Goyang, Korea – Autox has developed a process to injection-mould Adiprene C930 low-free castable polyurethane from Lanxess.
Autox started to develop the injection moulding process for PU in 2016. It has gone on to make commercially available vibrating screens for the mining industry.
While injection moulding machines and moulds themselves may be relatively expensive, the part cost is low because there is little human intervention in the process.
The process has other advantages. Because the polymer is injected under pressure, it is possible to make high-definition parts with fine details.
Secondly, the amount of material injected into the mould is closely controllable. This makes it possible to reduce the amount of waste by matching the shot size with the volume needed to fill the mould precisely.
Finally, cycle times can be much lower than they are when casting with polyurethane. For example, it takes five minutes to injection-mould a mesh screen. The pour-casting process will normally take 35 minutes.
Lanxess said that the low free grade offers improved industrial hygiene and ease of processing. ‘Because its viscosity is lower than conventional pre-polymers, it can be injection moulded,’ it added.
Adiprene technology is based on caprolactone chemistry, and parts moulded with it have good service life in the field. ‘The lifetime of a screen can be up to three times longer than the market’s high-quality reference,’ Lanxess said.