Gum rubber sheet is natural rubber in an industrial form. It’s very flexible, has great elongation, high resilience, and resists abrasion and tearing. This makes it one of the best materials for cushioning against impacts and damping vibration. There are a lot of man-made, synthetic versions of rubber but for many applications, and especially for cushioning, it’s hard to beat the original, natural gum rubber sheet material.
Gum Rubber: An Elastomer That’s Grown
Gum or natural gum rubber is made from the sap of the rubber tree, Hevea brasiliensis. The tree is cut to release the sap, also known as latex. This is allowed to coagulate before being passed through rollers to produce sheets. From here additives go in and the rubber is vulcanized to increase cross-linking. The resulting material is chemically very similar to synthetic rubbers like SBR and nitrile.
Properties of Gum Rubber Sheet
As a natural product, there’s always some variation in how gum rubber behaves. In general, though, tensile strength is around 2,800 psi, elongation is a hard-to-beat 550%, and compression set is very low. Gum rubber is known for being extremely flexible, and it remains so down to around -40 °F. Its upper-temperature limit is a relatively low 140 °F, making this one of its limitations.
Gum rubber resists attack by most acids, alkalies, and organic salts, (such as citrates.) Its chemical weaknesses are oils, gasoline, and hydrocarbon solvents. It’s also susceptible to attack by UV light and ozone, which means it’s not a material for prolonged outdoor use.
Gum Rubber Sheet Applications
Flexibility and resilience make impact absorption one of the main uses of this material. That’s why it’s a good choice for cushioning pads and bumpers and why it’s also used for vibration absorption.
Gum rubber is used in seals of various types, such as around doors and for skirting around containers and hoppers because it’s very flexible. Conveyor belt scrapers are another use.
Ask Hennig Gasket & Seals for Gum Rubber Sheet available up to 48″ wide and a range of thicknesses.