Thermoforming is a process of heating a thermoplastic sheet to its softening point. The sheet is stretched across a single-sided mold and then manipulated. Then, it cools into the desired shape. The most common methods to get the sheet to conform to its final shape are vacuum-forming, pressure-forming, and mechanical forming. Thermoforming has innumerable applications and can be used by several different industries. Here is a brief overview of thermoforming, its benefits, and applications.
Key terminology used
The process of thermoforming uses some specific terminology with which you should be familiar. Knowing the difference between these terms can be the difference between having a successful project and one that is lackluster.
Thermoforming – Thermoforming is a general term that refers to the process of transforming a plastic sheet into a 3-dimensional shape by using heat, vacuum, and pressure.
Vacuum Forming The specific process that involves forming a part by heating and stretching the plastic across a mold using a vacuum. Normally the mold is open and the force involved with forming the sheet is limited to about 15 psi.
Pressure Forming This process adds a pressure box to the tooling package. It utilizes both vacuum and positive air pressure. This process generates as much as three to four times the forming pressure as vacuum forming does. Therefore, fine details such as surface textures can be formed on the mold without incurring excessive extra costs.
Sandwich Pre Forming as the term suggests, there are two molds for this process: one on the top and one on the bottom. Therefore, two sheets of plastic must be heated and formed at the same time. A fused joint must be placed around the perimeter of the mold while air pressure is injected between the sheets. This process is ideal for forming hollow parts that require a distinct upper and lower shape.
Stages of thermoforming
As like any process, there are several stages of thermoforming. The typical thermoforming process goes through the following stages:
Equipment used for thermoforming
ZY Automation has redesigned every section of our thermoforming machine, to be competent at the strict hygiene and deep cleaning requirements demanded by today’s food and medical packaging industry. It has the ability to produce a variety of package types including Flexible Packaging, Vacuum Packaging and more.