How injection molding machine continuously produce

Injection molding machine is one of the widely used equipment in plastic processing industry, usually it needs to work for a long time, so how to ensure the normal and stable work of injection molding machine in continuous production, no matter for the manufacturer or the user of the injection molding machine, it is a problem worthy of attention and efforts to solve. As far as the user is concerned, under the premise of selecting the injection molding machine correctly, regular preventive maintenance is an effective way to ensure the normal work of injection molding machine. The so-called preventive maintenance is a series of preventive work and inspection, so as to avoid machine failure and extend the working life of all parts, for example, the purpose of preventive maintenance is to turn a failure that causes production stoppage into a predictable and planned downtime or overhaul, and to detect and replace damaged parts in a timely manner to prevent chain damage.

Hydraulic part of injection molding machine hydraulic

transmission is hydraulic oil as the working medium, the use of sealed working volume of hydraulic oil pressure can transfer energy or power or signal. The quality of hydraulic oil and seal directly affects the stable work of hydraulic system, and indirectly affects the quality of products. To prevent and reduce the hydraulic system failure, reduce wear and tear, extend life, we should strictly use and maintain hydraulic oil.

In general, 70% of failures of hydraulic devices are caused by incorrect or improper use and maintenance of hydraulic oil. Maintaining good maintenance habits and preventive maintenance is the most effective way to reduce and prevent hydraulic failure of the machine. So the fine maintenance of hydraulic oil and hydraulic system is very important. Therefore, it is necessary to introduce the characteristic requirements of hydraulic oil.

The most important properties of hydraulic oil are viscosity and cleanliness, as well as better oxidation resistance, anti-wear, anti-foaming, anti-corrosion and good lubrication performance

The viscosity of hydraulic oil is expressed as the average value of the kinematic viscosity at 40 °C. Our commonly used No. 46 anti-wear hydraulic oil (46csT / 40 °c) refers to this hydraulic oil at 40 °C for the average viscosity of 46 M2 / S.

The relationship between hydraulic oil viscosity and pressure and temperature is as follows: temperature increases, viscosity decreases; pressure increases, viscosity increases.

Periodic testing of hydraulic oil performance. If the oil is contaminated or deteriorated, the life of the injection molding machine will shorten, and failure may occur. Therefore, it is necessary to test oil regularly in order to detect changes in oil properties. Based on this, decide whether to change the oil.

We can use a simple visual method to understand the state of the oil:

Appearance Test: put the new oil sample and the old oil sample in their respective test tubes, compare their color, clarity, the presence of floating objects and water precipitation at the bottom of the test tubes.

Drop Test: put the old oil drop on the filter paper (dry sheet) , wait for 1 hour and then observe. If the oil is dirty or visibly deteriorated, the contaminant will be easily observed

Finger friction: The use of the old oil dip in the finger friction, if the viscosity reduction deterioration, feel very rough, there is no thick feeling. The oil drops fall smoothly from the fingers, and there is no rebound phenomenon.

Hydraulic maintenance starts from the following aspects:

Replace the old hydraulic oil

In principle, the hydraulic oil is changed every 5000 machine operating hours or at most one year. No matter how good the hydraulic oil is, after being used for a certain period of time, the metal and rubber particles of the worn pump and other moving parts will enter the oil, which will cause the generation of sludge and dirt. In normal maintenance, there will be some Contaminants are deposited on the parts and carried into the hydraulic oil.

Even if hydraulic oil is used correctly, it is generally considered that its working life is 1 year, up to 2-3 years. Once it deteriorates, do not hesitate to change to new oil. Good oil quality is the cornerstone of maintaining the stability of the hydraulic system.

Clean the inside of the fuel tank

Hydraulic maintenance is not as simple as pumping old oil, adding new oil, or just adding some new oil. Not only change the oil, but it is also important to clean the hydraulic equipment.

After draining the old oil, do not wipe the oil tank with a rag to prevent the end of the thread from blocking the filter. Use kerosene and copper brushes to clean the magnetic frame and filter in the fuel tank, and use an air gun to clean and blow dry.

