Ningbo Haijing plastic machinery

Mexico Rubber and Plastics Exhibition in November

Ningbo Haijing plastic machinery

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CHINAPLAS 2023 INVITATION LETTER

COME&VISIT CHINAPLAS 2023 INVITATION LETTER DATE:2023.4.17~4.20 ADD:SWECC,SHENZHEN BOOTH NUMBER:10D51 TEL:0086057462516518

Analysis on Temperature Control Methods and Influencing Factors of Injection Molding Mould

Many molds, especially thermoplastics for molding engineering, operate at relatively high temperatures, such as 80 degrees Celsius or 176 degrees Fahrenheit. If the mold is not insulated, the heat lost to the air and the injection molding machine can easily be as much as the injection cylinder. Therefore, the mold should be insulated with a skeleton board, and if possible, the surface of the mold should be insulated. If you consider using a hot runner mold, try to reduce the heat exchange between the hot runner portion and the cooled molded part. This method reduces energy loss and warm-up time. What are the effects of mold temperature on injection molding? Mold temperature is the most important variable in injection molding. No matter what kind of plastic is injected, it is necessary to ensure that the basic wetness of the mold surface is formed. A hot mold surface keeps the plastic surface liquid for a long time, enough to build up pressure in the cavity. If the cavity is filled and the cavity pressure presses the soft plastic against the metal before the frozen skin hardens, then the reproduction of the cavity surface is high. On the other hand, if the plastic entering the cavity at low pressure is suspended, no matter how short, then its slight contact with the metal will cause a stain, sometimes referred to as a gate stain. For each type of plastic and plastic part, there is a limit of mold surface temperature beyond which one or more adverse effects may occur (for example, components may spill out of burrs). Higher mold temperatures mean less flow resistance. On many injection molding machines, this naturally means faster flow through the gate and cavity, because the injection molding flow control valve used does not correct this change, and faster filling causes a higher effective pressure in the runner and cavity, which may lead to overflowing raw edges.

Causes and Solutions of Unstable Cycle in Injection Molding Machine

Reason 1. Time to keep the mold open 2. Pressure instability 3. Barrel temperature is not consistent 4. Mold temperature inconsistency 5. Feed instability Corresponding measures 1. Keep the mold open time: Maintain fixed cycle times for varying lengths of time using a die opening timer 2. Pressure instability: Maintain sufficient pressure to keep the discharge consistent Check the pressure system for oil leaks 3. Barrel temperature is inconsistent: Check the temperature control system to maintain normal operation Use the best temperature control system Check the voltage and stabilize it Make sure the heater is working properly Before material is added to the hopper, the temperature of each barrel of material should be maintained at the same level The amount of material at the front end of the plunger should be maintained in a consistent manner The machine should be maintained in a balanced condition 4. Mold temperature is inconsistent: Using a mold temperature controller There should be a proper channel in the mold The mold should have a proper exhaust pipe Usually the water pipe in the mold should have an appropriate connection 5. Unstable feeding: Check feeding mechanism

How to do the defect problem of the injection molding product bulging?

In the injection molding process, how should the delay valve and speed match? Let's take a look at this case today. This product is a car rear bumper, it has a lot of gate, using delayed sequence valve to shoot glue, this product has nine gates, from the middle one, and then to the two sides of the row of 4, this product is prone to a lot of problems, such as tiger skin grain, flow pattern, air pattern, size problem, today those questions do not talk about, we only talk about one drum problem. After this product will spray paint, but after painting will find a problem is the drum bag, the surface is like the field ridge drum bag, and then we found out that this is the reason? This is a drum bag at the junction of two different streams of material, so you might ask, if it's a delay room, how can there be a connection line? Yes, the delay valve is not connected to the line, the middle valve is opened first, the second valve is opened later, when the material of the first valve comes here, the second valve needle is passed, the second valve needle is opened again, and then, the third is the fourth. The position of the drum occurs in the edge area, that is to say, after the last valve needle is opened, and the material in front will form a joint line in the center, not on the surface, but on the combination line of the heart, this combination line will have a drum on the surface, so what about this drum? Picture This method is not the same as the adjustment of other conventional products. We use a pure injection molding process. Specifically, to solve the drum problem, the core of its solution is to reduce the speed of the glue. For the vicinity of drum defects, we should reduce the speed of glue injection, specifically, the whole product, if there is a drum bag, is in the second half. In the first half, it is not easy to have drum defects, and our speed is al

Identify injection molding material, simple physical identification method to get it!

