WO2007049901A1

WO2007049901A1 - Process of manufacture for bath utensils

Info

Publication number: WO2007049901A1
Application number: PCT/KR2006/004345
Authority: WO
Inventors: Byung-Ho Yoo
Original assignee: Byung-Ho Yoo
Priority date: 2005-10-25
Filing date: 2006-10-24
Publication date: 2007-05-03
Also published as: KR20070044763A; KR100748104B1

Abstract

Disclosed herein is a method of manufacturing bathroom products, which does not generate dust during a working process, thus being hygienic, and which does not use asbestos, thus being environmentally friendly and having superior abrasion resistance and impact resistance. According to the invention, an elastic member, such as sponge, is placed on a protrusion of a synthetic -resin molding product, a reinforcing material is disposed in the synthetic-resin molding product, and a second synthetic-resin sheet is placed on the reinforcing material to cover the reinforcing material. In this state, the second synthetic-resin sheet is pressed using a hydraulic cylinder. Thus, the reinforcing material expands without leaking out. Thanks to the heat generated by the expansion of the reinforcing material, the upper and lower synthetic-resin sheets are firmly coupled to each other via the reinforcing material.

Description

PROCESS OF MANUFACTURE FOR BATH UTENSILS

Technical Field

[1] The present invention relates, in general, to a method of manufacturing bathroom products and, more particularly, to a method of manufacturing bathroom products, including a finishing material for a ceiling or a wall of a bathroom, a washstand, or a bathtub, which are environmentally friendly and economical and have superior durability and appearance, compared to conventional bathroom products. Background Art

[2] Generally, a washstand or a bathtub installed in the bathroom of a building or a material for finishing the ceiling of the bathroom are made of clay or synthetic resin. Alternatively, the bathroom product is manufactured by molding a flat acryl sheet from thermoplastic resin, forming an additional reinforcing material on the back surface of the molding product, and thermally pressing the reinforcing material against the molding product. The reinforcing material is obtained by mixing asbestos with synthetic resin in a predetermined mixture ratio, and is sprayed using a high-pressure spray. However, when such a method is used, after the reinforcing material is thermally pressed, the product is finished to form a desired bathtub or washstand. At this time, the product must be cut using a saw. However, the product includes asbestos, and thus generates asbestos dust which is harmful to the human body. Further, as time goes by, the bathtub made of the acryl and the reinforcing material may become deformed. When the product is thermally pressed, the curved portion of the product may be undesirably wrinkled. Furthermore, the bathtub including asbestos is problematic in that it causes environmental pollution upon the disposal of the bathtub.

[3] Since such a bathroom product comprises only the acryl sheet and the sprayed reinforcing material, the bathroom product has low abrasion resistance and impact resistance. Further, the bottom of the bathroom product appears crude due to the use of the spray.

[4] Various conventional bathroom products have been proposed. For example,

Japanese Patent Laid-Open Publication No. 7-250772 discloses a sheet for bathtubs and a manufacturing method thereof. The sheet is manufactured by laminating a thermoplastic sheet, specifically, an ABS sheet, to an acryl sheet. The invention increases productivity simply by adding the ABS sheet to the acryl sheet. However, the invention does not solve the problems with the prior art.

[5] Further, Korean Patent No. 10-187809 has been proposed. However, this patent discloses the use of environmentally unfriendly material, such as glass fiber or asbestos, so that it is not environmentally friendly, and the material is very difficult to dispose of when the bathtub is to be discarded. Further, due to the use of a saw in the finishing operation, asbestos dust, which is harmful to the human body, is generated. Further, the invention proposes only elements pertaining to a bathtub. The manufacturing method of the invention is identical with the conventional manufacturing method.

[6] Further, the cited documents are problematic in that portions that are cut away when a product is finished cannot be recycled, thus causing an environmental problem.

[7] In order to solve the problems of the prior art, Korean Patent Appln No.

2001-16720 was filed by the applicant of the present invention. The invention discloses a method of manufacturing a bathroom product, which includes a mold manufacturing step, an acryl sheet molding step, a cooling step, a reinforcing-material pouring step, and a pressing step. However, the invention does not disclose the reason for limiting the numerical values of the compositions of the reinforcing material, and does not concretely illustrate the manufacturing method.

