Bending plastic - what are the differences between individual types of plastic?


Even plastic can usually be reshaped. But that does not apply to all types of plastic at the same time. Depending on the material properties of the plastic, the type and possibilities of forming are different. Everything about bending plastics can be found here.

Plastic types

  • thermoplastics
  • elastomers
  • thermosets

Plastics can be classified according to their mechanical-thermal properties in thermoplastics, elastomers and thermosets.

Formable, which means that they can also be bent, are only thermoplastics, to a lesser extent also a small special group of plastics, the thermoplastic elastomers.

thermoplastics

Examples of plastics from the group of thermoplastics include celluloid, ABS, polyamide, polyacetate, Plexiglas or acrylic glass, Makrolon and PVC.

All thermoplastics must first be brought into the thermoplastic state to be formable. This is done by heating beyond a certain temperature, which is different for each plastic.

After heating, thermoplastics can be bent or folded without much effort (in the case of plastic plates).

Heating the plastic

There are two options here.

Heating the entire workpiece

It can, if the workpiece size allows it, the entire workpiece can be brought to the target temperature. For smaller workpieces, this can be in the oven, for example, or in a special curing oven for plastics.

The problem here is often only the clamping or fastening of the workpiece before bending. The attachment, for example, in the vice can cause unwanted changes in shape in the mounting area when heated plastic workpiece.

Heating the bending edge

Alternatively, only the bending edge can be heated. This is done by heating rods and hot air devices, but also a normal hair dryer is able to produce the corresponding temperature on a case by case basis.

There are now also portable heating devices for plastic plates, such as Tempafix. After heating over a 15 mm wide heating strip, the plastic plate can be bent by hand at any angle.

It is important that the heat source has a sufficient distance from the workpiece. As a rule, one starts from at least 20 to 30 centimeters. Direct contact between workpiece and heat source must be avoided.

Workpieces with layer thicknesses of more than 4 mm must be heated from both sides at the same time. However, this value varies from type of plastic to type of plastic.

The bending edge must be heated particularly evenly so that as far as possible all parts of the area to be reshaped have the same temperature and thus a comparable state of aggregation.

If the bend is maintained up to the cooling temperature of around 50 to 60° C, then it will finally remain.

Bending by hand or over a template (matrix)

In order to ensure correct bending, templates can also be used, over which the workpiece is then bent. Such templates are also prefabricated in inch sizes.

Tips & Tricks

The bending of plastic plates can easily be done by yourself. The use of a template is recommended for folding.


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