Thermoforming or vacuum forming is a common method of processing plastic materials, and vacuum formed products are ubiquitous in daily life. The process involves heating a plastic sheet until soft and then placing it over a mold. A vacuum then draws the soft sheet into the mold. The sheet is allowed to cool and is then removed from the mold.
What is Vacuum Forming?
Vacuum forming is a thermoforming process. The processing principle of vacuum forming is to heat and soften the thermoplastic plastic sheet, then stick the sheet on the mold, and vacuum the side of the coating, so that the sheet can be more closely attached to the mold. After the sheet has cooled, it is set to the shape of the mold.
In simple terms, vacuum forming is a manufacturing method used to shape plastic material by heating a sheet of plastic and then pulling it around a mold using suction.
Processing of Vacuum Forming:
While the vacuum forming principle itself is fairly basic, vacuum forming processes often utilizes sophisticated pneumatic, hydraulic, and thermal controls to enable higher production speeds and a wider range of precision vacuum forming applications.
Applications of Vacuum Forming:
Vacuum forming can be used for a wide range of manufacturing applications, from small custom parts produced on benchtop equipment to large parts made on automated industrial machinery. It is often used in the production of blister packaging, handmade boxes, closures, workboxes, fruit and food boxes, and other products. Almost all thermoplastics can be manufactured by vacuum forming, including PVC, PTE, PS, PP, etc.
Production characteristics of Vacuum Forming:
- Vacuum forming offers several processing advantages over other forming processes. Relatively low-cost tooling can be achieved using low forming pressures. Since the vacuum forming process uses low pressure, the requirements for the mold material are not high, and the mold manufacturing time is relatively short. Therefore, it is a relatively economical production method to produce prototypes or to custom make small quantities of large parts. It can be used for continuous automated production of high-volume items such as disposable cups.
- Unlike other thermoplastic forming processes, vacuum forming uses extruded plastic sheets. For vacuum forming, secondary processing may be required to trim the formed sheet to complete the finished part. The trimmed waste can then be reground and recycled.
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