The cold room sandwich panel line is a specialized equipment system for manufacturing high-performance insulation panels. Through automated assembly line operations, the surface materials (such as color steel plates, aluminum foils, etc.) are composite formed with core materials (polyurethane, rock wool, etc.). This cold room sandwich panel machine represents the advanced level of today's building materials and equipment manufacturing industry, integrating technologies from multiple fields such as mechanical engineering, materials science, and automation control.
The coldroom sandwich panel machine usually consists of multiple functional modules: metal plate roll forming system, polyurethane high-pressure foaming system, double track laminating machine, cutting sawing machine, automatic palletizing device, and central control system. The entire coldroom sandwich panel line can reach a length of 60-120 meters and is controlled by PLC or industrial computer to achieve full process automation from coil unwinding to finished product stacking.
Core technology and equipment composition
High pressure foaming system
The high-pressure foaming system is the "heart" component of the polyurethane sandwich panel production line, and its technical performance directly determines product quality. Modern foaming systems use multi-component precise metering technology to achieve sufficient reaction of polyurethane raw materials through high-pressure impact mixing. Advanced equipment such as Sinowa's pentane foaming system can achieve free proportioning of 2-9 components to meet different formulation requirements.
The key parameters of the foaming system include: mixing pressure (usually 120-200 bar), flow control accuracy (within ± 1.5%), temperature control accuracy (± 1 ℃), and the degree of automation of the cleaning system. The high-quality foaming machine is also equipped with self diagnostic function and remote monitoring interface for easy maintenance and process optimization.
Double track laminating machine
The double track laminating machine is a key equipment to ensure the flatness and compactness of the sheet metal. It consists of two heavy-duty steel belts and a supporting roller system, forming an adjustable molding cavity. Modern laminating machines have the following characteristics:
Automatic adjustment system for pre tensioning force of steel strip to ensure operational stability
Partition temperature control (usually 6-12 temperature zones), precise regulation of foaming process
Hydraulic correction device to prevent steel strip deviation and damage
Online thickness detection, real-time monitoring of product quality
The length of the laminating machine is generally 20-40 meters, and the operating speed can reach 3-8 meters per minute depending on the thickness of the product. The advanced laminating machine is also equipped with a self-cleaning system and quick mold changing function to improve production efficiency.
Roll forming unit
The roll forming unit is used to process metal coils into the required surface material of the plate shape. Modern rolling equipment adopts modular design, and its main features include:
Precision rollers manufactured by CNC machining centers ensure forming accuracy
Servo motor-driven slitting device for precise edge cutting
Online surface treatment (such as embossing, coating) function
Quick mold changing system, suitable for multi variety production
The roll forming unit usually consists of 10-20 pass roll stations, and various plate types can be customized according to customer needs, such as corrugated boards, hidden buckle boards, etc.
intelligent control system
Modern coldroom sandwich panel production lines commonly use distributed control systems (DCS) to achieve automated operation of the entire line. The main functions of the control system include:
Production process parameter setting and storage (capable of storing hundreds of formulas)
Real time monitoring and fault diagnosis of equipment status
Production data recording and quality traceability
Energy consumption monitoring and optimization
Remote technical support interface
Advanced control systems also incorporate machine vision technology for surface quality inspection of products, as well as artificial intelligence algorithms to achieve adaptive optimization of process parameters.
The production of coldroom sandwich panels is a continuous precision process, and process control in each link is crucial. The following is the production process of a typical polyurethane sandwich panel:
Pre treatment of metal surface layer
Metal coils (usually color steel plates or aluminum coils) first undergo unwinding and leveling processes, and then enter the cleaning section to remove surface oil stains. Some high-end production lines are also equipped with plasma treatment or chemical conversion coating equipment to improve the bonding strength between the surface material and the core layer.Plate roll forming
The cleaned metal coil is gradually formed into the desired plate shape through a multi pass rolling machine. This process requires precise control of the forming angle, plate width, and straightness, with errors typically controlled within ± 0.5mm.Polyurethane foam infusion
The formed lower panel enters the foaming zone, and the high-pressure foaming machine evenly pours the mixed polyurethane raw materials onto the panel surface. The foaming process parameters include:
Raw material temperature: 20 ± 2 ℃
Mold temperature: 40-50 ℃
Foam density: 35-45kg/m ³ (adjusted according to insulation requirements)
Gel time: 90-150 secondsComposite lamination
The upper panel and the foaming lower panel are combined at the entrance of the laminating machine and enter the double track laminating machine. In the laminating machine, polyurethane completes the foaming and curing process, forming a strong bond with the surface layer. The temperature settings for each temperature zone of the laminating machine are usually:
Front zone: 50-55 ℃ (promotes foaming)
Central area: 60-65 ℃ (accelerated curing)
Rear area: 45-50 ℃ (stable cooling)Fixed length cutting
The fully cured continuous strip is cut to a fixed length using a flying saw or gantry saw. Modern cutting systems use servo drive, with cutting accuracy up to ± 1mm, and are equipped with dust removal devices to maintain a clean environment.Automatic palletizing
The cut boards are stacked into bundles by an automatic palletizer, usually equipped with a flipping mechanism to achieve alternating stacking of positive and negative boards, avoiding deformation. After palletizing, it is tied and covered with film before entering the finished product area.Quality control
Multiple quality inspection points are set up throughout the entire process, including:
Online thickness detection (laser thickness gauge)
Thermal conductivity sampling (heat flow meter method)
Adhesive strength test
Dimensional accuracy check
Surface quality inspection
The modern coldroom sandwich panel production line can produce various types of products to meet the needs of different application scenarios:
Polyurethane sandwich panel (PU board)
Structure: Double sided color steel/stainless steel/aluminum plate+polyurethane core material
Thickness: 50-200mm
Thermal conductivity: 0.018-0.022W/(m · K)
Fire rating: B1 level (flame retardant) or A2 level (special formula)
Applicable temperature range: -50 ℃ to+100 ℃
Rock wool edge sealed sandwich panel
Structure: Double sided metal plate+rock wool core material+polyurethane edge sealing
Thickness: 75-150mm
Thermal conductivity: 0.036-0.042W/(m · K)
Fire rating: Class A non combustible
Features: Excellent fire resistance, suitable for areas with high fire protection requirements
Phenolic sandwich panel (PF panel)
Structure: double-sided color steel/non-woven fabric/aluminum foil+phenolic foam
Thickness: 18-50mm
Thermal conductivity: 0.018-0.023W/(m · K)
Fire rating: A1 level (non combustible)
Features: High temperature resistance, low smoke, non-toxic, suitable for special coldroom such as pharmaceuticals
Main application areas
Food cold chain: refrigerated warehouses for meat, seafood, dairy products, etc., frozen tunnels
Medical storage: Constant temperature warehouses for drugs, vaccines, etc., GMP clean coldroom
Chemical storage: Low temperature storage of special raw materials, explosion-proof coldroom
Logistics Center: Regional Cold Chain Distribution Center, Automated Stereoscopic Cold Storage
Catering chain: central kitchen coldroom, chain supermarket refrigerated area
