13.10.2022

Molds, various molds and tools used in industrial production to obtain the desired products by injection molding, blow molding, extrusion, die casting or forging, smelting, stamping and other methods. In a nutshell, a mold is a tool used to make a shaped item, this tool is made up of various parts, and different molds are made up of different parts. It mainly realizes the processing of the shape of the object through the change of the physical state of the molded material, and is known as the "mother of industry". Under the action of external force, the blank becomes a tool with a specific shape and size. It is widely used in blanking, die forging, cold heading, extrusion, powder metallurgy parts pressing, pressure casting, and compression molding or injection molding of engineering plastics, rubber, ceramics and other products. The mold has a specific contour or cavity shape, and the application of the contour shape with the cutting edge can separate the blank according to the contour shape (blanking). Applying the cavity shape allows the blank to obtain a corresponding three-dimensional shape. The mold generally includes two parts, a movable mold and a fixed mold (or a punch and a concave mold), which can be divided and closed. The mold is a precision mold with complex shape, which bears the expansion force of the blank, and has high requirements on structural strength, rigidity, surface hardness, surface roughness and machining accuracy. The development level of mold production is one of the important signs of the level of machinery manufacturing.


Plastic mould is the abbreviation of a combined mold for compression molding, extrusion molding, injection molding, blow molding and low foam molding. The coordinated changes of the mold convex, concave mold and auxiliary molding system can process a series of plastic parts of different shapes and sizes. It mainly includes a concave die with variable cavity composed of a concave die combination substrate, a concave die assembly and a concave die combination card plate. A punch with a variable core composed of side-cut composite panels. In order to improve the performance of plastics, various auxiliary materials, such as fillers, plasticizers, lubricants, stabilizers, colorants, etc., must be added to the polymer to become a plastic with good performance. Among them, synthetic resin is the main component of plastic, and its content in plastic is generally 40% to 100%. Due to the large content and the properties of resins that often determine the properties of plastics, people often regard resins as synonymous with plastics. For example, polyvinyl chloride resin is confused with polyvinyl chloride plastic, phenolic resin and phenolic plastic. In fact, resin and plastic are two different concepts. Resin is an unprocessed raw polymer. It is not only used to make plastic, but also a raw material for coatings, adhesives and synthetic fibers. Except for a very small part of plastic, it contains 100% In addition to resin, most plastics need to add other substances besides the main component resin.


The appearance requirements of medical molds are relatively high. In addition to the absence of microcosm, trapped air, and strain, the finish must be very high. To achieve the mirror effect of the mold, polishing is required. Mold polishing has two purposes; one is to increase the smoothness of the mold, so that the surface of the product out of the mold is smooth, high and beautiful; , Mold polishing is generally the process of using oil stone, sandpaper, polishing paste, etc. to polish the cavity surface of the mold, so that the working surface of the mold can be as bright as a mirror, which is called mold polishing. Don't use the finest whetstone, sandpaper, and polishing paste at the beginning of medical mold polishing, which will not throw away the coarse texture. The live surface polished in that way looks bright and high, but when the side is photographed, the rough texture is revealed. Therefore, it is necessary to first grind with a coarse whetstone, sandpaper or grinding and polishing sound, and then change to a relatively fine whetstone, sandpaper or grinding and polishing paste for polishing, and finally use the finest grinding and polishing paste for polishing. This looks like a lot of trouble, there are many processes, but in fact it is not slow. One process after another, the rough processing lines in the front are polished off, and then the following processes are carried out, without rework, and the finish of the mold can be improved by one step. To meet the requirements of mold polishing, generally first use a coarse oilstone to roughen the surface of the machined mold cavity, grind to remove the knife marks of the machine tool, and then use a fine oilstone to polish the rough oilstone to achieve the marks, and then use a fine The surface polished by the fine oil stone is polished with sandpaper, and finally the cavity surface of the mold is polished with polishing paste or grinding paste to achieve a bright mirror-like effect. This is the general process of polishing medical molds. Of course, if possible, you can use an ultrasonic polishing machine to polish the mold, which is more efficient and less labor-intensive.


Since the auto lamp mould is a large mold and the parting surface is complex, the forming part and the template adopt an integrated structure, that is, the fixed mold A plate of the mold is the fixed mold forming part, and the movable mold B plate of the mold is the moving mold forming part. The advantages of this structure are compact structure, good strength and rigidity, and small size of the mold, which avoids cumbersome processes such as opening the frame, fitting the frame and manufacturing the wedge. When designing the mold, the following points should be done: 1. The parting surface is smooth and has no sharp corners, no thin steel, no wire or dispensing glue; the surface sealant is constructed, and the surface methods such as extending, sweeping, and meshing are used during parting, and the parting is based on the shape of the plastic part. The shape of the construction surface, the parting surface of the lamp mold is extremely demanding, and the built surface is not allowed to wrinkle. The constructed parting surface can effectively ensure the CNC machining accuracy, without EDM corner cleaning, and the parting surface is not easy to run burrs. A high-speed machine is required for the parting surface of the lamp mold, and the spindle speed of the machine tool is guaranteed to be at least 20,000 revolutions per minute; 2. In the matching part of the insert and the movable die, the root of the spigot is designed with a suitable process chamfering R angle or a space-avoiding position, which simplifies the processing procedure, reduces the processing time, and improves the processing efficiency; 3. All non-formed corners are designed with R angle to prevent stress cracking. The process R angle is not less than R5. According to the size of the mold, design a relatively large process R angle as much as possible; the sharp edges on the mold are easy to cause accidental injury to the operator. Edges that do not participate in molding or matching should be designed with chamfered C angle or R angle, and a relatively large chamfered angle should be designed according to the size of the mold.


Commodity mould is a kind of mold. The design of thin-wall daily necessities mold needs to consider the following points: product parting surface, product wall thickness design, exhaust design of daily necessities mold, waterway design of daily necessities mold, and blowing position of daily necessities mold With the direction design, these problems directly determine the success or failure of a thin-walled daily necessities mold. Commodity molds need to realize fully automatic production: thin-walled products are an industry with small profits but quick turnover. Equipping with a manipulator can make the production run faster. The manipulator can help you stack directly, and the belt can be directly packaged and shipped. The daily necessities molds for all stamping parts on automobiles are called "automotive stamping daily necessities molds".

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