Like TPF, LRM’s patent pending STF technology is unique, on a global scale.  At the heart, its strengths and benefits are derived from an innovative achievement no one else has ever been able to accomplish….

Coating molten plastic directly onto the mold, forming the product in true continuous manufacturing.

Conventional thermoforming uses pre-manufactured sheets of plastic formed at one thickness, which are supplied by large companies who have invested in expensive sheet manufacturing lines.  Thermoforming heats these pre-formed sheets in an oven until they are “soft”, and then stretches the warmed sheet over a male mold…or pushes the sheet into a female mold using a matched “plug” just before vacuum forms the product.  This process is expensive, slow and often produces products with variable wall thickness.

LRM’s innovative STF process uses no pre-formed sheet, thus eliminating a process step and the cost associated with the premiums charged by sheet manufacturers.  STF coats (or “drapes) the mold with a molten sheet profiled to the product shape.

The basic components of STF are illustrated in this graphic:

Here’s how STF works…

1. Virgin, regrind or recycled thermoplastic and additives are fed into the extruder using a computer controlled recipe blender.  If the product is to be a composite, reinforcement fiber is added as well.
2. The extruder melts and mixes the material, while pushing (extruding) it through a transfer pipe to the sheet die.
3. Trollies carrying product molds are always in continuous motion and have all process requirements onboard…air pressure, vacuum, chilled water for cooling.  All process steps and movement are controlled wirelessly by a computer program.
4. As a trolly approaches the coating station, it automatically signals the sheet die to extrude a profiled sheet of variable thickness onto the mold as the trolley moves beneath it.
5. The molten sheet is cut automatically at the end of the cycle, and it is draped over (or into) the mold.
6. Vacuum pulls the molten sheet to the mold, forming the product in an instant.
7. The trolley system automatically triggers chilled water circulation to cool the product as it moves around the track toward the extraction station where it automatically stops.
8. The product is robotically extracted from the mold.

Differentiation…What makes STF Sheetless ThermoForming™ Unique?

Coating the mold directly with molten and profiled plastic sheet eliminates the need for purchasing preformed thermoplastic sheets and the process step of heating them.  This forms the basis of STF’s competitive differentiation, with the following benefits:

• Lower Cost – Pre-manufactured sheet carries a 25 to 30% premium over raw polymer cost.
• Closed Loop Recycling – STF enables the onsite recycling of trim, which is put right back into the process.
• Very Large Product Capability – The current STF line is capable of producing products up to 10’ X 17’.
• Fast Cycle Times, Continuous Manufacturing – Extremely high flow-through productivity.  The line can have as many as 5 trolleys.  There is no “stop & start”, as with the heating cycle of conventional thermoforming, which is stationary.
• Uniform Product Thickness – With STF, we don’t “stretch” a warm sheet with constant thickness.  We coat or drape a molten sheet profiled in thickness to achieve uniformity on the product.

STF Sheetless ThermoForming™ is an easily scalable technology due to its:

• Simple, Versatile Design – The STF line can be scaled readily to product sizes and volumes, and can be constructed in 3 to 6 months.
• Use of Existing Thermoforming Molds – Any male or female aluminum cast molds used in thermoforming today can be utilized in the STF process.

STF is a Totally Computer Automated Manufacturing Process!