Use of injection molding machine and key points of operation



Classification and Use

The injection molding machine has the ability to form the plastic products with complex appearance, precise size or dense texture with metal inserts at a time. It is widely used in various fields of national defense, mechanical and electrical, automobile, transportation, building materials, packaging, agriculture, culture, education and health and People’s Daily life. With the rapid development of plastic industry, injection molding machine plays an important role in both quantity and variety. Its total production accounts for 20%-30% of the whole plastic molding equipment, thus becoming one of the fastest growing and most productive machines in plastic machinery.

According to relevant data statistics, from 1996 to 1998, China exported 8383 sets of injection molding machines (sets) and imported 42959 sets of injection molding machines (sets). In 1998, China’s injection molding machine output reached 20000 sets, and its sales accounted for 42.9% of the total sales of plastic machines.

China production injection molding machine manufacturers more, according to incomplete statistics has more than 2000. The structure of injection molding machine has two kinds: vertical and horizontal. According to the products produced can be divided into ordinary type and precision injection molding machine.

Development of the industry

Injection molding machine manipulator is able to imitate part of the functions of the upper limb of the human body, can be automatically controlled to make it in accordance with the predetermined requirements of the delivery of products or operating tools for production and operation of automatic production equipment. China’s plastic processing plants in the coastal areas of South China and East China show increasing interest in the manipulator, but the penetration rate of injection molding machine manipulator in the domestic molding machine industry is less than 10%. Manipulator can ensure the consistency of operation cycle, improve quality, and more safe. With the rapid development of plastic processing industry in our country, the automation of injection molding equipment becomes more and more high.

Modern injection molding machines are often equipped with manipulators to improve production efficiency. The number of injection molding machines exported and imported was roughly equal at about 15,000 units, but the import value was $920 million and the export value was $350 million. Precision injection molding machine is mainly a foreign brand, extrusion equipment in the two-way stretch PET, membrane unit, precision medical catheter extrusion unit has been the territory of foreign companies. The development of domestic precision injection molding and extrusion equipment with independent intellectual property rights is very necessary.

On the one hand, it can replace import and make our country take a place in the international high-end market of plastic machinery. Traditional plastic machinery also has a certain potential in energy saving, because the previous design often only focuses on the production capacity of a single machine. In the design of energy-saving plastic machinery, the production speed is not the most important index, the most important index is the energy consumption of processing unit weight products. Therefore, it is necessary to optimize the mechanical structure of the equipment, the control mode, and the operating process conditions based on the minimum energy consumption.

With the rise of energy saving and consumption reduction as a national strategy, the issue of energy saving of injection molding machine has been widely concerned. In the field of conventional injection molding machine, there are two mature ways to save energy for motor: inverter and servo motor, among which servo motor is more and more widely accepted.
Servo energy-saving series injection molding machine, equipped with high-performance servo dynamic variable speed control system, in the process of injection molding pressure on different traffic, make different frequency output, and closed loop control of pressure flow accurately, realize servo motor for injection molding machine high speed response and the best match of energy demand and adjust automatically.

1, the use of excellent performance servo controller, servo motor and other energy-saving devices.

2, sensitive servo control system, quick start reaction time only 0.04 S.

3,The servo motor and the hydraulic system are composed of closed-loop control, which greatly improves the repetition accuracy compared with the traditional models.

4, reduce the impact of mold opening, prolong the service life of mechanical parts and molds.

5, reduce the use of power, in the ideal working condition of the model than the traditional injection molding machine power saving efficiency can reach 20%-80%

6,The heat output of the system is much lower than that of the traditional injection molding machine, which saves about 30% of the consumption of cooling water and prolongs the service life of oil circuit seals and hydraulic parts.

7,The noise of the whole line is low, which is significantly lower than that of the traditional injection molding machine.

Operating points

Boot before

1.Before operation of injection molding machine, check whether there is water and oil in the electric control box. If the electric machine is damp, do not turn on. There should be maintenance personnel to blow dry the electrical parts before starting.

2.Before operation of injection molding machine, check whether the power supply voltage is consistent, generally should not exceed ±6%.

3.Check whether the emergency stop switch and the front and rear safety door switches are normal. Verify whether the motor and oil pump rotate in the same direction.

4.Check whether the cooling pipeline is smooth over a long distance, and pass cooling water into the cooling water jacket at the end of the oil cooler and barrel.

5.Before operation of injection molding machine, check whether there is lubricating oil in each moving part, and add enough lubricating oil.

6.Turn on the electric heating to heat each section of the barrel. When the temperature of each section reaches the requirement, hold it for another period of time to make the machine temperature tend to be stable. The holding time varies according to the requirements of different equipment and plastic raw materials.

7.Fill the hopper with enough plastic. According to the requirements of different plastics for injection molding, some raw materials are best dried first.

8.The heat shield on the barrel should be covered well to save power and extend the life of the heating ring and current contactor

The operation process

1.Do not be covet convenient, cancel the function of safety door at will.

2.Pay attention to the temperature of the pressure oil, oil temperature should not exceed the prescribed range. The ideal working temperature of hydraulic oil should be kept between 45-50℃, generally in the range of 35-60℃ is more appropriate.

3.Pay attention to adjust the travel switch to avoid the impact of the machine during operation.

End of the work

1.After the operation of the injection molding machine, the plastic in the cylinder should be cleaned up to prevent the oxidation of leftover materials or long-term heat decomposition.

2.The mould should be opened so that the toggle mechanism is locked for a long time.

3.The workshop must be equipped with lifting equipment. Great care should be taken when assembling and disassembling moulds to ensure production safety.