Rubber Extrusions and Moldings

Natural rubber is excellent as a general-purpose elastomer: it offers a good balance of superior tear strength, high resilience and tensile strength, good abrasion resistance, and good flexural qualities at low temperatures. Natural Rubber should not be used where it will be exposed to chemicals or oil. Also, it does not stand up well in outdoor use where it is subjected to oxygen, sunlight, ozone, and temperature extremes. Product examples using natural rubber include latex gloves and nursing equipment.

Neoprene is durable and water resistant. It also has good resistance to oils, hydraulic fluids, grease, and ozone attack and can be used to create a cushion and a barrier against damage to something being housed within it. Neoprene is noted for a unique combination of properties, which has led to its use in thousands of applications in diverse environments. Neoprene withstands fluctuations in temperature but fairs poorly in consistently low temperatures and will self extinguish a flame. Neoprene is a popular material for wetsuits, electrical insulation and car fan belts. Its resistance to chemicals makes it suitable for industrial applications such as gaskets, hoses and anti-corrosion coatings. It can also provide an effective base for adhesives, as well as an effective noise insulator in power transformer applications.

Nitrile rubber is resistant to petroleum oils and aromatic hydrocarbons and is also highly resistant to mineral oils, vegetable oils, and many acids. In addition, nitrile has good elongation properties as well as adequate resilience, tensile and compression set. Because of its cost, this elastomer is not usually recommended for applications where oil resistance is not a major problem. Where oil resistance is required, the cost is justified. NITRILE RUBBER is generally attacked by ozone, ketones, esters, aldehydes, chlorinated and nitro hydrocarbons.

Santoprene thermoplastic rubber is a family of high-performance elastomers which successfully combine performance characteristics of vulcanized rubber, such as flexibility and low compression set, with the processing ease of thermoplastics. Because of the longer life of Santoprene in both extreme hot and cold environments, the material is often preferred over the use of rubber. Santoprene rubber fits into the middle of the cost and performance spectrum of both thermoplastic and thermoset rubbers. The abrasive resistant material can be blow molded, teleformed, or injection molded with great ease. Along with the fact that the material is so easy and cost efficient to produce, Santoprene also can be recycled. Santoprene rubber has the environmental resistance equivalent to general purpose EPDM rubber compounds, while fluid resistance is comparable to general purpose polychloroprene rubber compounds. This unique combination of environmental resistance and fluid resistance provides a thermoplastic rubber suitable for a broad range of applications including:

• Appliances: pump gaskets, supports, boots, hose connectors, plugs, sump boots, baffles.
• Automotive: rack-and-pinion boots, air ducts, cable covers, bushings, windshield spacers, tubing, grommets, gaskets, body scals for windows and doors, body plugs, weather stripping, lamp covers, suspension dust covers, air bag doors.
• Building and construction: glazing gaskets, weather stripping for doors and windows, expansion joints, setting blocks.
• Business machines: rollers for printers, computer feet, vibration isolators.
• Electrical/electronic: molded connectors, power transmission and distribution components, linemen’s accessories, mining cable, control cable, power-limited circuit cable, submersible cable, coiled cords, flexible cords.
• Fluid delivery: plumbing seals, filter and pump seals, hose and tubing, pipe seals.
• Food contact: diaphragms, valve seals, closure seals, hose and tubing.
• Hardware: caster wheels, tool grips, industrial rollers.
• Medical devices: closures, gaskets, stoppers, plunger tips.

Silicone rubber is ideally suited for many automotive, appliance, electrical/electronic, and aerospace custom rubber requirements where high resistance to both high and low temperature extremes are required. Silicone has inherent resistance to ozone attack, ultraviolet light, corona discharge, moisture, and chemical attack. Silicone also has good tensile strength, elongation, compression-set, and abrasion resistance. Cost can be a limiting factor where extreme temperature resistance is not essential. Unreinforced silicones also have lower tensile strengths than most other members of the elastomer family. Silicone rubber is generally attacked by many solvents, oils, concentrated acids, dilute sodium hydroxide. Product examples using silicone include exhaust hoses.

SBR rubber is a versatile elastomer with above average flexibility, resilience, and abrasive resistance. SBR has good weathering characteristics and is resistant to mild-to-moderate chemicals, organic acids, and alcohols. SBR is easily formulated with high styrene resins to produce tough, hard rubber applications. Compounding with other elastomers greatly improves its oil and solvent resistance. It can be compounded to provide very fine abrasion, wear, and tensile qualities. SBR can be readily substituted for natural rubber in many applications with significant cost savings. Like natural rubber, SBR offers little resistance to oils and chemicals. SBR must be specially compounded to provide resistance to ozone, sunlight, and heat. Product examples using SBR include vehicle mats. Product examples using SBR include glass window sealing weatherstripping.

Viton rubber is a relatively new addition to the elastomer family; Fluoroelastomers resist a wide variety of corrosive fluids at elevated temperatures while retaining their mechanical properties. Other features include resistance to weathering, ozone, oxygen and flame, good tensile strength, resilience, and low compression set. Unlike many of their counterparts, Viton fluoroelastomers retain their basic properties at extremely high temperatures. Fluoroelastomers are still undergoing extensive development and their excellent mechanical stability under severe operating conditions making them an ideal component where the cost can be justified.