Appearance method: Appearance identification is mainly through vision, touch, smell and so on to observe the appearance characteristics of plastic products, such as the shape, transparency, color, luster, hardness and so on. Plastic after recycling and reprocessing process, color, luster, strength and so on will change, no return color will generally be more transparent, mixed with return products will reduce transparency; the luster of the return material is poor; experienced old injection molding personnel can use tooth bite to initially determine the strength of the plastic, with the addition of the return material is more brittle. The external method is generally used as a preliminary identification of plastic returns. Physical performance test method: The density of different kinds of plastics is usually quite different, and the density difference of the same kind of plastics before and after recycling will also be quite different. The density method can be used to identify the plastic return, but it can not be used to judge the plastic return completely, because there will be many voids or other defects in the process of plastic recovery and reproduction. For example, the regeneration process of ABS/PC produces a lot of small pores, and the number of holes increases with the increase of regeneration times. For impact strength, tensile strength, compression strength, bending strength and other strength properties, with the increase of plastic content, there will be a significant decrease trend, especially the tensile strength and bending strength will decrease obviously. The decrease of these strength properties is closely related to the formation of voids and the decrease of defect and molecular weight in the process of recycling. Therefore, for the identification of plastic return, these strength properties of plastics can be tested, and whether the product contains back

Operation of horizontal injection molding machine

Operation of horizontal injection molding machine 1. Boot check Check the power cord before turning on the power supply, confirm that the hydraulic oil is sufficient and check whether the close switch of the safety door is out of order and whether the switch of the safety door is smooth. 2. Install the mould, it must be operated manually The die is matched to the fixed circle of the fixed plate to close the safety door, and the mold switch is switched to the mold setting adjustment to carry out the die. Adjust the mold so that the center of the nozzle as far as the nozzle up and down, left and right alignment, after the horse, the mold will be fixed on the fixed plate. Adjust the stroke and speed of the thimble, the stroke of the thimble may damage the mold when the stroke is overrun. So at first, you have to set it a little shorter. 3. Adjust the safety device of the die. Manual operation of molding operation Switch the operation selection switch to the Manual position, and then press the pump enable button. The safety door on the left should also be closed. The die switching switch switches to the "die mode", then the action of the die mode begins and the high voltage is completed. The ejector switches to "forward" and the nozzle contact is completed. When the ejector switch switches to "eject", the ejection action is carried out, and the pressure is converted from the ejection (primary) pressure to the secondary pressure. Note: turn on the screw drive motor 15 minutes after the temperature of the heating cylinder reaches the set temperature to avoid damage to the screw. 4. Measure the holding time of the pressure. Switch the screw switch to the "rotating" position and measure it. Switch the ejector switch and back the ejector to the appropriate position. After measuring the cooling time, switch the mold switch to "open mode". Press the ej

Methods to extend the service life of injection molding machine screw, please close!

