Plastic Vacuum Forming Explained - Lerner Molded Plastics

Plastic molding applications frequently use vacuum forming to produce quality plastic molds for various objects and machinery. Also known as thermoforming, this process allows for greater speed and efficiency when molding plastics.

We’ll discuss what vacuum forming is and its uses to help you determine if this technique is right for your application.

What Is Vacuum Forming?

Vacuum forming is a highly cost-effective plastic molding method that has been used in industrial processes for many years. From small products to large industrial equipment, vacuum forming develops all types of molds.

Fabricators often use this process for its affordability, scalability, and overall ease of use, particularly for small items. The process involves applying a plastic layer to the mold before a force suctions the mold to form the final shape. Vacuum forming only requires one mold, which makes the process far simpler compared to other thermoforming processes.

How Does Plastic Vacuum Forming Work?

The vacuum-forming process involves the following basic steps:

Clamping. Fabricators place a single plastic sheet in an open frame and clamp the plastic to keep it in place.
Heating. A heat source softens the plastic sheet to soften it and make it more pliable.
Vacuum forming. The frame lowers to connect the plastic with the mold while a vacuum on the opposite side pulls the plastic into the mold. A convex mold requires small holes in the crevices to properly mold the sheet.
Cooling. Once the sheet has formed the desired shape, it will need to cool down. If a workpiece is particularly large, fans and other solutions can help accelerate the cooling process. Fabricators can then remove the mold from the frame.
Trimming. After removing the mold, fabricators assess the mold and make any final adjustments. This can include trimming or smoothing to remove unneeded material.

While heating and vacuuming may take minutes to complete, large and complex parts may take longer to process, especially in the cooling and trimming stages. More time may also be needed to develop molds for large, intricate designs.

Best Plastics for Vacuum Forming

Many thermoplastic materials lend well to vacuum forming. Some of the best plastics for vacuum forming include:

Acrylonitrile Butadiene Styrene (ABS)

This plastic offers a unique rigidity and hardness for increased impact resistance. It’s cost-effective and can hold up in inclement weather, which makes it ideal for vehicle components, luggage parts, and machine housings.

Polycarbonate (PC)

Like ABS, PC offers superior rigidity and impact strength. However, it comes at a somewhat higher cost due to its enhanced self-extinguishing capabilities. As such, this vacuum-formed plastic is often used with aerospace parts, riot shields, visors, and other components requiring sufficient impact resistance.

Polypropylene (PP)

Another affordable and impact-resistant material is polypropylene or PP. It’s also flexible and features a combination of chemical resistance and aesthetic appeal, which makes it ideal for use in automotive parts, medical equipment, and food and chemical containers.

Polyvinyl Chloride (PVC)

This plastic offers a cost-effective option with relatively high tensile strength. It’s machineable, weldable, and easy to form into different shapes. Its chemical and flame resistance capabilities make it popular in automotive, electronics, packaging, and other applications.

Plastic Vacuum Forming from Lerner Molded Plastics

Vacuum-forming plastic is a cost-effective alternative to other molding processes that can require a greater upfront investment. This versatile process is used to develop a range of products, from product packaging trays and display trays to paneling for electrical appliances.

At Lerner Molded Plastics, we offer a range of plastic molding services to meet each client’s unique needs. If you require dependable plastic vacuum forming for your application, we’re here to help.