Polyurethane moulding

Normally used for low to medium production runs, rigid polyurethane mouldings have unique properties that may also make them the ideal choice in other situations. The process uses two chemicals, combined in a mixing head which ‘foam’ and fill the tool, creating a hard outer surface and less dense core. Rimplas Technologies offer two material options from Bayer:

Baydur 60

This system can accommodate both very thick and variable wall sections. Ideal for large mouldings requiring high mechanical strength. We produced the largest moulding in the UK for our customer, De La Rue Cash Handling Systems.

Baydur 110

Is an advanced reaction injection moulding system, allowing thinner and more uniform sections, giving tremendous scope for designers and engineers. These parts have high impact strength.

Common features to both processes

• Practically unlimited scope for mechanical and appearance design
• Lower tooling costs
• Good strength to weight ratio
• Mouldings can be produced from 6g to 15kg!
• Parts normally require painting and can be RFI shielded
• Excellent chemical and heat resistant qualities
• Flame retardant to meet UL94V0 specification

FAQs for Polyurethane moulding

What is RIM Moulding (Reaction Injection Moulding)?

RIM moulding is a result of two chemicals (Polyol and Isocyanate) being injected into a closed mould tool at very low pressure. The tools need to be hot for the process to begin. As the two chemicals react together the result is a rigid polyurethane moulding. Generally used on low to medium volume batch sizes. Cycle times are determined by wall thickness but on average around 4 – 8 minutes.

What PU RIM SYSTEMS are used at Rimplas?

System 110 (Bayer) is an advanced moulding system specifically developed for the manufacture where low to medium batch sizes. Baydur PU 110 compares with Thermo plastics such as Noryl, HIPS and ABS in terms of physical and mechanical characteristics. Baydur PU 110 is ideal for moulding a variety of products, including medical & scientific enclosures and industrial electronic products. It is a very high spec material and is flame retardant to meet UL 94 V0 Specifications.

System 60 (Bayer) is a foamed integral skinned rigid PU ideal for a wide variety of areas where low to medium batch sizes are required. This material is extremely versatile and ideal for engineers and designers as it gives maximum mechanical and styling flexibility. Good thermal, electronical and sound insulation properties and ideal for audio speakers as well as medical and scientific enclosures and any type of rigid cover. It is a very high spec material and is flame retardant to meet UL 94 V0 Specifications.

PU RIM mould tools, are they different from thermoplastic mould tools?

Yes, PU RIM has very low fill pressures and tool clamping forces. Therefore, the construction is lighter, and materials are usually lighter grade Aluminium with temperature controls. Because of the reduced build requirement tool production lead-time are around 4 to 6 weeks. This will depend on the final design.

How do I know if PU RIM is the right process for my project?

Annual volumes decide this as well as component design – Please contact us to find out what process is best suited to your project.

PU RIM vs ESF (Engineered Structural Foam) Tooling costs and part prices.

PU RIM tooling is on average 20% cheaper against Engineered Structural Foam tooling
PU RIM part prices are generally 20% – 30% more expensive than Engineered Structural Foam tooling parts. The annual component quantities determine the most efficient process to use. (Breakeven point).

Case Study

comPOUND Samples Storage System for SPT Labtech

The very early prototype Carousels were machined from slabs of aluminium in sections which were then bolted together.
The tool design came with a high risk element & only by working closely with Rimplas Technologies on the tooling design, & subsequent post mould process, we have a cost effective, stable & consistent method of manufacture.