The Thermoforming Process Compared with Injection Molding

Plastic Thermoforming Process vs. Injection Molding – How to Choose?

Productive Plastics, Inc. is a premier manufacturer and supplier of thermoformed plastic components, offering pressure thermoforming, vacuum thermoforming and twin sheet thermoforming along with various value-added services. Thermoforming is a plastic production process that heats a two dimensional rigid thermoplastic sheet and uses vacuum and/or pressure to form that sheet into a three dimensional shape.

Thermoforming is a single sided process meaning that only one side of the sheet can be controlled by the tool surface. Consequently, finished wall thickness is determined mainly by the design of the component part. Thermoforming is typically used for production quantities of 250 to 3000 annually, offering lower tooling costs, rapid product development cycles, and parts with color and texture.

Plastic injection molding can be used to make plastic parts for similar applications. Injection molding has a very high tooling cost, but for large quantities, the cost per part is reduced. Here are some guidelines for making such decisions.

Product development cycle for tooling and production, pressure forming vs. injection molding

Choosing the Best Manufacturing Process for Your Plastic Part

Productive Plastics works with customers to make sure the technology, production processes, and materials are right for each individual job. The following comparison charts and information provide general guidelines for selecting the appropriate process, comparing the thermoforming process with plastic injection molding.

 

Product Development Cycle

The combination of tooling and production time provides a measure of comparison. For pressure forming, the typical tooling time is 0-8 weeks, and first production typically happens within 2 weeks of that. With injection molding, tooling usually takes 12-16 weeks with up to four more weeks for production.

So, thermoforming clearly is the preferred manufacturing product-dev-cycle.jpgtechnology when time-to-market is an important consideration.

Cost comparison for tooling and parts, pressure forming vs. injection molding

Part Cost Comparison

The cost comparison chart uses the total aggregate cost of parts and tooling for a large plastic part. With annual quantities of up to about 3000 parts, thermoforming is a better choice based solely on the economics.

 

Mold (Tooling) Cost Comparison

The size of the plastic part is also a consideration in the tooling cost. As the size of the part increases, so does the disparity in tooling costs between thermoforming and injection molding. For a 20″ x 30″ part, the injection molding tooling is about twice the cost of thermoforming. With a 50″ x 60″ part, injection molding is more than three times the cost. So as the size of the part increases, the economics of thermoforming are better.

Cost comparison for the mold, pressure forming vs. injection molding

Thermoforming Alternatives

While Productive Plastics exclusively offers thermoforming, there are circumstances where other plastic manufacturing processes such as plastic injection molding are a better choice. These circumstances include high volumes and very complex designs. Please Contact Us for assistance.

 

Terminology Note

Productive Plastics and the plastics industry typically use the terms “thermoforming” and “forming” interchangeably. So plastic thermoforming is the same as plastic forming.

 

Contact Productive Plastics for Plastic Thermoforming

Please Contact Productive Plastics, one of the most innovative thermoforming companies, for assistance or to get a quote for custom plastic thermoforming contract manufacturing using any of these thermoforming technologies.

Request a free Heavy Gauge Plastic Thermoforming Process and Design Guide from Productive Plastics.