TMF offers multiple options for blow molding depending on the application you are looking for, whether it be high quality, high volume, or both. TMF has manufactured crystal clear blow molded items that have the appearance of glass with our injection blow molding process and also produces well over a million extrusion stretch blow molded vessels that are high volume, functional items.
Injection Blow Molding
With injection blow molding, a parison is injection molded that will have the overall part weight of the finished blow molded part. This parison looks like a test tube with thick walls. This parison is then brought into a reheat blow molding machine. The preform is heated above the glass transition temperature, then high-pressure air is blown into the vessel until the outer walls of the parison are formed against the metal blow mold. Blow molding can achieve shapes like water bottles, 2 Liter bottles, spice containers, shampoo bottles, contoured walled beer glasses, milk jugs, and many more.
Extrusion Stretch Blow Molding
With extrusion blow molding, plastic is melted and extruded into a hollow tube. This tube continuously extrudes while a cooled metal mold closes around the extrusion and captures it between the mold halves. Air is then blown into the tube, or parison, inflating it into the shape of the hollow product. After the plastic has cooled sufficiently, the mold is opened and the part is ejected. In most cases, there will be excess material that is automatically trimmed within the operation and discarded or re-used if the customer allows regrind.
Examples of parts made with this process: most polyethylene hollow products, milk bottles, shampoo bottles, watering cans, and hollow industrial parts such as drums.