The use of plastic bottles has great market value. Whet […]
The use of plastic bottles has great market value. Whether it is food packaging, cosmetic packaging or medical packaging, plastic bottles are undeniable, and its use range is more and more extensive. Also because it has his own unique advantages, it has achieved the original good reputation. However, do you know the process and process of hand-made plastic bottles? Let's introduce the molding process of plastic bottles.
The molding of a plastic bottle refers to a process in which a polymer manufactured by a synthetic resin manufacturer is made into a final plastic article. Processing methods (often referred to as primary processing of plastics) include compression molding (molding), extrusion (extrusion), injection molding (injection molding), blow molding (hollow molding), calendering, totaling: compression molding, extrusion molding Six processes, such as injection molding, blow molding, calendering, and foam molding.
Now let me introduce you to the specific situation of these six processes.
Step one, compression molding
The opening and closing device rotates the screw shaft to bring the movable mold closer to or away from the fixed mold, thereby opening and closing the mold. The fixed mold can be removed from the fixed platen in a direction intersecting the opening and closing direction of the movable mold. The machine that keeps the molds in parallel, accurately grips the workpiece, and improves the quality of the molded article and improves productivity. It can also be called press molding.
Step two, extrusion
Extrusion is to heat the plastic raw material to make it a viscous flow state. Under the action of pressure, it is formed into a continuous body with a section similar to the shape of the die by extrusion molding, and then cooled and shaped into a glass state, which is obtained by cutting. Plastic products with a certain geometry and size.
Step three, injection molding
The molten plastic is injected into the mold of the plastic product by pressure, and is cooled and molded to obtain various plastic parts.
Step 4: Blow molding
The tubular plastic parison obtained by extrusion or injection molding of thermoplastic resin is heated (or heated to a softened state) and placed in a split mold. Immediately after closing the mold, compressed air is introduced into the parison to blow the plastic parison. It is inflated and adhered to the inner wall of the mold, and is cooled and demolded to obtain various hollow products.
Step 5: Calendering
A method of forming a film or sheet by continuously heating a thermoplasticized plastic through a series of heated press rolls. In the rubber processing process, the rubber can be calendered into a film of a certain thickness and width, or the pattern is pressed on the film for molding the next product.
Step 6: Foam molding
A foaming material (pvc/pe, ps, etc.) is added to a suitable foaming agent to cause the plastic to produce a microporous structure. Almost all thermosets and thermoplastics can be made into foam bottles. According to the cell structure, it is divided into open-cell foam (which means that most of the pores are connected to each other) and closed-cell foam (the majority of pores are separated from each other), which is mainly manufactured by chemical foaming and physical foaming. And mechanical foaming) decided.