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The Sandwich panels are widely used in food processing factories due to their excellent thermal insulation, good moisture and water resistance, corrosion resistance, and excellent fire resistance.     1. Excellent thermal insulation performance. Generally, the thermal conductivity of PU/PIR sandwich panels is between 0.020 and 0.024 [W/(m·K)], providing good thermal insulation and effectively controlling indoor and outdoor temperatures to ensure food freshness.   2. Seamless splicing during assembly ensures good sealing, reducing the risk of bacteria and mold growth and enabling dust-free workshops.   3. The core material used in sandwich panels has a high closed-cell rate, is non-absorbent, and offers excellent waterproof and moisture-proof performance, ensuring food freshness.   4. The color-coated steel plates used in sandwich panels have high structural strength, strong load-bearing capacity, and good corrosion resistance.   5. Sandwich panels generally have a fire rating of B1 (PIR sandwich panels) or A (rock wool sandwich panels), offering excellent fire resistance and making them more suitable for high-temperature food processing workshops;   6. Sandwich panels are produced in modular form, requiring only on-site installation and splicing, resulting in simple construction, short construction period, less dust, and high cost-effectiveness.

Currently, common sandwich panel include EPS sandwich panel, PU/PIR sandwich panel and rock wool sandwich panel.   Generally speaking, the thicker the sandwich panel, the better the insulation effect. PU/PIR has the best thermal insulation performance, rock wool has the best fire resistance, and EPS has the highest cost performance，but no fireproof.   Due to the different properties of the core material, the application of sandwich panels with different core materials is also different, as detailed below.   Thickness EPS Sandwich Panel PU/PIR Sandwich Panel Rock wool Sandwich panel 50mm Suitable for interior wall partitions in ordinary workshops and factories where insulation requirements are not high, as well as prefabricated houses, temporary houses, temporary buildings on construction sites, and general storage. Suitable for roofs and walls of warehouses at normal temperatures, as well as steel structure exterior walls and roofs. Suitable for interior walls and partitions of ordinary factory buildings with high fire protection requirements and general insulation requirements, as well as walls of simple warehouses and temporary buildings. 75mm Suitable for industrial buildings with no strict temperature requirements, such as general warehouses, logistics warehouses, steel structure workshops, and livestock farms. Suitable for general cold storage and insulation, constant temperature workshops (such as electronics, packaging, light industry, etc.), food processing plants, beverage plants, pharmaceutical and electronics cleanrooms, etc. Suitable for general warehouses, logistics centers, office buildings, workshops, and showrooms. 100mm Suitable for walls and roofs of large factories and warehouses, stadiums, markets, and large steel structure buildings, etc. Suitable for industrial buildings, cold storage (0-5℃), food processing workshops, cold chain warehouses, etc., where high insulation and fire protection requirements are needed. Suitable for high-standard factories, cleanrooms, hospitals, schools, public buildings, etc. 150mm Suitable for buildings with high insulation requirements but limited budgets, such as ordinary factories and warehouses in cold regions. Suitable for high-end constant temperature and humidity workshops, pharmaceutical warehouses, low-temperature cold storage (-18℃), cold chain logistics centers, dairy, meat and seafood processing workshops, etc. Suitable for public buildings with strict fire protection requirements, large warehouses, long-span factories, and buildings with extremely high requirements for thermal insulation/sound insulation, such as concert halls.     In short, 50mm sandwich panels are suitable for interior walls, simple interior partitions, etc.; 75mm sandwich panels are suitable for ordinary factories and warehouses, etc.; 100mm sandwich panels are suitable for food factories and low-temperature cold storage, etc.; and 150mm sandwich panels are suitable for low-temperature cold storage and high-standard buildings, etc.

PU, PIR, and Rock Wool are currently common core materials for sandwich panels. Due to differences in density, thermal insulation performance, water absorption, fire resistance, applicable temperature, and price, their applications also differ.     A detailed comparison is as follows:   Performance Index PU Sandwich Panel PIR Sandwich Panel Rock wool Sandwich panel Thermal Conductivity W/(m·K) 0.022-0.024 0.020-0.022 0.040-0.043 Heat preservation effect High Highest Low Flame-retardant grade B2 B1 A Waterproof Better Better Normal Soundproof Good Good Best Applicable temperature -180℃~+120℃ -180℃~+150℃ -200℃~+700℃           Based on the above, we found that PIR sandwich panels offer the best thermal insulation, followed by PU sandwich panels, with rock wool sandwich panels performing the worst. However, rock wool sandwich panels have the best fire resistance and good sound absorption. Therefore, we recommend PIR sandwich panels for cold storage, PU Sandwich panels for general factories and high-temperature cold chain applications, and rock wool sandwich panels for theaters and large warehouses with high fire resistance and sound insulation requirements.

