Experimental study on the compressive strength of

Experimental study on compressive strength of polyurethane composites under

3 bending and compression properties of polyurethane composite plates

3.1 orthogonal experiments and results

orthogonal experiments were designed by changing the density of panel materials (plywood, corrugated board, ordinary paper), foam core (foaming agent content is 0%, 8%, 25% respectively) and sandwich materials (copper and corrugated paper). The pressed plates are shown in Figure 3, The flexural elastic modulus of the front face of the 9 specimens is from 84 to 2916mpa, the flexural elastic modulus of the side is from 120 to 1970mpa, the compressive strength of the side is from 0.5 to 5.5mpa, and the compressive strength of the end face is from 0.82 to 5.2mpa. Fig. 4 is a photo of the specimen after the flexural elastic modulus and compressive strength tests

3.2 analysis of variance

see Table 2 for the results of analysis of variance

for polyurethane composite sandwich panels, such as Wuhan Shijijiayuan with an area of 250000 square meters, the panel material has the greatest influence on the flexural elastic modulus and compressive strength. The influence of various factors on the mechanical properties is as follows: panel material, foam density sandwich material

it can also complete various functions by computer, process and analyze the data, and print the experimental results. For plywood, a kind of material with high mechanical strength, as a composite plate of the panel, the density has a great influence on the flexural elastic modulus, and its value decreases significantly with the decrease of density, while the sandwich material has little effect. Compared with the influence of panel materials on the compressive strength, 2. Rubber tensile testing machine: the elongation of rubber or elastomer is relatively large, and the influence of density and clip, that is, the surface and internal degradation layer materials at the same time, on the compressive strength is very small, and the difference of the compressive strength values of the three specimens can be ignored

for the composite board with corrugated board and ordinary advertising color paper as panels, because the panel material and polyurethane are relatively soft, the sandwich material and density change have a great impact on the flexural elastic modulus and compressive strength of the composite board

4 conclusion

1) the flexural elastic modulus and compressive strength of polyurethane composite plate are several to dozens or even hundreds of times that of polyurethane foam itself

2) polyurethane composite plates with required mechanical strength can be made by using panel materials with different mechanical strength. If the mechanical strength of the panel material used is poor, the density of core foam can be appropriately increased or interlayer can be added to improve the mechanical strength. (text/Zhou Min and Li outline)