Maintenance and maintenance of screw cylinder It is found that the injection screw works in high temperature, high pressure, high mechanical torque and high friction environment for a long time. The first few factors are required by the process conditions, and the wear and tear caused by friction is inevitable. Generally, the screw is nitrided to improve the surface hardness, that is, to improve the wear resistance. However, if the cause of wear is ignored, if we do not try to reduce the wear as much as possible, the working life of the screw will be greatly reduced. Each kind of plastic has an ideal processing temperature range, and the processing temperature of the cylinder should be controlled so that it is close to this temperature range. When the granular plastic enters the cylinder from the hopper, it will first reach the feeding section, and dry friction will inevitably appear in the feeding section. When these plastics are not heated enough and the melting is uneven, it is easy to cause the inner wall of the cylinder and the surface wear of the screw to increase. Similarly, in the compression section and the homogenization section, if the melting state of the plastic is disordered and uneven, the wear will also increase. The speed should be adjusted properly. Because some plastics are reinforced, such as glass fiber, minerals, or other fillers. The friction of these substances on metal materials is often much greater than that of molten plastics. When injecting these plastics, if they are made with a high speed, the shear force of the plastics will be increased, and the strengthening will also result in more torn fibers, which contain sharp ends and greatly increase the wear force. When inorganic minerals glide at high speed on the metal surface, their scraping effect is not small. So the speed should not be set too high. 1. Do not start the machine when the cylinder does not reach the preset temperature. T

How to solve the injection molding defect - cracked steam white

First, what is cracked steam white? Cracking steam whitening: cracking is a common defect in plastic products, including filamentous crack, microcrack, top white, cracking and trauma caused by adhesive die and channel die of parts, which can be divided into demoulding cracking and applied cracking according to cracking time. The main reason is caused by stress and deformation (mainly residual stress, external stress and stress and deformation caused by external environment). 2. How can it be improved? 1. With regard to materials: Proper use of release agent, pay attention to often eliminate fog attached to the mold surface and other substances Fully dry the material before molding and processing Pay attention to the selection of coatings and diluents that will not crack. 2. Molding process: Avoid getting involved in the air because of poor feed in the plasticizing stage On the basis of increasing melt temperature and mold temperature to ensure melt flow, injection pressure should be reduced as much as possible. Reduce screw speed and injection speed, slow down the speed of melt passing through gate, and adopt multistage injection molding. Adjust the speed and pressure of die opening to avoid demoulding cracking caused by rapid tensile products Avoid cracking everywhere due to weld marks and degradation of plastics The internal stress is eliminated and the crack generation is reduced by annealing immediately after forming. If cracks have already occurred on the surface of the plastic parts, the annealing method can be considered to eliminate them. The annealing treatment makes the plastic part fully heated for about 1 hour at a temperature about 5 ℃ lower than the hot deformation temperature of the plastic part, and then cools it slowly. It is best to anneal the cracked plastic part immediately after forming, whic

Electroplating Encyclopedia: 17 kinds of electroplating equipment details

1. Potion Tank Body: Generally used materials are PP, PVC, stainless steel. If you do not need to heat can use PVC tank, the temperature below 70 °C can use PP tank, if the temperature exceeds 70 °C, you need to use stainless steel tank, but the electroplating tank is not available stainless steel tank (metal tank 0. In continuous plating, there are denominator slots and sub-slots. The mother tank is used for electroplating solution, and the child tank is for plating. At present, the child and mother groove are separated, the same body, and share three ways. The design of the main tank structure is relatively simple, only considering the factors such as water flow, stirring, steady flow, positioning, and the distance between yin and yang. 2. Groove base frame: There are generally derivative shelves of plastic medicine trough, angle iron, stainless steel square tube, black iron paint and so on. In order to consider the strength and corrosion resistance, it is recommended to use stainless steel square pipes. 3. Water Inlet System: Generally, pure water and tap water are used. Water intakes are provided on each medicine trough to replenish the water level and clean the trough. In order to avoid water pipe leakage or human negligence, the electroplating tank is not equipped with a water inlet device. 4. Drainage System: General drainage needs to be classified and then set up a drainage system. The waste water of terminal continuous electroplating is classified as acid liquid, alkali liquid, nickel liquid, gold liquid, tin and lead liquid, etc. It is recommended to use more than one inch of pipe for each groove drain. The drainage effect is better. The general washing tank is equipped with a single drain valve, and each electroplating medicine tank is equipped with a double drain valve to avoid human negligence will drain the medicine. Each water tank is provided with

