PU Sandwich Panel Line For Cold Storage Construction With Thermal Insulation

With the rapid development of the cold chain logistics industry, the demand for efficient insulation building materials is increasing day by day. Polyurethane sandwich panels have become the preferred material for refrigerated buildings due to their excellent thermal insulation performance.

sandwich panel line

Polyurethane sandwich panels have demonstrated unparalleled technological advantages in the field of refrigerated buildings, and their core value lies in their excellent thermal insulation performance. Compared with traditional refrigerated building materials, the thermal conductivity of polyurethane sandwich panels is only 0.018-0.024W/(m · K), which is significantly lower than traditional insulation materials such as EPS (polystyrene) and rock wool. This means that under the same insulation effect, polyurethane sandwich panels can be made thinner, directly increasing the effective utilization rate of refrigerated space.

In terms of energy efficiency, refrigeration facilities using polyurethane sandwich panels can reduce energy consumption by 30% -40%. This is due to the closed cell rate of polyurethane foam is up to 90%, which effectively blocks the heat transfer caused by air convection. In practical applications, cold storage built with polyurethane sandwich panels can save thousands of yuan in electricity bills per month compared to traditional cold storage, with significant advantages in long-term operating costs.

From the perspective of structural performance, the compressive strength of polyurethane sandwich panels can reach 150-300kPa, and the bending strength exceeds 200kPa, fully meeting the load-bearing requirements of various refrigerated buildings. At the same time, its lightweight (about 12-15kg per square meter) significantly reduces the load requirements of building structures and provides more flexibility for the design of large refrigeration facilities.

It is particularly noteworthy that modern polyurethane sandwich panels use environmentally friendly foaming agents (such as cyclopentane or HFOs), with zero ozone depletion potential (ODP) and significantly reduced global warming potential (GWP), fully complying with current strict environmental regulations. This makes polyurethane sandwich panels a core component of sustainable refrigerated building solutions.

The core of the pu sandwich panel line lies in its highly automated precision equipment system and advanced production process control. The entire production line usually consists of four modules: metal panel pretreatment system, polyurethane high-pressure foaming unit, continuous laminating machine, and finishing equipment. The total length can reach 60-100 meters, achieving full process automation production from raw materials to finished products.

The high-pressure foaming system is the technical core of the production line, using advanced metering pump sets with a metering accuracy of ± 1%, ensuring that polyols and isocyanates are mixed in precise proportions (usually 1:1 to 1:1.1). Modern production lines often use more reactive MDI systems, combined with efficient catalysts, to shorten the polyurethane foaming reaction time to 3-5 seconds, greatly improving production efficiency. The temperature control system maintains a constant temperature of 22 ± 1 ℃ for the raw materials to ensure the stability of the foaming reaction.

The continuous laminating molding machine adopts the double steel belt pressing molding technology, with the pressure adjustable range of 0.05-0.3MPa, and the precise temperature control (40-60 ℃), to ensure that the polyurethane foam expands evenly between the metal panels and is fully bonded. The advanced online density monitoring system can detect the density distribution of foam in real time to ensure that the density deviation of the whole board does not exceed ± 5%. The production line speed is usually 4-8 meters per minute, and a standard production line can have an annual production capacity of 1-2 million square meters.

The production process of polyurethane sandwich panels for refrigerated buildings has been specially optimized for extreme insulation requirements. The entire production process is strictly controlled in a clean and dust-free environment to ensure high consistency in product quality.

The pre-treatment stage of the metal panel adopts a fully automatic cleaning and chemical treatment line, which achieves the best bonding state on the metal surface through processes such as degreasing, passivation, and drying. Special refrigeration plates are often made of aluminum zinc coated steel or stainless steel plates with a thickness of 0.5-0.7mm, which have better anti-corrosion performance. The pre treated panel enters the adhesive coating process, using specialized polyurethane adhesive with a precise coating amount controlled between 80-120g/m ².

The polyurethane foaming process is a key control point in the production of refrigerated panels. Compared with traditional building panels, refrigerated panels use a higher density formula (42-45kg/m ³) and require a closed cell rate of ≥ 92%. The injection of cyclopentane and other foaming agents during the foaming process increases by 15% -20%, forming a finer pore structure. The high-precision temperature control system equipped on the production line maintains the temperature in the foaming area at 30 ± 2 ℃ and the relative humidity at 50% ± 5%, ensuring the optimal conditions for foaming reaction.

Gradient cooling process is adopted in the curing and curing stages, which is gradually reduced from 60 ℃ to room temperature, so that the polyurethane foam can form a stable three-dimensional network structure. Refrigerated plates need to be fully cured for at least 48 hours before further processing to ensure dimensional stability.

With the advancement of the "carbon peak and carbon neutrality" goals, the efficient and energy-saving polyurethane sandwich panel production line will continue to upgrade and iterate, providing more environmentally friendly and intelligent building solutions for the cold chain logistics industry.