Among Curtis TradeGroup’s ongoing activities since 1984 has been locating and purchasing on a world-wide basis scrap butyl inner tubes, which we supply to industrial consumers. These consumers recycle the scrap material into a raw material used by the rubber industry. Torn or damaged tubes are therefore completely acceptable. Most scrap inner tubes contain primarily one of three polymers:

BUTYL is a petroleum-derived synthetic rubber used mainly by the tire and inner tube industries. The vast majority of inner tubes in use today are produced from this material and they are the type in which we are interested. Butyl inner tubes are used largely with truck tires, although occasionally some passenger (automobile) as well as motorcycle and bicycle tubes are found. Butyl tubes are normally black in color and are usually identified by a single or double thin blue line which runs the circumference of the tube. A tear test can be performed to identify butyl inner tubes. Using a small knife, make a short tear in the tube. Grab the tube on both sides of the tear, and rip the tube two or three inches. A butyl tube will be difficult to rip, and when ripped will normally tear smoothly.

CHLOROBUTYL AND BROMOBUTYL (HALOBUTYL) are polymers similar to butyl but are heat resistant and are therefore not acceptable for our needs. They are normally black in color, are often identified by a green or yellowish-green line and perform similarly to the tear test for butyl tubes described above. The following burn test may be useful in differentiating between butyl and chlorobutyl: Crimp a small (roughly 1 cm x 1 cm) sample at the end of a clean (no residue or oxidation) copper wire or rod and hold the end of the copper in a low, open flame such as a propane torch or a Bunsen burner. As soon as the copper is heated and the rubber sample begins to burn, remove the sample from the torch flame and observe the flame emitting from the rubber sample. Chlorobutyl will show a definite green tint in the flame, while the flame from butyl will be mostly yellow and/or blue. CAUTION: As the copper will heat rapidly while in the flame, a glove should be worn or pliers used to hold the copper.

NATURAL RUBBER inner tubes, which are mainly used today in off-road vehicle, farm machinery and heavy equipment tires, were the only type available until World War II. They may be red or black in color and are often identified by a red or white line. When torn, they rip very easily; sometimes almost falling apart if old. In addition, the rip produced will normally be rough and jagged. Natural rubber tubes have a different "feel" - more floppy or bouncy than synthetic rubber. We are not currently accepting scrap natural rubber inner tubes.