Plastique
Clamped and heated plastic sheets are molded using a vacuum and simple dies.
Since usually only one surface of the sheet is in contact with the mold, wall thickness
control and desing details are limited. Decorative details are possible with the use of
textures or embossed sheets. Some scrap results from in-mold or secondary trimming of the
clamped edges of the molded plastic sheet. Process is useful for replacing sheet
metal housings or similar metal components that are relatively simple. This low-volume process with low
with low tooling costs but high labor costs produces moderate part costs.
The strengths of thermoforming are as follows:
- Parts have low internal stresses therefore good physical properties to work with.
- Lead time and mold changes are relatively short and easy to perform.
- Large part don't increase costs.
The downside to thermoforming:
- The raw plastic sheets are considerable cost since they are manufactured products themselves.
- Labor required for trimming scraps and other operations can be very costly.
- Quality control can be issue.
- Control of wallthickness is difficult to fully control.
The kinds of thermoforming vary depending on the kind of mold used in the process:
*** More information will be added as this section grows more...
- Vacuum forming
- Pressure forming
- Twin Sheet forming
Depth of Draw Ratios:
| Draw Ratio |
Draw |
Process |
| < 1:1 |
Shallow |
Vacuum |
| 2.5:1 |
Medium |
Plug Assisted |
| 3:1 |
Deep |
Reverse Draw, Vacuum/Snapback |
| 4:1 |
Deep |
Billow Vacuum/Snapback |
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