Rubber Band Basics
Common Rubber Band Terminology

Clay - Common filler in rubber band compounds. There is no such thing as a 100% pure rubber band. All compounds require the addition of other materials to create a finished product.

Compound - The formula for a particular rubber band compound. With over 80 years of experience and product development, Alliance has designed specific compounds with varying stretch performance to create application specific bands (soft stretch vs. tight stretch).

Curing - The process by which a compound reaches its final intended state through heat, chemical reaction, evaporation, etc.

Custom Bands - Bands that require a "custom" production run. Includes variations in wall thickness and or flat length and non-standard colors.

Cut Width - With the band laying flat, this would be measured across the band perpendicular to the flat length.

Durometer - Measure of the hardness of non-metallic materials or "resistance to indentation."

Elastomer - Generic term for various elastic substances resembling rubber

Elongation - extension or "stretch" of a rubber band

EPDM - (ETHYLENE PROPYLENE DIENE MONOMER) Synthetic rubber compound which provides superior properties for outdoor and all-weather temperature applications because of its excellent resistance to ozone, oxidants and severe weather conditions.

Extrusion - The process of creating rubber tubing in a defined shape by forcing uncured material through a die.

Flat Length - Pinch the two ends of the band together and lay on a flat surface. The measurement from end to end equals the flat length. (If you were to cut one end of the band and unfold it, the flat length would be approximately half the overall length)

Latex - Many plants produce latex, which oozes from cuts and injuries as a milky sap. Rubber is a coagulated, elastic latex containing long-chain hydrocarbons.

Latex Free - Containing no latex proteins. Alliance offers a custom line of bands produced from synthetic polyisoprene (synthetic rubber) for applications with potential allergic reactions to latex proteins.

Memory - The ability of a rubber band to return to its original shape after being stretched.

Modulus - Ratio of stress to strain. Also expressed as the tensile strength at a given percentage of elongation.

Non-standard Bands - Variation in standard cut width or packaging versus standard bands.

Permanent Set - After a rubber band has been stretched, it will typically come to rest at a longer length than before it was stretched. This increase in length is commonly referred to as "permanent set" and is expressed as a percent of the original length of the band.

Set - The extent to which a rubber band does not return to its original shape after being stretched.

Specific Gravity - the ratio of the density (weight) of a substance to the density of water.

Standard Bands - Alliance currently offers several hundred of the most common sizes of rubber bands. These are produced in four distinct lines (with varying stretch performance and count per pound) and a variety of colors. Deviations from standard items are classified as either non-standard or "custom".

Tensile Strength - resistance of a material to stretch. Typically expressed as pounds per inch at the breaking point of a particular rubber band.

Tolerance - the allowable deviation from a standard; the range of variation permitted in maintaining a specified dimension.

Ultimate Elongation - Elongation at point of failure.

Vulcanization - The curing process of rubber which cross-links the molecules into a strong chain, giving the rubber its stretch and strength. This is achieved through the application of heat combined with the appropriate chemicals.

Wall - Refers to the thickness of the wall of the extruded rubber tube.

Yield/Count per Pound - The number of rubber bands per pound.