Lubricated Compounds

There are a variety of techniques to lower the coefficient of friction on a rubber component. A common technique includes the induction of low friction filters, such as PTFE, molybdenum disulfide or graphite into the compound during mixing. Coating or surface treatment is another method to reduce friction whereby alteration of the rubber is limited to only the surface of the rubber.

A unique method used by Minnesota Rubber to provide friction reduction is by the addition of lubrication chemicals into the elastomer mixture. These chemicals modify the surface of the part to provide an "internally lubricated" compound. The mechanism of the lubricant does not affect the long term physical properties of the rubber part. The internally lubricated compounds are designed for intermittent or slow cycling type applications. It is highly recommended that designs have long idle times use these compounds to assure minimum startup friction.

FDA Regulations / Food & Beverage Applications

The United States Government regulates the ingredients in rubber products that are intended for use in food contact application. The controlling agency is the Food and Drug Administration (FDA), whose guidelines are stated through the Code of Federal Regulations(CFR). The regulations covering rubber articles are contained in CFR Title 21, Chapter 1, Subchapter B, Part 177, Subpart C, Paragraph 2600.

The FDA provides two categories to individual food types with rubber compatibility. The Class I category designates of foods, including edible oils, butter, milk and mild based products and cooking oils. The second category, Class 11, pertains to foods that do not contain edible oils or milk products. Water, soft drinks, alcoholic beverages and other aqueous solutions are typical Class 11 environments. Minnesota Rubber has a large selection of polymers with varying physical ranges to meet your application needs. The following table gives a listing of recommendations as a starting point.

ASTM D2000 and SAE J200

The American Society for Testing and Materials (ASTM) and the Society of Automotive Engineers (SAE) have developed similar systems for designating physical qualities of rubber products under specific test conditions. Both systems grade elastomers according to heat aging resistance, swilling in oil (ASTM #3 Oil) and special property requirements.

UL Listed Compounds

The Underwrites Laboratories (UL) is a non-profit organization that operates laboratories to examine and test devices, systems and materials manufactured by non-affiliated industries. UL provides a rating on how these products correspond to hazards affecting part life and properties. Products that maintain UL designed safety limits are approved and given the UL trademark label.

In order for a product to carry a UL label, a series of rigorous tests must be passed annually, insuring that the product will withstand conditions beyond those normally encountered. UL has provided the elastomer industry with set standards for compounds in different working environments.

Minnesota Rubber has six compounds carrying the UL label; the following table lists these compounds and their respective working environment. However, a customer should not limit their design goals to these six compounds, Minnesota Rubber will work with any customer in applying for a UL approval.

National Sanitation Foundation (NSF) - Potable Water Applications

The National Sanitation Foundation (NSF) acts as a neutral agency between business, government and the public. The NSF mark symbolizes the standards and criteria under which the product has been tested. The NSF is particularly known for its health related specification.

Like the UL label, the NSF mark is given to the finished consumer product. Minnesota Rubber will assist any customer requiring the NSF mark to comply with all necessary NSF rubber standards.

NSF standard 61 compounds listed for use in potable water applications are 559PE, 559N, 56ORJ, 559TM, 565CZ, and 56OYH, and all are EPDM materials.

One Nitrile (NBR) compound having certification is 366SN.

In addition we have a number of compounds always in the process of submission for certification.

International Certifications- Potable Water

Minnesota Rubber has the most extensive international potable water certified elastomers/materials list in the world today.

Laboratory and Medical Requirements

Medical grade" is a term used to designate compounds that will be put to use in diagnostic devices and medical equipment. "Medical grade" compounds can be thought of as "non-contaminating" to their surrounding media.

Most elastomeric polymers can be designed to be medically acceptable using the proper ingredients. Silicones are generally the first choice for a medical part. Silicone's inertness to body fluids and ability to met USP Class IV regulations make it a very feasible medical grade polymer. Natural rubber/synthetic polyisoprene is another widely used for medical grade components. Natural rubber is noted for its compatibility with insulin. Butyl, nitrile, ethylene propylene, urethane, fluorocarbon, epichlorohydrin, polychloroprene and CSM provide serviceable parts to medical applications in non-critical areas.

When designing parts for use in medical applications, it is necessary for us to have complete details as to have complete details as to the media to be encountered and the environmental conditions expected (i.e.: gases, solution, vaccines, serums, sterilization, freezing, immersion, cleanliness), as well as any applicable standards and cleanliness requirements. This will enable us to accurately recommend a specific rubber formulation for the part application.

Taste and Odor Specifications

Minnesota Rubber has considerable experience with materials that will not affect the taste or odor of a product. Taste and odor testing is usually structured to a particular product. Testing can then be done through either the lab facility at Minnesota Rubber or the customer's facility.

Computer Applications

Minnesota Rubber makes rubber compounds that are ideal for vibration control and "perfect sealing" component requirements of the compute industry. A number of elastomers have been designed at Minnesota Rubber that are suited to meet varying degrees of vibration through the absorption of mechanical energy by the rubber component. Bumper pads or shock mounts and crash stops are typical components encountered.

Certain electrical areas of computer design require separation from contaminating environments. Minnesota Rubber's low outgassing and low extractable compounds, especially the 487 compound series.