Detailed Specifications for Storage Environment and Maintenance of Injection Molds
Injection molds are high-precision core tooling for plastic manufacturing, composed of cavities, cores, guide pins, ejector pins and hot runners. High production costs and long processing cycles make mold precision critical to product appearance and dimensional stability. Many factories adopt rough mold management, leading to condensation corrosion, seized moving parts and scratched mold surfaces. In severe cases, mold base deformation and permanent precision loss drive up maintenance costs or result in complete scrapping. Forming standardized storage and maintenance rules covering warehouse environment, offline protection, classified stacking, regular upkeep, transfer and scrapping can effectively prolong mold service life and cut production losses.
I. Mold Storage Environment Standards
Temperature and humidity control
The warehouse must be an independent closed space equipped with constant temperature and dehumidification equipment. Temperature should stay between 10℃ and 25℃, with relative humidity kept at 40%–60%. Humidity above 65% triggers steel electrochemical corrosion, while humidity below 30% volatilizes anti-rust oil quickly. Daily temperature fluctuation shall not exceed 8℃ to avoid condensation on mirror mold surfaces. Basements, workshop aisles and open-air zones are banned for mold storage. Dehumidifiers run all day in humid seasons, with temperature and humidity recorded twice daily.
Indoor cleanliness requirements
The warehouse must be physically separated from production workshops with ventilation and dust removal systems. Acidic fumes and release agent mist from molding workshops will leave irreversible pits on high-gloss cavities. Mold grinding, cleaning and chemical storage are forbidden indoors. Epoxy flooring prevents cement dust, and daily cleaning avoids hard particles scratching mold surfaces.
Warehouse hardware standards
Windows are fitted with blackout curtains to block ultraviolet rays that degrade anti-rust coating and nitride layers. The ground is raised with drainage ditches to prevent water soaking. All molds are placed on load-bearing shelves instead of the ground to block ground moisture. Fire equipment is placed away from flammable chemicals, and shelf load limits are clearly marked.
II. Standard Pre-storage Anti-rust Treatment
After production, molds go through five protection steps before warehousing:
Disassemble and clean all sliding blocks, inserts and ejector pins to clear plastic residue and carbon deposits. Mirror molds are wiped with neutral cleaner and dust-free cloth; hard abrasives are prohibited. Tiny gaps are blown dry with air guns.
Fully dry molds for over 30 minutes to remove water stains. Dry air flushes cooling channels, and both channel ends are sealed to stop internal rust.
Apply targeted anti-rust materials: transparent anti-rust oil for cavities, anti-rust grease for moving parts, thin oil for electroplated surfaces, covering every gap and hole without dead zones.
Small accessories including springs and tiny inserts are soaked in anti-rust oil, stored in labeled sealed boxes matched to corresponding molds to avoid loss.
Lock closed molds with anti-rust paper between cavities, wrap thick moisture-proof film and lay moisture-proof cardboard at the bottom; large molds are covered with waterproof tarpaulins.
III. Classified Stacking and Label Management
The warehouse is split into five independent zones: frequently-used molds, spare molds, long-term storage, pending repair and scrapped molds. High-frequency molds are placed near entrances; long-discontinued molds are isolated separately. Heavy molds occupy shelf bottom layers, small precision molds on upper layers. All molds lie flat with 5cm gaps between them to prevent collision. Each mold carries a label with serial number, product info and maintenance schedule. Dual electronic and paper ledgers record all inbound, outbound and maintenance records for full traceability.
IV. Periodic Inspection and Maintenance Rules
Maintenance frequency varies by storage duration:
Short-term storage (1–3 months): Monthly inspection to repair broken moisture-proof film and replenish anti-rust oil.
Medium-long storage (3–12 months): Bi-monthly full maintenance to remove old oil, re-clean, re-protect and replace sealing materials.
Long-term storage (over 1 year): Quarterly full disassembly maintenance for rust removal and part inspection.
Any excess humidity triggers emergency dehumidification and secondary anti-rust treatment for damp molds.
V. Transfer, Long-term Storage and Scrapping Rules
When transporting molds, rubber-padded forklifts and nylon slings are used; steel wire ropes are forbidden to prevent scratches. Operators must handle molds gently to avoid sliding and collision. Before production, all anti-rust packaging and oil are thoroughly cleaned.
Molds halted for over two years receive top-level protection with vacuum film and wooden boxes filled with desiccants, requiring semi-annual maintenance. Molds with repair costs exceeding 30% of new mold value are moved to scrapped areas. Recyclable standard parts are sorted separately, while scrapped molds are strictly isolated from intact ones.
VI. Personnel Management
Full-time warehouse staff are assigned to monitor environmental data, clean the warehouse and maintain mold records. Monthly management inspections check mold storage conditions and maintenance logs. Regular training improves staff awareness of mold protection to reduce artificial damage.
Standardized mold storage and maintenance is a core cost-control measure for injection molding factories. Proper environmental control and operation rules effectively reduce rust, deformation and collision damage, lower maintenance expenditure, extend mold service life and guarantee stable mass production.
