Page 204

192

9 Facilitating Disassembly

Fig. 9.5 A screw with an insert

Metal screws are contra-indicated for polymer recycling and can create several problems (Fig. 9.5). At last, some screw heads (e. g. hexagonal) are removed more easily than others and do not any require previous cleaning operations. Inserts (for screws): an insert is a supplementary unit that is hardly removable and usually compromising; it should be employed only if no other solutions are available. It is recommended to facilitate the break-off of the insert before the recycling process (Fig. 9.6). Guidelines for engaging reversible joining systems • Employ a two-way snap-fit • Employ joints that are opened with common tools • Employ joints that are opened with special tools, when opening could be dangerous • Design joints made of materials that become reversible only in determined conditions (Example 9.7) • Use screws with hexagonal heads • Prefer removable nuts and clips to self-tapping screws

Fig. 9.6 Pre-disposed break-off areas

Design for Environmental Sustainability  

Download: versi pdf [http://www.ziddu.com/download/12569881/DesignforEnvironmentalSustainability.pdf.html] versi zip [http://www.ziddu.com/...

Design for Environmental Sustainability  

Download: versi pdf [http://www.ziddu.com/download/12569881/DesignforEnvironmentalSustainability.pdf.html] versi zip [http://www.ziddu.com/...

Advertisement