All About Pressure Thermoforming

Updated , by John Dahlstrom

All About Pressure Thermoforming

Pressure Forming #

Pressure forming helps produce injection-mold-quality high-definition plastic components, housing, containers, and without the high cost and tooling. Positive pressure is used to force the heated plastic parts into the mold cavity in the process. The method is known as Blow Forming or Pressure Thermoforming.

Pressure Forming Working Operation #

Pressure forming is a highly versatile method that uses air pressure from 20 to 150 psi to force the heated sheet of plastic into the temperature-controlled mold cavity. The mold consists of vent holes so that the trapped air can escape. The final part features tight radii, intricate contours, and sharp definition. In fact, accurate details and textures are usually built right into the tooling. The method helps produce aesthetically pleasing plastic parts of varying sizes at a much lower cost. The method also helps better monitor sheet and tool temperatures and control material shrinkage.

Types Of Molding Operation #

  • Positive Mold
  • Negative Mold

The positive mold has a convex shape, while the negative mold has concave cavities.

Pressure Forming VS Thermo Forming #

Pressure forming is quite cost-effective when producing small items. This is the basic advantage of pressure forming compared to thermoforming. In fact, the cost of the mold in thermoforming is quite high. Hence, lower quantity precision jobs are best suited for pressure forming.

Application #

Pressure forming is mostly used to create a wide range of plastic products used in the food industry, including food trays. Some of the other products include internal parts, covers, blisters, bezels, housings, bases, and spare parts used in business machines, computers, peripherals, electronics, bio-medical applications, and instruments.

Features #

Pressure forming helps achieve many features beyond vacuum forming capabilities - such as ribs, louvers, crisp details, logos, and recessed areas. The method is great for small and medium-sized production processes that don't justify the cost of molding dies. On the other hand, the aluminum tooling used in the method has an extended lifecycle due to the non-abrasive process. Hence, it helps save a great deal of money in your business. Pressure forming tools are inexpensive compared to injection tools. It costs less than 10% of the cost of an injection tool. Tooling lead time is also saved by at least 25%. Sheet gauges between .020" – .500" can be pressure formed.