Malfunction law research is favorable for development of maintenance measures, as well as to establish a scientific system maintenance. When injection molding machine is in use, its performance or status will gradually decline as the time goes on. There will be a lot of malfunction before some of the warning, which is called a potential malfunction, which can identify the physical parameters indicate that a functional failure is imminent, the functional breakdown shows that machine is disabling the specified performance standards.
Injection molding machine failure rate was changing as the time, often called the bathtub curve. It can roughly be divided into three stages: early failure period, occasional failure period and depletion failure period.
1.1Cleaning the barrel
Before using, newly purchased injection molding machines, changing products in the production, replacing other raw materials, exchanging or finding plastic in color decomposition phenomena, injection molding machine barrel need to be cleaning or washing after removing. Washing machines generally use heating cylinder barrel cleaning method. Cleaning materials for general use of plastic materials (or plastic recycled materials). For heat-sensitive plastics such as PVC material existence, available low-density polyethylene, polystyrene and other transition refueling clean, new material and then the processing of the replacement of transition purge.
1.2Choosing the mold release agent
Mold release agent is substances that easy to release the product from the mold. Zinc stearate is suitable for general plastic material except polyamide; liquid paraffin is better suitable for Polyamides, silicone oil is expensive, it`s problem and less to use.
2.Attention for the injection molding machine during operation process
Develop good habits to improve the operation of the injection molding machine machine, is good for machine lifespan and safety.
2.1Before starting the machine:
(1) Check the electrical control box whether there is water, oil enter, if getting damp, do not start the machine. Operator should dry the electrical parts before starting the machine.
(2) Check the voltage, generally should not exceed ± 15%.
(3) Check the emergency stop switch, whether the front and rear safety door switch is normal. Verify that the direction of rotation of the motor and pump are the same. Check if all electrical connector is loose.
(4) Check if the cooling hose is not blocked, and route the cooling water to oil cooler and barrel on top.
(5) Check if the movement parts have lubrication, and lubricate it properly.
(6) Open heating power, heating the each section on barrel . When the temperature meet the requirements, then holding for some time to stabilize the temperature of the machine. Holding time in accordance with the requirements of different devices and plastic raw materials.
(7) Add enough plastic material in the hopper. According to the requirements of different plastics, some material is best to be dried.
(8) Cover the thermal shroud on the barrel, it can save energy, but also can extend the lifespan of electric rings and contactors.
2.2 Operation process:
(1) Do not for the sake of convenience, free to cancel the role of security doors. (2) To observe the temperature of the oil pressure, oil temperature should not exceed the specified range. Hydraulic oil ideal operating temperature should be maintained between 45 ~ 50 ℃, generally in the range of 35 ~ 60 ℃ appropriate.
(3) Note that adjust the stroke limit switch, to avoid the impact produced by the machine in the action.
3. At the end of work
(1) Before shutdown, plastic barrel should be clean, prevent long-term thermal oxidation or remaining material decomposition.
(2) Open the mold, make the crank toggle mechanism in a locked state for a long time.
(3) Lifting equipment must be provided. Detach mold and other bulky components should be very careful to ensure production safety.