Polyurethane composite board

Abstract

The utility model relates to a kind of polyurethane composite board, mainly solve the problem that existing technology exists glass fiber powder random distribution, cannot be targeted to enhance high stress area.The utility model by using a new polyurethane composite board, from top to bottom sequentially include first layer non-woven fabric (1), glass fiber felt (2), first layer glass fiber powder (3), glue powder (4), first layer high molecular film (5), polyurethane foam (6), second layer high molecular film (7), second layer glass fiber powder (8), second layer non-woven fabric (9), wherein, glass fiber felt (2) is composed of chopped glass fiber (10) and polyethylene powder (11), chopped glass fiber (10) is randomly laid and forms porous mesh structure, the technical scheme that first layer high molecular film (5), second layer high molecular film (7), glue powder (4) and polyethylene powder (11) play the role of connecting each layer structure, better solve the problem, can be used in automobile roof base material industrial application.

Description

Technical Field

[0001] This utility model relates to a polyurethane composite board. Background Technology

[0002] With the development of the automotive industry, the requirements for lightweight and strong automotive interiors are becoming increasingly stringent. In existing technologies, polyurethane composite panels are used in automotive headliners. However, when applied to areas such as door handles, the headliners lack sufficient rigidity and are prone to tearing. Typically, the rigidity of polyurethane panels used in automotive headliners is characterized by flexural strength.

[0003] Chinese patent CN 212708335 U discloses a high-flexural-strength polyurethane composite board, which, from top to bottom, comprises a first layer of non-woven fabric 1, a first layer of polymer film 2, a first layer of glass fiber 3, a first layer of polyethylene powder 4, a fiberglass mat 5, a second layer of polymer film 6, polyurethane foam 7, a third layer of polymer film 8, a second layer of glass fiber 9, a second layer of polyethylene powder 10, and a polyethylene film 11. The fiberglass mat 5 is composed of glass fiber 12 and polyethylene powder 13. The rectangular polyurethane composite board is formed by combining the polyurethane foam 7 and the second polymer film 6. A first fiberglass mat 5-1, with a width of 200-300mm and a length of 1350-1500mm, is pasted 0-10mm from the short side A of the rectangular polyurethane composite board. A second fiberglass mat 5-2 and a third fiberglass mat 5-3, each 45-55mm wide and long, are symmetrically pasted along the two long sides of the rectangular polyurethane composite board at a distance of 45-55mm from the long side A of the first fiberglass mat 5-1. A fourth fiberglass mat 5-4 and a fifth fiberglass mat 5-5, each 45-55mm wide and long, are symmetrically pasted along the two long sides of the rectangular polyurethane composite board at a distance of 1300-1500mm from the short side A of the rectangular polyurethane composite board. However, this polyurethane composite board has the following defects:

[0004] 1. Unreasonable structural design: The use of globally randomly distributed short glass fiber powder results in uneven fiber dispersion, which easily leads to stress concentration and weakens the strength of key areas; the reliance on five small glass fiber mats for local bonding enhances the fragmentation of the area, which cannot match the actual stress path of the car roof and has insufficient tear resistance; the use of a 13-layer stacked structure, including redundant functional layers, leads to an increase in interfaces and a decrease in stress transfer efficiency.

[0005] 2. Insufficient mechanical properties: The bending strength is too low, making it difficult to meet the rigidity requirements of the car roof; the edge strength is weak, and the edge area is not specifically reinforced, resulting in an edge / center strength ratio that is significantly lower than that of this utility model, making it prone to edge tearing.

[0006] 3. Complex process and a lot of waste: Five independent pieces of fiberglass felt need to be precisely cut and glued, the effective load-bearing capacity of the material is only 40%, and there is serious waste of scrap materials.

[0007] 4. High VOC release: Relying on traditional adhesives for compounding, the VOC release is high and cannot meet the stringent VDA 278 standard. Utility Model Content

[0008] The technical problem to be solved by this utility model is that the existing technology has the problem of random distribution of glass fiber powder, which cannot specifically reinforce high stress areas. This utility model provides a new polyurethane composite board with the advantage of high bending strength.

