Established in 1971, Lehigh Valley Plastics (LVP) is a state-of-the-art plastic materials manufacturer and supplier of plastic materials. They are located in Bethlehem, Pa., and employ about 85.
LVP is one of the few remaining plastics manufacturers in the industry that offer full-service capabilities from design and engineering to the production of nearly any plastic product, quickly and cost effectively.
Situation
LVP is experiencing efficiency issues with their turning centers. The four machines are shut down every three minutes during the production process for one minute to remove stringers, excess material from the work area. The company would like to find a way to eliminate shutting down these four machines to increase their productivity and therefore their revenue.
The machining centers utilized in this process were originally designed for machining metals, not plastics. When the plastic is machined, the ductile properties of the plastics cause the removed mass to stay together rather than “chip” as in a normal metal machining process. The fusing creates stringers which wrap around the chucks of the turning centers causing the machines to be shut down and the wraps cleared manually.
Currently, to minimize the problem, LVP is adding a cooling fluid to the machine part interface, an additional cost to the production process, in an attempt to reduce the time involved in this process failure. There is some questions whether this fluid actually produces a better part; however, it is agreed that LVP would like to eliminate the need to use the cooling fluid which would reduce costs.
In addition, if the stringer gets caught on the part, a quality product defect is likely to occur causing the part to be scrapped and remade, which increases production time and the per part costs. In rare cases, the wrap ups can also cause machine damage which would result in machine repairs and another increased cost.
Solution
LVP was selected as a participant in the Technology Scouting Pilot Research Initiative offered by NIST MEP, MRC and RTI International. This initiative identified targeted, potential solutions to their technical problem from the hundreds of universities, federal labs, and companies where solutions reside.
As one of eight companies nationwide selected for this program, LVP received this assistance at no charge. The solution space landscape included pneumatics and/or mechanical solutions, chip embrittlement techniques, tooling design, and in practice technologies. The optimum solution is a patented, controllable Liquid Nitrogen (LN2) based cooling technology that is specifically utilized for plastics. This technique precisely controls temperatures, increases machine efficiency, improves the surface finish, and is designed specifically for very soft to very dense plastics. It is a proven technology patented by a major, local company, Air Products.
They have offered the use of a demo unit for $2,000 per month. The machine is quiet (no noise or safety hazard) and costs around $10,000 to $20,000 to purchase which may be negotiable. And, the adjustable temperature feature allows for more flexibility and positioning of the cooling stream.
Results
The solution will eliminate the cooling fluid at $1,000 per drum, increase machine capacity of 1,920 hours/year/machine for three shifts, and reduce the risk of safety issues resulting from the slippery stringer material falling on the plant floor.