Silicone Properties

Properties

Some of the most useful properties of silicone include:

1. Good electrical insulation. Because silicone can be formulated to be electrically insulative or conductive, it is suitable for a wide range of electrical applications.
2. Thermal stability (constancy of properties over a wide operating range of −100 to 250 °C).
3. Though not a hydrophobe, the ability to repel water and form watertight seals.
4. Excellent resistance to oxygen, ozone and UV light (sunlight). This has led to widespread use in the construction industry (e.g. coatings, fire protection, glazing seals), and automotive industry (external gaskets, external trim).
5. Non-stick.
6. Low chemical reactivity.
7. Low toxicity, but does not support microbiological growth.
8. High gas permeability: at room temperature (25 °C) the permeability of silicone rubber for gases like oxygen is approximately 400 times that of butyl rubber, making silicone useful for medical applications (though precluding it from applications where gas-tight seals are necessary).

Rubber Stamp

Rubber Stamp

Raw Materials

Rubber stamp manufacturers do not produce the elements that make a rubber stamp directly from raw materials. Raw materials include latex rubber, wood for the mounting blocks, adhesive-backed padding that is placed between the rubber and the block, and adhesive-backed labels. All of these items are produced by specialty manufacturers who supply them to rubber stamp makers.

NBR Rubber

NBR Rubber

The total capacity of NBR (acrylonitrile-butadiene rubber) in the world increased from 546.5 thousand t/a in 2004 to 566.5 thousand t/a in 2005. Major NBR producers include Lanxess of Germany, Zeon and JSR of Japan and Nitrilo Paratec Elastomers of Mexico. The total capacity in these 4 producers accounts for around 50% of the world total.

USES
Hose, belting and cable, 28 percent; O-rings and seals, 20 percent; latex applications, 14 percent; molded and extruded products, 14 percent; adhesives and sealants, 10 percent; sponges, 5 percent; footwear, 4 percent; other, 5 percent.

STRENGTH
Nitrile rubber is highly resistant to petroleum products such as gasoline, diesel oil and other fuels over a wide temperature range. NBR is also noted for high strength and excellent resistance to abrasion, water, alcohols and heat. Special forms of NBR continue to grow in importance. Powdered NBR finds widespread use in polyvinyl chloride and ABS resins as an impact modifier in such products as automotive dashboards and kick panels. Industry consolidation has strengthened the remaining suppliers and eliminated a net 12% of the installed capacity.

WEAKNESS
Only modest overall growth can be expected in nitrile rubber. With 50 percent of its end-use in automotive components, NBR is overly dependent on that cyclical industry. NBR latex has lost market share to styrene-butadiene and acrylic latex products in non-woven fabrics and some paper applications. Competition in hose and belting markets is intense, although superior oil resistance gives NBR the edge in some hose applications.