There are many types of sandwich panels, and common mistakes when choosing industrial sandwich panels include:   1. Focusing solely on price and selecting panels incompatible with the core material. EPS sandwich panels are the cheapest and generally only used in ordinary factories. PU/PIR sandwich panels are chosen for cold storage, while rock wool sandwich panels are chosen for large logistics warehouses.   2.Confusing roofing and wall panels. Wall panels cannot be used directly for roofing. Roofing requires high-strength roofing panels with corrugated peaks to withstand strong winds and rain/snow.   3.Ignoring the density of the core material. Generally, EPS density ranges from 10kg/m³ to 20kg/m³, which can be selected based on different insulation requirements; Rock wool density ranges from 80kg/m³ to 140kg/m³. It is generally not recommended to use less than 90kg/m³ for walls and less than 100kg/m³ for roofs.   4.     Ignoring the thickness requirements of the sandwich panel steel plate The thickness of the top and bottom plates of the sandwich panel can be determined according to the strength requirements of the building. Common thicknesses are 0.4mm to 0.8mm.   5.Ignoring the zinc coating thickness requirements of the sandwich panel Generally, the thicker the zinc coating, the better the corrosion resistance. Industrial buildings typically require AZ100 or AZ150.   6.Ignoring the color coating requirements of the sandwich panel steel plate PE coating can be used in ordinary environments, while PVDF coating can be used in coastal or highly corrosive environments.   7.Incorrect calculation of sandwich panel length, leading to excessive splicing It is recommended to provide CAD drawings. Our technical engineers will calculate the accurate number and length of panels to avoid errors.   8.Ignoring panel load-bearing capacity and span The panel thickness needs to be calculated based on the purlin spacing, load, and wind force of the industrial building to avoid placing orders blindly.  

Can you take down old sandwich panels and use them somewhere else? Yes, you can reuse them if they are still in good shape.   Not all panels can be reused. You need to remove them without damage. Panels with tongue-and-groove or cam locks are easier to take apart. If the installer used a lot of sealant or screws every few inches, it will be hard to remove them cleanly. If a panel is bent or the edges are crushed, you can’t use it again. The locks won’t work and you will have gaps.   The inside material matters. Polyurethane and PIR foam resist moisture but can lose insulation if wet. You can’t always see this from outside. Rockwool panels handle heat and fire better but are heavier and can soak moisture if seals fail. Check for soft spots, layers coming apart, or rust before reusing.   The steel surface shows wear. Small scratches may be okay, but if the metal shows through the coating, rust will start. In clean areas like food plants, scratches can trap bacteria. You can repaint small damaged spots if you clean and prep them well. If damage is widespread, the panel is not worth saving. Also, remove old gaskets and sealant before reinstalling. Use new sealant for a proper seal.   Where the panels came from matters. Panels from a dry warehouse may be fine. Panels from places like fish plants may have grease or chemicals baked in. Sometimes you can clean them, sometimes not. Also, check fire ratings. If your project needs a certain fire class, make sure your old panels still meet it after years of use.

You need to focus on fire safety with prefab homes. Looks and build time are less important.   Not all panels fight fire the same. The core material matters most. Rockwool is the best. It comes from volcanic stone and can handle heat over 1000°C. It won’t burn or spread fire. PIR panels are better than regular PU and often meet the B1 fire rating. EPS is cheap but burns easily. Use rockwool if fire safety matters to you.   Good materials don’t help if panels are installed badly. Fire can get in through gaps, corners, and holes for pipes or wires. You need a system that fits tight and seals well. Panels that come pre-cut reduce gaps and mistakes on site.     The steel outside matters too. It’s not just for looks. Zinc coatings like Z150 stop rust and keep fire protection working for years. Check for fire tests like ASTM E-84 or EN 13501. These prove the panels work in real fires.   Work with a supplier who knows fire safety. Propanel (propaneltech.com) sells fire-rated rockwool sandwich panels that resist heat up to 800°C. We help you pick the right panels for your project. We have 15 years of experience and treat fire safety as a must, not a bonus.

