Sooner or later every thermoformer who buys sheet from others will ask themselves "Would I be better off extruding my own sheet?" The answer is rather complex and will depend on many factors.

In most cases, the usual break even point for making your own sheet from commodity resins is about 3 million pounds per year of the same material. At capacities below that, it is less expensive to outsource your sheet.

Sheet lines operate most efficiently on a limited range of products. Sheet extrusion is a process that is best run continuously over extended runs. An extruder requires about 2 hours to heat up from scratch and perhaps 10 minutes to a half hour to stabilize and run good sheet. While color changes on the same polymer are relatively easy, extruders often require lengthy changes for different materials or radical changes in thickness and width.

The sheet extrusion market is a highly competitive business, and those who are in it deserve to make a profit so that they can continue to provide excellent products and service to their customers.

We recommend that you do not buy a sheet line if:

• You use a wide range of different materials in many sizes.
• You need small quantities of many different colors.
• You can only use a small part of the capacity and are thinking of selling the remainder to others.
• You think that you can easily obtain unlimited garbage and convert it into good sheet.

On the other hand, if you use more than 3 million pounds per year of a specific sheet product, you do have an opportunity to save money, improve your final product quality, and be happy with your decision to become a sheet extruder.

Welex specializes in making experts out of novices.