Vacuum forming and thermoforming are similar methods of manipulating plastics to create packaging, though they aren't exactly alike. Both methods rely on heating plastic sheets to make them conform to the shape of a mold, but the ways in which the plastic is pulled into the mold differs between processes, making thermoforming more precise, consistent and high-quality, while vacuum forming is less expensive and easier for simple products.
How Thermoforming Works
When a packaging company makes plastic products in a thermoformer, the sheet of plastic is fed into the machine and heated. As the plastic heats, it softens and can be molded—you can see this for yourself when you expose plastic to an open flame, although in plastic manufacturing, the process is much more refined. When the plastic is soft and flexible enough, it is pressed into a mold, and it conforms to that shape. The plastic is allowed to cool, at which point it is hard again but retains the shape of the mold.
The Vacuum Forming Difference
In principle, vacuum forming is performed almost the exact same way—plastic is heated to increase its malleability, then pressed into a mold and allowed to cool, retaining its new shape. The fundamental difference between vacuum forming and thermoforming, then, is how the material is pulled into the crevices of the mold. Vacuum forming gets its name by nature of the process—when the plastic is softened, it is pulled into the mold using vacuum suction. During thermoforming, a considerably higher level of pressure is utilized, making the final product an overall higher quality.
Pros and Cons
While less expensive than thermoforming, vacuum forming is also less precise. The plastic is generally of an uneven thickness, and it can't be formed to molds that are as deep or intricate in size and shape. The cost of operating the machine, as well as the cost of the materials used, is lower than the cost of thermoforming, but the process isn't as fast. That being the case, vacuum forming is typically used for smaller-volume jobs, and ones that do not rely on a particularly high level of detail or consistency.
To learn more about the pros, cons, and different applications of these two packaging methods, contact Plastic Ingenuity today.