Polyurethane rubber are low odor, fast-setting urethane elastomers which offers very high tear strength, impact resistance and wear resistance. Liquid polyurethane rubber consist of two parts (A and B), which, after mixing, cure at room temperature to flexible rubber, the hardness range is usually Shore A20 - A90. they can be poured, brushed or sprayed and cure with negligible shrinkage.
Chemical properties
Polyurethane products are simply called "urethanes", but should not be confused with ethyl carbamate, which is also called urethane. Polyurethanes neither contain nor are produced from ethyl carbamate. Generally, polyurethane polymers are formed by reacting diisocyanates or triisocyanates with polyols. Other materials are added to aid processing the polymer or to modify the properties of the polymer. Since polyurethanes contain two types of monomers, which polymerise one after the other, they are classed as alternating copolymers.
Polyurethane rubber is a low odor, low shrink formulation that is phthalate free, mercury free and MOCA free.
Feature
Polyurethanes are easy to use, with having a simple mix ratio by volume (part A : part B=1: 1) . They are available for making molds that are poured, brushed or sprayed onto a model.
It features a low viscosity for easy mixing and pouring and cures with minimal bubble entrapment. The low viscosity of urethanes rubber allows the best penetration even into the finest details of the mold, always guaranteeing perfect reproduction of details.
Polyurethane rubber is a tough material. It has outstanding cut and tear resistance.
Polyurethanes rubber perform very well when used in high flex fatigue applications. Flexural properties can be isolated allowing for very good elongation and recovery properties.
Very low shrinkage, cure with negligible shrinkage.
Polyurethane rubbers are less expensive than silicones and polysulfides, are economical, reproduce exceptional detail.
The release performance of polyurethane rubber will be worse than that of silicone rubber.
Applications
Polyurethane rubber easy to use, reproduce excellent detail and exhibit great wear resistance. Ideal for the production casting of concrete, gypsum or wax. Applications include making clear-cut molds, model reproductions, decorative cast pieces, special effects, prototype parts.
Typical uses include but are not limited to:
- Precast Concrete
- Sculpture & Foundry
- Field of rapid prototyping
- Special effects or cosplay.
- Plaster Millwork & Ornamentation
- Industrial production (gaskets, encapsulations, protective, prototypes, etc.)
- Theming & Scenic Design
- Model Making
Polyurethane VS Rubber
Urethanes have better abrasion and tear resistance than rubbers, while offering higher load bearing capacity.
Rubbers are a family of polymeric materials based on the chemistry of natural rubber latex. Rubber is biodegradable, it tends to rot and degrade over time with exposure to the elements. Polyurethane has higher abrasion, cut, and tear resistance. It can be made in a higher hardness rating and it has better load bearing capacity. Polyurethane is easily colored, in some cases chemical resistant, and much easier and cost effective to mold into shapes and sizes.
In the case of tires, seals, and some belts, rubber is the best material. In the case of bushings, spacers, and high load components, polyurethane is the better choice.
