Production method of stainless steel and foam composite board

Abstract

The invention discloses a production method of a stainless steel and foam composite board. The method comprises the following steps: 1) polishing and cleaning the surface of a stainless steel substrate; (2) foam priming spraying is conducted on the cleaned surface of the stainless steel base material, the thickness of sprayed foam is controlled to be 1-2 mm, the spraying state is discontinuous distribution, and it is ensured that a stainless steel base material body can be seen; and (3) the stainless steel base material subjected to bottoming spraying is put into a special mold, pouring forming of the foam raw material is conducted, and finally the stainless steel / foam composite board is obtained. Through the innovative combination of pretreatment and discontinuous thin-spraying bottoming, the subsequent pouring foam and the stainless steel base material form the double combination effect of mechanical occlusion and interface fusion, the combination strength of the composite interface is remarkably improved, the problems of hollowing and falling are thoroughly solved, and the method is suitable for production of various stainless steel / foam composite plates for insulation with specific sizes and has wide application prospects. The method has the advantages of simple process, stable quality and high applicability.

Description

Technical Field

[0001] This invention relates to a method for producing stainless steel and foam composite boards, belonging to the field of insulation materials technology. Background Technology

[0002] Stainless steel / foam composite panels combine the high strength and corrosion resistance of stainless steel with the lightweight, thermal insulation, and electrical properties of foam materials, making them promising for a wide range of applications in the insulation field. In existing technologies, the production of stainless steel / foam composite panels of specific sizes typically involves directly placing stainless steel sheets into a mold and then pouring foam raw materials into the mold. However, due to the smooth surface and strong chemical inertness of stainless steel, the interfacial bonding between the solidified foam raw materials and the stainless steel substrate is weak. This leads to quality problems such as delamination, peeling, and even detachment during use, severely affecting the structural stability and service life of the composite panel and limiting its application in demanding environments.

[0003] To improve the bonding effect, some existing technologies attempt to sandblast or coat the stainless steel surface with adhesives. However, sandblasting can easily cause excessive damage to the stainless steel surface, affecting the appearance and structural integrity of the sheet. The use of adhesives not only increases production costs but may also lead to poor interfacial bonding due to compatibility issues between the adhesive and the foam raw materials, failing to fundamentally solve the problem of delamination and detachment. Therefore, developing a simple, cost-effective production method that can significantly improve the bonding strength between stainless steel and foam has become a pressing technical challenge in this field. Summary of the Invention

[0004] To address the problems existing in the prior art, the present invention provides a method for producing stainless steel and foam composite boards, thereby solving the aforementioned technical problems.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is: a method for producing stainless steel and foam composite boards, comprising the following steps: Step 1) Surface pretreatment: Grind the composite surface of the stainless steel substrate to remove the surface oxide layer and impurities, and then clean and dry it; Step 2) Discontinuous primer spraying: Foam material is sprayed onto the composite surface of the stainless steel substrate. The thickness of the sprayed foam is controlled to be 1-2mm, and the spraying area is discontinuously distributed to ensure that the composite surface of the stainless steel substrate is partially exposed and visible. Step 3) Mold casting: Fix the stainless steel substrate with the base coating in the mold, inject foam casting material into the mold, and after the foam material solidifies, a stainless steel / foam composite board is obtained.

[0006] Furthermore, the polishing process described in step 1) is carried out using sandpaper or a grinding wheel, and the surface roughness Ra of the stainless steel substrate after polishing is 0.8-3.2μm.

[0007] Furthermore, in step 1), the cleaning and drying process involves wiping the surface with anhydrous ethanol and then drying it at 60-80°C for 10-20 minutes.

[0008] Furthermore, the discontinuously distributed sprayed areas mentioned in step 2) are dot-shaped or strip-shaped, and the total area of ​​the sprayed areas accounts for 30%-60% of the total area of ​​the stainless steel substrate composite surface.

[0009] Furthermore, the foam raw material mentioned in step 2) and the foam casting raw material mentioned in step 3) are the same type of polyurethane foam or polystyrene foam raw material.

[0010] Furthermore, in step 3), the ambient temperature during the pouring process is controlled at 20-30℃, the pouring pressure is 0.1-0.3MPa, and the curing time is 2-8h.

[0011] Compared with the prior art, the production method of the present invention has the following key advantages: 1. Completely solves the problem of hollowing and falling off: Through the innovative design of "surface pretreatment + discontinuous thin spray base", the rough surface after pretreatment increases the physical contact area. The "anchor points" formed by the discontinuous base spray coating form a mechanical interlocking structure with the subsequent poured foam. At the same time, the base foam and the poured foam are made of the same type of raw materials, realizing the chemical fusion of the interface. Under the dual effect, the bonding strength between stainless steel and foam is significantly improved. The test shows that the shear strength of the composite interface is ≥1.5MPa, which completely solves the problem of hollowing and falling off that is easy to occur in traditional processes.

[0012] 2. Simple process and controllable cost: No additional adhesive is required, nor is complex surface treatment equipment. It can be achieved using only conventional grinding, spraying and casting equipment. The process steps are simple, the production efficiency is high, and the increased cost and compatibility issues caused by adhesives are avoided, thus reducing production costs.

