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    2. HaiYi  Plastic

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      Plastic injection molding of the working principle and maintenance
      Time:2009/5/4    The number of readers:1972    【Print
      Injection molding machine has to form a complex, precise size or with metal insert to the dense texture of the plastic products, are widely used in national defense, machinery and electronics, automotive, transportation, building materials, packaging, agriculture, culture, education, health and people's day-to-day all areas of life. Injection molding process on a variety of plastics processing and has a good adaptability, high capacity and easy to automate. The rapid development in the plastics industry today, both in the number of injection molding machine or both species play an important role, thus becoming the fastest growing plastic machinery, production of one of the largest models.
      China's plastics processing industry stars Luo its cloth across the country, levels of equipment, the majority of processing enterprises in need of technology equipment. In recent years, China's machine industry, significant technological advances, especially in the skill level of injection molding machine with foreign brands has greatly narrowed the gap in the level of control, product quality and internal appearance and so to make significant change. Choice of domestic equipment to the smaller input, but also can produce the quality of imported equipment and products fairly. These enterprises have created conditions.
      To have good products, must have good equipment. Equipment wear and corrosion is a natural law that people have such a law, they can prevent or reduce equipment wear and corrosion, extending the equipment life cycle to ensure that the rate of equipment in good condition.
      To enhance the use of plastic machinery, maintenance and management of the relevant departments in China have been drawn up on the standards and implementation details of the requirements of the equipment management sector and manufacturers of equipment to do the management and use of "scientific management, proper use and reasonable lubrication, careful maintenance, regular maintenance, scheduled maintenance to enhance the rate of equipment in good condition, so that equipment always in good condition.
      This article written by the injection molding machine maintenance, maintenance of relevant knowledge and technical information for equipment management and production management and technical staff.
      Plastic injection molding die-casting technology is based on the principle of development from the late nineteenth century with the beginning of the twentieth century is the most common plastics processing in one of the methods used. The Law is applicable to all thermoplastic and thermoset plastic parts (total about plastic 1 / 3).


      1.1 Injection Molding Machine working principle
      The working principle of injection molding machine with an injection syringe used is similar to it by drawing on the screw (or plunger) of thrust, will have good melt plasticization state (that is, viscous flow) to the closure of the plastic injection mold cavity good, stereotyping by the curing process after the process of products.
      Injection molding process is a cycle, with each cycle include: quantitative feed - molten plastics - pressure injection - filling cooling - Kai-mode pickup. Remove the plastic parts and then re-closed mode, the next cycle.


      1.2 The structure of injection molding machine
      Plastics injection molding machine based on the way into the plunger-type injection molding machine and injection molding machine screw; by the drive machine can be divided into hydraulic, mechanical and hydraulic - mechanical (link)-type; by operation hours for automatic, semi-automatic, manual injection molding machine.
      (1) horizontal injection molding machine: This is the most common type. Its part and injection mold parts at the same level as the center line, and the mold is opened along the horizontal direction. Its characteristics are: body short, easy operation and maintenance; machine center of gravity low, the installation of relatively stable; products can be used after the top of gravity down automatically, easy to achieve fully automatic operation. At present, the injection molding machine market, the use of such type.
      (2) vertical injection molding machine: its parts and injection mold parts at the same vertical center line, and the mold is opened along the vertical direction. Therefore, its area of relatively small and can easily insert installation, loading and unloading more convenient tool, since the material could fall into the hopper more evenly for plastics. Top products after but not automatically fall, must be removed by hand, it is not easy to achieve automatic operation. Vertical injection molding machine should be used for small injection molding machine, generally below 60 grams in the injection molding machine using more large and medium-sized machines should not be used.
      (3) The angle-type injection molding machine: the injection and mold the direction of the interface in the same plane, it is particularly suited to the processing center of the gate does not allow leaves traces of products of the plane. It covers an area smaller than the horizontal injection molding machines, but embedded within the mold Add easy tilt down. This type of injection molding machine should be used for small aircraft.
      (4) multi-mode rotary injection molding machine: It is a multi-stage injection molding machine of special operations, which is characterized by combined use of the rotary die device structure, and mold around the rotating shaft. This type of injection molding machine and give full play to the plastics injection device capable of shortening the production cycle and enhance the productive capacity of the machine, which is particularly suited to long cooling stereotypes or insert the installation need more time supporting high-volume plastic products, but a huge mold system, the complexity of Die Die edge devices tend to be smaller, so that the soles of plastic injection molding machine, such as in the application of more products.
      General injection molding machine, including injection devices, mold installation, hydraulic system and electrical control system parts.


