Pouching machine...Laser-printable labels...
Dear Search Engineer: I have a "pouching" machine that takes a roll of plastic material and folds it under itself and heat-crimp seals the plastic into a tube shape and then crimp seals again at the ends with another set of heat sealing rollers. The end result is like a candy wrapper used to wrap individual candy bars. This machine also has a thermal transfer printer that imprints a date code onto the film just before the film is converted or shaped into a pouch. There are two heater elements under a steel plate that crimp and fuse or seal the plastic into a "tube" shape. As the thermal transfer imprinted image passes over this plate that is covering the heater elements, the printed image smears off the plastic onto the steel plate. Does anyone know of a material that I can coat this heated steel plate with that will dissipate the heat quickly? The plate is about 300F on the surface. I do not have much height room to add on. —D. D., Design News reader
Dear D.D.: One reader says that he used a glass tape with adhesive backing on it which came in sheets approximately 3 ft wide. Then he would cut out a piece to size, peel off the back and stick it onto the surface. "I sourced it from Cadillac Plastics here in Australia so I would expect the same overseas. I can't remember the exact name of it but it is the same stuff used on portable bag sealers and the like between the sealing element and the machine. It is also used by high frequency welders on their dies. It is a light brown color and the thickness is roughly the same as a thick sheet of paper (anyone know the proper name for it—I used it 6 years ago)."
Another reader suggested: How about relocating the imprinting to after the tube sealing operations? You don't say how much height you have, but an alternative might be to lift it slightly above the plate and blow cold air across the plate. Any coating on the plate will also be at 300F, so the plastic or ink will just stick to it.
Another engineer replied: It seems to me that heat removal from the proximity of the smearable imprint is a better approach than insulating the heat source. Try to position a cooling air jet on the print. If the air spreads too wide and interferes with the sealing function, use two air orifices and play with the angles until the combination actually entraps the jets to "focus" on the target.
Dear Search Engineer: I am looking for a permanent self-sticking laser printable label material with a tough clear outer layer. We need to print labels with the company name and logo and with bar codes and alphanumerics for the serial number and part number. The goal is to replace the engraved metal labels that are riveted to a product, with something like the above that has comparable or superior durability.—L. W., Design News reader
Dear D.D.: One reader replied that 3M (www.3m.com) makes several polyester labelstocks with paper liners that are designed to be used in desktop laser printers. 7842TL, 7845TL, 7850TL are all available, each with a different adhesive. These adhesives are designed to give adhesion to a range of surfaces so it is important to know what surface or surfaces to which you plan to attach the label.