The Advantages and Disadvantages of Vacuum Forming
If you want to quickly create precise, cost-effective, and versatile products, it’s hard to beat vacuum forming. This process, which involves heating, stretching, and vacuuming plastic over a mold, is one of the most popular methods for making many 3D objects. It’s usually the go-to choice for short run productions of shallow plastic parts like containers or custom coverings.
However, there are pros and cons to using this method for prototyping and manufacturing products. In this detailed guide to the advantages and disadvantages of vacuum forming, you’ll learn whether this method is the best approach for your project or if there’s another method you should use instead.
Why Vacuum Forming is a Popular Method
Many industries use vacuum forming because it’s a streamlined manufacturing method. The process involves placing a sheet of plastic inside vacuum forming equipment and heating the sheet until it’s soft. Next, the sheet is placed over a pre-made mold (sometimes made from aluminum, which is relatively durable and can be used multiple times). Once the sheet has made contact with the mold, operators engage the vacuum, which removes air from the chamber and causes the plastic to tighten against the mold and take on its shape.
After letting the plastic cool, engineers can then use a CNC machine or another tool to cut off any excess plastic. They can also perform an additional pressure forming step, where positive air pressure pushes plastic into crevices in the mold for added detail. Once the plastic is removed from the mold and trimmed, you’re left with a finished product or component.
The ease and consistency of this process are just two of the many reasons it’s a top choice for making shallow plastic parts. However, there are advantages and disadvantages of vacuum forming, so you’ll need to think carefully about this process before you begin.
What Are the Advantages and Disadvantages of Vacuum Forming?
Vacuum forming is more appropriate for some projects and uses than for others. For example, if you need the walls of your product or component to be extremely thick and durable, this may not be possible to achieve using this method alone. This is why it’s important to consider all of the potential advantages and disadvantages of vacuum forming, including the ones below:
|✔ Each individual piece is relatively fast to produce||✖ Only one part or product can be made at a time (best for small-scale production)|
|✔ Low manufacturing costs||✖ There may be additional costs or resources needed to finish components|
|✔ Low molding costs (especially when using cost-effective materials like high-density foam)||✖ There may be additional costs or resources needed to finish components|
|✔ Typically consistent shapes and sizes from batch to batch, particularly when using the same mold multiple times||✖ Thick plastic sheets can warp during vacuuming (the plastic has to be carefully stretched to prevent this)|
|✔ Versatile and customizable mold shapes and sizes||✖ Designs have to be relatively simple, as there’s a limit to how much detail you can achieve from a mold|
|✔ Easily scale production up or down and make new components as needed||✖ If the mold isn’t properly made, the final product or component will also be flawed|
|✔ Excess plastic can be recycled into more sheets for future production needs||✖ Excess moisture can cause unwanted bubbles to form|
|✔ Supports rapid prototyping processes||✖ Clear or light-colored parts can show debris from the mold|
Generally speaking, there are more benefits of vacuum forming than there are downsides. As long as the product or component you’re making isn’t too thick or complex, vacuum forming is likely a good option. It’s also recommended for short run manufacturing. If any of these qualities apply to your project, you should discuss vacuum forming options with your manufacturer.
How to Decide Whether Vacuum Forming is Right for You
Now that you know the general advantages and disadvantages of vacuum forming, you should decide whether this method is the best approach for your specific project. A skilled team of engineers and manufacturers can help you make this decision. They’ll ask you questions like:
- How many components do you need to manufacture?
- What is your ideal time to market?
- What is your total product development budget?
- How complex is your design?
- Does your design need to pass certain durability or quality control tests, and if so, which ones?
- How precise does your final product or component have to be?
Your answers to each of these questions will help engineers determine whether vacuum forming is right for your needs. Your manufacturer may recommend using an alternative method, such as injection molding, if they feel it’s a faster, more cost-effective, or more precise option for your product.
This is why it’s important to work with a manufacturer that offers multiple options and capabilities. Even if vacuum forming isn’t the right choice for your project, an experienced and capable manufacturer will guide you to a more viable alternative that will get your product to market fast and at the lowest possible cost.
PRL’s engineers have dozens of manufacturing options available to help you solve any challenge facing your product: CNC machining, custom tooling, 3D printing, thermoplastic molding, reverse engineering, and more. No matter what stage your product is currently at, we can create it and optimize it for manufacturing.