Issues such as water leakage, mold sticking, ejector pin jamming, parting line damage, and slide block seizure occurring after a mold is mounted can lead to machine downtime, disrupt production schedules, and result in defective semi-finished products. Standardizing the entire workflow-including pre-installation inspections, production process control, post-removal maintenance, and storage management-can reduce the frequency of in-process mold failures and enhance production continuity.
Before the mold is hoisted onto the machine, it must be confirmed by the machine adjustment personnel one by one. It is prohibited to go on the machine with faults.
Inspect the water circuit system: conduct a water test to confirm there are no leaks or blockages and that connection seals are intact; if there is significant scale buildup, schedule cleaning in advance to prevent cooling failure during production.
Inspect moving components: ensure ejector pins, ejector sleeves, sliders, and core-pulling mechanisms operate smoothly without seizing, binding, or scoring; verify proper lubrication and appropriate clearances.
Inspect the parting surface and mold cavity: clean away carbon deposits and material debris; verify that inserts and locating pins are secure; and check that the venting channels are not extensively clogged.
Verify that standard accessories-heat insulation plates, mold clamping screws, limit blocks, and lifting eye bolts-are complete and in good condition; ensure guide pillars and guide bushings are clean and lubricated with grease.
Perform a dry run of the mold opening and closing: cycle the mold open and close several times at low speed, checking for abnormal noises, interference, or scraping; lock the mold only after confirming there are no irregularities.
Many mold failures stem from unreasonable machine setup parameters and rough handling during operation.
Increase the clamping force gradually; do not apply full clamping pressure immediately, so as to prevent the parting surface from collapsing or the mold core from deforming.
Initially, use low speed and low pressure for test shots, then gradually increase injection pressure and speed to prevent high-pressure impact from causing slider displacement or jamming due to flashing.
Properly set the ejection stroke and speed to prevent the ejector pins from piercing the product and the ejector plate from colliding with the mold body.
The mold must be fully preheated before full-scale production begins; an excessive temperature difference between the mold and the material can easily lead to water leakage or stress cracking.
Continue monitoring the first 3 to 5 shots of the mass production run; watch for flash or material debris entering the gaps around slides and ejector pins, and clear them away promptly.
Conduct regular inspections during production to address minor issues early and prevent them from escalating into breakdowns that cause downtime.
Key inspection points: signs of water leakage or material spillage, overheating of slide blocks, abnormal noise from ejector pins, and lack of lubrication on guide pillars.
Regularly remove flash and material residue from the parting surface to prevent damage to the mold cavity caused by metal being crushed during mold closing.
For high-temperature molding materials and molds used in long-term continuous production, replenish specialized lubricants for ejector pins and slides as needed.
If white stress marks or scuffing consistently appear on the product, promptly inspect the mold for friction points; do not rely solely on process adjustments to mask underlying mold issues.
Once mold production is complete and the mold is removed from the machine, it must not be placed directly into storage; instead, a standardized maintenance procedure must be carried out.
Clean carbon deposits and plastic residues from mold cavities, runners, and venting channels;
Inspect ejector pins, sliders, and guide pillars for scoring or wear; promptly polish and repair any minor scoring.
Inspect sealing rings and water pipe connections, and replace any aged components immediately;
Clear the water channels and blow out any accumulated water inside to prevent rust during long-term storage;
Spray anti-rust agent into the mold cavity, close the mold, and apply appropriate protective labeling.
Store molds in designated zones and place them flat to prevent deformation caused by prolonged uneven loading.
Follow standard procedures for hoisting and mold disassembly; strictly prevent impacts or drops that could damage the mold cavity.
For molds that have been idle for an extended period, periodically inspect their rust-prevention status to prevent jamming during machine operation caused by rust.
Mold records track failure history, and specialized maintenance plans are established for molds that fail frequently.
Clearly distinguish the roles and responsibilities of machine operators and machine setup personnel; prohibit untrained personnel from arbitrarily altering parameters related to mold opening/closing and ejection.
Train personnel to identify early warning signs of mold anomalies: abnormal noise, localized temperature rise, intermittent sticking, and minor water leakage.
Establish a mold fault reporting process; immediately halt the machine to investigate upon detecting any anomaly, and strictly prohibit forced continued production that could exacerbate damage.
Focus on the key management and control of aging molds, complex core-pulling molds, and thin-walled precision molds:
Avoid scheduling long, continuous production runs during night shifts as much as possible;
Shorten inspection intervals;
Stock spare parts prone to wear (seals, ejector pins, springs) to reduce the time required for breakdown repairs.
By implementing standardized procedures for inspections, maintenance, and operations, the frequency of unexpected mold failures during production can be controlled, downtime for repairs reduced, and scheduling stability further improved.
