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3. Effect of physical properties of polymers
The low thermal conductivity, very high viscosity and volume variations of polymers play a major role in injection molding.
The viscosity of plastics is very high at injection temperatures. It is on the order of 100,000 to 10 million times that of water under forming conditions.
This implies, on the one hand, very high injection pressures (up to 200 MPa), and on the other hand, significant temperature variations generated by the importance of the viscous dissipation phenomenon in the feed device, in the absence of specific precautions.
What's more, the low thermal conductivity of plastics - a thousand times lower than that of copper - means that cold feed channels can be used, but requires a long cooling time, depending on thickness.
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Effect of physical properties of polymers
General mold design
Bibliography
Software tools
CADMOULD http://www.cadflow.fr/
Moldflow http://www.moldflow.com/
Simpoe http://www.simpoe.com/
Events
Forum International de la Plasturgie, takes place every three years in Lyon : http://www.f-i-p.com
K– Messe, Europe's leading plastics trade fair, is held every three years in Düsseldorf: http://www.k-online.de
Standards and norms
- Moulding tools – Thermal insulation foils in injection molds - NF ISO 15600 - Avril 2001
- Moulding tools – Tool specification form for injection molds - NF ISO 16916 - Août 2004
- Moulding tools – Injection nozzles – Dimensions - NF ISO 10072 - Mai 2004
- Moulding tools – Bracing pillars - NF ISO 10073 - Février 2009
- Moulding tools – Cylindrical-head ejectors - NF ISO 6751 - Avril 1999 ...
Directory
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