Building a cold room is not the same as building a regular shed.   Before you start, make sure the ground is flat and clean. If the floor slab is uneven, panels won‘t fit right. Even small gaps let cold air out and warm air in. Mark your wall lines clearly. Don’t rush this step. If you do, the cold room will have problems fast.   When fitting panels, focus on the joints. Most leaks happen here. Seal the gaps fully with a good cold-temperature sealant. Don’t just put small spots of sealant. Run one solid line. If your panels have cam-locks, tighten them to pull edges together. For tongue-and-groove panels, put sealant inside the groove. The joint must be very tight.   Don’t forget holes for pipes or wires. Every hole can leak air. Seal these with closed-cell foam or flexible grommets made for cold. Don’t just stuff regular foam in. Check door seals too. Magnetic gaskets must touch fully. If you see light at the door edges, air is leaking.Choose your panels carefully. Not all insulation works the same. PIR panels repel moisture and keep working in damp places. EPS panels cost less but lose insulation if wet. For freezers below -20°C, get panels made for that cold. Use a supplier who knows this. Propanel (propaneltech.com) sells PU and PIR panels and helps you pick the right ones.   After installation, inspect every joint, corner, and hole. Use smoke tests to find leaks you can’t see. Don’t stop here. Cold rooms settle, seals wear out, and parts shift. Check regularly to fix small leaks early. This saves money and keeps your cold room working well.   An airtight cold room needs three things: good prep, careful fitting, and quality panels. Skip any of these and you waste energy and product. Take your time. Do it right. Work with experts. Your cold room and your wallet will thank you.

First, decide what core material you need in your panels. EPS (expanded polystyrene) is cheap and light. Use it only in dry places where fire risk is low. Rockwool is fireproof and blocks sound well. It works for factories or places with strict fire rules. PU (polyurethane) and PIR (polyisocyanurate) are best for tight temperature control. PU keeps cold in with low thermal conductivity. PIR is like PU but better at resisting fire. Choose PU or PIR for cold rooms or cleanrooms.   Next, the steel skin matters. Check three things: thickness, zinc coating, and paint. Use steel 0.5mm to 0.6mm thick. Thinner steel dents and bends too easily. Zinc coating should be at least Z100 or Z150 to stop rust. If you are near the ocean or in humid areas, ask for zinc-aluminum-magnesium coatings—they resist rust better. For paint, polyester is okay indoors. For sun or washdowns, use PVDF or special antibacterial paint.   A good supplier will ask about your project: location, temperature needs, and how long you want it to last. They will match core thickness, steel thickness, and coating to your needs. Propanel focuses on PU and PIR panels because they work best for cold and clean rooms. They don’t just sell panels; they help you build something that lasts.   Cheapest panels cost more in the long run. Panels that fail in a few years mean more money wasted. Pick a supplier who cares about your project. Ask questions, check details, and choose a partner who supports you. That’s who you want.

For modern construction projects, to use the right building materials is very important, cause buildings require excellent thermal performance--Once the insulation cannot be guaranteed, it may greatly increase energy consumption and operational costs. The sandwich panel—it is usually composed with two metal sheets with insulated core material in between. As is known to all, the sandwich panel is the perfect building material for thermal insulation—so it gives the best insulation performance with structural strength at the same time.   First of all, There are 3 core material of sandwich panel: EPS, rock wool, and PU—each have unique advantages for specific applications. EPS panels provide cost-effective insulation for warehouses and cold storage. Rock wool panels offer superior fire resistance for industrial plants and commercial buildings. PU panels gives the highest thermal efficiency for temperature-sensitive environments. Propanel, just focus on supplying all types of sandwich panels, gives customers the best solution also professional advice at the same time.   Secondly, each core material provides different levels of insulation effectiveness and additional advantages:   Core Material Thermal Conductivity Key Advantages Best Applications EPS 0.032-0.038 W/m·K Lightweight, Cost-effective Warehouses, Distribution Centers Rock Wool 0.035-0.042 W/m·K Fire-resistant, Sound-absorbing Industrial Plants, Public Buildings PU 0.022-0.024 W/m·K High efficiency, Best thermal insulation Cold Storage, Pharmaceutical Facilities The low thermal conductivity values—especially PU's exceptional performance—directly translate to reduced heating and cooling costs, preventing energy loss through walls and roofs.   Thirdly, good installation also ensures insulation - if panels are installed incorrectly - gaps can form - which can lead to the development of cold bridges. Professional installation according to Propanel specifications is important to achieve the advertised R-value and energy savings.  

