Casting grade of polyurethane can be injection-molded

Adiprene C930, a low free methylene diphenyl diisocyanate (MDI) -based cast urethane from Lanxess, has been proven as an appropriate material for being processed via injection molding. Korean company Autox developed a production process that allows the cast polyurethane grade to be injection-molded.

This innovation brings a new perspective to the cast polyurethane (CPU) world as it combines the processing advantages of injection molding along with the properties of cast urethane. Autox has recently launched a new vibrating screen for the mining industry which is made from this Adiprene cast PU prepolymer by injection molding.

One of the benefits in working with injection molding is the high production output rate that makes the process highly efficient and cost-effective. In a limited amount of time and with a single mold, more parts can be manufactured.

Cost efficiency is also influenced by labor cost which is typically lower than in pour casting. As an example, the current production time of an injection molded mesh screen is five minutes, while the pour casting process will normally take 35 minutes to manufacture the screen. Adiprene LF (Low Free) prepolymer delivers improved industrial hygiene, along with ease of processing. It offers a perfect fit with the injection molding process, as the viscosity is lower than of a conventional prepolymer.

Vibrating screen mesh is a highly demanding application needed to withstand challenging mining operation conditions.

The Adiprene C930 mining screen offers outstanding abrasion resistance and rebounding properties, improving the lifetime and screening efficiency of the part. The performance of this caprolactone-based technology has been supported by field testing. The lifetime of the screen can be up to three times longer than the market high-quality reference screen. This unique development allows less downtime in the mine operation leading to maintenance savings.

Autox’ new development allows the processing of cast PU prepolymers into complex shape parts that are easier to mold as the injection pressure employed allows the flow to get into the part details. Further, the injection process answers one of the main concerns of the industry: waste management, as it also allows for better quality consistency, leading to less trimming but also less waste from reduced scrap.

Autox and Lanxess are confident that Adiprene C930 can be applied to other applications besides mining screens.