Key Points to Note During Production on Rock Wool Sandwich Panel Production Line
1. Raw Material Receiving & Feeding Control (Root Cause of Defect Prevention)
(1) Color Steel Coil (Surface Layer)
Verify substrate thickness, galvanized/aluzinc coating weight and coating type (PE/HDP/PVDF). Ensure surfaces are free of scratches, missing coating, rust spots and bulges.
Secure steel coils before uncoiling to avoid rolling. Install deviation correction devices to prevent plate deviation and edge wrinkling.
Keep the inner surface of steel plates clean; oil and dust will directly cause delamination. Add dust wiping stations if necessary.
(2) Rock Wool Core (Key Material)
Adopt basalt rock wool with acidity coefficient ≥1.8. The national standard density is ≥100kg/m³ (commonly 120–150kg/m³). Too low density leads to poor fire resistance and compression resistance; excessive density raises costs and causes compaction difficulty.
Rock wool shall be dry without caking due to moisture. Damp wool prevents adhesive curing and results in later delamination.
Loosen rock wool evenly before laying to eliminate cavities, delamination and uneven thickness. The cotton spreading machine shall run at constant speed with density deviation controlled within ±3%.
Forbid rock wool containing asbestos or excessive impurities; fiber dust pollutes workshops and harms operators.
(3) Adhesive (Mainly Two-component PU Adhesive)
Mix strictly according to proportion. Deviation of curing agent ratio causes uncured adhesive or brittle delamination.
Match adhesive temperature with ambient temperature and humidity; low temperature reduces fluidity and causes uneven coating.
Clean glue barrels and pipelines regularly to avoid blockage from solidified glue, preventing missing or broken coating.
2. Glue Coating Process (Determines Bond Strength, Top Cause of Delamination)
Control coating volume precisely: insufficient glue weakens bonding; excessive glue contaminates plates and increases costs. Coating thickness fluctuation ≤±5μm.
Coat upper and lower steel plates uniformly; insufficient glue at side tenons leads to water leakage and exposed rock wool fibers.
Maintain stable pressure of spraying/roller coating equipment without glue dripping, breakage or pipeline leakage.
Shorten the interval after coating to avoid premature pre-curing before lamination.
3. Rock Wool Laying & Centering Positioning
Align rock wool width with steel plates accurately to avoid offset, which causes cotton shortage on one side and overflow on the other.
Ensure continuous rock wool without gaps; gaps create thermal bridges and reduce sound & fire insulation performance.
For thick panels with multi-layer rock wool, stagger fiber directions to improve overall compression resistance.
Stabilize air volume of negative-pressure cotton-laying fans to stop rock wool displacement or lifting by conveyor belts.
4. Hot Press Lamination & Curing (Core Process of Production Line)
Temperature control: double-belt hot press section at 180–220℃ with temperature accuracy ±1.5℃. Low temperature fails glue curing and causes delamination; overheat yellows steel coating and embrittles rock wool.
Pressure control: adjust belt pressure based on panel thickness. Insufficient pressure leads to weak bonding; excessive pressure creates indentations and crushes rock wool.
Match running speed with temperature and glue curing time. Excessively fast speed leaves uncured glue; slow speed overheats and discolors steel surfaces.
Keep belt plates clean without accumulated glue or debris to avoid pits and scratches on panels.
Conduct peeling tests per shift; national standard bonding strength ≥0.08MPa, high-quality panels ≥0.15MPa.
5. Fixed-length Cutting, Edge Trimming & Edge Sealing
Keep cutting blades sharp with synchronous conveying. Cut surfaces shall be flat without burrs or slants; length tolerance ≤±2mm, thickness tolerance ±0.5mm.
Seal side edges with polyurethane immediately after cutting to fully cover rock wool fibers for fireproof, waterproof and dust-proof purposes. Complete sealing is mandatory for cleanroom panels.
Equip cutting stations with dust collectors to prevent fiber contamination on finished panels.
Calibrate tenon forming rollers regularly to guarantee tight splicing and avoid later water & heat leakage.
6. Panel Curing & Finished Product Stacking
Newly produced panels require curing for over 24 hours at constant temperature (20±2℃, humidity ≤65%) before heavy stacking, as adhesive is not fully cured.
Store finished goods in dry and rain-proof areas with wooden sleepers at the bottom to prevent scratches and dampness.
Control stacking height to avoid deformation of lower panels under heavy load; cover plates with protective films to prevent collision scratches.
7. Daily Equipment Maintenance (Reduce Shutdowns & Defects)
Lubricate transmission rollers, chains and belts regularly to eliminate jamming and deviation; calibrate deviation correction and speed measuring sensors daily.
Inspect heating tubes and temperature controllers of hot press furnaces daily; stop production immediately for abnormal temperature.
Clean glue pumps and pipelines per shift to prevent blockage by solidified adhesive.
Clear rock wool dust and accumulated glue from cutting saws and forming rollers timely.
