Plastic Processing

    Over the last 90 years Smithers has gained an unparalleled knowledge of the relationships between polymers, product design, performance, durability and manufacture.

    Our processing services are designed to support our client's product or material development throughout the production process, to optimise material selection, product and process performance and to improve existing production. The service offering covers compound formulation, prototype manufacture and pre-production trials to machinery selection and novel process development. Smithers Rapra’s expertise includes commodity resins through to engineering and specialty polymers.

    Smithers provides technical support to processors and product manufacturers on a confidential basis, non-disclosure documents can be completed prior to the commencement of work.

    Our services cover a broad spectrum and we are always keen to discuss a custom solution but generally they fall into the following categories:

    Compounding

    Technologists can process quantities from a few grams of materials to hundreds of kilos. We deliver manufacture or compound development trials. Attention to detail is always evident, for example our equipment is stripped and cleaned before use to avoid potential contamination issues. Our technologists can select the most appropriate set-up, configure the machines and develop screw profiles to suit the process requirements.

    • Twin-screw compounding – Smithers is equipped with 21mm and 30 mm diameter co-rotating extruders. These are equipped with gravimetric feeders, volumetric feeders, side feeders and liquid feeders. Most additives can be handled to make samples as small as 500g up to hundreds of kilos.
    • Counter-rotating twin screw for PVC compounding
    • Small batch mixers are available to process as little as 20g. This is ideal for early evaluation and expensive additives.
    • Single screw compounding with or without cavity transfer mixer

    Extrusion

    A range of extrusion processes are available for manufacturing and sample production. We are equipped with a range of 25, 38, 45 and 50 mm single screw extruders to produce a range of different product types.

    • Blown film – A laboratory size line is available, ideal for testing the effect of new additives or optimising additive levels without stopping a production line.
    • Sheet line – we can produce sheet of approximately 300 mm width and at thicknesses of up to approximately 1.5 mm.
    • Pipe – Our process laboratory is equipped with a vacuum shaping bath suitable for trial quantities of pipe.
    • Wire – Wire coating is available, along with the ability to devise novel coating procedures.
    • Custom - Dies are often developed to make individual products. Following the successful development of dies some contracts have become part of our continuing manufacturing service.

    Injection moulding

    Small injection moulding machines are available; these are typically used for producing test samples but can also be equipped with customer moulds for trials. In addition we can offer problem solving advice and process audits.

    Materials Selection and Formulation

    Smithers Rapra can provide advice on the most appropriate material or formulation to satisfy client requirements for a wide range of different projects. For demanding applications Smithers Rapra can tailor individual solutions to address specific issues relating to design, performance and durability.

    After establishing the right material our technicians can prepare test pieces for mechanical and chemical characterisation. Existing formulations can be re-designed to enhance existing performance.

    Process Development

    With almost an unrivalled position of having expertise in virtually every sector of the polymer industry Smithers Rapra advises on all aspects of the process, from tool design and scale up, through to complete line layout. Smithers Rapra consultants can create custom processes or tailor existing ones to solve difficult or novel applications.

    Specialist production

    Smithers undertake the manufacture of specialised or niche products for various industries including medical, security and aerospace. Our technologists are experienced in designing and utilising small scale production lines and developing novel processing technology. The highest production standards are maintained by in house auditing systems to ensure product quality and consistency.

    Smithers Cavity Transfer Mixer (CTM)

    Developed by Smithers Rapra, the Cavity Transfer Mixer is a cost effective solution designed to increase the distributive mixing performance of a single screw extruder. The CTM can be retrofitted to both twin and single screw extruders. The device has found successful, industry wide application in areas ranging from polymer and colour blending, liquid additive incorporation, through to reactive and direct product extrusion. A variation, the By-pass CTM has been designed specifically for skin colouring applications in the pipe and cable industries.