[8] Further, it is very difficult to adhere an acryl sheet to an ABS sheet, so that it is difficult to manufacture a durable bathroom product. Disclosure of Invention Technical Problem

[9] Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a method of manufacturing bathroom products and a bathroom product manufactured using the method, which does not use substances that are harmful to the human body, such as glass fiber, and has a good appearance, and in which a reinforcing material is disposed between two layers of synthetic-resin sheets to adhere the sheets to each other, thus enhancing abrasion resistance and impact resistance, and which enables portions that are removed upon a finishing process to be recycled. Technical Solution

[10] In order to accomplish the object, the present invention provides a method of manufacturing bathroom products, including step Sl of molding a first synthetic-resin sheet to have a desired shape using a mold, thus making a first synthetic-resin sheet molding product having an upwardly protruding protrusion; step S2 of charging a reinforcing material in the first synthetic-resin sheet molding product after step S 1 has been completed; step S3 of applying an elastic member along the protrusion of the first synthetic-resin sheet molding product, after the step S2 has been completed; and step S4 of placing a second synthetic-resin sheet on the first synthetic -resin sheet molding product, and pressing the second synthetic -resin sheet using a press, after step S3 has been completed. Further, the invention provides a bathroom product manufactured using the manufacturing method.

[11] Here, steps S2 and S3 may be simultaneously conducted, or step S3 may be conducted before step S2. Further, the first and second synthetic-resin sheets may be made of an ABS sheet or an acryl sheet. At step S2, the reinforcing material may use a mixture obtained by mixing synthetic resin with calcium carbonate at a ratio of 1:1.0 to 1.7, or may use a mixture obtained by mixing synthetic resin, calcium carbonate, and the phyllite at a ratio of 1:1.0 to 1.7:0.3 to 1.2. In this case, the ratio denotes a weight ratio.

[12] Among the bathroom products, it is not necessary to add phyllite to the reinforcing material of a bathtub or a washstand, because the phyllite is preferably used to reduce weight. When the weight ratio of the calcium carbonate to the synthetic resin is less than 1.0, the reinforcing material is thin, so that adhesive strength is reduced. Meanwhile, when the weight ratio of the calcium carbonate to the synthetic resin is more than 1.7, the reinforcing material is too thick, so that adhesive strength is poor. The quantity of the phyllite is determined in consideration of volume expansion. Ultralight phyllite, which is a kind of volcanic ash, may be used. In the present invention, the calcium carbonate and the phyllite are general calcium carbonate and general phyllite.

[13] Further, the elastic member of step S3 may use all thermoplastic materials having elasticity, such as rubber or non-woven fabric. However, it is most preferable that sponge be used as the elastic member, in consideration of cost.

[14] Preferably, the sponge covers an edge of a protrusion of the first synthetic-resin sheet molding product to the width of the edge.

[15] In the present invention, the sponge prevents the reinforcing material from leaking out when the second synthetic-resin sheet is pressed over the reinforcing material charged in the first synthetic-resin sheet molding product. As such, the reinforcing material does not leak out during the pressing process, so that expansion pressure is generated in the reinforcing material. The reinforcing material penetrates into the synthetic resin, thus carrying out a melting and adhering operation. Further, the sponge is made of a thermoplastic material so that removed portions thereof can be reused. The sponge plays a very important role in the present invention.

[16] Further, at the pressing step S4, a hydraulic cylinder is preferably used as a press.

Since one shaft of the hydraulic cylinder is a load of 3,000 to 4,000kg, a hydraulic cylinder having only one shaft is sufficient to achieve the object of this invention. At first, the pressing process is slowly executed, so that air is discharged from the interior. Next, the pressing process is rapidly executed and maintained for 10 to 30 minutes to provide sufficient hardening time. In this case, upper and lower molding devices provide a bathroom product having a desired shape. When the molding operation is terminated, a cutting operation, which is the finishing operation, is conducted. The cutting operation is conducted at the inside portion of the sponge, which is used as the elastic member. That is, predetermined portions are cut, so that the bathroom product is completed. The cut portions can be ground and reused. Since no asbestos is present in the cut portions, little dust is generated. All of the generated dust is absorbed by frictional heat. As a result, the generation of dust is prevented.

