the product to cool quicker in the mould, reducing moulding cycle times.

Environment – what is the normal application environment of the product? The product design will be influenced by the environment and external properties that the product is subjected to. The product must be able to function reliably and consistently under its normal operating conditions: temperature, humidity, vibration and shock characteristics should be considered.

Compliance – All products will need to comply with safety and quality standards. These may include international standards such as TÜV, BSI, IEC and ISO, industry specific compliance standards, and other third-party standards. Internal, company-specific standards may also apply.

Expert knowledge of Plastic product design for manufacture

Tex Plastics has considerable knowledge and experience designing and manufacturing complex technical plastic moulded products and components that are used across a broad range of high-reliability and safety critical industries. Design for manufacture is actively employed and applied during Tex Plastics design and manufacturing processes.

Find out how we can help you drive waste out of your plastics injection moulded parts and associated supply chain