Stabilize pressure of hydraulic and pneumatic systems without oil or air leakage; keep safety limit switches and emergency stop devices functional.
Conduct no-load trial run before each shift to check abnormal noise, plate deviation, glue leakage and temperature faults.
8. Safety Operation Precautions (Risks: Rock Wool Dust, High Temperature & Machinery)
Personal protective equipment: dust masks, goggles, heat-resistant gloves and protective suits to avoid skin and respiratory irritation from rock wool fibers.
Install workshop ventilation and central dust removal systems; fully enclose dust collection at cotton-laying and cutting stations, and clean dust removal equipment regularly.
No direct contact with high-temperature hot press area by bare hands; install safety guards on transmission rollers and cutting zones.
Adhesives are flammable chemicals; open flames are strictly forbidden in workshops, with complete fire extinguishers and explosion-proof ventilation.
Certified operators for steel coil hoisting; no personnel standing under hoisting areas to prevent extrusion injuries from falling coils.
Cut off power and hang warning tags during equipment maintenance; never operate with faulty machines.
9. Environmental Compliance Requirements
Collect 100% rock wool dust to meet emission standards and eliminate fugitive diffusion.
Collect and treat VOC waste gas from adhesives centrally to comply with industrial waste gas discharge standards.
Classify and recycle waste rock wool, waste adhesive and steel scrap; prohibit random dumping.
Collect workshop wastewater and glue barrel cleaning liquid separately without direct discharge.
10. On-line Finished Product Inspection (Mandatory per Shift)
Appearance: no scratches, bulges, glue overflow, color difference or indentations; complete edge sealing without exposed rock wool.
Dimension: tolerance of length, width, thickness and tenon width.
Bonding: peeling test without large-area separation between steel plate and rock wool.
Core material: no cavities, delamination or damp caking inside rock wool.
Sampling inspection: density, water repellency, thermal conductivity and fire resistance; retain all test records.
Common Production Defects & Solutions
Delamination between steel plate and rock wool: oil contamination on steel surfaces, incorrect adhesive ratio, mismatched hot press temperature/speed or insufficient coating volume.
Yellow discoloration of steel coating: excessive hot press temperature or friction from accumulated glue on belts.
Uneven panel thickness and cotton shortage: deviation of cotton spreading machine, unstable rock wool density or failed centering device.
Exposed fibers and water leakage at side edges: missing edge sealing, insufficient sealing glue or defective tenon forming.
Mass dust and scratches on panels: failed dust removal, debris on rollers/belts or missing protective films on finished products.
Key Points to Note During Production on Rock Wool Sandwich Panel Production Line
1. Raw Material Receiving & Feeding Control (Root Cause of Defect Prevention)
(1) Color Steel Coil (Surface Layer)
Verify substrate thickness, galvanized/aluzinc coating weight and coating type (PE/HDP/PVDF). Ensure surfaces are free of scratches, missing coating, rust spots and bulges.
Secure steel coils before uncoiling to avoid rolling. Install deviation correction devices to prevent plate deviation and edge wrinkling.
Keep the inner surface of steel plates clean; oil and dust will directly cause delamination. Add dust wiping stations if necessary.
(2) Rock Wool Core (Key Material)
Adopt basalt rock wool with acidity coefficient ≥1.8. The national standard density is ≥100kg/m³ (commonly 120–150kg/m³). Too low density leads to poor fire resistance and compression resistance; excessive density raises costs and causes compaction difficulty.
Rock wool shall be dry without caking due to moisture. Damp wool prevents adhesive curing and results in later delamination.
Loosen rock wool evenly before laying to eliminate cavities, delamination and uneven thickness. The cotton spreading machine shall run at constant speed with density deviation controlled within ±3%.
Forbid rock wool containing asbestos or excessive impurities; fiber dust pollutes workshops and harms operators.
(3) Adhesive (Mainly Two-component PU Adhesive)
Mix strictly according to proportion. Deviation of curing agent ratio causes uncured adhesive or brittle delamination.
Match adhesive temperature with ambient temperature and humidity; low temperature reduces fluidity and causes uneven coating.
Clean glue barrels and pipelines regularly to avoid blockage from solidified glue, preventing missing or broken coating.
2. Glue Coating Process (Determines Bond Strength, Top Cause of Delamination)
Control coating volume precisely: insufficient glue weakens bonding; excessive glue contaminates plates and increases costs. Coating thickness fluctuation ≤±5μm.
Coat upper and lower steel plates uniformly; insufficient glue at side tenons leads to water leakage and exposed rock wool fibers.
Maintain stable pressure of spraying/roller coating equipment without glue dripping, breakage or pipeline leakage.
Shorten the interval after coating to avoid premature pre-curing before lamination.
3. Rock Wool Laying & Centering Positioning
Align rock wool width with steel plates accurately to avoid offset, which causes cotton shortage on one side and overflow on the other.
Ensure continuous rock wool without gaps; gaps create thermal bridges and reduce sound & fire insulation performance.