Injection Molding Process - Correct Setting of Holding Pressure

When the mold cavity is not filled, the injection pressure (read from the pressure gauge) is very low, because the resistance to melt flow in the nozzle, runner and mold cavity can be overcome. This continues until the cavity is filled with 100%. The pressure control of the injection molding machine is only the upper pressure control. If the pressure of an injection section is set to 90 bar, it only means that the pressure in this section cannot exceed 90 bar, but which pressure below 90 bar is determined by the melting resistance. This pressure can be read from the pressure gauge at the time of injection. Therefore, before the cavity is filled, the injection molding machine can not be controlled by pressure, but can only be controlled by speed. Pressure comes from resistance, but resistance is not controlled by injection molding machines. The stability of the injection product is closely related to the stability of the injection speed. Full closed-loop injection is aimed at achieving the specified injection rate for each injection. For the pressure setting of the injection section, please use the system pressure, which is the maximum pressure such as 140 bar or 160 bar. There is enough pressure to ensure that the injection can effectively control the speed. Because the mold cavity is not full, the high pressure setting will not be the reason for the hairy edge. Filling the mold cavity does not mean that the injection process is over, but also extrusion. In fact, the most different between injection and other molding methods is the extremely high injection pressure. This pressure is usually between 1000 and 2000 bar. You know, at the bottom of the deepest abyss on Earth, the water pressure is less than 2000 bar. Extrusion is produced by the compression of melting and the continuous injection of screw. It can also be seen as super full filling. A few percentage points of me

Characteristics of Injection Molding Technology for Insert

Insert molding (insert molding) refers to the molding method in which the resin is injected into the mold after the pre-prepared different material insert is loaded into the mold, and the molten material is joined and cured with the insert to form an integrated product. Out-sert molding refers to the injection molding process in which a part of a metal plate is embedded. The above two molding methods are essentially the same, and their characteristics are as follows. 1. The combination of easy formability, bending and metal rigidity, strength and heat resistance can be used to make complex and exquisite metal plastic integrated products. 2. In particular, the combination of insulation of resin and conductivity of metal can meet the basic function of electrical products. 3. The pre-molding combination of multiple inserts makes the post-engineering of product unit combination more reasonable. 4. Inlay products are not limited to metal, but also cloth, paper, wire, plastic, glass, wood, wire ring, electrical parts and so on. 5. For rigid molding products and flexible elastic products on rubber sealing gasket, the complex operation of arranging sealing ring can be saved after the integrated product is made by injection molding on the matrix, which makes the automatic combination of the later process easier. 6. because it is the joint between the molten material and the metal insert, compared with the pressing method, the gap between the metal insert can be designed narrower and the reliability of the composite product is higher. 7. Select the appropriate resin and molding conditions, that is, for products that are easy to be damaged (such as glass, coils, electrical parts, etc.), the resin can also be sealed and fixed. 8. select the appropriate mold structure, the inlay can also be completely sealed into the resin. 9.

How to calculate the amount of glue?

Usually the factory in the purchase of injection molding machine is based on the weight of their own products to choose the appropriate injection molding machine. But many people on some injection molding machine manufacturers to provide the theoretical injection volume, theoretical injection volume, the actual injection volume is not very understanding, now will be the calculation method of these data and how to choose the injection molding machine according to the plastic parts of the common sense problem. Introduced as follows: Theoretical injection volume and theoretical injection amount The theoretical injection volume is calculated according to the design value, and the formula is V= π/4 Ds2*S ( Formula 1) V - on the injection volume cm3Ds-screw diameter cmS - injection stroke cm The theoretical amount of injection is equal to the theoretical injection volume multiplied by the density of the plastic at room temperature. G = VXRHO (Formula 2) G - Theoretical gel ejection g V - Theoretical injection volume cm3 Plastic density g / cm3 at room temperature Based on the characteristics of polystyrene (ps) plastics, its density value is usually used as a standard for calculation: the density of ps at room temperature is 1.05 g / cm3. For example, the 160F machine in the company's product version has a theoretical injection volume of 307 cm3 and a theoretical injection volume of 307 × 1.05 = 322.4 g

Transparent plastic injection molding process, do you know?

