It’s incredibly frustrating when the vacuum forming process ends in a warped or wrinkled part. It wastes your materials, time, and effort.
The best way to avoid disaster is to know the warning signs, and how to fix them.
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Preventing Webbing During the Vacuum Forming Process
One very common vacuum forming issue is webbing. Webbing is the presence of unwanted wrinkles or pleats in the finished product. They often appear between the tool and the base area and look the webbing of a duck’s feet (hence the name).
Causes of Webbing
There are a few common causes for webbing:
- The mold or tool is too high in relation to the base area
- Sharp vertical corners with minimal draught angles
- Deep male (positive) molds in close proximity to each other
- Too much material
Regardless of the cause, there are some best practice steps to take to troubleshoot these errors.
How to Prevent Webbing
- Smaller sheet size – In this case, less is more. Reduce the amount of material used for a tighter fit.
- Angled blocks around the mold – Place angled blocks around the corners of your mold, to gather any excess material. These can then be removed along with the base area.
- Extra frames in clamping frame – Adding extra frames to your clamping frame can also reduce the likelihood of webbing. You can use wires or steel blades for this purpose.
- Extra frame on the plug-assist – Attach a frame to the plug-assist. This helps force the material down.
- Add radius corners – Add draught angle/radius corners to allow the material to flow over the tool and mold.
- Use female (negative) molds – Using a female mold will reduce or prevent the number of webbing between molds.
- Reduce speed of vacuum – Sometimes a high vacuum speed can cause webbing issues, and simply reducing the speed will resolve them.
- Increase the mold height – Add a 45-degree apron to the base of your tool. This pulls excess material away from your mold, so it can be easily removed.
Here is an example of a vacuum formed part created using some of the above troubleshooting methods:
Some vacuum forming issues involve webbing, and a majority of webbing issues can be resolved by following the above tips. Still encountering issues you don’t see here? For expert assistance with your vacuum formed part, contact Industrial Custom Products. Our engineers and materials experts are well-equipped to troubleshoot problem parts and processes.
Contact us and speak with an engineer about your project at (612) 781-2255, or request a quote online. You will receive a prompt response.
Industrial Custom Products is a one-stop-shop for custom manufacturing and plastic fabrication, including: prototyping and product development, die cutting and dieless knife cutting, thermoforming and vacuum forming, large part thermoforming, CNC plastic routing, fabrication and assembly and drape forming.
