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Injection molding machine

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Update time : 2017-06-13 10:00:53
Injection molding machine
 
    The injection molding machine is a kind of plastic machinery, referred to as the injection molding machine or injection molding machine, thermoplastic or thermosetting material the use of plastic mold into various shapes of plastics molding equipment. Injection molding by the injection molding machine and mold.
Type
 
    The type of injection molding machine: vertical, horizontal, all-electric, but no matter the kind of injection molding machines, the basic functions of two (1) heating plastic to reach the molten state (2) to exert high pressure on the molten plastic. it shot full of mold cavity.
 
Working principle and mode of
 
    The working principle of injection molding machine and injection syringe, it is with the thrust of the screw (or plunger), the plasticizing good molten state (ie, viscous flow state), the plastic injected into the mold cavity closed good. After curing stereotypes made the process of the products. Injection molding is a cyclical process, with each cycle including: dosing - molten plastics - to put
pressure injection - filling Cooling - Kai-mode pickup.
    Remove the plastic parts and then re-closed mode, the next cycle. Injection molding machine operating items: injection molding machine operating projects including the control keyboard operation, the operation of electrical control system and hydraulic systems operating in three aspects. Separate action of the injection process, feeding action, injection pressure, injection speed, the top choice of the type, barrel temperature of each monitor, injection pressure and back pressure regulation. Screw injection molding machine molding process:
    First, granular or powdered plastic in the machine barrel, through which the screw rotates and the outer wall of the barrel, heating the plastic to become molten state, then the machine before clamping and injection shift, so that the nozzle closely aligns the mold gate Road, then the oil pressure to the injection cylinder Walter, screw forward to high pressure and a faster speed will melt into the closed mold temperature is low , after a certain period of time and pressure to keep (also known as pressure), cooling, curing, the mold can be opened to remove the products (the purpose of holding pressure to prevent the reflux of the melt in the mold cavity, supplementary material to the mold cavity, and to ensure that products have a certain density and dimensional tolerances). The basic requirements of the injection molded plastics, injection and molding.
    The plasticizing premise to achieve and guarantee the quality of the molded part, to meet the requirements of forming, injection must ensure there is enough pressure and speed. The same time, due to the high injection pressure, the corresponding cavity to produce a high pressure (average pressure of the cavity is generally between 20 ~ 45MPa), so there must be large enough clamping force. 
    Thus, the injection unit and clamping devices are key components of the injection molding machine. Mainly in three aspects of the evaluation of plastic products, and the first appearance of quality, integrity, color, luster; the second is between the size and relative position accuracy; the third is to use the corresponding physical properties, chemical properties, electrical properties.     These quality requirements are also different according to the different products using the occasion to require the scale. Defects of products is that the
mold design, manufacturing precision and wear. In fact, the technical staff of the plastic processing plants often suffer from the face of technology means to compensate for the problems brought about by the mold defects but not the effectiveness of a difficult situation.
    Regulation of technology in the production process is the essential way to improve product quality and yield. Injection cycle is very short, if the process conditions are handled badly, the waste will be an endless supply. Adjustment process when the best time to change a condition to observe a few times, pressure, temperature, time, all with the tone, it could easily lead to confusion and misunderstanding, a problem do not know what reason. Measures to adjust the process, means, in many ways. Example: solving products Note
dissatisfaction there is more than a dozen possible solutions to choose to address the crux of the problem, two major programs, in order to really solve the problem. In addition, attention should be paid to the dialectical relationship between the solution. Such as: products the depression, sometimes to raise the melt temperature, sometimes to reduce the melt temperature; sometimes to increase the quantity, and sometimes to reduce the feeding amount. To recognize the inverse feasibility of measures to solve the problem.
 
