| Abstract: | The bondability of the following polymers as a function of length of exposure to excited helium or oxygen was investigated: low-density polyethylene, high-density polyethylene (two types), poly(4-methyl-1-pentene), poly(vinyl fluoride), poly(vinylidene fluoride), FEP Teflon, poly(oxymethylene) copolymer, nylon 6, nylon 66, poly(ethylene terephthalate), and polystyrene. Generally, the bond strength increase rapidly initially and then remains nearly constant, perhaps decreasing in some cases at long exposure times. A method is presented for calculating bond strength-versus-exposure time curves. The calculated curves generally fit the data reasonably well. Polypropylene showed a rapid increase in bondability with exposure to excited oxygen. Helium was ineffective toward this polymer under normal conditions, but could produce good bond strength at higher temperatures. |
