Mold Cleaning, Storage, and Preservation Guide

Perform in-press cleaning every 8-12 hours of continuous production or whenever reject rates exceed 2% from surface-related defects. With the HWAMDA SPV5 machine in manual mode and the mold open to its full daylight distance (1,160-1,730mm depending on model), spray the cavity and core surfaces with a food-grade mold cleaner approved for food packaging applications. Use lint-free cloths to remove residue buildup from the parting line surfaces, paying particular attention to the vent channels where PP off-gassing deposits accumulate. Vent channels in thin-wall molds are typically 0.02-0.03mm deep and 3-6mm wide—blockage causes burn marks and short shots. Use a brass or copper brush (never steel) to clean vent slots without damaging the precision-ground surfaces. Inspect the gate areas on YUDO or Synventive valve gate nozzles for material buildup that can affect gate quality. Clean the ejector pin holes by spraying with mold cleaner and cycling the ejector three times through the full 160-200mm stroke. Wipe the mold alignment components including guide pins, guide bushings, and interlocks. Apply a light coat of food-grade mold release spray only if sticking occurs—excessive release agent contaminates parts and builds up in cavities.

After deep cleaning, perform a dimensional inspection to track mold wear and predict remaining service life. Measure critical cavity dimensions using a coordinate measuring machine (CMM) at the gate area, sidewall transitions, and rim sections. For thin-wall packaging molds producing parts with 0.4-0.8mm wall thickness, cavity wear of 0.02mm on diameter represents a 2.5-5% increase in wall thickness that affects part weight and stacking performance. Record all measurements in the mold history file and compare against the original mold qualification data. Inspect the parting line surfaces for compression damage using a surface plate and blue dye—any high spots or depression exceeding 0.01mm can cause flash at the injection pressures of 150-200 MPa used in thin-wall molding. Check guide pin and bushing fit by measuring clearance with pin gauges; replace bushings when clearance exceeds 0.03mm. Inspect the water cooling circuits by pressure testing at 0.6 MPa for 30 minutes—any pressure drop indicates internal leaks that require seal replacement. Examine the hot runner nozzle tips for wear at the gate seal diameter. Document all findings with photographs and measurements in the mold maintenance database.

Rust is the primary threat to idle mold surfaces, particularly in humid manufacturing environments common in Southeast Asia, Africa, and coastal regions. After cleaning and drying, apply a VCI (Vapor Corrosion Inhibitor) spray to all exposed steel surfaces including cavities, cores, parting lines, ejector pins, and guide components. VCI compounds provide protection for 6-12 months in sealed packaging by releasing corrosion-inhibiting vapors that form a molecular barrier on metal surfaces. For long-term storage exceeding 3 months, apply a rust-preventive oil coating (such as Castrol Rustilo DWX 30 or equivalent) over the VCI treatment. Avoid using general-purpose WD-40 or machine oil, as these products leave residues that contaminate food-grade mold cavities and require extensive cleaning before production restart. For molds with polished mirror finishes (SPI A-1 to A-3 grade), use only non-staining preservation products specifically rated for optical-quality surfaces. Wrap preserved molds in VCI film or paper before placing in storage. Insert desiccant packets (100-200 grams of silica gel per mold half) inside the wrapping to absorb moisture. Seal all water connection ports with threaded plastic plugs to prevent moisture entry into cooling channels.

Before mounting a stored mold onto the HWAMDA SPV5 machine, perform a systematic preparation sequence. Remove all preservation compounds by wiping with a clean cloth dampened with a food-grade degreaser. Inspect all surfaces for any rust formation that may have occurred during storage—treat minor surface rust with a non-abrasive rust remover and re-polish affected areas. Verify all ejector pins move freely by manually pushing each pin through its full stroke. Reconnect cooling lines and pressure test at 0.6 MPa before mounting to the machine. Install the mold on the SPV5 platen using the T-slot clamps and torque all mounting bolts to specification. Connect the hot runner cables and verify all zone temperatures reach setpoint within the manufacturer's specified tolerance of plus or minus 2°C. Run 10 slow clamp cycles at low pressure (5kN mold protection setting) to verify proper alignment and no mechanical interference. Gradually increase to full clamping force (2,700-6,000kN depending on model) over 5 cycles. Inject 20-30 short shots at reduced speed (50% of production speed) while checking for leaks and mechanical issues. Ramp to full production speed and run 50-100 setup shots before beginning quality-verified production.