Cast Urethane

Cast Urethane is one of the methods of low volume production, used to produce plastic materials later used in prototyping purposes. Other methods may include RTV molding and polyurethanes. In simpler terms, it is an adaptable type of plastic material which is created from the chemical reaction of polyether and polyesters diisocyanates.

Cast Urethane

Cast Urethane products are mostly used for industrial purposes like pressure transducers, water treatment facilities, or even petroleum products. There are additives which can be added so as to reduce friction and improve UV resistance as well as increasing the retardation of flames.  Basically, Urethane appears like a white crystalline powder, and has to be converted into a liquid if any reaction is to occur.   The liquid is poured or injected into a mold which contains the product and due to reactions, it hardens and expands. When Urethane is being used to make products, they may have to be cured in industrial ovens so as to make them durable.

However, it is worth noting that much as it is a great protective material in making products, Urethane is a dangerous material which is already recognized as a carcinogen. It is toxic to the gastrointestinal system, liver, kidney, the skin, as well as the respiratory tract.  It has also been found to be hazardous to developing fetuses.

All these effects can be prevented by wearing protective clothing and having proper ventilation. After one has exposed themselves to it, they should wash themselves thoroughly. Suffice it to note that industrial workers have a higher risk of getting ill from its exposure, compared to people residing near where it is being processed.

But as long as safety measures and proper care is adhered to, these adverse effects can be controlled. Besides, once it has been processed into cast Urethane it poses no health hazard at all.

Away from its health effects, there are many advantages of products and parts which are made of custom cast Urethane. First and foremost, they are known to have excellent physical properties like high abrasion, superb tensile strength, as well as resistance to tear. The parts and products are also durable and tough. Still, the good thing about Urethane is its flexibility, which makes it possible to cast it with fiber or a glass material reinforcement material. Features like size and location can be enhanced by processing cast Urethane using milling and other processes. The fact that it is processed when in liquid form which is very hot means that mold pressures are low and tolling costs are greatly reduced, as well as the mass. Molds used can be manufactured from steel, aluminum and even wood.

Indeed, the low viscosity of Urethane is the key to its flexibility in regards to creating tools made of plastic or metal. Therefore if you happen to have any business needs relating to cast Urethane, you can talk to the manufacturer and spell out your needs, design required, and all these can be easily incorporated. Some manufacturers will even deliver the products to your business once they are done with the work.

Polyurethane casting is a resin casting production process used for casting components made from urethane materials. The process uses temporary polymer molds that are produced from a master pattern or part. This type of casting is a popular process used for the rapid prototyping of components, especially in cases where the production material is not suitable for rapid prototyping.

Polyurethane casting is chosen for this process mainly because it is a cost effective option and offers material choice for matching the production materials’ mechanical properties. In addition, by using polyurethane castings, manufacturers are also able to duplicate their production parts with detailed precision. Drift angles and under cuts are easily reproduced due to the flexible nature of the mold. The molds that are used for the production of the castings are usually made from RTV (room-temperature vulcanization) silicone.

Polyurethane casting

This prototyping process creates polyurethane parts with size, form, as well as properties similar to the production parts. Using this method, manufacturers can economically produce multiple polyurethane prototypes of their components, which can be used for various purposes, including sales and marketing, focus groups, and as early part samples for customers. Apart from these applications, polyurethane casting can also be used for testing prototypes. It should be noted that polyurethane cast parts are not ideal substitutes for tests where the production materials play a significant role, such as failure mode testing and life testing of components. However, in many cases polyurethane materials that have properties similar to the production material, can be used for these tests.

The polyurethane casting process begins with the production of a master pattern or part, from which the molds and eventually the castings are produced. A number of methods, including conventional machining, can be used to produce this master pattern. However, the most common method of producing the master pattern is by stereolithography (SLA) – an additive production process that involves using a UV-curable photopolymer resin in combination with a UV laser, to produce 3D components. Other similar additive production processes, such as selective laser sintering (SLS) and Polyjet 3D resin printing, are also commonly used to produce the master pattern.

Once the master pattern is created to exact specifications, it is suspended in a box or frame with a gate assembly, and RTV silicone is poured around it so that the pattern is completely encased by silicone. The silicone is allowed to cure, and once completely cured, a few cuts are made to remove the master pattern from the mold. This leaves behind a silicone mold with a precise negative image of the master pattern. Polyurethane casting material is then poured into the silicone mold and allowed to harden. The hardened urethane casting is removed from the silicone mold and the RTV silicone molds can be reused again for casting additional urethane parts. Depending on the shore hardness of the silicone rubber used to produce the mold, 8 to 75 urethane castings can be produced from a single silicone mold tooling.

Colors as well as textures can be precisely replicated on the polyurethane part. While the former is facilitated by either adding the dye to the urethane material prior to pouring into the mold or painting the final part the latter is achieved by including the texturing in the master pattern. An advantage of using dye rather than painting the final urethane casting is that the colors do not get chipped off easily, as in painted components.