Natural rubber tubing is derived from natural latex, which is a product of several plant species, most notably the Pará rubber tree. Synthetic rubber is made from various molecules derived from petroleum. The inner diameter, outer diameter and thickness of rubber tubing can range in size from a few thousandths of an inch to several inches.
Rubber tubes, like all other tubes, require connectors, hose barbs or other attachments in order to be connected to tools, instruments or more tubing. Both natural and synthetic rubber tubing are polymers with repeating molecules called monomers. Natural rubber is only made with isoprene monomers while artificial rubber can be made from many different kinds. The variations in materials and chemicals added to the mixture result in a range of characteristics and uses.
Rubber products are everywhere and rubber tubes are used in many industries including medical, pharmaceutical, chemical, laboratory, food and beverage processing, sports, manufacturing, hydraulic, pneumatic and specialty applications. These tubes can be spark-resistant, explosion-proof, sterilized, reinforced or conductive and are inherently flexible, resilient and elastic.
Gum rubber is made from natural latex. Once harvested, it is taken to a processing plant and mixed with chemicals so it thickens. In synthetic rubber, certain additives can influence the attributes of the final product. For example, some rubber tubing is conductive while other tubing is sterile and inert. Neoprene, silicone and Viton are a few examples of materials that have different characteristics while still being classified as rubber tubing. For instance, neoprene is buoyant, silicone is very smooth and elastic and Viton tubing is highly resilient. When sulfur is added, a process called vulcanization takes place and the rubber becomes hard and mostly inelastic. After mixing, the rubber must be given its shape.
There are three main ways this is done: molding, extrusion and dipping. Liquid rubber can be poured into molds and pressed into place; the two halves will later be attached and smoothed together. Rubber extrusion involves forcing raw rubber materials through an extrusion die. Dipping rubber tubes involves long cylinders called mandrels whose thickness is the width of the desired internal diameter. They are dipped into vats of rubber and then dried and steam cured.