Complete Production Process of PU Edge-sealed Rockwool Sandwich Panel Production Line

The core of the process is PU foaming edge sealing on side edges + lamination bonding of upper and lower layers. Different from ordinary rockwool panels, it adds exclusive PU edge sealing procedures and realizes fully automatic continuous production of panels.
The core production logic of PU edge-sealed rockwool panels is: cold roll forming of upper and lower metal face sheets + precise processing of rockwool core material + glue spraying and bonding of face sheets and core material + high-pressure PU foaming, sealing and curing of side edges. It not only retains the fire resistance and thermal insulation of rockwool panels, but also solves the problems of easy water absorption and low strength of rockwool panel side edges through PU edge sealing. The whole process is carried out in five stages: face sheet preprocessing → core material processing → PU edge sealing + composite forming → curing and cutting → finished product packaging. The specific procedures and operation details are as follows:
Stage 1: Uncoiling and Preprocessing of Metal Face Sheets
(Ensure the flatness of face sheets and adapt to subsequent forming and bonding)
1.Steel coil uncoiling: Put color-coated steel coils/galvanized steel coils/stainless steel coils into a full-automatic decoiler, and release the metal face sheets stably with tension control to avoid wrinkling and deformation of the face sheets.
2.Face sheet leveling and edge trimming: The uncoiled face sheets enter a leveler, and the warpage and unevenness of the sheet surface are corrected through multiple sets of rolling rolls. Then the rough edges on both sides of the face sheets are precisely cut by an edge trimmer to ensure the consistent width of the face sheets and adapt to the occlusal size of the subsequent production line.
3.Sheet surface dust removal: The face sheets pass through a dust remover (brush + high-pressure air) to remove surface dust and oil stains, so as to avoid poor glue adhesion after glue spraying and affect the bonding strength.
Stage 2: Precise Processing of Rockwool Core Material
(Adapt to the size of face sheets and prepare for bonding and edge sealing)
1.Rockwool slitting: Put the whole rockwool board into a rockwool slitting machine, and slit it into rockwool strips of equal width and thickness according to the panel thickness/width required by the order, with the error controlled within ±1mm.
2.Rockwool edge milling and turning: The slit rockwool strips enter an edge milling machine to mill the edges on both sides to form a bevel matching with PU edge sealing and metal face sheets; then the rockwool turner turns the rockwool strips to a vertical fiber arrangement (vertical fiber rockwool has higher bending and compressive strength and better sound insulation effect than horizontal fiber rockwool).
3.Core material conveying and positioning: The processed rockwool strips are accurately conveyed to the composite station by a special conveyor roller table and aligned with the upper and lower metal face sheets to avoid eccentric core and gaps in subsequent bonding.
Stage 3: PU Edge Sealing + Core and Sheet Composite Forming
(Core procedure of the production line, the key step different from ordinary rockwool panels)
This stage is a continuous and synchronous operation. Glue spraying, PU edge sealing and lamination bonding are completed at the same station, which is the core to ensure the sealing performance and structural strength of the panels:
1.Glue spraying on upper and lower face sheets: The upper and lower metal face sheets, which have undergone preprocessing and cold roll forming (pressed into interlock/corrugated type by rolling rolls), are evenly sprayed with polyurethane (PU) adhesive at the designated positions on the inner side by an automatic glue sprayer. The glue spraying amount is precisely controlled according to the rockwool density and panel application, without glue missing and accumulation.
2.Glue spraying on rockwool core material: The upper and lower surfaces of the rockwool strips are sprayed with PU adhesive synchronously to form corresponding bonding surfaces with the glue on the face sheets.
3.High-pressure PU foaming edge sealing on side edges: This is the exclusive core procedure of PU edge sealing — at the moment when the upper and lower face sheets are jointed with the rockwool strips, the PU edge sealing forming machines on both sides of the production line inject PU foaming material (polyether polyol + isocyanate) into the gaps on both sides of the panel through high-pressure nozzles. The PU material foams rapidly at room temperature, fills the gaps on the rockwool side edges instantly, and forms a dense PU sealing edge.
4.High-pressure composite lamination: After the PU edge sealing material is injected, the panel enters a composite laminating machine, and the upper and lower face sheets + rockwool core material are continuously laminated through multiple sets of high-pressure rolling rolls to make the face sheets and core material bond tightly. At the same time, the side PU foaming material is firmly combined with the metal face sheets and rockwool core material under pressure to form an integrated sealing edge without looseness and gaps.
Stage 4: Heating Curing + Fixed-length Cutting
(Ensure the full curing of glue and PU edge sealing and the stability of the panels)
1.Continuous heating curing: The bonded panels enter a constant temperature curing oven (the oven temperature is 60-90℃, and the conveying speed is adjustable). After 1-3 minutes of continuous heating, the PU adhesive between the face sheets and rockwool is fully cured, and the side PU edge sealing material is completely foamed and shaped to ensure the bonding strength and edge sealing tightness. After curing, the panels have no degumming and edge sealing cracking.
2.Precise fixed-length cutting: The whole cured panel is precisely cut to the length required by the customer's order (such as 3m, 6m, customized length) by a CNC fixed-length cutting machine (laser/saw blade cutting), with a flat cutting surface, no burrs and edge chipping, and no falling off of the side PU edge sealing.
3.Finished product edge trimming: The cut panels are slightly trimmed at the edges by a trimming machine to ensure the dimensional accuracy of the panels (length ±2mm, width ±1mm).
Stage 5: Automatic Stacking + Film Laminating and Packaging
(Finished product protection, convenient for warehousing and transportation)
1.Automatic stacking: The trimmed finished panels are neatly stacked according to the set number of layers (such as 50 pieces per stack) by a full-automatic stacker to avoid panel deformation and edge sealing damage caused by manual stacking.
2.Film laminating and packaging: The whole stack of panels is wrapped with waterproof plastic film by a film laminating machine, and the edges are fixed with packing belts to prevent moisture and collision during transportation and warehousing, and protect the sheet surface coating and side PU edge sealing.
3.Finished product warehousing: After packaging, the panels are transferred to the finished product warehouse by forklift, stacked by specification and order, and waiting for delivery.