Color Steel Polyurethane Sandwich Panel Production Line

The color steel polyurethane sandwich panel production line is the core equipment in modern industrial construction production. It combines color coated steel plates with polyurethane insulation materials through automated processes to produce building enclosure materials that combine structural strength and thermal insulation performance. This type of production line is widely used in industrial plants, cold chain logistics, clean workshops and other fields, meeting the urgent demand for high-efficiency and energy-saving materials in modern buildings.

sandwich panel line

The color steel polyurethane sandwich panel production line is a highly integrated industrial manufacturing system, consisting of multiple functional modules working together to achieve full process automation from raw materials to finished products. According to the production process flow, the entire line can be divided into five core parts: pre-treatment system, molding processing system, foaming composite system, post-treatment system, and intelligent control system, each of which contains several key equipment units.

The pre-processing system is the starting section of the production line, mainly responsible for the preparation and pretreatment of raw materials. The hydraulic uncoiler is the core equipment of this system, equipped with an automatic correction device and tension control system, capable of smoothly unfolding steel coils weighing 5-10 tons, ensuring that the plates are not wrinkled or scratched during transportation. Modern uncoiler adopts a dual station design, supporting automatic roll changing without stopping the machine, greatly improving production efficiency. The cleaning device uses a combination of high-pressure airflow and chemical degreasing to remove oil and impurities from the surface of the steel plate, providing a clean base for subsequent composite processes. Some high-end production lines are also equipped with plasma treatment equipment, which significantly improves the bonding strength between polyurethane and steel plates by changing the surface energy of the steel plates.

The forming processing system is responsible for the key task of processing flat color steel plates into the desired cross-sectional shape. The system consists of multiple sets of precision rolling rolls arranged in series. Through progressive deformation technology, the flat plate is processed into complex cross-sections such as trapezoidal ribs and hidden interlocking edges. Modern molding units adopt double-sided synchronous technology, with a molding speed of up to 15 meters per minute and dimensional accuracy controlled within ± 0.2mm. Modular design makes mold replacement more convenient, with board type switching completed within 2-4 hours, allowing the same production line to produce sandwich panels with multiple cross-sectional shapes to meet the installation needs of different building parts.

The foam composite system is the technical core of the production line, which determines the insulation performance and structural strength of the final product. The high-pressure foaming machine is the key equipment of this system, which adopts six component online automatic mixing technology to transport the combined polyether, polymer MDI and various additives to the mixing head in precise proportions, and inject them into the color steel plate interlayer after thorough mixing under a pressure of 120-150 bar. The double track laminating machine provides a stable temperature and pressure environment to make polyurethane foam and solidify within the set gel time, forming a uniform closed cell foam structure. The advanced density control system can monitor and adjust the raw material ratio in real time to ensure that the density deviation of foam core material does not exceed ± 5%.

The post-processing system is responsible for cutting, cooling, and stacking packaging the composite completed boards to a fixed length. The high-precision band saw cutting machine adopts a servo drive system, with a cutting frequency of 30 times/minute, a length error of no more than ± 1mm, and a diagonal deviation controlled within ± 2mm. The automatic stacker crane uses vacuum suction cups or mechanical grippers to stack finished products in a preset mode, with a maximum stacking height of up to 2 meters. The cooling and conveying section uses forced air cooling to quickly reduce the temperature of the board to a safe range. Some high-end production lines also integrate online film coating devices to cover the surface of the board with protective film, avoiding scratches during transportation and installation.

The intelligent control system is like the brain of a production line, coordinating the running rhythm and process parameters of each section. Modern production lines commonly use industrial grade PLCs and HMI human-machine interfaces to achieve real-time collection, storage, and analysis of production data. The intelligent control system has a fault self diagnosis function, which can immediately alarm and automatically adjust when parameter abnormalities are detected, minimizing waste rate and downtime. Through industrial IoT technology, the control system can also be integrated with the enterprise MES system to achieve remote scheduling of production plans and full traceability of product quality, providing data support for lean production.

The production line of color steel polyurethane sandwich panels integrates multiple fields of technology such as materials science, mechanical engineering, and automation control, and its production process reflects the precision and efficiency of modern industrial manufacturing. The complete production process can be divided into five key stages, and the process control of each stage directly affects the performance indicators of the final product.

