Reaching New Performance in Thermoforming CPM

by Michaela Cultrara

The simple definition of thermoforming is the process of using heat to shape plastic into a mold. Although this sounds simple there are many components that play into a successful thermoforming process. Between the sheet and machines themselves, below is practical information for thermoforming a clean foam product.

In foam thermoforming, quality foam sheet production is an important aspect in ensuring a successful finished product. The first part of this is sheet size. Using a sheet optimized to your mold size and thermoformer will reduce your scrap rate, in turn, putting your business in a better competitive position. Advances in motor and control technology can increase your plant productivity either in a new machine or through retrofitting your existing machinery. Obsolete machinery and control systems cannot match modern equipment in terms of cycle time. Many different factors go into cycle time and it will vary according to different product lines. Either your forming or trimming process will be your governing factor in calculating how many cycles per minute you can perform. The amount of mold cavities plays a crucial role, for every one forming cycle you will need to perform multiple trimming cycles. If your tool has five rows of cavities, and your trim station can perform 190 cpm, you will need to perform 38 mold cycles.

What can impact the cycle time? Foremost, your equipment capability will constrain your cycle time.

  • Different products will have different forming requirements; shallower products will need less time per cycle than something that is deeper.

How can you assure your product is running at optimal cycle time?

  • Although most machines/controls can run faster than optimal performance the governing factor to increased CPM is maintaining molding and trim accuracy.       
  • Your machine control system should ensure that you are running the correct trim speed for a given mold. Quality control of your finished product should be implemented to make sure your molding time is set correctly.

It is very important to match your thermoformer output with your trimpress speed. If you are trimming faster than your molding process, you will have a break in your sheet. If you are molding faster than you can trim, you will have excess material build up between the processes.

How has Commodore improved on this?

Increases in CPM have been made with the new generation SX-28S thermoformer and TP-30HS trimpress thru the use of servo technology for the forming and trimming process, increased oven length, introduction of a power canopy, and increases in machine rigidity. The SX-28S Thermoformer has the ability to reach trim station speeds of 190 cpm while maintaining trim accuracy. This makes our machine one of the fastest for the 28th To find out more about this thermoformer click here.