Transparent plastic as a result of high transmittance, the inevitable requirements for quality plastic products strict, can not have any markings, stomata, white. Fog halo, black spots, discoloration, poor gloss and other defects, so in the entire injection molding process on raw materials, equipment. Mold, and even product design, must pay great attention to and put forward strict or even special requirements. Secondly, because transparent plastics are mostly high melting point and poor fluidity, in order to ensure the surface quality of products, It is often necessary to make subtle adjustments in the process parameters such as high machine temperature, injection pressure, injection speed, etc., so that the injection plastic can be filled with mold, and will not produce internal stress and cause product deformation and cracking. Therefore, from the raw material preparation, the equipment and mold requirements, the injection molding process and the raw material treatment of the product must be strictly operated. 1. Preparation and drying of the material Due to the inclusion of any impurities in the plastic, it may affect the transparency of the product, so it is easy to store and transport. During the feeding process, attention must be paid to sealing to ensure that the raw materials are clean. In particular, the raw material contains water, which will cause the raw material to deteriorate after heating, so it must be dried, and when injection molding, the feeding must use a dry hopper. It should also be noted that during the drying process, the input air should preferably be filtered and dehumidified to ensure that the raw materials will not be contaminated. Its drying process such as, Drying process of transparent plastics: material processDrying temperature (°C) Drying time (h) Material layer thickness (mm) Remarks pmma70 ~ 802 ~ 430 ~ 40pc120 ~ 130 > 6 < 30 Adopt hot air circulation drying pet140 ~ 1803 ~

Prevent the injection molding machine screw slip, from these aspects to consider!

When the screw slippage, the material is likely to gather in the feed mouth, and can not be normally transported to the end of the injection machine. When the screw rotates and retreats in the barrel to transport the material and prepare for the next injection, screw slippage occurs in the plasticizing section. At this time, the rotation of the screw is still inherited, but the axial activity of the screw will stop, that is, the slippage will occur. Screw slip often causes the material degradation before injection, the product quality will be reduced (such as lack of material), and the molding cycle will be prolonged. The reasons for screw slipping are various, Probably because the back pressure is too high, the end of the barrel is too hot or too cold, barrel or screw wear, feeding section thread is too shallow, hopper is blocked, resin wet, resin lubrication, material is too fine resin and recycled material unfair cutting and other factors. Process setting The undercooling at the end of the cylinder is one of the main reasons for screw skidding. The cylinder of the injection machine is divided into three sections At the end, that is, the feeding section, in the process of heating and compression, a layer of melt film will be formed and bonded to the screw. Without this film, the particles are not easily transported to the front end. The material in the feeding section must be heated to a critical temperature to form a melt film. However, the residence time of the material in the feeding section is usually very short and can not reach the required temperature. This environment is generally produced on small injection machines. Too short residence time will cause the melting of polymer and the incomplete process of inclusion, which will lead to screw slippage or stall. There are two simple ways to determine whether the screw produces skidding. One way is, to the end of the cylinder. A sm

How to Avoid Oil Pollution of Injection Molding Products

In the past few days, most of the companies have started. For process commissioning personnel, mold maintenance personnel and product sorting personnel, the product often has oil pollution after the injection molding machine is turned on, which is a headache problem. Sorting personnel often find the process debugging staff to complain that: pick up several machines, this piece of oil too much, wipe not come over, this place how to wipe the oil can not wipe off. The craftsmen observed that there was a problem in mold maintenance, the mold was not used for too long, and the oil was decomposed into black water in the gap of the insert and the gap of the thimble hole. Use alcohol, cleaning agent, release agent for form work, A set of processes down the product oil pollution may be reduced, but can not remove the root cause, if continue to maintain production, the workload of employees increased, when there is leakage will bring quality risks. 1. the cause of oil pollution in the mold The oil is caused by decomposition or carbonization of the oil, which seeps into the slider gap and thimble gap of the mold. For the injection molding workshop, when the injection molding machine is stopped in order to prevent the mold temperature from being higher than the ambient temperature and form water vapor (anti-moisture), Because the antirust agent has the effect of blocking oxygen and water, forming an oil (wax) film on the metal surface, so spray the antirust agent to prevent the mold from rusting after the unfinished mold is shut down, and the mold that has been produced needs to be removed, washed, and oiled for maintenance. 1, mold under the machine maintenance, should control the use of grease and thimble oil, to avoid due to excessive smear caused by a lot of oil, should be used to evenly smear cotton thimble oil, reasonable control mold maintenance should use the dose.