      The basic requirements of injection molding is a plastics injection and molding. Plastics molding and guarantee the realization of the premise of quality products, and to meet the requirements of molding, injection must ensure that sufficient pressure and speed. At the same time, high injection pressure, the corresponding cavity in the mold have a very high pressure (average pressure mold cavity generally between 20 ~ 45MPa, it must be large enough to force compliance mode. This shows that the injection device Hop-mode device is a key component of injection molding machine.
      1.4 the operation of injection molding machine
      1.4.1 action process injection molding machine
      → forward nozzle injection pressure → → → pre-plastic nozzle was shrinking back → cooling → → open → mode → top of a back pin closed → open → → → Die nozzle forward.
      1.4.2 injection molding machine operating items: injection molding machine operations include the control of the keyboard operation, electrical control cabinet and hydraulic operation of the three aspects of system operation. Injections, respectively, the process of movement, feeding action, injection pressure, injection speed, the top choice of the type, temperature and paragraphs cylinder current, voltage monitoring, injection pressure and back pressure regulator, such as pressure.
      1.4.2.1 Action Selection injection process:
      General injection molding machine can be operated manually, or semi-automatic and fully automatic operation.
      Manual operation in a production cycle, each movement are struck by the operator and the realization of the operation switch. General in the test machine when the selected transfer mode.
      Semi-automatic operation of a machine can automatically complete the working cycle of action, but a production cycle of each operation after the security gate must be opened, remove the workpiece, and then close the security door, the machine can continue to the next production cycle.
      Fully automated injection molding machines in operation and the completion of a cycle of work in action, you can automatically enter the next cycle. In the normal course of its work, there is no need for control and adjustment of downtime. It should be noted, such as the need for fully automated work (1) Do not open the security door half-way, or interruption of automatic operation; (2) to feed a timely manner; (3) if the choice of electric eye sensors, care should be taken not to cover the closed eye.
      In fact, in the fully automatic operation, usually midway of the temporary stands, such as the release agent, such as injection mold machine.
      Normal production, the general choice of semi-automatic or fully automatic operation. The beginning of the operation should be selected according to the production mode of operation (manual, semi-automatic or fully automatic) and the corresponding switch to manually, semi-automatic or automatic switch.
      Semi-automatic and fully automated procedures identified by the line itself, and the operator need only counter power to change the speed and pressure on the size, the length of the number of thimble and so on, the operator would not transfer the wrong button and working procedures to make confusion.
      When a cycle is not adjusted properly in all movements, we should first select manual operation, ensure that each action after the normal, and then select the semi-automatic or fully automatic operation.

      Pre-plastic 1.4.2.2 Action Selection
      According to pre-feeding before and after the injection of plastic whether the back seat, that is, whether or not to leave the nozzle mold, injection molding machine has three options in general. (1) a fixed feeding: pre-plastic before and after the pre-plastic nozzle always paste into the mold, do not move Note Block. (2) pre-feeding: nozzle under plastic mold pre-feeding, pre-finished plastic injection back seat, leaving the die nozzle. The purpose of choice in this way is: the use of pre-plastic mold injection nozzle hole arrived to help, to avoid melting at high pressure is expected in the outflow from the nozzle, the nozzle can be avoided after the pre-plastic and mold resulting from prolonged exposure to heat, impact on their their temperature is relatively stable. (3) after feeding: injection is complete, note seat back, the nozzle and then leave the pre-mold plastic, pre-finished plastic seat forward again. The action applies to the processing molding temperature particularly narrow plastic nozzle and die as a result of the short contact time to avoid the loss of heat, but also to avoid a melt solidification in the nozzle hole.
      Injection end of the cooling time after the timer, pre-plastic action began. Rotary screw and squeeze the plastic melt to the screw head in front. As the screw back the front of the ring by only one-way valve from the role of accumulation of molten plastic in the front barrel will screw迫退back. When the screw back to a predetermined location (the location determined by the trip switch to control the distance between screw back and realize quantitative feeding), pre-plastic stop, stop rotating screw. Reduction was followed by action, but that is reduced for the small amount of axial screw back, this action will enable the Department gathered in the nozzle melt pressure to disarm, to overcome the barrel as a result of internal and external pressures arising from the imbalance in the "left salivary "phenomenon. Do not need to shrink, it should be reduced to stop the switch back to the appropriate place, so that was pre-plastic pressure switch to stop the same time, it has also been reduced to stop pressure on the switch. Was reduced when the screw for movement back to stop pressure on the switch, the reduction was stopped. Note Block, and then began to retreat. When injected back seat to stop the pressure on the switch, the note to stop back seat. If the use of fixed-feeding methods, care should be taken to adjust the location of a good trip switch.
      General production means the use of fixed-feeding in order to save operation time Note Block advance and retreat, to speed up the production cycle.


