Reversibility and disassembly time of part connection

The reversibility and disassembly time of part connections were experimentally examined through the actual disassembly work of some spent industrial products. The disassembly time for connections depends on the joining method, joining direction, length of product life and chemical and physical deformation. The strongest relation was observed between the joining method and disassembly time. The male-female joint (socket joint) and snap fitting had a relatively short disassembly time of < 10 s. The screw and threaded fastener took 20-100 s to disassemble. Joining with adhesive reagent, soldering and welding showed a very long disassembly time. Joining with short disassembly time showed a relatively good reversibility. The male-female joint and plug socket have the best reversibility. In the snap fitting, the disjoining often gave some damage on the connecting portion. On the other hand, the damage of threaded fastener had no influence upon the deformation of a component fixed with the threaded fastener. Permanent joining, such as soldering and welding, showed a poor reversibility. A convenient method to evaluate the disassembly time of a product was introduced. The estimated disassembly time fairly agreed with the experimental time. (C) 2002 Elsevier Science B.V. All rights reserved.