For a good cold room, using the right insulation system is very important—cause the entire refrigeration efficiency depends on how well the structure keeps cold air inside. Energy loss not only increases electricity consumption but also affects product freshness and storage stability. Insulated sandwich panels are the key solution to keep consistent temperature and reduce energy waste effectively.   The PU sandwich panel is the most common and efficient insulation material used in modern cold storage construction. It is made of two layers of pre-painted steel sheet with a polyurethane (PU) insulated core in between. PU foam has one of the lowest thermal conductivity levels among building materials, meaning it minimizes heat transfer between the inside and outside of the room. Propanel (propaneltech.com) focuses on manufacturing high-performance PU cold room panels, providing customers with stable insulation, long lifespan, and fire-resistant performance at the same time.   Before selecting insulated panels, it is important to match the panel thickness with the target temperature of the cold room. The following table shows the general recommendation: Panel Thickness (mm) Storage Temperature (°C) Typical Application 75 mm +10°C to +5°C Food processing, air-conditioned room 100 mm +5°C to -5°C Chiller room, fruit and vegetable storage 150 mm -5°C to -20°C Frozen meat, dairy storage 200 mm -20°C to -40°C Deep freezer, ice cream cold room   Proper installation and sealing of the PU sandwich panels are equally important. Gaps, uneven joints, or unsealed corners may cause cold air leakage—resulting in continuous energy loss and compressor overload. That’s why Propanel emphasizes professional installation guidance and precise joint systems to ensure the panels fit tightly, keeping the cold room fully sealed.  

For successful international shipping, to use the correct loading method is very important, because sandwich panels need to be carefully packaged, loaded and transported--Once the loading procedure goes wrong, it may cause product damage and financial losses.   First of all, to make sure that the container condition meets transportation standards is the first step. Propanel will conduct a thorough inspection of the container before loading operations begin. If the container floor has protruding nails or sharp objects - the panel surfaces will get scratched easily - this can cause quality problem, finally leading to customer dissatisfaction.   Secondly, packaging and weight distribution calculations must be done before actual loading. It is recommended to use pallets to protect the bottom layer. Never load above the recommended height - otherwise damage may occur - ultimately resulting in the product being damaged and unable to be installed correctly.   Thirdly, security measures should be strictly done before loading. Key points such as angle brackets, protective plates, tension adjustment of straps, and filling of gaps between stacks require experienced workers to handle them according to standard operating procedures. Appropriate inflatable bags or air cushions should fill the empty space and prevent unnecessary movement of the container in rough sea conditions.  

For a good cold room, to use the right way to finish the installation is very important, cause the cold storage room requires excellent sealing performance--Once the sealing performance cannot be guaranteed, It may greatly increase energy loss and spoilage of goods.    The cold storage sandwich panels—it is usually composed with 2-layer pre-painted steel sheet with polyurethane(pu)/polyisocyanurate(pir) insulated core material. As is known to all, the pu/pir is the best thermal insulation building material—so it gives the best cold storage performance with B1 fireproof at the same time.    First of all, ensuring that the quality of the cold storage composite panels is good is the top priority. Propanel, just focus on supplying the pu/pir cold room sandwich panels, give customers the best solution also best price at the same time.   Secondly, ground site preparation and inspection must be done before installation. If the foundation is uneven - the panels won't line up properly - this can cause gaps to appear, ultimately allowing cold air to escape.   Thirdly, node connections are easily handled improperly. Nodes such as column edge connections, wall corner connections, and suspended ceiling points require professional personnel to connect them according to professional instructions. Improper operation can cause cold bridge phenomenon, finally leading to energy loss and damage to the cold storage panels.