      Choice of injection pressure 1.4.2.3
      Injection molding machine injection pressure regulated by the調壓閥, is set in the case of pressure, through high pressure and low pressure off the circuit to control the pre-and post-injection of high and low pressure.
      More than an ordinary medium-sized injection molding machine has three pressure settings, that is, high pressure, low pressure and low pressure after the first high-pressure. High-pressure injection is access to high-pressure injection of the fuel tank to achieve oil pressure. Because of the high-pressure, plastic from the start in the high-pressure, high speed into the mold cavity. High-pressure injection of plastic into the mold quickly, injecting the fuel tank pressure gauge readings increased rapidly. Low-pressure injection of the fuel tank pass by the injection of oil into the low pressure to achieve, and injection process of the slow rise in pressure gauge readings, plastic in the low-voltage, low-speed into the mold cavity. After the first high-voltage low-voltage is based on the type of plastic and die from the time of the actual requirements up to control access to the pressure of the fuel tank of oil to achieve the high and low pressure.
      In order to meet the different requirements of different plastic injection pressure, but also can be used to switch to a different diameter of the screw or plunger method, so that the injection pressure to meet and give full play to the productive capacity of the machine. In large-scale injection molding machine is often injected with a multi-stage multi-stage injection pressure and speed control function, so that products can better ensure the quality and accuracy.


      1.4.2.4 The choice of injection speed
      General injection molding machine control panel are fast - the slow speed knob used to meet the requirements of injection. In the hydraulic system has a large flow pumps and pump a small flow of oil to run. When the circuit when connected to high-volume, injection molding machine for rapid opening and closing of mold, such as rapid injection, when the hydraulic circuit to provide only a small flow, the injection molding machine to carry out various actions on the slow.


      1.4.2.5 Selection of the top of the form
      Top of the form of injection molding machines have mechanical and hydraulic roof top of the two kinds, some of the top also has a pneumatic system, the number of the top with a single and a series of two kinds. Top of actions can be manually, or automatically.
      Top of action to stop by the open limit switch mode to start. The operator may, as required, by adjusting the control cabinet button on the top of the time to achieve. Top of the speed and also by controlling the counter pressure on the switch to control movement of the thimble before and after the switch to determine the distance from the trip.


      1.4.2.6 Temperature Control
      Thermocouple for temperature measurement in components, with temperature as a temperature control device mV of command Barrel and mold electric current on-off circle, selected paragraphs fixed cylinder temperature and die temperature. Table 5 lists the number of plastic processing temperature range, for reference.
      Barrel heating coil will generally be divided into bis, three or four control. Electrical cabinet of the ammeter paragraphs show the size of electric current loop. Ammeter reading is relatively fixed, if found running relatively long ammeter reading low heating coil may be broken, or bad wire or electric wire thin oxide, or a heating coil to burn, these are connected in parallel circuit will increase the resistance of the current decline.
      Ammeter reading at a certain time can also be a simple plastic one by one in the designated cleaning electric wall outside, to see whether or not expected to be melted to determine whether an electric power or the burning circle.


      Die Control 1.4.2.7
      Die is a huge mechanical thrust will mold together tightly so as to resist melting plastic injection molding process and the high-pressure injection mold and the mold filled with tremendous force open.
      Proper security clearance door, the trip switch signals are given, move immediately die. First, move the template to a slow start, a small short distance ahead, the original slow-down lever switches from the Press, the activities of board to move forward quickly. In advance to die near the end, the control rod and bar the other end of the slow pressure switch, the activities board at this time to slow and turn to low-voltage forward. Die in the low-pressure process, if there is no obstacle between the mold, you can close up to the pressure on a smooth high-pressure switch, switch to high-pressure machine to straight hinge action to complete the mold. The distance is very short, generally only 0.3 ~ 1.0mm, just switch to high-pressure die soon reach the termination of the limit switch when the action stopped, the process of the end of mold.
      Mold injection molding machine has the entire structure of hydraulic and mechanical link. No matter what kind of structure, and finally by the connecting rod are fully extended to implement the power die. Link the activities of the extension process is the end plate and open the process of plate, rod 4 is also being stretched by the force of the process.
      Die size of power, you can die from the combined moment tight hydraulic table up deserve to know the highest, with the hydraulic power module of maximum value will be high, otherwise low. Smaller-scale injection molding machine with mold is not a hydraulic table, when extended to the case under the link to determine whether mold really tight together. If a mold injection molding machine easily when the rod straight, or "almost point" can not extend, or several vice-link in a not yet fully extended, there will be inflation when the injection mold, parts on the there will be flash or other defects.