How to control the size of injection molding products?

1, mold design control 1, we must first fully understand the technical requirements of the mold structure, materials, hardness, accuracy and other users, including whether the shrinkage rate of the forming plastic material is correct, whether the 3D size of the product is complete, and reasonable processing analysis. 2, the injection molding product shrinkage, flow marks, dialing mold slope, weld lines and cracks and other aspects of the appearance of various places to fully consider. 3, without interfering with the function of the injection molding product and the design of the premise, as far as possible to simplify the mold processing method. 4, the choice of parting surface is appropriate, the mold processing, forming appearance and forming parts to burr must be carefully selected. 5, whether the pushing method is appropriate, the use of push rod, discharge plate, push sleeve or other methods, the position of the push rod and discharge plate is appropriate. 6, the use of side core-pulling mechanism is appropriate, flexible and reliable action, there should be no card lag phenomenon. 7, the temperature control method is easy to use for plastic products more suitable for temperature control oil, temperature control water, coolant, etc. What kind of structure circulation system is used, and whether the size, number, position, etc. of the coolant hole is appropriate. 8, the form of the gate, the size of the material channel and the feed port, the location and size of the gate are appropriate. 9, all kinds of modules and mold core heat treatment deformation effect and the selection of standard parts is appropriate. 10, injection molding machine injection volume, injection pressure and clamping force is sufficient, nozzle R, gate sleeve aperture is appropriate. And so on these aspects of comprehensive analys

What kind of trouble has your injection molding machine had?

Injection molding machine failures are diverse and can be classified from different angles. 1. According to the state of failure, it can be divided into: (1) gradual failure. It is caused by the gradual deterioration of the initial performance of the injection molding machine, and most of the faults of the injection molding machine belong to this type of fault. This kind of failure is closely related to the wear, corrosion, fatigue and creep process of electronic control and hydraulic machinery components. (2) Sudden failure. It is caused by a variety of adverse factors and accidental external influences, which exceeds the limit that the injection molding machine can withstand. For example: due to the barrel into the iron overload caused by screw break; Breakdown of the electronic board of the injection molding machine due to high voltage series entry. Such failures often occur suddenly and without any warning. Sudden failures occur in the use of injection molding machines, often due to design, manufacturing, assembly and material defects, or operational errors, caused by illegal operations. 2. According to the nature of the fault, it can be divided into: (1) intermittent fault. The injection molding machine loses some of its functions in the short term, and can be restored with a little repair and debugging, without the need to replace parts. (2) Permanent failure. Some parts of the injection molding machine are damaged and need to be replaced or repaired before they can be restored to use. 3. According to the degree of fault influence, it can be divided into: (1) complete failure. Resulting in a complete loss of function of the injection molding machine. (2) Local failure. Resulting in the loss of certain functions of the injection molding machine. 4. According to the cause of failure, it can be divided into: (1) wear failure. Failure due to normal wear and

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injection molding machine

The high efficiency servo energy saving injection molding machine has the precise positioning mold lock structure, the stable injection device, the perfect hydraulic system and the trustworthy control system. According to customer requirements, we can be widely used in the following industries, auto parts industry, beverage packaging, electronic communications, household appliances industry, daily supplies, pharmaceutical industry, toys and gifts industry and construction, Haijing is a good decision, we have shorter delivery time, more outstanding machines.