Maintenance and care of injection molding machine-Open mold control
Open mold control When the molten plastic is injected into the mold cavity and the cooling is completed, the mold is removed and the product is removed. The mold opening process is also divided into three phases. The first stage slows the mold opening to prevent the part from tearing in the cavity. The second stage quickly opens the mold to shorten the mold opening time. The third stage slows the mold opening to reduce the impact and vibration caused by open mold inertia.
Maintenance and care of injection molding machine - Closing Control
1.4.2.7 Closing Control Closing is the use of huge mechanical thrust to tighten the mold to withstand the high pressure injection and filling molds of the molten plastic in the injection molding process, so that the mold will have a huge opening force. The safety gate is closed and each trip switch gives a signal and the closing action starts immediately. The first is the slow start of the moving plate. After a short distance, the control bar that originally pressed the slow switch is...
Maintenance and care of injection molding machine - Temperature control
Temperature Control A thermocouple is used as a temperature measuring element, and a millivolt meter is used as a temperature control device to direct the on-off of the barrel and die heating coil current to selectively fix the temperature and mold of the barrel. The barrel electric heating ring is generally divided into two sections, three sections or four sections of control. The ammeter on the electrical cabinet shows the size of each segment of the electric heating coil. The reading of the...
Maintenance and Maintenance of Plastic Injection Molding Machines 2-1
1.4.2.4 Selection of injection speed General injection molding machine control board has a fast-slow knob to meet the injection speed requirements. In the hydraulic system there is a large flow pump and a small flow pump running oil supply at the same time. When the oil circuit is connected to a large flow, the injection molding machine can realize fast opening and closing of the mold, rapid injection, etc. When the hydraulic oil circuit only provides a small flow rate, various actions of the...
Main performance features of the automatic cable tying machine
Main performance characteristics of automatic cable tying machine manufacturers Performance description. 1 The automatic wire tying machine can greatly reduce the fatigue intensity of employees, improve work efficiency and save tying. 2 Employees only need to put the wire on the reel, step on the foot switch and wind the wire automatically. The machine will automatically place the wound wire on the cable tying belt and the machine will automatically tie the cable. 3 The machine can adjust the...
Cable Plug Force Tester
Plug force life tester is suitable for various connector insertion force and plug life conduction test, can display the continuous change value and peak value of insertion force, and has the number setting, can display the test speed, and set the number of tests; connector plug life test, and has the number setting, adjustable speed stroke, and display the speed value, with continuity test function, if the product is not conductive, it means the product is broken, the counter has Stops
Technical serialisation - maintenance and servicing of plastic injection moulding machines (2)
1.4.2.3 Selection of injection pressure The injection pressure of the injection moulding machine is regulated by a pressure regulating valve. Under set pressure conditions, the injection pressure in the high pressure and low pressure oil channels is controlled to control the pre- and post-injection pressure. There are three pressure options for normal medium-sized and above injection moulding machines, namely high pressure, low pressure and high pressure followed by low pressure. High pressure...
PP plastics forming and use
Drying process conditions for injection molding: if stored properly, no drying is required. Melting temperature: 220~275°C, please be careful not to exceed 275°C. Mold temperature. 40~80°C, 50°C recommended. The degree of crystallisation is mainly determined by the mould temperature. Injection pressure: up to 1800 bar. Injection speed: In general, high speed injection can be used to reduce internal pressure. If the product has surface defects. Then use a lower injection speed at a higher...
Plastic machinery and molds for a wide range of applications
Polymer materials represented by plastics have become the four basic materials alongside steel, wood and cement. Plastic products have also been widely used in various fields of national economy and people's life. As all plastic raw materials need to be processed by plastic machinery and molds in order to be shaped into various plastic products. Therefore, plastic machinery has become an important support for the national economy and aerospace, national defense, petrochemical, shipping,...
Key knowledge: What is injection molding?
Overview Injection molding (injection molding) is a method in which a thermoplastic or thermosetting molding compound is uniformly plasticized in a heating cylinder and then pushed by a plunger or a moving screw into a cavity of a closed mold. The granulated or powdered plastic is added to the heated barrel through the hopper of the injection molding machine, and the plastic is heated and melted. Under the pressure of the screw or the piston of the injection molding machine, the nozzle enters...
Overall economic situation is getting better The plastic molding and processing equipment market is in high demand
China remains by far the world's largest market for machinery and equipment, accounting for 29% of the global market in 2012, and will continue to lead the global market. India will be the fastest growing country in the world, accounting for 12% of the global market share in 2013. According to the global regional markets, the fastest growth will be in the central and southern US markets, followed by Africa and the Middle East. Machinery manufacturers in the Asia Pacific region are expected to...
What is the injection molding process of acrylic plastic of PMMA?
PMMA is often referred to as plexiglass, acrylic, etc. Its chemical name is polymethyl methacrylate. Due to the disadvantages of PMMA such as high surface hardness, easy wiping, low impact resistance and poor molding fluidity, PMMA modifications have appeared one after another. For example, the copolymerization of methyl methacrylate with styrene and butadiene, the mixture of PMMA and PC, etc. 372 plexiglass is obtained from the copolymerization of methyl methacrylate and styrene. If a small...
