Although some solid wood floorings are not in use during installation or after the installed floor has been installed, after a certain period of time has elapsed after installation, cracks will appear on the floorboards, sometimes accompanied by tile deformation and bulging. Faced with such problems, many consumers first complained about the quality of the product, and some dealers could not figure out what caused the problem and explained it unclear. The individual complaint handling departments also lack the means and experience to identify and divide responsibilities, which brings many difficulties to the handling and resolution of such complaints. Therefore, based on the identification experience of dealing with relevant complaints over the years, the authors comprehensively and systematically analyzed the causes of the problems and provided reference for relevant parties to deal with such issues (the cracks caused by product quality problems will be explained in the subsequent case analysis).
First, the monolithic floor moisture absorption characteristics
In order to illustrate the use of solid wood flooring, the cause of cracks in the floor after the damp, but also to do a test. We have selected several floorboards in the flooring factory where the floor has been dried, and we have selected several floorboards with many micro cracks (plane cracks) on the board surface. After planing, the board surface cracks are clearly visible. Then, we placed the billet in the test box and gradually increased the humidity inside the box. The floor billet expanded after absorbing moisture, and the crack on the board surface became blurred. The cracks decreased with the increase of the moisture content of the floor. When we put it in water again and make the moisture content of the floor blank reach the fiber saturation point (above 30%), we can hardly see cracks in the surface layer of the blank. If the floorboard that has been sucked up is once again dried to a dry state, cracks on the board surface can be seen again. After further drying, cracks on the board surface tend to increase. Similarly, we placed a cracked floor on the end of the water in the water and the cracks did not become apparent. The test results show that the surface cracking or end cracking of single-piece floor or floor blanks is caused by internal stress. During the process of moisture absorption, the internal stress of the single-layer flooring is decreasing. For monolithic flooring, moisture absorption or water absorption on the floor will not cause cracks and cracks in the floor panel. This is also an important reason why wood should not be cracked in water.
Second, the expansion of the single floor
After the wood absorbs moisture, it will expand. If it is a single floor, it can expand freely without restrictions. During the installation of the floor, due to lack of reserved space, or the user's environment is humid, there is not enough space for expansion of the floor to absorb water, which means that
The stress of expansion, the density of wood, and the expansion stress are also different. The greater the density, the greater the expansion stress. The expansion stress of wood can be calculated by the following formula:
PE=Kf/s-----------------------------------(1)
PE----Wood expansion stress (kg/
Floor space
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