For thick panels with multi-layer rock wool, stagger fiber directions to improve overall compression resistance.
Stabilize air volume of negative-pressure cotton-laying fans to stop rock wool displacement or lifting by conveyor belts.
4. Hot Press Lamination & Curing (Core Process of Production Line)
Temperature control: double-belt hot press section at 180–220℃ with temperature accuracy ±1.5℃. Low temperature fails glue curing and causes delamination; overheat yellows steel coating and embrittles rock wool.
Pressure control: adjust belt pressure based on panel thickness. Insufficient pressure leads to weak bonding; excessive pressure creates indentations and crushes rock wool.
Match running speed with temperature and glue curing time. Excessively fast speed leaves uncured glue; slow speed overheats and discolors steel surfaces.
Keep belt plates clean without accumulated glue or debris to avoid pits and scratches on panels.
Conduct peeling tests per shift; national standard bonding strength ≥0.08MPa, high-quality panels ≥0.15MPa.
5. Fixed-length Cutting, Edge Trimming & Edge Sealing
Keep cutting blades sharp with synchronous conveying. Cut surfaces shall be flat without burrs or slants; length tolerance ≤±2mm, thickness tolerance ±0.5mm.
Seal side edges with polyurethane immediately after cutting to fully cover rock wool fibers for fireproof, waterproof and dust-proof purposes. Complete sealing is mandatory for cleanroom panels.
Equip cutting stations with dust collectors to prevent fiber contamination on finished panels.
Calibrate tenon forming rollers regularly to guarantee tight splicing and avoid later water & heat leakage.
6. Panel Curing & Finished Product Stacking
Newly produced panels require curing for over 24 hours at constant temperature (20±2℃, humidity ≤65%) before heavy stacking, as adhesive is not fully cured.
Store finished goods in dry and rain-proof areas with wooden sleepers at the bottom to prevent scratches and dampness.
Control stacking height to avoid deformation of lower panels under heavy load; cover plates with protective films to prevent collision scratches.
7. Daily Equipment Maintenance (Reduce Shutdowns & Defects)
Lubricate transmission rollers, chains and belts regularly to eliminate jamming and deviation; calibrate deviation correction and speed measuring sensors daily.
Inspect heating tubes and temperature controllers of hot press furnaces daily; stop production immediately for abnormal temperature.
Clean glue pumps and pipelines per shift to prevent blockage by solidified adhesive.
Clear rock wool dust and accumulated glue from cutting saws and forming rollers timely.
Stabilize pressure of hydraulic and pneumatic systems without oil or air leakage; keep safety limit switches and emergency stop devices functional.
Conduct no-load trial run before each shift to check abnormal noise, plate deviation, glue leakage and temperature faults.
8. Safety Operation Precautions (Risks: Rock Wool Dust, High Temperature & Machinery)
Personal protective equipment: dust masks, goggles, heat-resistant gloves and protective suits to avoid skin and respiratory irritation from rock wool fibers.
Install workshop ventilation and central dust removal systems; fully enclose dust collection at cotton-laying and cutting stations, and clean dust removal equipment regularly.
No direct contact with high-temperature hot press area by bare hands; install safety guards on transmission rollers and cutting zones.
Adhesives are flammable chemicals; open flames are strictly forbidden in workshops, with complete fire extinguishers and explosion-proof ventilation.
Certified operators for steel coil hoisting; no personnel standing under hoisting areas to prevent extrusion injuries from falling coils.
Cut off power and hang warning tags during equipment maintenance; never operate with faulty machines.
9. Environmental Compliance Requirements
Collect 100% rock wool dust to meet emission standards and eliminate fugitive diffusion.
Collect and treat VOC waste gas from adhesives centrally to comply with industrial waste gas discharge standards.
Classify and recycle waste rock wool, waste adhesive and steel scrap; prohibit random dumping.
Collect workshop wastewater and glue barrel cleaning liquid separately without direct discharge.
10. On-line Finished Product Inspection (Mandatory per Shift)
Appearance: no scratches, bulges, glue overflow, color difference or indentations; complete edge sealing without exposed rock wool.
Dimension: tolerance of length, width, thickness and tenon width.
Bonding: peeling test without large-area separation between steel plate and rock wool.
Core material: no cavities, delamination or damp caking inside rock wool.
Sampling inspection: density, water repellency, thermal conductivity and fire resistance; retain all test records.
Common Production Defects & Solutions
Delamination between steel plate and rock wool: oil contamination on steel surfaces, incorrect adhesive ratio, mismatched hot press temperature/speed or insufficient coating volume.
Yellow discoloration of steel coating: excessive hot press temperature or friction from accumulated glue on belts.
Uneven panel thickness and cotton shortage: deviation of cotton spreading machine, unstable rock wool density or failed centering device.
Exposed fibers and water leakage at side edges: missing edge sealing, insufficient sealing glue or defective tenon forming.
Mass dust and scratches on panels: failed dust removal, debris on rollers/belts or missing protective films on finished products.
