What is vacuum forming?
Forming soft heat sheets by direct or inductive heating and evaporating air between the sheet and the mold and ductility of the sheet as a mold is called vacuum forming.
All soft heat sheets (ABS, PVC, PET, high impact, crystal, etc.) are ductile.
Devices that do this can be as simple or complex as the task at hand. Simple devices consist of a heater and a sheet holder and a part called the mold holder, which first the sheet is placed in the sheet holder section, then the heater heats the sheet and then the mold contacts the sheet and at the same time the air between the mold and the sheet is evacuated. Takes the mold.
In more complex machines, which include semi-automatic and automatic machines and disposable tableware machines; A number of tasks are performed by the operator and the device, which varies depending on the type of device; In semi-automatic machines, the percentage of operator and machine work is 50% to 50%. In automatic machines, the percentage of operator and machine work is 20% to 80%, and in disposable tableware machines, the machine does all the work and the operator is the only quality control supervisor.
Did you know that many plastic parts, from disposable containers (for example, yellow flakes) to product packaging lids or even car dashboards, are made by thermoforming method!
Thermoforming, or thermal forming, is one of the most widely used methods of forming plastics. In this process, the soft plastic sheet (thermoplastic) is first heated enough to become soft and flexible. This sheet is then placed on the mold and is pulled on the mold by applying air pressure or creating a vacuum or mechanically and takes the shape of the mold.
The raw material sheet is produced by extrusion method. Depending on the thickness, the primary sheet can be in the form of separate sheets or continuous ball sheets.
The thermoforming process consists of two main stages: a) heating b) shaping
A) Heating: At this stage, the thermoplastic plastic sheet (thermoplastic) is heated enough to become soft and flexible. The heating operation is usually using heating elements that one or both sides of the plastic sheet is placed at a certain distance from it. Get done. Depending on the polymer material and the thickness of the sheet, the amount of heating must be completely specified and adjusted.
B) Shaping: The methods used to perform the shaping step can be divided into three categories:
- Vacuum Forming
- Pressure Forming
- Mechanical Thermoforming