Abstract: Disclosed is a battery charging system according to an embodiment present invention including a battery module having a plurality of rechargeable batteries, and a charger connected to the battery module for charging, wherein when the battery module and the charger are connected, the plurality of rechargeable batteries are disconnected from each other to receive external power separately from the charger, thereby reducing the charging time of the battery module.

Abstract: Disclosed herein is a back-grooved laminate wood flooring in which a wood veneer of high pressure resin impregnation laminate (WPL) is laminated on a base selected from a vinyl chloride (PVC) resin layer, on oriented strand board (OSB), a high-density fiberboard (HDF) and a waterproof plywood. More specifically, the back-grooved laminate wood flooring comprises a WPL (20), an adhesive layer (40) and a base (10) (a polyvinyl chloride resin layer, OSB, HDF or waterproof plywood) wherein the WPL (20) includes a base-reinforcing layer (24), a natural veneer layer (23), a resin-impregnated overlay layer (22) and a surface UV coating layer (21) layered in this order from the bottom. The back-grooved laminate wood flooring further exhibits excellent soundproofing performance.

Abstract: Provided is a functional adhesive including or a mixture thereof, wherein the flavonoid-based compound, the polyphenol-based compound, or the steroid-based compound has a molecular weight of 250 to 1000. The functional adhesive has a low concentration of VOCs and HCHO, and also facilitates a low concentration of VOCs in products to which the functional adhesive is applied.

Abstract: Disclosed herein is a back-grooved laminate wood flooring in which a wood veneer of high pressure resin impregnation laminate (WPL) is laminated on a base selected from a vinyl chloride (PVC) resin layer, on oriented strand board (OSB), a high-density fiberboard (HDF) and a waterproof plywood. More specifically, the back-grooved laminate wood flooring comprises a WPL (20), an adhesive layer (40) and a base (10) (a polyvinyl chloride resin layer, OSB, HDF or waterproof plywood) wherein the WPL (20) includes a base-reinforcing layer (24), a natural veneer layer (23), a resin-impregnated overlay layer (22) and a surface UV coating layer (21) layered in this order from the bottom. The back-grooved laminate wood flooring further exhibits excellent soundproofing performance.