[0013] 3. Stable product quality: The parameters of the entire process are easy to control. The thickness, distribution ratio and other parameters of discontinuous primer spraying can be adjusted according to actual needs to ensure the consistency of bonding performance of different batches of products. The product qualification rate is ≥98%, which is suitable for large-scale industrial production.

[0014] 4. Strong applicability: This method can be applied to the production of stainless steel / foam composite boards of different sizes and specifications, and is compatible with various foam raw materials such as polyurethane and polystyrene, meeting the diverse application needs in the field of insulation. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below through embodiments. However, it should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the scope of the invention.

[0016] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. Example

[0017] 304 stainless steel sheet was selected as the base material, with dimensions of 1000mm×500mm×2mm. The composite surface was polished with 100-grit sandpaper, and the surface roughness Ra=1.6μm after polishing. After wiping the surface with anhydrous ethanol, it was dried in an oven at 70℃ for 15min.

[0018] Polyurethane foam raw material is used, and it is applied to the stainless steel composite surface in a dotted, discontinuous manner using a high-pressure spraying device. The thickness of the sprayed foam is 1.5 mm, and the total area of ​​the dotted spraying area accounts for 45% of the total area of ​​the composite surface. After spraying, the exposed part of the stainless steel substrate is visible.

[0019] The treated stainless steel substrate is fixed in a mold, and polyurethane foam casting material is injected into the mold. The ambient temperature is controlled at 25℃, the casting pressure is 0.2MPa, and the curing time is 4 hours before demolding to obtain a stainless steel / foam composite board.

[0020] Tests showed that the composite panel had a shear strength of 1.8 MPa, with no hollowing or detachment. After high and low temperature cycling tests from -20℃ to 80℃, the interface remained intact. Example

[0021] 316L stainless steel sheet was selected as the base material, with dimensions of 1200mm×600mm×3mm. The composite surface was polished with a 120-grit abrasive wheel, and the surface roughness Ra=2.5μm after polishing. After wiping the surface with anhydrous ethanol, it was dried in an 80℃ oven for 10min.

[0022] Polystyrene foam raw material is used, and a strip-shaped discontinuous spraying is performed on the stainless steel composite surface using a high-pressure spraying equipment. The thickness of the sprayed foam is 1 mm, and the total area of ​​the strip-shaped spraying area accounts for 30% of the total area of ​​the composite surface. After spraying, the exposed part of the stainless steel substrate can be seen.

[0023] The treated stainless steel substrate is fixed in a mold, and polystyrene foam casting material is injected into the mold. The ambient temperature is controlled at 22℃, the casting pressure is 0.1MPa, and the curing time is 6 hours before demolding to obtain a stainless steel / foam composite board.

[0024] Tests showed that the composite panel had a composite interface shear strength of 1.6 MPa, with no hollowing or detachment. After long-term static and vibration tests, the interface bonding performance remained stable.

[0025] Comparative example (traditional process) The same 304 stainless steel sheet as in Example 1 was selected, but without any pre-coating, and polyurethane foam raw material was directly poured into the mold. Other parameters were the same as in Example 1. Testing showed that the composite panel's interfacial shear strength was only 0.6 MPa, and multiple blistering occurred after slight vibration. During the peel test, the foam completely separated from the stainless steel.

[0026] As can be seen from the comparison of the above embodiments and comparative examples, the production method of the present invention can significantly improve the bonding strength between stainless steel and foam, effectively solve the quality defects of traditional processes, and has significant technical advantages and practical value.

[0027] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for producing a stainless steel and foam composite board, characterized in that, Includes the following steps: Step 1) Surface pretreatment: Grind the composite surface of the stainless steel substrate to remove the surface oxide layer and impurities, and then clean and dry it; Step 2) Discontinuous primer spraying: Foam material is sprayed onto the composite surface of the stainless steel substrate. The thickness of the sprayed foam is controlled to be 1-2mm, and the spraying area is discontinuously distributed to ensure that the composite surface of the stainless steel substrate is partially exposed and visible. Step 3) Mold casting: Fix the stainless steel substrate with the base coating in the mold, inject foam casting material into the mold, and after the foam material solidifies, a stainless steel and foam composite board is obtained.

2. The method for producing stainless steel and foam composite panels according to claim 1, characterized in that, The polishing process described in step 1) is carried out using sandpaper or a grinding wheel. After polishing, the surface roughness Ra of the stainless steel substrate is 0.8-3.2μm.

3. The method for producing stainless steel and foam composite panels according to claim 1, characterized in that, The cleaning and drying process described in step 1) involves wiping the surface with anhydrous ethanol and then drying it at 60-80℃ for 10-20 minutes.

4. The method for producing stainless steel and foam composite panels according to claim 1, characterized in that, The discontinuously distributed sprayed areas mentioned in step 2) are dot-shaped or strip-shaped, and the total area of ​​the sprayed areas accounts for 30%-60% of the total area of ​​the stainless steel substrate composite surface.

5. The method for producing stainless steel and foam composite panels according to claim 1, characterized in that, The foam raw material mentioned in step 2) and the foam casting raw material mentioned in step 3) are the same type of polyurethane foam or polystyrene foam raw material.

6. The method for producing stainless steel and foam composite panels according to claim 1, characterized in that, The ambient temperature during the pouring process described in step 3) is controlled at 20-30℃, the pouring pressure is 0.1-0.3MPa, and the curing time is 2-8h.