[17] As such, the present invention does not use asbestos, so that it is environmentally friendly. The first synthetic-resin sheet, the reinforcing material, and the second synthetic-resin sheet form a triple structure, so that the bathroom product is not deformed and does not break during the cutting operation. Thereby, impact resistance and abrasion resistance are enhanced. Further, dust is not generated during the finishing cutting operation, so that it is possible to manufacture an excellent bathroom product in a clean environment. Brief Description of the Drawings

[18] FIG. 1 is a view schematically showing a mold used in the present invention;

[19] FIG. 2 is a view showing the process of manufacturing a first synthetic-resin sheet molding product, according to the present invention;

[20] FIG. 3 is a view showing the state where a reinforcing material is charged in the first synthetic-resin sheet molding product, according to the present invention;

[21] FIG. 4 is a view showing the state where a molding process is conducted after a second synthetic-resin sheet of the present invention has been placed;

[22] FIG. 5 is a sectional view showing a finished product, according to the present invention;

[23] FIGS. 6 to 8 are views showing steps of a manufacturing process, according to another embodiment of the present invention; and

[24] FIG. 9 is a sectional view showing a bathroom product manufactured according to another embodiment of the present invention. Best Mode for Carrying Out the Invention

[25] Hereinafter, a method of manufacturing a bathroom product according to the preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[26] (First Embodiment)

[27] The embodiment illustrates the method of manufacturing a bathtub, as an example of a bathroom product, according to the present invention.

[28] FIG. 1 is a sectional view showing a mold so as to illustrate the mold for making a first synthetic-resin sheet molding product at a first step. As shown in FIG. 1, a mold 10, having a protrusion 12 (dotted line) which protrudes further upwards than the shape 11 (see, FIG. 2) of the bathtub to be manufactured, is prepared.

[29] After a first synthetic-resin sheet, namely, an ABS sheet 100, is placed on the prepared mold 10, the ABS sheet is pressed in the direction of the arrow, so that an ABS sheet molding product 111 having a protrusion 112 is obtained at step Sl (see, FIG. 3). In this case, the pressure forming method is performed in a general way.

[30] A reinforcing material 200 is poured into the ABS sheet molding product 111, at step S2.

[31] Since this embodiment relates to the manufacture of the bathtub, reinforcing materials having various compositions are used and compared with each other. That is, a reinforcing material is produced by mixing synthetic resin only with calcium carbonate at a ratio of 1:1.5. Another reinforcing material is produced by mixing synthetic resin, calcium carbonate, and phyllite at a ratio of 1:1.5:0.3. A further reinforcing material is produced by mixing synthetic resin, calcium carbonate, and phyllite at a ratio of 1:1.7:1. When the reinforcing materials having the above- mentioned compositions are compared with each other, the more phyllite there is, the thicker the finished bathtub is. The strength of the finished bathtub is almost constant regardless of the quantity of the phyllite. Thus, it is not necessary to add phyllite to the reinforcing material for the bathtub. Further, only a small quantity of phyllite need be used.

[32] As such, the protrusion 112 of the ABS sheet molding product 111, into which the reinforcing material 200 is poured, is surrounded with sponge 300 at step S3 (see, FIG. 4). The sponge 300 is laid along the edge of the protrusion 112.

[33] An acryl sheet 400 is placed over the ABS sheet molding product 111, which is surrounded with the sponge 300 and in which the reinforcing material 200 is placed. The acryl sheet 400 is slowly pressed in the direction of the arrow using a hydraulic cylinder having one shaft and a load of 3500kg. Subsequently, the acryl sheet is rapidly pressed. Such a state is maintained for 20 minutes at step S4. The molding and pressing processes are performed in the mold.

[34] At step S4, as shown in FIG. 4, when the acryl sheet 400 starts to be pressed in the direction of the arrow by the hydraulic cylinder (not shown), the interior air starts to be discharged through pores of the sponge 300 to the outside. When the pressure of the hydraulic cylinder becomes high, the interior is sealed, and thus heat is generated by the expansion pressure of the reinforcing material 200. Thereby, the upper acryl sheet 400 and the lower ABS sheet molding product 111 are plastically deformed via the reinforcing material 200 so as to completely adhere to each other.

