How do we maintain the plastic injection mold

- Dec 25, 2018-

Injection mold maintenance procedures and management regulations

First, the purpose:

The equipment can maintain the best performance state and prolong the service life to ensure the normal production.

Second, the responsibilities:

2.1 This standard must be implemented by trained injection molding technicians and mold managers.

2.2 The injection molding foreman is responsible for the implementation and inspection supervision, and the supervisor is responsible for regular supervision.

Third, the maintenance content of the injection mold is divided into:

3.1 Maintenance of the mold before production

3.1.1 The oil stain on the surface of the mold shall be cleaned, and the rust of the mold shall be checked for foreign matter and whether there is a waterway.

3.1.2 It is necessary to check whether the arc in the mold rubber sleeve is damaged and whether there is residual foreign matter.

3.1.3 Is the screw and the clamping clamp of the fixed template of the mold tightened?

3.1.4 After the mold is mounted on the injection machine, the empty mold must be operated first. Observe whether the operation of each part is flexible, whether there is abnormal phenomenon, whether the active part such as the guide post, the ejector pin, the row position is worn, whether the lubrication is good, the ejection stroke, the opening stroke is in place, and whether the parting surface is in conformity when the mold is closed Strictly wait.

3.2 Maintenance of molds in production

3.2.1 When using the mold, keep it at a normal temperature. Working at normal temperatures increases mold life.

3.2.2 Check all guide pillars, guide sleeves, return needles, push rods, sliders, cores, etc. of the mold every day for damage. Always observe, check regularly, scrub at the right time, and regularly refuel and maintain it. Take care to work twice to ensure that these sliders are flexible and prevent tight seizures.

3.2.3 Before each mold clamping, it should be noted that whether the cavity is cleaned or not, no residual products or any other foreign objects are allowed. It is strictly forbidden to use hard tools during cleaning to prevent the surface of the cavity from being damaged.

3.2.4 The surface of the cavity has special requirements, the surface roughness Ra is less than or equal to 0.2cm, absolutely can not be wiped by hand or cotton, apply compressed air, or use advanced napkins and high-grade cotton wool to gently alcohol Wipe.

3.2.5 Regularly clean the foreign body glue wire, foreign matter, oil, etc. of the mold parting surface and the exhaust groove, and clean the mold surface and runner surface twice a day. In the molding process, the injection mold tends to decompose the low-molecular compound to corrode the mold cavity, so that the surface of the bright cavity gradually becomes dull and reduces the quality of the product. Therefore, it is necessary to periodically scrub, and the scrub can use an alcohol or a ketone preparation. Dry it in time after scrubbing.

3.2.6 Regularly check that the water path of the mold is unblocked and tighten all the fastening screws.

3.2.7 Check if the limit switch of the mold is abnormal, and the skew pin.

3.3 Maintenance of the shutdown mold

3.3.1 When the operation needs to be temporarily stopped, the mold should be closed to prevent the cavity and core from being exposed to prevent accidental damage. The downtime is expected to exceed 24 hours, and the surface of the cavity and core should be sprayed with anti-rust. Oil or mold release agent, especially in wet areas and rainy seasons, should be rust-proofed for a short time.

The moisture in the air will reduce the surface quality of the cavity and the surface quality of the product will decrease. When the mold is used again, the oil on the mold should be removed and wiped clean before use. The cleaned compressed air required by the mirror surface is dried and then dried with hot air, otherwise it will ooze out during molding and cause defects in the product.

3.3.2 Start up after temporary shutdown. After opening the mold, check whether the slider limit is moved. If no abnormality is found, the mold can be closed. In short, be careful before starting the machine, don't be careless.

3.3.3 In order to extend the service life of the cooling water channel, the water in the cooling water channel should be immediately removed with compressed air when the mold is deactivated, and a small amount of oil is put into the mouth of the nozzle, and then compressed air is used to blow all the cooling pipes. Layer of anti-rust oil layer.

3.3.4 Carefully check the working status of each control component during work, and prevent abnormalities in the auxiliary system, heating, and maintenance of the control system is especially important for hot runner molds. At the end of each production cycle, rod heaters, band heaters, and thermocouples should be measured with the mother-in-law and compared with the technical description of the mold to ensure that the function is intact. At the same time, the control loop may be tested by an ammeter mounted in the loop. The oil in the hydraulic cylinder for core pulling is drained as much as possible, and the nozzle is sealed to prevent the hydraulic oil from leaking out or polluting the surrounding environment during storage and transportation.

3.3.5 If the mold is heard abnormally or other abnormal conditions occur during production, it should be stopped immediately. The mold maintenance personnel shall conduct a patrol inspection on the normal running molds in the workshop, and when there are abnormal phenomena, they shall be dealt with in time.

3.3.6 When the operator is in the handover class, in addition to handing over the production, the process is critical to the record, and the use of the mold must be detailed.

3.3.7 When the mold completes the production quantity of the product, when replacing other molds, the mold cavity should be coated with anti-rust agent, the attachment of the mold should be sent to the mold maintenance staff, and the final mold can be used to produce qualified products. The samples are sent to the maintenance staff together. In addition, you should also send a mold use list, fill in the machine on which the mold is, how many products are produced from a certain day of the year, and whether the mold is good now. If there is a problem with the mold, it is necessary to fill in the mold on the use sheet, propose specific requirements for modification and improvement, and submit an unprocessed sample to the custodian, and leave it to the mold for repair.

3.3.8 After stopping, check the surface of the mold for residual rubber filaments, clean the foreign objects, and evenly spray the anti-rust agent to fill in the relevant records accurately.

3.4 Routine inspections per season:

Mainly for the cleaning and maintenance of molds that have not been used for more than two months.

3.4.1 Open the mold and check the internal anti-rust effect. If there is any abnormality, it must be re-rust-proofed. The mold that has not been used for a long time must be buttered.

3.4.2 Put it back in place and make a record

3.5 Storage of molds

A mold library should be set up, special personnel should be set up, and mold files should be established. If possible, computer management should be carried out on the molds. The mold library should choose a place with low moisture and ventilation. The humidity should be kept below 70%. If the humidity exceeds 70%, the mold will be easy to rust. The mold should be stored on the shelf, pay attention to anti-corrosion and dustproof.

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