Commercially available laminate flooring (using high or medium density fiberboard or particle board as the core layer) has gained overwhelming success in the flooring market. The growth rate of the laminate flooring has remained in the double digits since the product was introduced in the United States market. The success of this product is credited to certain properties such as stain resistance, wear resistance, fire resistance, good cleanability, and the ability to use just about any type of printed design. In addition, the overall emission of organic compound vapor is low and the laminate flooring is considered color stable and environmentally friendly over other competing flooring products.
The biggest concern with commercially available laminate flooring is the moisture resistance of the finished product and the sensitivity of the raw materials (high or medium density fiberboard, paper, and particle board) to moisture during the manufacturing process. In some instances, the moisture can lead to some serious quality control issues and application restraints. For instance, and just to name a few, the higher moisture content in the product, such as in the particle board or fiberboard, can cause blistering and adhesion failure of the melamine surface to the core. Also, higher moisture contents can lead to dimensional instability of the finished product, which then results in the cupping or doming of the product, which is extremely undesirable, especially when installers are laying down the flooring. Also, excessive moisture contents can create edge peaking due to the swelling of the product and such edge peaking can result in edge chip-off or premature wear-out or can soil more quickly. The susceptibility to moisture content also leads to some installers not wishing to place such laminate flooring in areas which are subject to having water on the surface of the floor, such as in the kitchen and bathroom areas.
The suppliers of such laminate flooring have appreciated the problems associated with their products and have attempted to overcome these problems by developing laminate flooring having better moisture resistance by using melamine, phenolic, or isocyanate binders to partially replace urea resins present in the laminate flooring. While this improvement has made the product more moisture resistant, the current commercially available laminate floorings are still prone to moisture damage. For instance, the thickness swelling of laminate flooring can increase by 10% and water absorbency can exceed more than 15% according to the 24 hours water absorption test. Another attempted solution at the moisture resistance weaknesses of current laminate flooring has led some manufactures to apply a water-repellant material on the upper edges of the tongue and groove areas which further serve to resist any moisture penetration through joints. Still another attempted solution involves applying silicone caulk to seal the edges and voids of the laminate perimeter where the laminate flooring meets the wall. However, if very stringent installation instructions are not followed, the laminate flooring will still be subjected to moisture damage.
Accordingly, there is a need to develop a laminate flooring system which overcomes the above weaknesses and disadvantages of current commercially available laminate flooring.
USPTO Backgrounds
USPTO Backgrounds