Thermoforming

The most unique quality of PMMA that is unreachable for traditional quartz glass is the ability of shaping by thermoforming.

In order to achieve desired shape of a panel, we need to make a reverse form, a so called "hoof". On this element we install a sheet of a given thickness and put it into a cooled furnace.

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The furnace is being heated to preset values, dependent on a thickness of the panel. Then, the slow process of PMMA aligning along the hoof starts. Last element is the gradual cooling of the material. Depending on the thickness of the panel, the process can take more than ten days and the temperature is set with the precision of up to 0.5 degree. In addition to the aesthetics, thermoforming also allows to correctly set the thickness of a panel, which leads to savings on the material.

 

For example, cylinder with dimentions of 100 x 200 cm can be made with a 2 mm thick material, but cuboid would require 6 mm. Cylinders of diameter of up to 100 cm is a one-piece pipe, above that it we use two halfs and weld it together.

The welding, or glueing is basically invisible and resembles a faint 2 mm smudge, but visible only by the certain angle. Thermoforming, when done right, is not affecting PMMA in any way, neither structure or surface. 

Determining of the right time and temperature presets for thermoforming requires skill and experience. Quite common practice is a forced thermoforming that causes a pleated surface and results in need to gather the material, additional three phase grinding and final polish. 

Renovation of PMMA can be very demanding if the damage is severe but is very easy with just surface scratches. It needs right tools and chemical compounds though.

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