Advantages of Custom Plastic Moulding

One of the significant advantages of custom plastic moulding is its exceptional design flexibility. Manufacturers can produce highly complex geometries with intricate details that would be challenging or impossible to achieve with other manufacturing methods. Furthermore, the process offers a wide range of material choices, including various thermoplastics with diverse properties like strength, heat resistance, and flexibility, allowing for tailored solutions to specific product requirements. This versatility extends to colour control and surface finishes, ensuring the final product meets aesthetic and functional demands.

Beyond its technical capabilities, custom plastic moulding offers considerable benefits in terms of efficiency and cost-effectiveness for high-volume production. Once the initial tooling is complete, the automated nature of the injection moulding process leads to fast cycle times and minimal labour costs. This translates into a low cost per part, making it an ideal choice for mass production runs. Additionally, the process is highly repeatable, ensuring consistent quality across thousands or even millions of identical parts, while also minimizing material waste, as excess plastic can often be re-ground and recycled.

What is the maximum size of part PRP can mould?

PRP specialises in producing parts up to approximately 175mm square and with a maximum weight of 200g. Depending on the design of the part, larger products can be produced, complex parts need larger tools, and the tool size can become the limiting factor.

How much does tooling cost?

We have a modular tooling system that can offer an economic solution for simple parts, tooling for basic spacers may only cost £500. As the complexity and size of the moulded parts increase, so does the cost of the tooling. Tooling for grommets can often be produced for less than £2000. Tooling for complex parts increases beyond these levels. We are always happy to discuss the tooling options available and find the right solution for the required end product.

What types of material do you use?

PRP offer a range of materials from engineering grades with high temperature and chemical resistance, and certified flammability performance through to commodity grades for less demanding applications, with options for rigid and flexible materials
An example of material types are:
• High-density polyethylene (HDPE)
• Low-density polyethylene (LDPE)
• Polypropylene (PP)
• Polyethylene (PE)
• Polyoxymethylene (POM, a.k.a. acetal)
• Polyamide (PA, a.k.a. nylon)
• Acrylonitrile butadiene styrene (ABS)
• Thermoplastic Elastomer (TPE)
• Thermoplastic Rubber (TPR)
• Thermoplastic Polyurethane (TPU)

What traceability is available for the moulded products?

Traceability of materials is a core part of our manufacturing process. Each shipment of a moulded part can be quickly traced back to the incoming material delivery certificates and suppliers’ lot numbers.

How long does the tooling last?

The life of the tooling is a factor of the materials being processed and the number of parts required. Aggressive materials, such as glass-filled PA66, will cause more wear, but this can be addressed by using hardened cavity plates. Knowing what to expect from the product’s life at the enquiry stage helps us provide the most cost-effective solution. We have tooling in production that has exceeded 10 million cycles.

What tolerances can you work to?

The tolerance of the moulded part is a function of the tooling and the material, the tooling cavities are made to a tolerance of less than 0.05mm. All materials shrink during cooling, some more than others, and some exhibit a shrinkage range depending on the tooling design. As a guide +/-0.1mm on 25mm diameter is achievable. We have tools available to assess the risk of a material shrinkage range on a dimension and the required tolerance. This can all be done at the enquiry stage.

Where is the tooling made?

We have a well-equipped tool room and CAD/CAM facilities in-house, and almost every tool is made here. Subcontractors are required for specialist processes such as deep-hole drilling and heat treatment, but all projects are managed in-house.

Are samples provided?

Samples are provided for approval before going into full production. The number of samples and level of reporting are decided at the enquiry stage; we can use our own sample inspection report or use customer-provided systems.

Are recycled or bioplastics used?

The range of recycled and bioplastics materials available is growing all the time. Knowing what is required of the end products will help establish the material options available. We can provide material data sheets detailing what performance to expect.

How many parts are moulded at a time?

Some tools produce 16+ parts per cycle. This level of production improves productivity and reduces costs, but requires a larger investment in tooling at the start. For complex or low-volume parts, single cavity tooling can often be the best option. We can always review several options to determine the optimal tooling size.

What are the minimum order requirements for plastic moulding?

We will supply as few as 100 products if required, the set-up times do impact the costs, ordering 1000 pars would reduce this significantly. We are happy to quote for a range of order volumes to help provide perspective.

Do you offer post-moulding assembly?

Assembly can be provided. We would always look to automate where possible; however, in some cases, we can provide more complex tooling and parts to reduce or remove the need for assembly.

What packaging and labelling are available?

With the use of dedicated labelling software and our ERP system we can offer bespoke labelling to customer requirements, each product can have up to 32 data fields available to include text, number, barcodes and images plus order specific information. Customer-specific labels are simple to produce.