Liquid Silicone Rubber (LSR) Mold Manufacturing

Liquid Silicone Rubber, with its low compression set, fast cure cycles, great stability and ability to resist extreme temperatures of heat and cold makes it ideally suitable for the production of parts where high quality is a must. Unlike most thermoplastic elastomers (TPRs and TPEs), LSR remains flexible and elastic down to -70^o F and retains its properties up to 450^o F. In addition to these qualities, the wide range of hardness and colors, silicone elastomers have become the material of choice for an ever increasing amount of applications.

M.R. Mold and Engineering is one of the few companies in the United States offering waste-free liquid silicone rubber molds. Waste-free molds coupled with various types of automation devices, such as M.R. Mold's Cold Runner System, provide our customers with 'lights-out' molding. M.R. Mold's tight tolerance, flashless liquid silicone molds offer a high level of productivity and value throughout the life of the mold. Depending on the complexity of the tool, we present our customers with a wide range of automation capabilities. M.R. Mold’s in-depth knowledge of building tight tolerance, flashless molds for LSR has led them to become industry specialists in processing this material. Although we specialize in liquid silicone rubber molds for medical applications, M.R. Mold serves many industries, including OEMs and job shop molders in the primary markets of surgical, aviation, fluid transfer and consumer products.  
 
M.R. Mold is proficient in over molding silicone on silicone, silicone on plastic, silicone on glass, and silicone onto metals.  With the benefit of knowing what is critical in each mold, M.R. Mold builds
quality liquid silicone molds to produce the finest finished product.   
 
M.R. Mold has extensive experience building micro molds, such as a punctum plug which fits in the tear duct of an eye, .060 long and .040 in diameter with a .008 core pin inside. 

All of our tools are built to SPI standards using only the finest steels and components available.

Historical footnote:
Dumas predicted the existence of silicone rubbers in 1840. However, it was not until 1872, that Ladenburg produced the first example, a very viscous oil, by reacting diethoxydiethysilane with water and trace amounts of acids. The first commercial grades were produced in 1943 by the Dow Chemical Company, with many other companies following shortly after.