What's the difference for Polyurethane Mold Rubber or Silicone Mold Rubber 

When you plan for your mold making project, you need to decide which mold making material is more suitable for your process: polyurethane mold rubber or silicone mold rubber?

Each material has advantages and disadvantages and there are a wide variety of options in each of the product lines themselves.

General Advantages & Disadvantages of Each Rubber

If your casting materials is Wax or Plaster and product pattern is very fine, silicone mold rubber is very good for your mold making project. Most popular is YJS-510, YJS-515 and YJS-520. 

If your casting material is Polyurethane and Polyester Resins – Silicone rubbers are often used to cast these resins. In most cases, a release agent is not necessary and a large quantity of castings can be made from one mold when designed and used properly. Best-seller silicone for polyurethane casting is our NP25 rtv2 silicone, and mold making silicone YJS-525 very nice for polyester resins casting.

Polyurethane foam– Silicone rubbers are usually recommended for use when casting polyurethane foam, as they last longer than polyurethane rubber molds and do not require application of a release agent (e.g., paste wax, PVA) prior to casting.