Extruder thermoforming line

Turnkey operation A complete fabrication line or system, such as an extruder with a thermoformer line with upstream and downstream equipment. Controls interface all the equipment in-line from material delivery to the end of the line handling the product for in-plant storage or shipment out of the plant. 

At least 30wt% percent of all extruded products are thermoformed. They have many advantages over other manufacturing methods. For the mass production of products (packaging, picnic dishes, cups, etc.) sheets and films can be produced in-line with... 

Figure 7,2 (1) In-line high-speed sheet extruder feeding a rotary thermoformer and (2) view of the thermoforming drum (courtesy of Welex/lrwin)...

With very large volumes a fully integrated in-line, closed loop system can be justified. The line is fed with plastics raw material, with extruders feeding directly into the thermoforming machine. 

Extruded articles Mater-Bi can be extruded and rolled with water cooling. For example, it is possible to produce completely biodegradable cotton buds of Mater-Bi on traditional extrusion lines. Other examples include extruded nets for fruit and vegetables and sheets for thermoforming. 

At its plant in Mont-de-Marsan, France, Autobar begins the production process by creating 330 micron film sheets from the NatureWorks PLA resin using a standard cast extrusion line. The extruded sheet is then thermoformed. 

Environment — All thermoplastic sheet material can be recycled and extruded to new semi-finished products — High energy consumption for off- line thermoforming — High amounts of waste material fiom trimming to be transported for recycling, except thermoformer has own extrusion facilities... 

In-line thermoforming production lines, particularly those being fed directly from an extruder, have to be completely synchronized, or inferior parts result, and/or the cost of the operation goes up. For example, if the trimmer operation has to be slowed down, the extruder output has to be reduced. In fact, a slowdown can result in a shutdown if the extruder cannot operate at the slower speed required. All functions and stations have to be properly interrelated. 

In the thermoforming process, the sheet is extruded either in-line or off-line and formed, either in melt phase or solid phase, into a part of desired shape. Sheet uniformity is important. Historically, iPP has not been used in conventional melt-phase thermoforming equipment because of its narrow forming temperature range and the tendency of the melt to sag. Controlling the sag is particularly important... 

Fig. 16.15 shows one method of web take-up. The roll is replaced when the spool has reached a specific diameter. For longer production runs, the web or trim is guillotined either at the end of the thermoformer or at the end of the in-line trim press. The trim strips are either collected and baled or are fed directly to a grinder/chipper for shipment to the extruder. 

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