What is thermoforming?
Thermoforming technology basics
Thermoforming is a process, in which the plastic film or plates are pre-heated to a certain temperature that softens them in order to be formed into products of specific shapes. Due to relatively simple and cheap processing this technology is commonly used in large-scale production. Depending on the technical solutions required and the scope of processing one can conduct both single unit manufacturing and mass production.
Thermoforming of large products is done in two stages: heating of the material and forming of the final product. Processed material is fixed on the edges of the forming area. Heating is executed through electrical infrared heaters located at a distance of ca. 125 mm (5 inches), on both sides of the plastic sheet. Heating softens material and its time depends on the type of material, its thickness and color. White boards absorb infrared radiation much slower than dark-colored items. The darker the plate, the shorter the heating cycle gets.
There are 3 basic types of thermoforming process:
● Vacuum forming
● Pressure forming
● Mechanical forming
Usually a combination of methods is used as it improves productivity and quality of the products.
Stretching of the plate during thermoforming changes the thickness of the material, usually reduces it deeply formed areas. The process is fully controlled and deviations are determined already at the stage of product design, tooling and selecting the forming technology.
During the vacuum forming we apply:
● negative tools (representation of the shape and dimensions of the product takes place on the outer side of the sheet)
● positive tools (representation of the shape and dimensions of the product takes place on the inner side of the sheet).
Tagi strony:
thermoforming •
plates thermoforming