      Open model control 1.4.2.8
      When the molten plastic injected into the mold cavity until after the completion of cooling, with the action mode is open, take out products. Open mold process in three phases. Opened the first phase of the slow mode, to prevent tearing parts in the mold cavity. The second phase of rapid open mode, so as to shorten the time to open mode. Slow to open the third phase of mold, so as to reduce the open-mode inertia and vibration impact.


      1.4.3 Process conditions for the control of injection
      At present, the injection molding machine manufacturers have developed a wide range of process control methods in general are: injection speed control, pressure control injection, plastic injection mold cavity filling the volume control, back pressure and screw rotation speed of the chain, such as a state of plastic control. To achieve the purpose of process control products is to improve the quality of the machine to maximize the effectiveness of the play.


      Injection speed control 1.4.3.1
      Injection speed is to control the injection screw itinerary divided into 3 ~ 4 stage, respectively, at each stage of the injection of the appropriate use of their speed. For example: in the molten plastic through the gate at the beginning of slow injection speed, mold filling process in the use of high-speed injection molding the end of the slow down. In such a way to prevent the overflow is expected to eliminate the flow marks and reduce the residual stress and other products.
      At low filling rate stable, relatively stable size products, fluctuations in the smaller, low-stress products, manufactured both inside and outside the line to stress (such as parts of a polycarbonate immersed in carbon tetrachloride, using high-speed injection molding of parts have a tendency to cracking, low-speed non-cracking). In a relatively slow under the conditions of filling, the temperature difference between feed flow, especially before and after the gate of the temperature difference is expected, and help to avoid the occurrence of shrinkage and depression. However, due to continuation of a longer filling time there is easy layering and combination of parts of the weld marks bad, not only affect the appearance, but also significantly reduced mechanical strength.
      High-speed injection, the material flow speed, when the smooth high-speed filling, the cavity filled with melt soon expected temperature drop in a small drop in viscosity was also small, can be used with lower injection pressure, is a hot-filling material die situation. High-speed molding parts can improve the gloss and smoothness to eliminate the phenomenon of the joints and stratification lines, contraction depression small, uniform color, the larger part of the parts to ensure full. But it is easy to generate fat products or parts sparkling yellow, and even zoom burn, or cause Demoulding difficulties, or uneven filling. For the high-viscosity melt plastic could lead to rupture, so that the surface of cloud pattern parts.
      The following could be considered high-speed high-pressure injection: (1) high plastic viscosity, cooling speed, a long slow process parts using low-pressure can not be completely filled every corner of the cavity; (2) of the thin wall parts, melt easy to reach the condensation of thin-walled and stranded Department, must be a high-speed injection, so that a large number of melt energy consumption immediately before entering the cavity; (3) with glass fiber reinforced plastic, or contains a large number of filler material than plastic, because of mobility poor, in order to obtain smooth surface and uniform parts, to adopt the high-speed high-pressure injection.
      High precision of the products, thick-walled parts, large changes in wall thickness and nosing and thicker parts of the tendons, the best use of multi-stage injection, such as two, three, four or even five.


      Injection pressure control 1.4.3.2
      Usually control the injection pressure will be a sub-injection pressure, the second injection pressure (pressure) or more than three injections to control pressure. Timing of the pressure switch if it is appropriate to prevent excessive pressure mode to prevent overflow or缺料such materials are very important. Products depends on the volume modulus pressure phase gate closed at the time of melt pressure and temperature. If each switch to the pressure from the cooling phase of the products of pressure and temperature the same, then the specific volume products will not change. Molded in a constant temperature to determine the size of the most important products is the pressure pressure parameters, the impact of product dimensional tolerances of the most important variable is the pressure pressure and temperature. For example: after the end of the filling, the pressure to immediately reduce the pressure, when the surface of a certain thickness, the pressure increased the pressure further, which would force the use of low molding mold of the large thick-walled products, the elimination of pits and flash collapse.
      Packing pressure and speed are usually plastic cavity filling pressure and the maximum speed at 50% ~ 65%, that is the pressure pressure lower than the injection pressure of about 0.6 ~ 0.8MPa. Pressure as a result of injection pressure than the pressure of low pressure in the considerable time, low-load pump, solid-fuel pump to extend the service life, at the same time pump motor power consumption is also reduced.
      Both three-pressure injection molding so that the smooth parts, and weld line does not appear, dents, warpage and flash. For thin-walled parts, small pieces of long, long process of molding large parts, and even less balanced configuration and the cavity mold parts do not quite close the molding as a whole.


