WHY CHOOSE PU?
What is it?
Our Polyurethane is a rigid, self-skinning, thermosetting, expanded foam system specifically blended to produce tough, rigid and structural mouldings.
What is it good for?
Low-run batch quantities, from two or three, up to two or three hundred, moulded covers, instrument cases and awkwardly-shaped components that have to perform strongly, be very cost-effective and still look great!
What’s the process?
Reactive Injection Moulding (RIM) – We inject a reactive mixture of resin polyol with an ISO curing agent into a closed mould-tool. The mixture instantly reacts and greatly expands, filling the tool cavity to a density of around 600 kg/m3 and at the same time forming a hard, solid resin skin all round.
Why is it cost-effective?
For small batch mouldings for high-value products PU is extremely cost-effective due to the low start up costs of our resin/aluminium mould-making process – considerably less than for plastic injection mould tooling.
FREQUENTLY ASKED QUESTIONS
What size limits do we have?
We can mould and process parts up to 1.5m x 1m x 0.5m right down to small complex hand-held parts.
What tolerances do we work to?
We can create parts with a linear tolerance of +/- 0.4mm from drawings to first-off samples, and thereafter those dimensions can be repeated within +/-0.25mm.
What timescales do we work to?
Our normal order-to-first-off timescale is usually around 8 weeks from go ahead.
What densities do we work to?
An optimum mixture of mechanical properties is achieved within a density range of 600 to 650 kg/m3, given correct mixing and mould temperature conditions. Lower densities can be moulded in order to reduce weight or improve temperature insulation properties.
What temperature limits will PU withstand safely?
Parts produced at our recommended 600 to 650 kg/m3 density have proved to be stable down to temperatures of minus 40 °C and up to 80 °C. This is a manufacturer’s stated top limit-before distortion however, so we recommend a safe upper temperature limit of around 60 °C to preserve cosmetic integrity.
Do we produce models?
We can produce SLA models from CAD – finished and painted to exactly replicate the final part.
What processing equipment do we have?
We currently run three high pressure dispensing machines and a low-pressure mechanical-mixing unit for small components.