Classification and characteristics
 
    Injection molding machine in accordance with the arrangement of the injection unit and clamping devices can be divided into vertical, horizontal and vertical and horizontal composite. Its own characteristics as follows:
    a.the characteristics of vertical injection molding machine:
    1, the injection unit and clamping devices in the same vertical center line, and the mold opening and closing along the upper and lower direction. Its covers an area of only about half of the horizontal plane, therefore, converted into an area of production around about twice.
    2, easy to insert molding. Mold surface facing up, insert into the positioning easy. Using fixed under the template, the template movable machine, pull the belt conveyor, then a combination of plant and machinery
palmistry can easily implement automatic insert molding.
    3, the weight of the mold level template support for up and down the opening and closing movements, similar to the horizontal plane not occur before mold gravity down, making the template can not be opening and closing of the phenomenon. Conducive to the persistence to maintain the accuracy of the machinery and tooling.
    4, through a simple robot can remove each plastic cavity, is conducive to precision molding.
    5, generally around the clamping device open open, easy to configure various types of automated devices, adapted to the automatic forming of the complex and sophisticated products. 
    6.drawstring lose conveying device is easy to achieve string mold the middle of installation, ease of forming automatic production.
    7, is easy to ensure the consistency of the resin flow and mold temperature distribution within the mold.
    8, equipped with a rotary table, mobile table and tilt table is easy to insert molding,combination molding mold.
    9, small batch trial production, the mold structure is simple, low cost, and easy to uninstall.
    10, has stood the test of several earthquakes, the vertical plane due to the low center of gravity, the relative horizontal plane better shock resistance.
    (B) the characteristics of the horizontal injection molding machine:
    1, ie, the mainframe due to low body height restrictions for the placement of the plant.
    2, the product can be automatically fall occasions, without the use of the robot can also be automatically molding.
    3, the fuselage, easy feeding, maintenance easy.
    4, the mold needs to be installed by crane.
    5, multiple parallel arrangement, the moldings easily collected from the conveyor belt packaging.
Use and the status quo
    The injection molding machine has a complex shape, size, precision, or with metal inserts, texture, dense plastics molding, widely used in defense, electronic mechanical, automotive, transportation, building materials, packaging, agriculture, culture, education, health and people daily life in various fields.
    China's plastics processing enterprises Xing Luo cloth across the country, the skill levels of the equipment, the equipment of most of the processing enterprises need technological innovation. In recent years, China's press industry's technological progress is very significant, especially the gap between the technological level of the injection molding machine with foreign brand names is greatly reduced, and made a significant change in the level of control, internal quality and appearance. Select the domestic equipment, a smaller investment, also can produce the quality of imported equipment products. These create the conditions for the technological transformation of enterprises. 
    China Injection Molding Machine Development of China's production of injection molding machine manufacturers more, according to incomplete statistics, more than 60. The structure of the injection molding machine with vertical and horizontal. Press to produce the products can be divided into common type and precision injection molding machine.
     An injection volume of 45-51000g; 200-36000kN The clamping force; processing raw materials, thermosetting plastics, thermoplastics and rubber three.
    Thermoplastics, including polystyrene, polyethylene, polypropylene, nylon, polyurethane, polycarbonate, acrylic, polysulfone and (acrylonitrile / butadiene / styrene) copolymer (ABS). From the processed products, monochrome, color and general and precision plastic products.
   Ordinary horizontal injection molding machine is still the dominant direction of the injection molding machine, its basic structure is almost no major changes in addition to continue to improve its control and level of automation, reducing energy consumption, manufacturers according to market changes is the combination of series direction as a model of the injection molding machine configuration, the small three injection device, a combination of standard and combination, increase flexibility, expanding the scope of use, and improve economic efficiency.
    In recent years, industrial countries in the world of injection molding machine manufacturer in the continuous improvement of the supporting capacity of the function, quality of ordinary injection molding machines, auxiliary equipment, as well as the level of automation. Vigorously develop the development of large injection molding machines, injection molding machines, reaction injection molding machines and precision injection molding machines to meet the production of plastic alloys, magnetic plastic, with the demand for plastic products inserts.
    The injection molding machine is one of the fastest, the gap between the level of industrial countries small presses varieties of the pace of development in China's plastics machinery. But mainly refers to the ordinary injection molding machine, in most varieties of extra large, a variety of special, dedicated, precision injection molding machine, and some still blank, which is the main gap with industrial countries.