Clean the air filter

The air filter outside the fuel tank makes the air in and out of the fuel tank easy according to the change of the oil level in the fuel tank. Every time the oil is changed for maintenance, the air filter should be taken out, cleaned with kerosene, and dried with an air gun. Failure to clean may cause stolen goods to enter the fuel tank and affect the oil quality.

Clean the inner and outer walls of the oil-water cooler

To clean the scale inside and outside of the cooler tube, you can use a weak hydrochloric acid solution to wash, rinse with water, and blow dry with an air gun. Use a copper brush to clean the dirt on the barrier.

Clean the oil valve

First use a waste cloth and air gun to clean the dirt outside the valve. Unplug the plug and disassemble the oil valve. Use a kerosene brush to clean the valve core, the sludge and debris on the valve body, and blow dry with an air gun, pay attention to the valve core disassembly and assembly do not install the reverse, do not miss the O-ring.

Cleaning cylinder

Mechanical part maintenance of injection molding machines

1. Template parallelism

The parallelism of the template can best reflect the condition of the clamping part. The non-parallel template will make the product unqualified and increase the wear of the equipment and mold. The parallelism of the template can be initially reflected by the movement of the tail plate during mold clamping and the appearance analysis of the product, but the exact situation needs to be detected with a dial indicator and other instruments. The adjustment of the parallelism of the template must be carried out by a familiar person in steps, otherwise improper adjustment will cause greater damage to the machine.

2. Mold thickness adjustment

The mold thickness adjustment system should be used regularly to adjust the mold thickness from the thickest to the thinnest to ensure smooth movement. For machines that use the same mold for a long time, this inspection must be performed to avoid malfunctions.

3. Central lubrication system

All mechanical moving parts need to be properly lubricated, and the central lubrication system is one of the must-haves for the current injection molding machine. The amount of oil in the central lubrication system should be checked frequently to see if it is full, and the lubricating oil used must be clean and free of impurities to ensure that all lubricating positions have lubricating oil supply. If the oil pipe is blocked or leaking, it should be replaced or repaired immediately. Most mechanical wear occurs due to lack of lubrication, so adequate attention must be paid to lubrication.

4. Keep all movements smooth

Vibration or unsmooth movement may be caused by improper speed adjustment, speed change and uncoordinated time, or mechanical or oil pressure adjustment. This kind of vibration will accelerate the wear of the mechanical parts and loosen the tightened screws, so vibration should be reduced and avoided.

5. Bearing inspection

When the bearing is working, there are abnormal noises, or the temperature rises, it means that the inside of the bearing has been worn out, and it should be checked or replaced in time and refilled with grease.
6. Injection system

The injection screw, check ring and barrel constitute the heart of the injection molding machine, which determines the quality and efficiency of the processing and must be kept in good working condition. First, take necessary measures to prevent non-plastic debris from mixing into the plastic material flow, and then pay attention to checking the correct gap between the screw and the barrel, and the check ring and the barrel. The normal gap should be able to seal the plastic backflow and produce plastic When it is found that the melting action is slow, the melting material has spots and black spots, or the product is unstable, the wear of the screw, the non-return ring and the barrel should be checked.

Electrical parts maintenance of injection molding machines

1. Wire connector inspection

Unfastened wires in the connector will cause high temperature or spark damage at the connector position. A poor connector will also affect the signal transmission; the connector on the contactor will be easier to loose due to the vibration of the electromagnetic action, so it is necessary to check the wire connector regularly Position and tighten.

2. Electric motor

Generally, the motor is air-cooled. The accumulation of dust causes difficulty in heat dissipation. Therefore, it is cleaned regularly every year. A motor overload cutoff is usually installed in the circuit. The limit current of the protection device is adjustable and should be adjusted according to the motor power. At the same time, once the overload protector is activated, it should be determined to check whether there is phase loss, poor contact or high oil temperature before pressing the return position switch.

3. Heating cylinder and thermocouple

The heating cylinder should be checked regularly to ensure that it is fastened to ensure effective heat transfer. The burning of the heating cylinder is not easy to detect in normal production. For this reason, pay attention to the working condition of the temperature controller and judge whether the heating cylinder is normal. In addition, the common damage of the heating cylinder is the wire connection. Due to the poor joint, the contact resistance increases, and the local overheating of the connection causes the interface to be oxidized and damaged.

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