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How to maintain injection moulding? - Eight aspects of injection moulding maintenance

Time：2019-04-17 08:55:17 / Popularity： / Source：

Price of injection moulding is very high. Therefore, how to maintain injection moulding becomes a very important issue for injection molding manufacturers! Most of injection moulding machines are continuously produced, which is destined to have a long operation time of injection mold, and timely maintenance and repair of mold is very important. Maintenance of injection moulding is mostly from following eight aspects!
 
  • Sliding parts, guide parts, cores, on the mold should be observed at any time, regularly checked, and explained in shift record
Successor should refuel working surface of sliding parts, especially in the case of high summer temperatures, oil should be applied twice per shift to prevent dry friction and cause work surface strain. In normal operation, short-term shutdown, it is expected to be more than half a day, surface of cavity should be coated with anti-rust oil, especially in rainy season and when air is humid, even if time is short, it should be treated accordingly to prevent moisture in the air from modulating mold. Corrosion of cavity surface affects quality of injection molded plastic parts.
  • Mold rust and oil removal treatment
During use of mold, there are often residues, scraps, oils and the like in mold release. If it is not cleaned in time, it will affect molding of mold. After removing these impurities, butter is used to prevent rust. However after butter is oxidized, it absorbs moisture in the air, and adhesion to mold is not strong. Moisture is generated from gap between grease and cavity surface, thereby causing rust. Therefore, special rust preventive oil should be used for maintenance. Before using mold that has been stored for a period of time, it is necessary to remove oil. Otherwise, oil entering surface of cavity, inlaid part and ejector pin will often ooze out during molding, which will cause defects in injection molded plastic parts. Especially for injection molded plastic parts with transparent surface parts such as transparent injection molded plastic parts, degreasing is very important. Method of removing oil is to first disassemble mold, and then scrub rod and the core inlay with a solvent such as kerosene. For parts that cannot be disassembled, solvent can be injected and blown with compressed air while scrubbing. Cavity degreasing can be cleaned with a solvent such as ethanol or acetone.
  • Heating, maintenance of control system is especially important for hot runner molds
At the end of each production cycle, rod heaters, thermocouples should be measured with a multimeter, and faults are eliminated in time.
  • Operator should remove residual materials in time, keep inside and outside of mold inside injection moulding machine clean and tidy, and do a good job in resettlement management and civilized production
When working continuously, debris should be removed regularly. For high surface quality requirements of injection molded plastic parts, surface of cavity should be treated with a skin texture to increase frequency of cleaning, to ensure that surface of cavity is bright and clean.
  • Strengthen life cycle management of mold and strictly implement mold resume card system
This card is used as a record of plastic molding manufacturing, trial, use, repair, improvement and scrapping, describing in detail information in above process. Contents of this card include plastic molding manufacturing records (description of properties of mold itself, such as mold name, mold number, mold size, etc.), initial test mode, mold ejection mechanism and cooling circuit description, process adjustment points during mass production, use and maintenance records, mold improvement records, mold scrap records, and so on. Mold history card transfers information from molding workshop to mold shop during mold repair, and records mold.
Basis for mold overhaul comes from three aspects: contents of mold history card (based on data recorded, which are the most common damages of mold, which parts are most susceptible to mold damage, which mold is most vulnerable, the most common causes of mold damage, and which damages have the most serious consequences). First-line technicians and operators summarize problems that may arise during molding of injection molded plastic parts and problems, technical department summarize problems of plastic structure according to requirements of injection molding manufacturers. Mold resume card is mainly used for two aspects: one is to monitor direct or indirect costs generated; the other is a special analysis for mold problems. Of course, people are interested not only in the damage of mold, but also to find out cause, find a solution, and try to prevent similar problems from happening.
  • Full-time maintenance personnel of injection moulding should prepare a mold maintenance plan and maintain mold as planned.
Maintenance content includes: cleaning and cleaning foreign objects in mold, re-applying rust inhibitor, checking whether accessories can be used normally (some work needs to be done by mold department).
  • A mold library should be set up, special personnel should be set up, and mold files should be established, and computer management should be carried out on molds if conditions permit.
Mold library should choose a place with low moisture and ventilation, and humidity should be kept below 70%. If humidity exceeds 70%, mold is easily rusted. Mold should be stored on the shelf, pay attention to anti-corrosion, dustproof and so on.
  • For storage and retrieval of forming mold, special tools (such as electric forklifts) should be used as much as possible to make mold move smoothly.
It is strictly forbidden to flip or move mold or drop mold from bowl to lower cart.
Whether it is maintenance of screw, barrel of injection moulding machine, condensation of injection moulding machine, even injection moulding maintenance, it is of vital importance to injection molding manufacturers. Above eight aspects are main methods and points of attention for injection moulding maintenance. Warranty of injection moulding is of great significance for reducing injection molding manufacturers costs and improving injection molding manufacturers profits!
 
Last article：Application of Moldflow Software in Plastic Injection Mould Design Next article：Comparative analysis of technological advantages for seven major mold powerhouses in the world

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