Traditionally, the lubricity of a fluoropolymer tube surface makes it unable to bond to other materials. But when PTFE, FEP, and PFA tubing is etched by Parker TexLoc, Fort Worth, Tex., the surface can be adhered.

In the process, etching chemicals modify the surface of the fluoropolymer to enhance its bondability. The chemical reaction strips the fluorine from the tubing, eliminating its smoothness. After altering the surface lubricity, the tubing can be bonded to almost any surface. Tubing can be etched on its I.D., O.D. or both, and comes in I.D.s from 0.004 to 4-in.

Etching alters the color of the tube, which ranges from a light brown to a darker, burnished brown. However, the color of the etch does not affect strength.

Unlike natural fluoropolymer tubing, etched tubing must be stored in black plastic bags to keep out light and retain the effects of chemical alteration. If the product is stored unprotected, ultraviolet rays eliminate its ability to bond.