[0009] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows: A polyurethane composite board, comprising, from top to bottom, a first layer of non-woven fabric 1, a fiberglass mat 2, a first layer of fiberglass powder 3, adhesive powder 4, a first layer of polymer film 5, polyurethane foam 6, a second layer of polymer film 7, a second layer of fiberglass powder 8, and a second layer of non-woven fabric 9, wherein the fiberglass mat 2 is composed of chopped glass fibers 10 and polyethylene powder 11, the chopped glass fibers 10 are laid to form a porous mesh structure, the first layer of polymer film 5, the second layer of polymer film 7, the adhesive powder 4, and the polyethylene powder 11 serve to connect the various layers of the structure, the melting point of the first layer of polymer film 5 and the second layer of polymer film 7 is 130-142℃, the melting point of the adhesive powder 4 is 96-110℃, and the melting point of the polyethylene powder 11 is 96-110℃, during the composite process, the average temperature of 170℃ between the upper and lower layers melts, firmly adhering the fiberglass mat and other raw materials to the upper and lower surfaces of the polyurethane board; characterized in that, at a distance A from the long side of the rectangular polyurethane composite board... A first fiberglass mat 2-1 with a width of 190-210mm and a length of 1860-1880mm is pasted at a distance of 0-10mm from the long side B of the rectangular polyurethane composite board; a second fiberglass mat 2-2 with a width of 190-210mm and a length of 1860-1880mm is pasted at a distance of 0-10mm from the long side B of the rectangular polyurethane composite board; a third fiberglass mat 2-3 with a length and width of 290-310mm is pasted at a distance of 515-535mm from the short side away from A or B of the first fiberglass mat 2-1 or the second fiberglass mat 2-2.

[0010] In the above technical solution, preferably, the first layer of nonwoven fabric 1 is selected from one of thermally rolled nonwoven fabric, spunlace nonwoven fabric, meltblown nonwoven fabric or spunbond nonwoven fabric, and the thickness is 0.1 to 0.5 mm.

[0011] In the above technical solution, preferably, the fiberglass mat has a weight of 200-400 g / m². 2 Of which chopped glass fiber 10 accounts for 60-80 wt%, and the monofilament diameter of the chopped glass fiber is 5-7 mm. μm The fiber length is 3-5 mm and the thickness is 3-5 mm. μmPolyethylene powder accounts for 20-40 wt%.

[0012] In the above technical solution, preferably, the thickness of the first layer of glass fiber powder 3 and the second layer of glass fiber powder 8 is 0.05-0.15 mm, and the basis weight is 55-65 g / m³. 2 .

[0013] In the above technical solution, preferably, the thickness of the adhesive powder 4 is 0.05-0.15 mm, and the basis weight is 55-65 g / m³. 2 .

[0014] In the above technical solution, preferably, the first polymer membrane 5 and the second polymer membrane 7 are selected from polypropylene polymer membranes or polyamide polymer membranes, with a thickness of 60-80 μm and a basis weight of 65-75 g / m³. 2 .

[0015] In the above technical solution, preferably, the thickness of the polyurethane foam 6 is 5-15 mm.

[0016] This invention provides a polyurethane composite board, which is formed by randomly laying short-cut glass fibers 10 to form a porous mesh structure. This structure provides reinforcement and facilitates the penetration and bonding of glass fiber powder, adhesive powder, and polymer film. It is further formed by uniformly dispersing and bonding hot-melt polyethylene powder 11. By integrating the polyethylene powder 11 into the glass fiber mat 2 and eliminating independent adhesive layers, the total number of layers is optimized to 9, fundamentally avoiding the risk of delamination and interface failure. The reduced number of layers significantly lowers the heat conduction gradient, ensuring uniform melt penetration and solving the problem of poor local bonding that easily occurs in traditional multi-layered boards, achieving better technical results.

[0017] The bonding methods for each layer of the polyurethane composite board of this utility model are as follows:

[0018] The first layer of nonwoven fabric 1 directly covers the fiberglass mat 2. The polyethylene powder 11 in the fiberglass mat 2 melts during the hot pressing process at 170℃. The liquid polyethylene penetrates into the gaps between the nonwoven fabric fibers. The porous network structure formed by the short glass fibers 10 provides a flow channel for the molten polyethylene and bonds it together with the first layer of fiberglass powder. The lower layer of the fiberglass mat 2 comes into contact with the first layer of fiberglass powder 3 and the adhesive powder 4 in sequence. The adhesive powder 4 has the lowest melting point and melts completely into a liquid state first. The liquid adhesive powder penetrates upward into the first layer of fiberglass powder 3 and downward into the first layer of polymer film 5. The polyethylene powder 11 in the fiberglass mat melts simultaneously and forms a blended adhesive phase with the adhesive powder. The molten adhesive powder wraps around the fiberglass powder particles to form a continuous adhesive layer. The ends of the short glass fibers 10 are embedded in the adhesive powder layer to enhance the interfacial shear strength. The first layer of polymer film 5 is located between the adhesive powder 4 and the polyurethane foam 6. The polymer film is in a semi-molten state at 170℃: the surface molecular chain movement intensifies and forms molecular-level diffusion with the melted adhesive powder. The bottom layer intercalates with the micropores on the surface of the polyurethane foam through viscoelastic flow.

