The reason the shelf furniture plywood deformation and solution
As everyone knows, constitute the main parts furniture plywood has a side plywood, shelf, door, roof or panel and backplanes, plywoods are the main deformation of the elastic plywood bending, warping, creep, the creep buckling and the intrinsic quality depends largely on the substrate itself, and parts of the elastic bending in addition, the quality of the plywood itself, mainly depends on the management of the production process and process. For the problem of the substrate itself, you can choose the internal stress is small, the strength of the brand products. The elastic deformation under the action of external force is a complicated problem.
The furniture board shelf is subjected to the following stress:
1) stress is the stress bearing objects and shelf weight formation pressure. Is the main cause of the deformation of the shelf.
2) bending stress, stress bearing bending forming, bending and creep to the shelf.
3) shear stress, the bearing shelf support or connection interface shear stress and support force resulting in the formation of.
4) curing stress, stress due to curing surface coating in the form of shelf contraction is not consistent, the bending deformation of the shelf.
More than 4 kinds of stress caused by the bending deformation of panel furniture shelf.
The stress in the bending effect on the shelf is the largest compressive stress, the bending degree depends on the size of load characteristics, configuration and material size and itself.
Although the effect of bending shelf functions of the furniture itself is not too big, but affect the appearance, especially for those who open the glass door and the cabinet is even more so, the calculation formula of bending deformation from the shelf can know, bending with the following method can reduce the shelf:
1) the base material with high elastic modulus. Such as joinery board, veneer board, veneer board, etc..
Section 2) increase the width and thickness of the shelf. That is, the use of a wider and thicker materials, but for fiberboard and particleboard, the thickness of both increased costs and affect the appearance, therefore, the actual production of the general use of 19mm thickness is more appropriate. Of course, in the edge of the shelf with reinforced thin strips of metal or hard wood reinforcement, is a good way.
3) reduce the shelf span. In the formula, the length of the shelf is a very important data, therefore, reduce the shelf span is also an important means of reducing shelf bending, there are two methods, one is to reduce the shelf itself length, and addition of clapboard for support, therefore, in the actual production of rarely used 1000mm shelf, in addition to special circumstances, the general use of 800-900mm.
4) the shelf connected with the back board. If conditions permit, the shelf can be fixed on the backboard, or on the back. Now back general furniture uses 3mm 3mm plywood and MDF, its intensity is not large, not in the above drilling, but add special shelf rack shelf pin with glue strip or fixed type, which can greatly reduce the bending degree of the shelf.
5) the use of movable shelf. For a lot of furniture, there is a certain number of shelves of the bending deformation of large span, for those shelves, even if there is no load, also because of its own weight drop, if the shelf, when the bending deformation, can be put in use over, after a period of time, due to the external force and the effect of the phase plywood and restored to the original state, but that by easily accelerated creep.
6) strengthening process management. A lot of bending deformation is caused by human factors in the process, such as improper placement, moisture absorption, finishing process improper. Therefore, strengthening production management is an important means to reduce the plywood bending deformation.