Casting Urethane for Different Purposes

There has been lots of advancement in the processes of the casting urethane manufacturing over last few years. This method has become a very useful way to production parts and prototypes. The components of cast urethane are as small as an inch square and can be five feet square large. Casting urethane is used for creating the medical items to be supplied to various hospitals and health care institutes. Cast urethane processing used for prototypes and production parts is now a very fast growing business. There is huge demand for the skins that will cover the external parts of a medical cart or to produce the items like wrist and head coils for MRIs and cast urethane is the most economical product method for the same.

At first the model is produces using an additive manufacturing process e.g. PolyJet or sterolithography or using the CNC machining. Then this model is used as the master pattern to produce a mold of silicone rubber. Some high end supplier use platinum based silicone as it could be better for holding tolerances, replicating surfaces and extends the mold life. The silicone material is then poured over the pattern and allowed to cure. The pattern gets revoked. The time of curing may vary and it is ideally 24 hours for every pour made or it could be more.

Polyurethane molding uses reactive liquid chemicals called pre-polymers and curatives which get mixed under a particular condition. When the chemicals start reacting with each other, the polymer chains get formed and a liquid-to-solid transition is formed which is also called the “gel time”. This “gel-time” controls the time that processors have to use to cast the material into the rubber mold. The colors could be mixed with the polymer so that cast-in color parts could be produced.

When the casting process is over, the part solidifies and undergoes a number of controlled steps which involve heat and pressure. These steps enhance cross-linking and develop optimum mechanical properties. This process is a crucial phase and affects the physical properties of the part. The complete part is kept in the mold for minutes to hours before they get extracted. This phase is also called post-curing phase. Using Polyurethane in place of aluminum, rubber, steel and other thermoplastic processes is much more beneficial as these can outperform any other material and help in getting maximum revenue. For more information visit us at: http://www.focuspdm.com/services/cast-urethanes.html