[0019] By utilizing the difference in melting points—the melting point of the adhesive powder (96-110℃) < the melting point of the polymer film (130-142℃) < the processing temperature (170℃)—the dimensional stability of the polymer film is ensured when the adhesive powder is fully flowing.

[0020] The core bonding mechanism of this invention is achieved through a precise gradient design of material melting points: adhesive powder 96-110℃ → polyethylene powder 110℃ → polymer film 130-142℃, under hot pressing conditions at 170℃.

[0021] Ultimately, a multi-layered molecular entanglement network is formed, while the expansion pressure of polyurethane foam is used to strengthen the interfacial bonding, fundamentally solving the delamination problem of traditional composite panels. Attached Figure Description

[0022] Appendix Figure 1 This is a schematic diagram of a polyurethane composite panel;

[0023] Appendix Figure 2 This is a schematic diagram of the composition and structure of fiberglass mat 2;

[0024] Appendix Figure 3 This is a schematic diagram of the fiberglass mat distribution;

[0025] Among them, 1 is the first layer of nonwoven fabric, 2 is fiberglass mat, 2-1 is the first layer of fiberglass mat, 2-2 is the second layer of fiberglass mat, 2-3 is the third layer of fiberglass mat, 3 is the first layer of fiberglass powder, 4 is adhesive powder, 5 is the first layer of polymer film, 6 is polyurethane foam, 7 is the second layer of polymer film, 8 is the second layer of fiberglass powder, 9 is the second layer of nonwoven fabric, 10 is chopped glass fiber, and 11 is polyethylene powder. Detailed Implementation

[0026] Example 1:

[0027] A polyurethane composite board, comprising, from top to bottom, a first layer of hot-rolled nonwoven fabric with a thickness of 0.2 mm, and a 2-gram fiberglass mat with a weight of 200 g / m². 2 The mixture contains 60 wt% chopped glass fiber 10, 20 wt% polyethylene powder 11, and a first layer of glass fiber powder 3 with a thickness of 0.05 mm and a basis weight of 55 g / m³. 2 The thickness of the adhesive powder 4 is 0.05mm, and the basis weight is 55g / m². 2 The first polymer membrane 5 is selected from polypropylene polymer membrane, with a thickness of 60μm and a basis weight of 65g / m³. 2 The polyurethane foam 6 has a thickness of 5mm, and the second polymer film 7 is selected from polypropylene polymer film, with a thickness of 60μm and a basis weight of 65g / m³. 2 The second layer of glass fiber powder has a thickness of 0.05mm and a basis weight of 55g / m². 2The second layer of nonwoven fabric 9, wherein the fiberglass mat 2 is composed of chopped glass fibers 10 and polyethylene powder 11. The chopped glass fibers 10 are laid to form a porous mesh structure. The first layer of polymer film 5, the second layer of polymer film 7, the adhesive powder 4 and the polyethylene powder 11 serve to connect the various layers. The melting points of the first layer of polymer film 5 and the second layer of polymer film 7 are 130-142℃ and the melting point of the adhesive powder is 96-110℃. During the composite process, the average temperature of 170℃ between the upper and lower layers melts, firmly adhering the fiberglass mat and other raw materials to the polyurethane board. The feature is that a first fiberglass mat 2-1 with a width of 200mm and a length of 1870mm is adhered at a distance of 100mm from the long side A of the rectangular polyurethane composite board; at a distance of 100mm from the long side B of the rectangular polyurethane composite board... A second fiberglass mat 2-2 with a width of 200mm and a length of 1870mm is pasted at a distance of 100mm; a third fiberglass mat 2-3 with a length and width of 300mm is pasted at a distance of 525mm from the short side away from A or B of the first fiberglass mat 2-1 or the second fiberglass mat 2-2.

[0028] Examples 2-5 are polyurethane composite boards formed by combining the layers of the structure in Example 1. The only difference is that the types of materials in each layer of the polyurethane composite board are different, and the various performance indicators of the materials are different, as shown in Table 1. The position of the fiberglass mat 2 and the size data of the fiberglass mat 5 are shown in Table 2. The product test data of the prepared polyurethane composite board are shown in Table 3.

[0029] Comparative Example 1: The test results of Example 1 of Chinese Utility Model Patent Application No. 202020835853.8.

[0030] Comparative Example 2 is a layer of the present invention, but the distribution of the fiberglass mat is the same as that of Comparative Example 2.

[0031] Table 1. Material properties of each layer of the polyurethane composite panels in Examples 1-5.

[0032]

[0033] Table 2. Dimensional data of the bonding position of fiberglass mat 5 in Examples 1-5.

