Vacuum molding, what is it?
This type of processing is the forming of sheet plastics under the influence of high temperature and negative pressure (vacuum). Thanks to this technology, it is possible to produce bulky products from such plastics as: polystyrene, PVC, PTH (Pat), and other plastics. The most common material in vacuum molding is polystyrene. Since polystyrene is quite plastic material with a wide range of color solutions. Polystyrene is a mirror, glossy, matte, transparent, light-scattering.
Where Vacuum Forming Products are Used
Vacuum molding is widely used in the production of blister packs , outdoor advertising , interior items etc. As for advertising structures made with molding, we can observe them at sales points, namely light boxes (with bulk panels), stands for products , volumetric letters, molded displays, molded shelves, voluminous posters, mannequins, individual elements of promotional products, various models, blister packs, logos, etc. It should be noted that the molding of plastic can already be done with a printed seal (silk-screen printing). And as a result of molding, the surface of our product acquires volume, which looks quite impressive. Such a product always attracts attention.
Vacuum Forming Technology
About 70% of success in vacuum molding depends on the quality of the mold. After all, it is her form that will eventually receive all the products. The most common materials in the manufacture of a press mold for vacuum molding are composite materials, MDF, light metals, etc. The choice of material for molds depends on the print run of the parts being manufactured. When the circulation is more than 5000 pieces, then for the manufacture of the mold it is necessary to use aluminum. When the circulation is less, then composite materials or MDF are used. An important point in the manufacture of the mold is properly placed holes for vacuum, in other words, ways for pumping out excess air. The mold is fixed in a molding machine. After that, it is treated with silicone grease so that the finished product can be conveniently removed from the mold. Before work, it is heated to a temperature of 60-70 degrees. Then the workpiece is set and the machine starts to warm the sheet of plastic evenly. The temperature regime of the molding machine is selected depending on the thickness of the material. The thicker the plastic sheet, the longer it takes to warm up. As soon as the preform has warmed up and turned into an elastic material, a platform with a pre-established shape rises. The plastic is stretched uniformly on the mold, but there is still excess air inside, which is pumped out with a vacuum. As a result, the plastic completely tightens the mold. Then the future product is cooled with compressed air. When the plastic is completely cooled, it is easily separated from the mold by forcing the same compressed air and we pull the molded product out of the vacuum of the molding machine. But this is not a finished product, because it has extra fields that need to be cut with a milling cutter or laser. And finally it remains only to clean the sharp edges of the products.