Formulating unified and standardized thermocouple replacement timing and scrap judgment standards, and establishing perfect daily accessory use management specifications, are important management means for injection molding enterprises to control accessory use costs, stabilize production quality and reduce production line sudden failure shutdowns. Many factories have always adopted the backward management mode of using thermocouples until they are completely damaged and out of service, which leads to frequent sudden production failures, a large number of defective products in batches and increased comprehensive production losses. Therefore, clear replacement cycles and scientific scrap judgment criteria must be formulated according to different production working conditions.
First of all, classify and formulate regular replacement cycles according to the severity of working conditions. For conventional general plastic production lines with stable working environment, less dust and no strong corrosive gas, the continuous safe service cycle of standard thermocouples can be set as six to eight months. For production lines processing modified plastics filled with glass fiber, flame retardant materials and recycled materials with harsh working conditions, due to serious probe wear, fast carbon deposition speed and rapid performance aging, the regular replacement cycle needs to be shortened to three to four months. For high-temperature special plastic production workshops with long-term ultra-high temperature operation and medical high-precision production sites, the replacement cycle shall be strictly controlled within three months to ensure that all temperature measuring components are always in high-precision and high-stability working state.
Secondly, clarify clear on-site judgment standards for early mandatory replacement. In daily equipment inspection, once the thermocouple has obvious performance decline phenomena such as increased temperature measurement drift error beyond the allowable range, obvious slow temperature response and unstable constant temperature data floating, it must be replaced in a timely manner without continuing to use it reluctantly. When the surface of the probe is severely worn, corroded and deformed, the internal compensation wire is aged, hardened and cracked, and the wiring terminal is severely oxidized and cannot be repaired, it also needs to be included in the early replacement list. In addition, all thermocouples that have experienced open circuit, short circuit and other sudden faults, even if they are temporarily repaired, are not allowed to be reused on formal production lines and must be replaced uniformly.
Furthermore, formulate strict scrap judgment standards to standardize the scrapping process of waste accessories. All thermocouples that have reached the specified service cycle, have excessive precision errors that cannot be calibrated and repaired, have internal wire core fracture and welding failure, and have severely damaged outer protective structures that lose protective performance shall be uniformly classified as scrap products. It is forbidden to disassemble and splice waste thermocouple accessories for secondary assembly and reuse, so as to avoid hidden safety and quality troubles caused by the reuse of unqualified accessories. The scrapped thermocouples shall be uniformly collected, sorted and stored by special personnel, and disposed of in a standardized manner regularly, so as to avoid random stacking and mixing with new spare parts.
Finally, match the perfect spare parts reserve and use management system. According to the regular replacement quantity of each production line, reasonably reserve various types of thermocouple spare parts, implement the first-in first-out use principle of spare parts, and avoid long-term backlog and natural aging of new accessories. Record the replacement time, use position and failure reason of each batch of replaced thermocouples in detail, sort out and count the use data regularly, dynamically optimize the replacement cycle and management standards according to the actual use effect, realize the refined whole-process management of thermocouple use, replacement and scrapping, effectively control the use cost of accessories, and provide solid management guarantee for the stable and efficient operation of hot runner temperature control system.
