General knowledge of plastic mold
Extrusion blow molding is a method for manufacturing hollow thermoplastic parts. Widely known as blow molding objects are bottles, barrels, cans, and boxes, as well as containers for all packaged foods, beverages, cosmetics, medicines, and daily necessities. Large blow-molded containers are usually used for packaging chemicals, lubricants and bulk materials. Other blow-molded products include balls, bellows and toys. For the automotive industry, fuel tanks, car shock absorbers, seat backs, center brackets and armrests and headrest coverings are blown. For machinery and furniture manufacturing, blow molding parts have enclosures, door frames, frames, POTS, or boxes with an open surface.
Three quarters of blow molding products are made by extrusion blow molding. Extrusion is the process of forcing material through a hole or mold to produce a product.
Extrusion blow molding process consists of 5 steps :1. Plastic embryo (extrusion of hollow plastic pipe); 2. 2. Close the flap mould on the mould embryo, clamp the mould and cut off the mould embryo; 3. Blow the mold into the cold wall of the mold cavity, adjust the opening and maintain a certain pressure during cooling; 4. Open the mold and remove the blown parts; 5. Trim flying edges to get finished products.
Polymer blending is defined as the process of elevating a polymer or polymer system by melt mixing. The mixing process ranges from the addition of a single additive to the treatment of a variety of additives, polymer alloys and reactive mixtures. It is estimated that a third of polymer production in the United States goes through blending. Mixing ingredients can be customized according to the performance requirements of the final application. Mixed products have mixed properties, such as high gloss and excellent impact strength, or precision molding and good stiffness.
Blended polymers are usually granulated for further processing. However, there is growing industrial interest in combining blends with further processes, such as profile extrusion, to avoid reheating the polymer.
Various types of melt mixing equipment are used, from rollers and batch mixers to single-screw and double-screw extruders. Continuous mixing (extruder) is the most common equipment because it provides consistent quality and reduces operating costs. There are two types of mixtures: distributed mixtures can be evenly distributed in a mixture without the need for high shear stress. Such mixtures are called extensional mixtures or laminar mixtures.
Dispersive mixing, also known as strong mixing, in which a high shear stress is applied to break up a cohesive mass of solid. For example, when the additive aggregate is broken, the actual particle size becomes smaller.
Mixing operations often require two types of mixing in one process.
Folding edit this section blow molding scope
Generally common are People's Daily necessities such as: bottles, cans, baby supplies, sports goods and so on