Daily Management Specifications for Thermocouple Replacement and Scrap Standards

In order to control accessory use costs, stabilize production quality, and minimize production line sudden failure shutdowns, injection molding companies must develop unified and standardized thermocouple replacement timing and scrap judgment standards as well as perfect daily accessory use management specifications. The backward management approach of utilizing thermocouples until they are totally broken and out of service has long been used by many manufacturers. This results in a high number of defective goods in batches, frequent abrupt production failures, and increased overall production losses. As a result, it is necessary to develop precise replacement cycles and scientific scrap judgment standards in accordance with various manufacturing operating situations.

First, based on the severity of working conditions, categorize and create regular replacement cycles. The continuous safe service cycle of typical thermocouples can be set at six to eight months for conventional general plastic production lines with a steady working environment, minimal dust, and no strong corrosive gas. The regular replacement cycle must be shortened to three to four months for production lines processing modified plastics filled with glass fiber, flame-retardant materials, and recycled materials under harsh working conditions because of significant probe wear, quick carbon deposition, and rapid performance aging. In order to guaranty that all temperature measuring components are always in a high-precision and high-stability operating state, the replacement cycle for high-temperature special plastic production workshops with long-term ultrahigh temperature operation and medical high-precision production sites must be strictly controlled within three months.

Second, make explicit the standards for on-site judgment regarding early required replacement. The thermocouple must be replaced promptly without being used reluctantly if it exhibits clear performance decline phenomena during daily equipment inspection, such as increased temperature measurement drift error beyond the permitted range, a noticeable slow temperature response, and unstable constant temperature data floating. It must also be included to the early replacement list if the probe's surface is extremely worn, corroded, and distorted, the internal compensating wire is old, hardened, and cracked, and the wiring termination is severely oxidized and irreparable. Furthermore, even if they are temporarily fixed, all thermocouples that have encountered open circuit, short circuit, or other unexpected problems must be replaced consistently and cannot be utilized on official manufacturing lines.

Additionally, establish stringent scrap judgment guidelines to standardize the waste accessory scrapping procedure. All thermocouples with internal wire core fracture and welding failure, excessive precision errors that cannot be calibrated and repaired, and severely damaged outer protective structures that lose protective performance must be categorized as scrap products. In order to prevent hidden safety and quality issues brought on by the reuse of unqualified accessories, it is prohibited to disassemble and splice waste thermocouple accessories for secondary assembly and reuse. In order to prevent haphazard stacking and mixing with new spare parts, the scrapped thermocouples must be consistently gathered, sorted, and kept by specialized staff before being routinely disposed of in a regulated manner.

Lastly, match the ideal reserve and use management system for spare parts. Avoid long-term backlogs and the natural aging of new accessories, adopt the first-in, first-out spare part concept, and appropriately reserve different types of thermocouple spare parts based on the regular replacement quantity of each production line. In order to achieve the refined whole-process management of thermocouple use, replacement, and scrapping, it is necessary to record the replacement time, use position, and failure reason of each batch of replaced thermocouples in detail, sort and count the use data on a regular basis, dynamically optimize the replacement cycle and management standards according to the actual use effect, effectively control the use cost of accessories, and provide a solid management guaranty for the stable and efficient operation of the hot runner temperature control system.