This process is divided into two categories: roll pre-lamination (large-scale factory production) and sheet precision lamination (custom/small-batch production). Large-scale factory production is the industry mainstream. The following is the core standardized process flow (including process parameters and key points), along with core process requirements and key environmental control measures:
I. Core Pre-Preparation (Key Processes Before Lamination) Pre-treatment of the substrate and membrane material before lamination is crucial to avoiding poor lamination and directly affects the final bonding effect, requiring strict control:
Substrate Treatment: The surface of the flooring substrate (SPC/LVT/WPC, etc.) is sanded to a roughness of Ra 3.0~5.0μm to remove dust, oil, and burrs. The moisture content of the substrate is controlled at 2~6% (especially important for solid wood/wood-plastic composite substrates). SPC/LVT stone-plastic composite substrates must be ensured to be dry and free of condensation. They should be placed in a constant temperature workshop at 23±2℃ for 4~6 hours to achieve temperature and humidity synchronization with the membrane material.
Membrane Material Treatment: After unwinding the environmentally friendly PVC flooring film (with hot melt adhesive layer), allow it to stand in a workshop with the same temperature and humidity for 2-4 hours to release the winding stress and prevent shrinkage and warping after lamination. Check the hot melt adhesive layer for damage, dust, and missed areas, ensuring uniform adhesive thickness (typically 0.05-0.15mm).
Equipment Preheating: Start the hot press laminating equipment (roller/flat press), preheat the hot press rollers/plates to the process value, and simultaneously adjust the material feeding speed and pressing force. Run the machine idle for 3-5 minutes to ensure no jamming and no temperature fluctuations.
II. Large-Scale Factory Production (Roll-to-Roll Hot Press Lamination, Mainstream Process) Suitable for mass production of SPC/LVT/WPC flooring. Utilizing a continuous hot roll lamination machine, this fully automated, high-efficiency process achieves high lamination precision. The specific process is as follows:
Unrolling and Positioning: The environmentally friendly PVC flooring film (hot melt adhesive layer down) and the flooring substrate are placed on the unrolling rack of the equipment. Precise positioning using guide rollers ensures that the film and substrate are aligned horizontally with a deviation of ≤0.5mm, preventing misalignment and missed areas.
Preheating and Activation:The film and substrate simultaneously enter the preheating zone (temperature 60~80℃). The hot melt adhesive layer of the film is preheated at a low temperature, initially softening (but not melting) the adhesive layer. Simultaneously, the surface temperature of the substrate is increased to prevent uneven curing of the adhesive layer due to temperature differences during subsequent hot pressing.
Hot-pressing and Melting Bonding: After preheating, the membrane and substrate enter the main hot-pressing zone. Core parameters are adjusted according to the substrate material (environmentally friendly hot melt adhesives are mostly EVA/PUR type, suitable for PVC flooring films). Industry standard core parameters are as follows:
Substrate Type | Hot-pressing Temperature | Hot-pressing Pressure | Feeding Speed | Adhesive Layer Melting Thickness
SPC (Stone Plastic Composite) Substrate | 100~120℃ | 8~12MPa | 15~25m/min | 0.03~0.08mm
LVT (Elastic Substrate) Substrate | 90~110℃ | 6~10MPa | 15~20m/min | 0.03~0.07mm
WPC (Wood Plastic Composite) Substrate | 85~100℃ | 7~9MPa | 10~15m/min | 0.02~0.06mm
At this stage, the hot melt adhesive layer completely melts, penetrating to the tiny pores on the substrate surface, forming mechanical interlocking + molecular bonding, achieving a strong bond between the membrane and the substrate. Cooling and Curing: The hot-pressed composite board immediately enters the cooling zone, employing a dual-effect cooling system of air and water cooling (air cooling temperature 25±3℃, water cooling roller temperature 18~22℃) to rapidly cool the molten hot melt adhesive to room temperature, completing curing and shaping. The curing time is approximately 1~3 minutes; after cooling, the composite board surface is free of indentations and bubbles.
Edge Trimming and Slitting: The cooled and shaped roll composite board is precisely slit according to flooring specifications (e.g., 1220×180mm, 600×600mm) using a slitting machine. Excess film material is trimmed from the edges to ensure neat edges and that the film layer is flush with the substrate without any warping.
Post-processing and Inspection: The slit flooring is placed in a constant-temperature workshop for 24~48 hours to release hot-press stress. Adhesion, warpage, and edge adhesion are then tested. After passing these tests, the flooring is packaged and stored.
III. Custom/Small Batch Production (Sheet Flat Press Lamination, Auxiliary Processes) Suitable for customized parquet flooring and small batches of engineered wood flooring. Utilizing a flatbed hot press, the lamination pressure is more uniform. Specific process:
Substrate/Film Pretreatment (same as before) → Cut environmentally friendly PVC film to the flooring size (leaving a 2-3mm trimming allowance), place it with the hot melt adhesive layer facing down on the substrate surface, manually positioning it to ensure no misalignment;
Place it in the flatbed hot press, set the parameters (temperature 85-110℃, pressure 7-10MPa, holding time 15-30s/sheet, adjusted according to substrate thickness);
After pressure holding, remove it and immediately air-cool it to room temperature. After trimming, allow it to mature for 12-24 hours. Once inspected and approved, it is ready.
IV. Key Process Control Points (To Avoid Poor Bonding)
Temperature Control: The hot-pressing temperature should not be too high (easily causing PVC film heat shrinkage, hot melt adhesive carbonization, and film yellowing), nor too low (incomplete adhesive melting, insufficient adhesion, and easy delamination); the temperature of the hot press rollers/board must be monitored in real time, with a deviation ≤ ±2℃.
Uniform Pressure: The pressing force must be uniform throughout the process. Insufficient local pressure can easily generate bubbles and weak adhesion, while excessive pressure can easily cause substrate deformation (especially WPC/solid wood substrates) and thinning of the film.
Bubble-Free Treatment: Before bonding, ensure that the substrate/film surface is free of dust and air. Use a vacuum hot press (high-end production lines) during hot pressing to completely remove interlayer air and avoid bubble formation; conventional production lines can use guide rollers to flatten the film and reduce air introduction.
Adhesive Layer Protection: The environmentally friendly hot melt adhesive layer should not be exposed to oil, high temperatures, or direct sunlight. The film must be sealed during storage. Do not touch the adhesive layer directly with your hands before bonding to prevent dust from affecting adhesion.
V. Environmental Requirements (Compliant with the Core Attributes of Environmentally Friendly PVC Film)
Hot Melt Adhesive Selection: Environmentally friendly EVA/PUR hot melt adhesive must be used, free of phthalates, formaldehyde, and low in VOCs, matching the environmentally friendly PVC film to prevent the release of harmful substances from the adhesive layer that could affect the finished product's environmental rating.
Production Environment: The workshop is equipped with a negative pressure dust removal and ventilation system to reduce dust pollution. No solvents are added throughout the process, meeting green production standards.
Waste Recycling: Film scraps and defective products generated during the lamination process can be collected, granulated, and reused in the production of environmentally friendly PVC film (recycling, reducing carbon emissions).
