HONY Blow Molding
Blow molding of hollow articles includes three main methods: extrusion blow molding: mainly for unsupported parison processing; injection blow molding: mainly for parison processing supported by metal cores; stretch blow molding: including The two methods of extrusion, stretching, blow molding, injection-stretching and blow molding can process biaxially oriented articles, greatly reducing production costs and improving product performance. In addition, there are multilayer blow molding, press blow molding, sputum blow molding, foam blow molding, three-dimensional blow molding and the like.
75 % of the blow molded product is extrusion blow molded, 24% is injection blow molded, 1 % is blow molded, and 75% of all blow molded products are biaxially stretched. The advantages of extrusion blow molding are high production efficiency, low equipment cost, wide selection of molds and machinery, disadvantages of high scrap rate, poor recycling and utilization of waste, thickness control of products, and limited dispersion of raw materials. Trimming must be performed afterwards. The advantage of injection blow molding is that no waste is generated during the processing, the wall thickness of the product and the dispersion of the material can be well controlled, the forming precision of the thin neck product is high, the surface of the product is smooth, and the small batch production can be economically carried out. The disadvantage is that the molding equipment is costly and, to a certain extent, only suitable for small blow molded articles.