Preventive maintenance and repair work for injection molding machines
Injection molding machine is one of the common equipment used in plastic processing industry. Usually, it takes a long time to work. Therefore, how to ensure the normal operation of injection molding machine in continuous production is a concern for both injection molding machine manufacturers and users. In order to solve this problem, from the user's point of view, regular preventive maintenance is an effective way to ensure the normal operation of injection molding machine under the premise...
What are the causes of product cracking during injection molding?
There are several reasons for product cracking during injection molding. Processing aspect (1) If the processing pressure is too high, the speed is too fast, the filling volume is high, and the injection and holding time is too long, it will make the internal stress too large and crack. (2) Adjust the mold opening speed and pressure to prevent the mold release from cracking due to rapid pulling of the workpiece. (3) Properly raise the mold temperature to make the workpiece easy to demold, and...
Reasons and countermeasures for mold scale after injection molding of engineering plastics
When we can't eliminate mold scale by using various measures, we must strengthen the maintenance and upkeep of the mold. At the beginning of mold formation, the mold surface is relatively easy to remove, so it is necessary to clean and maintain the cavities and exhaust channels regularly (such as after each batch of molding). If the mold is not maintained and serviced for a long time, it is very difficult and time consuming to remove the mold after a thick layer of mold is formed. The sprays...
Analysis of the causes of bad floating fibers in injection molding and solutions
In injection molding production, have you encountered the problem of floating fiber, floating fiber refers to the glass fiber exposed to the surface of the product, relatively rough, the appearance is more difficult to accept, the possible causes of analysis: when adding such fillers, generally used physical mixing method, so only the glass fiber is uniformly dispersed in the middle of the plastic, but the plastic melting, the mixture will have different degrees of separation (depending on the...
What is the cause of excessive burrs on injection molded products?
Excessive burrs usually occur on the parting surface, i.e. between the moving mold and the static mold, the sliding part of the slider, the gap of the insert, the hole of the ejector rod, etc., forming excess melt on the injection molded product. Such a burr, which will be pried during the molding process, will further increase the burr, thus causing a partial depression of the mold, and the burr forms an expanding vicious circle. Therefore, if a flash point burr is found for the first time,...
How to overcome the process of incomplete injection molded products?
Question. The injection molded product is incomplete, how can the process be overcome? The answer is. Slow injection speed Injection speed is of great significance for some products with complex shapes, large thickness, long process flow, and high viscosity plastics such as tough ABS. When high pressure is not enough to fill the product, high speed injection should be considered to overcome the unsatisfactory problem. Improper feed adjustment, missing or overfilled material Inaccurate...
What should be noted in heat-resistant ABS injection molding?
In this article, we will discuss the processing points of heat-resistant ABS resin molding from five aspects: mold design, material drying, molding temperature, holding pressure and time, and mold temperature. 1. Product mold design Product wall thickness requires uniformity, and the wall thickness difference of ABS products should be controlled within 25% to prevent local stress concentration caused by excessive wall thickness difference. The root of the column with weaker strength needs to...
Analysis of injection molding process of two-color plastic products
Injection molding of two-color or mixed-color plastic products is to mix the same raw materials into two different colors, plasticize the melt of two colors by two injection molding machines with the same structure and specifications, and then inject through the nozzle. in the mold. The formed plastic products are color-separated, mixed or irregular, and the appearance effect is not obtained by ordinary injection molding and surface modification. The alternate plasticized melt of two injection...
The need for temperature adjustment of injection molds
The temperature of the injection mold has a great influence on the filling fluidity, curing and shaping of the plastic melt, production efficiency, as well as shape and dimensional accuracy. Every plastic injection molding has a reasonable mold temperature zone, so that the fluidity of the melt is easy to fill the cavity, the shrinkage and warpage of the plastic part after demolding is small, the size is stable, and the mechanical properties and surface quality are high. In order to control the...
Knowledge about LCP injection molding
The knowledge related to LCP injection molding is as follows. 1. Processing of LCP material (liquid crystal polymer) Key point. LCP material should be dried before use. The temperature is about 150℃ and the time is about 4~6 hours. The residual moisture content of the dehumidified LCP should be less than 0.02% and the dew point should be kept at -35℃. Note: It is recommended to use a vacuum dehumidifier dryer for drying. Do not use a general dryer. Because the vacuum dehumidification dryer can...
80 terms related to injection molding
The 80 terms related to injection molding are listed below. Dry A method of forming reinforced products from prepreg or premixed materials. 2. One-step mixing method When mixing, each component is added and mixed at once. 3. Dry Winding A method of forming reinforced plastic products by winding prepreg (or tape) around a mandrel. 4. Inner lining In order to meet the required usage properties (such as corrosion resistance, ablation resistance, leakage resistance, etc.), the inner wall of the...
Discussion on UPVC plastic injection molding process
UPVC is also known as hard PVC. in addition to additives, UPVC is mixed with other resins to make it more practical. These resins are PE, ABS, EVA, CPVC, MBS, etc. UPVC has high melt viscosity and poor flowability, and even if the injection pressure and melt temperature are increased, the change in flowability is small. In addition, the molding temperature of the resin is almost close to the thermal decomposition temperature, and the temperature range in which molding can be performed is...
