Description TIMBER BATHTUB WITH FRP LAYER

Technical Field

[1] The present invention relates to a bathtub and, more particularly, to a timber bathtub. Background Art

[2] A timber exhibits a high contraction and expansion coefficient with respect to water and has a nature of being discolored by water and quite vulnerable to mold. Thus, there is a limit in using the timber as a material for the manufacture of a bathtub. A composite timber bathtub has been proposed that uses paint to makes up for the weak nature to water. However, the composite bathtub requires use of a timber having an increased thickness to assure durability and therefore is costly to manufacture. This imposes restrictions on the composite bathtub in its use as a built-in type (embedded type) bathtub. Furthermore, the paint on the composite bathtub may suffer from damage due to installation and use of the composite bathtub in harsh surroundings, which makes it difficult for the composite bathtub to maintain its function. In addition, the necessity of assuring structural integrity of bathtub walls makes it difficult to reduce the weight of the composite bathtub, which leads to an increase in price. In a nutshell, the composite bathtub is restricted in terms of function and economy. Disclosure of Invention Technical Problem

[3] In view of the above-noted problems, it is an object of the present invention to provide a timber bathtub capable of minimizing the thickness of a wood material and curtailing the use of a raw timber. Another object of the present invention to provide a timber bathtub that can be installed and used as a built-in type (embedded type) bathtub.

Technical Solution

[4] In one aspect of the present invention, there is provided a timber bathtub including a first structural part made of a wood material and a second structural part bonded to an outer surface of the first structural part and made of fiber-reinforced plastic (FRP).

[5] In the timber bathtub, the second structural part may include a plurality of fiber- reinforced plastic laminate layers.

[6] In the timber bathtub, the second structural part may include a first fiber-reinforced plastic laminate layer making contact with the outer surface of the first structural part and a second fiber-reinforced plastic laminate layer kept in contact with an outer surface of the first fiber-reinforced plastic laminate layer.

Advantageous Effects

[7] The objects of the present invention set forth above can be accomplished in their entirety by the configuration of the present invention. More specifically, a wood material layer formed on an inner surface of the timber bathtub provides a beautiful appearance by sustaining its natural texture. Furthermore, the timber bathtub allows a user to enjoy the intrinsic properties of a timber, thus making the user who has a bath feel pleasant with no sense of incongruity which would be given in other materials. Thanks to an improved heat preservation and thermal insulation property, the timber bathtub can keep its internal temperature constant for an extended period of time, thereby helping to save energy. Moreover, a FRP layer formed on an outer surface of the timber bathtub and bonded to the wood material layer assists in minimizing the thickness of the wood material and reducing use of an expensive raw timber. This makes it possible to manufacture the timber bathtub in a cost-effective manner. In addition, the FRP layer is good in its function and can make up for the weak points of a conventional timber bathtub, i.e., the vulnerability to water. Thus, the timber bathtub can be extensively used as a built-in type (embedded type) bathtub in a bath room of apartments and other newly built houses. Brief Description of the Drawings

[8] Fig. 1 is a partially cut away side elevational view showing a bathtub in accordance with one embodiment of the present invention. Best Mode for Carrying Out the Invention

[9] Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawing.

[10] Referring to Fig. 1, a bathtub 10 includes a first structural part 20 and a second structural part 30. The first structural part 20 defines an interior space of the bathtub 10 and is made of a wood material, preferably a cypress or a red cedarwood. The second structural part 30 makes direct contact with an outer surface of the first structural part 20 and forms an outer portion of the bathtub 10. The second structural part 30 is made of fiber-reinforced plastic (FRP) and includes a first fiber-reinforced plastic laminate layer 40 and a second fiber-reinforced plastic laminate layer 50. The first fiber- reinforced plastic laminate layer 40 makes direct contact with the outer surface of the first structural part 20. The second fiber-reinforced plastic laminate layer 50 is brought into direct contact with an outer surface of the first fiber-reinforced plastic laminate layer 40. In case the second structural part 30 is formed too thin, water leakage and fracture may possibly occur in an irregular surface portion of the first structural part 20. In case the second structural part 30 is formed too thick, the bathtub 10 becomes too heavy and inconvenient to install in place. In view of this, it is preferred that the

second structural part 30 has a thickness of about 3mm. Fiber-reinforced plastic employed in the present invention is of strong nature owing to its increased specific strength and has a greater freedom of design owing to its high formability. Furthermore, the fiber-reinforced plastic is good in chemical resistance and heat resistance.

[11] A method of manufacturing the bathtub 10 having the structure noted above will now be described in detail. First, a timber obtained by thinning a cypress or a red cedarwood is sawed and artificially dried to a water content ratio of 12%, after which planks are produced from the dried timber through a typical method (cutting, sanding (grinding) and moisture-adjusting processes). Then, the planks are cut into assembly members of a specified size which in turn are assembled together to form a first structural part 20 of the bathtub 10. Subsequently, fiber-reinforced plastic is laminated once on the entire outer surface of the first structural part 20. The fiber-reinforced plastic is prepared by applying unsaturated polyester resin on glass fibers and compressing them together. A first fiber-reinforced plastic laminate layer 40 having a thickness of 1.7mm is formed by laminating the first fiber-reinforced plastic. Thereafter, a second fiber-reinforced plastic laminate layer 50 is formed on the entire outer surface of the first fiber-reinforced plastic laminate layer 40 to thereby form a second structural part 30 having a thickness of about 3mm. The method of forming the second fiber-reinforced plastic laminate layer 50 is the same as the method of forming the first fiber-reinforced plastic laminate layer 40 noted above.

[12] Although the second structural part 30 has two FRP laminate layers 40 and 50 in the foregoing embodiment, the present invention is not limited thereto. Three or more FRP laminate layers may be formed by performing FRP laminating treatments three times or more.

[13] Not only coniferous trees but also broadleaf trees may be extensively used as a timber or wood material in the present bathtub.

[14] While an embodiment of the present invention has been set forth hereinabove, the present invention is not limited to this embodiment. It will be understood by those skilled in the art that various changes and modifications may be made without departing from the scope of the invention defined in the claims.