| Fifteen solvents were evaluated as replacements for methylene chloride in the solvent welding of ABS and HIPS. The solvents were divided into three general categories: traditional, “new”, and “green.” Specific goals decided for the methylene chloride replacement candidates included similar bonding in ABS and HIPS with respect to time and strength, as well as minimizing explosive and health hazards. Furthermore, a relative hazard rating was assigned to each solvent by taking the maximum concentration that the solvent would remain in the state of equilibrium in a specified air space, and dividing this value by the Threshold Limit Value (TLV). The resulting composite joint system was tested in both tension and shear specimen. The parameters affecting bond strength that were quantified included: polymer/solvent contact time, surface to surface bonding time, pre- and post-bond temperature, contact pressure, and vacuum. |