      1.4.3.3 plastic injection mold cavity to fill the volume control
      Pre-conditioning a good measurement, making the end of trip in the vicinity of injection, screw the end of a small amount of residual melt (buffer volume), according to the fill mode to exert further pressure injection (twice or three times injection pressure) , added a little melt. In this way, products can prevent depression or adjustment of the contraction rate of products.


      1.4.3.4 screw back pressure and speed control
      High back pressure can melt shear was strong, low-speed plastic will also be longer in the machine inside the plasticization time. Hence the current use of more pressure and speed of programming at the same time control. For example: measurement of the whole trip in the first screw high-speed, low back pressure, and then switch to a lower speed, higher pressure, and then switch to high-pressure, low speed, and finally in the low back-pressure, low speed for plastics In this way, the front screw melt most of the pressure has been released, reducing the moment of inertia of the screw, the screw so as to enhance the accuracy of the measurement. Often caused by back pressure too high colorants increase the degree of discoloration; pre-plastic bodies screw barrel increase mechanical wear; plastic pre-cycle, declining productivity; nozzle prone salivation, increase renewable charge; even with self-locking nozzle if the pressure is higher than the design pressure of the spring latch-up may also cause fatigue failure. So, back pressure must be adjusted properly.
      With technological progress, will be incorporated into the small computer control system for injection molding machine, injection molding using a computer to control the process has become possible. Japan Steel N-PACS (micro-electronic computer control system) of four feedback control can be done (pressure adjustment, molded adjustment, automatic measurement adjustment, resin temperature adjustment) and four process control (control injection speed, pressure inspection, screw speed control, pressure control).

      1.4.4 Injection Molding preparation
      Pre-forming may include the contents of the work of many. Such as: materials processing performance test (determination of the mobility of plastic, moisture content, etc.); raw materials before processing and staining tablets election; the preheating and drying aggregates; Insert cleaning and preheating; test cylinder mold and cleaning and so on.


      1.4.4.1 Pre-processing of raw materials
      According to the characteristics of plastic materials and for the situation, the general response in the raw materials before molding the appearance and performance testing process. If the plastic used for the powder, such as: polyvinyl chloride, and dry ingredients should be mixed; asked if the products are colored, then adding the right amount of coloring agent or masterbatch; supply aggregates often contain varying degrees of water , flux and other volatile low-molecular-weight materials, especially the tendency of some plastic water absorption is always more than the limits allowed by the processing. As a result, the processing must be carried out before drying and determination of water content. Of water under high temperature-sensitive polycarbonate water content of 0.2 percent in the following requirements, or even 0.03% ~ 0.05%, so commonly used vacuum drying oven. Has been dry preservation of plastic must be sealed properly to prevent the plastic from the air and then the loss of moisture and drying effects, for hopper drying chamber can be used for the injection molding machine for the provision of dry heat is expected to simplify operations, maintain a clean, improving quality, increase in injection rate are favorable. Drying hopper generally take charge of the injection molding machine per hour charge with 2.5 times.


      1.4.4.2 Insert the pre -
      Injection molding products and the strength to assembly requirements, the need to embed products Metal Insert. Injection molding, the mold cavity placed in the cold and hot pieces of metal embedded with the cooling melt plastic, metal and plastic as a result of shrinkage of the markedly different, often around the insert have a lot of internal stress (especially as polyphenylene ethylene polymers such as rigid chain significantly more). The existence of such internal stress so that the cracks around the insert, resulting in the use of performance products greatly reduced. This can be achieved through selection of a large thermal expansion coefficient of metals (aluminum, steel, etc.) for the insert and the insert (especially large pieces of metal embedded) preheating. At the same time, the design of embedded products in the arrangements around the larger pieces of thick-walled and other measures.