[0034]

[0035]

[0036] Table 3 Performance test reports of polyurethane composite panels in Examples 1-5 and Comparative Example 1

[0037]

[0038] As shown in the table, compared with Comparative Example 1, the utility model optimizes the 13-layer structure to 9 layers, eliminating redundant layers such as independent polyethylene powder layers and glass fiber layers, thus reducing the amount of non-reinforcing materials. Polyethylene powder 11 is directly integrated into the glass fiber felt 2 as a binder, replacing independent adhesive layers and reducing overall weight. The flexural strength is as high as 3.5 kPa, an increase of 65%. The first and second glass fiber felts are 190-210 mm × 1860-1880 mm in size, completely covering the long side, i.e., the edge strip of the car roof; the third glass fiber felt 2-3 is 290-310 mm × 290-310 mm in size, only reinforcing the handle installation area to achieve stress concentration point effect. The edge strength of the board is 30% higher than the center strength. The first and second glass fiber felts are directly pasted to the long side A / B at a distance of 0-10 mm, forming a continuous edge reinforcement strip to resist tearing stress. Comparative Example 1 only pasted small felts on the short side, and the edge reinforcement felt was insufficient in size, resulting in weak edge strength. By using a polymer film (melting point 130-142℃) and adhesive powder (melting point 96-110℃) to melt and bond at 170℃, organic solvent-based adhesives are completely eliminated (Comparative Example 1 requires traditional adhesives with high VOC emissions). Polyethylene powder 11 is integrated into the fiberglass mat, avoiding the introduction of VOC sources by separate adhesive layers. This effectively improves rigidity requirements while simultaneously reducing VOCs by 50%.

Claims

1. A polyurethane composite board, comprising, from top to bottom, a first layer of nonwoven fabric (1), a fiberglass mat (2), a first layer of fiberglass powder (3), adhesive powder (4), a first layer of polymer film (5), polyurethane foam (6), a second layer of polymer film (7), a second layer of fiberglass powder (8), and a second layer of nonwoven fabric (9), wherein, The fiberglass mat (2) is composed of chopped glass fibers (10) and polyethylene powder (11). The chopped glass fibers (10) are laid to form a porous network structure. The first layer of polymer film (5), the second layer of polymer film (7), the adhesive powder (4), and the polyethylene powder (11) play the role of connecting the structure of each layer. The melting point of the first layer of polymer film (5) and the second layer of polymer film (7) is 130-142℃, the melting point of the adhesive powder (4) is 96-110℃, and the melting point of the polyethylene powder (11) is 96-110℃. During the composite process, the fiberglass mat material is firmly bonded to the upper and lower parts of the polyurethane board by the average heat melting of the upper and lower layers at 170℃. The feature is that the first fiberglass mat (2-1) with a width of 190-210mm and a length of 1860-1880mm is pasted at a distance of 0-10mm from the long side A of the rectangular polyurethane composite board; at a distance of 0-10mm from the long side B of the rectangular polyurethane composite board, the first fiberglass mat (2-1) with a width of 190-210mm and a length of 1860-1880mm is pasted. A second fiberglass mat (2-2) with a width of 190-210 mm and a length of 1860-1880 mm is pasted at a distance of 0-10 mm; a third fiberglass mat (2-3) with a length and width of 290-310 mm is pasted at a distance of 515-535 mm from the short side away from A or B of the first fiberglass mat (2-1) or the second fiberglass mat (2-2).

2. The polyurethane composite board according to claim 1, characterized in that, The first layer of nonwoven fabric (1) and the second layer of nonwoven fabric (9) are selected from one of thermally rolled nonwoven fabric, spunlace nonwoven fabric, meltblown nonwoven fabric or spunbond nonwoven fabric, and the thickness is 0.1~0.5mm.

3. The polyurethane composite board according to claim 1, characterized in that, The fiberglass mat (2) has a basis weight of 200-400 g / m², wherein chopped glass fiber (10) accounts for 60-80 wt%, the chopped glass fiber has a single filament diameter of 5-7µm, a fiber length of 3-5mm, a thickness of 3-5µm, and polyethylene powder (11) accounts for 20-40 wt%.

4. The polyurethane composite board according to claim 1, characterized in that, The thickness of the first layer of glass fiber powder (3) and the second layer of glass fiber powder (8) is 0.05-0.15 mm, and the basis weight is 55-65 g / m³. 2 .

5. The polyurethane composite board according to claim 1, characterized in that, The adhesive powder (4) has a thickness of 0.05–0.15 mm and a basis weight of 55–65 g / m³. 2 .

6. The polyurethane composite board according to claim 1, characterized in that, The first polymer membrane (5) and the second polymer membrane (7) are selected from polypropylene polymer membranes or polyamide polymer membranes, with a thickness of 60-80 μm and a basis weight of 65-75 g / m³. 2 .

7. The polyurethane composite board according to claim 1, characterized in that, The thickness of the polyurethane foam (6) is 5-15 mm.

Images