Plastics PRAXIS - PFERD
Plastics PRAXIS - PFERD
Plastics PRAXIS - PFERD
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Which groups of plastics exist?<br />
<strong>Plastics</strong> can be divided into the following groups on the basis of the differences in their<br />
thermal-mechanical behaviour in accordance with DIN 7724:<br />
■■ Duroplastics (thermosets)<br />
■■ Thermoplastics<br />
■■ Elastomers<br />
■■ Thermoplastic elastomers<br />
<strong>Plastics</strong><br />
Groups of <strong>Plastics</strong> and their Properties<br />
Properties Duroplastics Thermoplastics Elastomers Thermoplastic<br />
elastomers<br />
Structure Close-meshed<br />
three-dimensionally<br />
chemically cross-linked<br />
macro-molecules<br />
Behaviour at normal<br />
temperature<br />
Forming<br />
Hard and brittle to<br />
viscoplastic<br />
Cannot be formed<br />
plastically following<br />
cross-linking<br />
Chain-shaped<br />
macro-molecules with<br />
little or no branching<br />
Amorphous<br />
Completely disordered<br />
structure of the polymer<br />
chains<br />
Partially crystalline<br />
Contains areas with parallel<br />
arrangement of the polymer<br />
chains<br />
Soft to hard-viscous or<br />
hard-brittle<br />
Can be formed plastically<br />
at increased temperature<br />
Wide-meshed<br />
three-dimensionally<br />
chemically cross-linked<br />
rubber macro-molecules<br />
Co-polymer comprising<br />
hard and soft blocks<br />
or<br />
Blend of thermoplastic<br />
with (non-/partially)<br />
cross-linked rubber<br />
Soft/rubbery and<br />
hard/glass-like areas<br />
Rubbery-elastic Rubbery-elastic<br />
Can only be formed<br />
elastically<br />
Meltability No Yes No Yes<br />
Behaviour towards<br />
solvents<br />
■■swellable ■■soluble No<br />
No<br />
Yes<br />
Yes<br />
Yes<br />
No<br />
Plastic pipes.<br />
Resistance to chemicals High High Moderate High<br />
Weldability No Yes No Yes<br />
Adhesive ability Yes Mainly yes Yes Mainly yes<br />
Machinability Yes Yes Yes Yes<br />
Recycling ability No Yes No Yes<br />
Can be formed plastically<br />
at increased temperature<br />
(yield range)<br />
Yes<br />
Yes<br />
5
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