The pre-treatment and forming stage of steel plates begins with the unwinding and cleaning of color steel plates. The rolled color steel plate (commonly with a thickness of 0.4-0.8mm) is smoothly unfolded by a hydraulic unwinding machine, and the photoelectric correction system ensures that the plate travels along the centerline with a deviation of no more than ± 1mm. The cleaned steel plate is heated to 50-70 ℃ in a preheating furnace, which significantly improves the wettability of polyurethane raw materials on the steel plate and avoids interface defects between the foam and the substrate. The preheated steel plate enters the forming unit and is processed into the target cross-sectional shape through multiple progressive deformations. During the forming process, the roller pressure needs to be precisely controlled. If it is too high, it will cause damage to the coating, while if it is too low, the shape will not be fully formed. Modern molding technology optimizes roller profiles through computer-aided design, increasing molding speed to 12-15m/min while ensuring shape accuracy.

The preparation and pouring stage of polyurethane raw materials adopts high-pressure six component mixing technology. The combined polyether and polymeric MDI are respectively transported to the mixing head through precision metering pumps (flow accuracy ± 1%), while auxiliary materials such as catalysts, foaming agents, and flame retardants are added. Under a high-pressure environment of 120-150 bar, the raw materials collide and mix violently in the mixing head, forming a uniform mixture. The mixing head evenly distributes the raw materials on the moving lower steel plate through a reciprocating pouring rod, and the pouring amount is automatically adjusted according to the plate thickness, usually 1.5-3.5 kg/m ². The key to this stage is to control the temperature of the raw materials and the mixing ratio. Temperature fluctuations should be controlled within ± 2 ℃, and the ratio error should not exceed ± 1%, otherwise it will seriously affect the foaming quality and product performance.

The composite foaming stage is completed in a double track laminating machine. The upper steel plate and the lower steel plate after injection enter the laminating machine synchronously. Under the set temperature and pressure environment, the polyurethane raw material begins to foam and fill the cavity between the two layers of steel plates. The foaming process involves complex physical and chemical reactions: on the one hand, the foaming agent vaporizes to form a fine pore structure; On the other hand, isocyanates undergo polymerization reactions with polyols to form a polymer network. The advanced temperature control system maintains the track temperature at 60-80 ℃, ensuring the formation of a uniform and fine closed cell structure, with a thermal conductivity coefficient as low as 0.022-0.024W/(m · K). The laminating pressure is usually controlled at 1.5-2.5 kg/cm ². Insufficient pressure can lead to uneven density, while excessive pressure may cause deformation of the color steel plate.

The curing and maturation stage is crucial for the final performance of the product. After leaving the laminating machine, the board enters the 20-30 meter curing zone, where polyurethane completes the final cross-linking and curing process, achieving the designed mechanical properties. The curing temperature and time need to be precisely controlled according to the raw material system, usually maintained at 40-60 ℃ for 10-15 minutes. Insufficient ripening will lead to low strength and dimensional instability of the board, while excessive ripening may cause foam embrittlement. Modern production lines are equipped with infrared thermometers and hardness testing devices to monitor the degree of curing in real time, ensuring consistency in product quality.

The final processing of the product is completed during the fixed length cutting and packaging stage. The high-precision band saw cutting machine cuts the sheet according to the set length, and the cutting system is equipped with an automatic dust removal device to maintain a clean working environment. The cut sheet is cooled to below 40 ℃ through a cooling section, and then stacked in a predetermined mode by an automatic stacker crane to prepare for leaving the factory.

Energy saving and environmental protection technologies have been widely applied in modern production lines. The heat recovery device can use the heat generated by the foaming reaction for preheating the board, reducing energy consumption by 15-20%; Closed raw material conveying system reduces volatile emissions; Activated carbon adsorption device is used to treat production waste gas and ensure compliance with VOCs emissions standards. These technologies not only reduce production costs, but also make the production process more environmentally friendly, in line with the development trend of green manufacturing.

The continuous polyurethane sandwich panel production line represents the highest level in the industry, adopting an assembly line operation mode to achieve full process automation production from unwinding to palletizing. This type of production line is usually over 50 meters long and includes core equipment such as double track laminating machines and high-pressure foaming machines. The production speed can reach 3-8 meters per minute and the daily production capacity is about 200-300 cubic meters. The advantage of continuous production lies in good product consistency and high efficiency, suitable for the production of large quantities of single specification products, such as standard specification industrial plant boards. Typical technical parameters include: working width 1000-1200mm, plate thickness 30-200mm, foam density 35-45kg/m ³, thermal conductivity ≤ 0.024W/(m · K).

The fully automatic polyurethane sandwich panel production line integrates fully automated equipment for unwinding, forming, foaming, cutting, stacking, and other processes, requiring only 2-3 people to complete the entire production process. This type of production line is equipped with advanced PLC control system to achieve automatic adjustment of process parameters and fault diagnosis. The production speed can reach 15-20 meters/minute, and the product size accuracy can be as high as ± 0.5mm. The advantages of fully automatic lines are low labor costs and stable quality, but the initial investment is large, and the investment payback period usually takes 3-5 years.