      Barrel Cleaning 1.4.4.3
      The new injection molding machine purchased before the beginning of, or need to change in the production of products, the replacement of raw materials, change color or found in the decomposition of the phenomenon of plastic when the need for injection molding machine or the washing machine drum拆洗.
      Generally use the washing machine drum machine drum cleaning method of heating. Cleaning materials in the plastic raw materials (or plastic recycling materials). For heat-sensitive plastics, such as the survival of PVC material, can be low density polyethylene, polystyrene and other materials for the transition to clean, and then processing the new material by replacement of the transition to clean material.


      1.4.4.4 The selection of release agent
      Release agent is easy to make plastics material release. Zinc stearate apply outside of the general plastic polyamide; liquid paraffin polyamide type of plastic used to good effect; silicone oil is expensive, cumbersome to use and less use.
      Appropriate use of release agent should be controlled as little as possible or not. Excessive spray products will affect the appearance of the color of the products will have a negative impact on decoration.

      The process of injection molding machine 1.5 Notes
      Injection molding machine to develop good habits to improve the operating life of machinery and production safety have a lot of good.


      1.5.1 Prior to boot:
      (1) The electrical control box to check whether there is water, oil entered, if the electrical damp, do not boot. Maintenance personnel should be dry before electrical components to boot. (2) to check whether the supply voltage, the general should not exceed ± 15%. (3) check the stop switch, door safety switch before and after normal. Verify motor and pump the same direction of rotation. (4) to check the flow of cooling pipes and oil cooler and the barrel end of the cooling water jacket cooling water access. (5) to check whether there is any part of the activities of oil (fat) and add enough oil. (6) Open the heater on the barrel of the heating section. When the temperature reaches above the request, and then heat for some time, so that the machine temperature to stabilize. Holding time according to different equipment and the requirements of plastic raw materials vary. (7) in the hopper with a plastic foot enough. Plastic injection molding in accordance with different requirements, some of the best pass through the dry raw materials. (8) to cover the barrel shrouds, it saves energy, but also to extend the electric contactor coil and current life.


      1.5.2 operation:
      (1) not for the sake of convenience, arbitrary cancellation of the role of the security door. (2) to observe the temperature of the oil pressure, oil temperature should not exceed the scope of the provision. Ideal for hydraulic oil temperature should be maintained at between 45 ~ 50 ℃, the general in the 35 ~ 60 ℃ more appropriate framework. (3) attention to the adjustment of the travel limit switch, the machine in action to avoid collision when.


      The end of 1.5.3:
      (1) stands before the machine should be clean plastic tube to prevent oxidation of residual materials or long-term heat decomposition. (2) molds should be open, so long elbow-bar mechanism in the closed state. (3) must be equipped with lifting equipment workshop. Assembly and Disassembly Mold and other heavy components should be very careful to ensure production safety.


      1.6 Injection of the reasons for product defects and their treatment
      In the injection molding process may be due to poor handling of raw materials, products or unreasonable mold design, operatives do not have the appropriate operating conditions of the process, or because of mechanical reasons, so that products often have a note dissatisfaction depression, flash, air bubbles , cracks, warpage, changes in defect size.
      Evaluation of plastic products, there are three main aspects, the first is the appearance of quality, including the integrity, color, luster, etc.; the second is between the size and relative position of accuracy; the third is with the use of the corresponding mechanical properties, chemical properties, such as electrical properties. Quality requirements of these products to use based on different occasions, the requirements of different scales.
      Practice has proved that the production, mainly due to defects in products, mold design, manufacturing accuracy and the degree of wear and tear and so on. But in fact, the technology of plastic processing plants often suffer from the face of technology means used to make up for deficiencies in the problems brought about by mold and the difficult situation without much success.
      The production process of the adjustment process is to improve the products quality and the essential means of production. As the injection molding cycle itself is very short, if the conditions have not, will come and scrap. During the adjustment process only when the best time to change a condition to observe several times, if the pressure, temperature, time transfer, then all together, it is easy to cause confusion and misunderstanding of the problem do not know what reason. Measures to adjust the process, means are manifold. For example: to resolve the issue of dissatisfaction with products Note there is more than 10 possible solutions, it is necessary to choose a solution to the problem of one or two major programs in order to truly solve the problem. In addition, the solution should also be noted that the relationship between the differentiation. For example: a depression products, sometimes to raise the material temperature, sometimes to reduce the material temperature; sometimes to increase the charge, and sometimes to reduce the charge. Measures to reverse recognition of the feasibility to solve the problem.
       
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