Improvements in and relating to the fixing of thermoplastic members to walls or other surfaces

摘要

Fixing screws for sheets 5 of thermoplastic material such as polyvinyl chloride are covered by caps of the same or other thermoplastic material welded in place. The cap has an enlarged body part 8 with an annular flange to cover the screw head and a square projection 9 for gripping in the chuck of a portable drill. The cap is pressed on to the sheet whilst rapidly rotating and is friction welded in place as indicated in Fig. 2. The part 9 may be sawn or filed off. The caps may initially be of the general shape shown in Fig. 2 and be welded on by heat.ALSO:In the lining of chemical apparatus with sheets 5 of thermoplastic material such as polyvinyl chloride the fixing screws are covered by caps of the same or other thermoplastic material welded in place. The cap has an enlarged body part 8 with an annular flange to cover the screw head and a square projection 9 for gripping in the chuck of a portable drill. The cap is pressed on to the sheet whilst rapidly rotating and is friction welded in place as indicated in Fig. 2. The part 9 may be sawn or filed off. The caps may initially be of the general shape shown in Fig. 2 and be welded on by heat.