[35] At this time, the sponge 300 is slowly pressed, thus preventing the reinforcing material 200 from being discharged to the outside, and functioning to close the interior. The sponge serves to minimize the leakage of the reinforcing material in the event that the reinforcing material leaks out.

[36] A bathtub manufactured through the above-mentioned steps and then sufficiently hardened has the shape of FIG. 5. That is, the ABS sheet molding product 111 is provided at the lowermost position, and the reinforcing material 200 is superposed on the ABS sheet molding product to be in close contact therewith. An acryl sheet molding product 411 is provided on the reinforcing material. The protrusions 112 and 412 and the sponge 300 are provided on both sides of the bathtub.

[37] The bathtub which has the above-mentioned shape just before the bathtub is finished is cut along lines A-A and B-B, which are provided at positions inside the sponge 300, using a saw or a similar tool, so that the protrusions 112 and 412 and the sponge 300 are removed. Thereby, the finished bathtub is obtained.

[38] Typically, during the cutting operation, asbestos is scattered, so that dust harmful to the human body is generated. However, according to the present invention, the ABS sheet is a kind of synthetic resin, the reinforcing material is made of a mixture of synthetic resin and calcium carbonate or a mixture of synthetic resin, calcium carbonate, and phyllite, and the acryl sheet is a kind of synthetic resin. Thus, the small quantity of dust that is generated during the cutting operation using a saw or a similar tool is absorbed due to frictional heat, and thus is not scattered to the outside. Further, since all of the materials are thermal plastic, portions cut by the saw more firmly and completely adhere to each other due to the frictional heat.

[39]

[40] (Second Embodiment)

[41] The second embodiment of the present invention illustrates the method of manufacturing a material for finishing a ceiling of a bathroom or the like.

[42] First, as shown in FIG. 6, a mold 500 which has the shape 511 of a finishing material to be manufactured and has an upwardly protruding protrusion 512 is prepared. Next, as in the first embodiment, an ABS sheet 600 is formed using the mold 500 (see, FIG. 7), so that an ABS sheet molding product 611 is obtained (see, FIG. 8). After a reinforcing material 700 is charged in the ABS sheet molding product, sponge 900 is laid on the protrusion 612, as in the first embodiment. An acryl sheet 800 is placed on the sponge, and thereafter is pressed using a hydraulic cylinder, in the same manner as the first embodiment. Here, the ABS sheet is interchangeable with an acryl sheet.

[43] Since the second embodiment of this invention relates to the method of manufacturing the material for finishing the ceiling of the bathroom, the reinforcing material is made of a mixture obtained by mixing synthetic resin, calcium carbonate, and phyllite at a ratio of 1:1.0:0.3. Further, the quantity of phyllite may be further added so that the composition of the reinforcing material is 1:1.0:0.7 or 1:1.0:1.2. Comparing the reinforcing materials having various compositions with each other, the strength is almost constant. However, as the quantity of added phyllite is increased, the finishing material becomes slightly thick but becomes considerably light.

[44] The state of the ceiling material obtained through the above-mentioned steps just before the ceiling material is finished is as follows. That is, as shown in FIG. 9, the ABS sheet 611 is provided on the lower portion, the reinforcing material 700 is placed on the ABS sheet, and the acryl sheet 811 is placed on the reinforcing material. Further, the pressed sponge 900 and the protrusions 612 and 812 are provided on both sides of the acryl sheet. When the product is finished, unneeded portions are cut along line A-A and B-B using a saw or a similar tool. Thereby, the finishing material for the ceiling of the bathroom is completed.

[45] A washstand, an example of a bathroom product, can be manufactured through the above-mentioned method.

[46] Further, the cut and separated protrusions 112, 412, 612, and 812, the portion of the reinforcing material that is exposed to the outside, and the pressed sponge 300 and 900 can be recycled.

[47] That is, after the cut portions are ground, the crushed powder is separated into ABS and acryl using a difference in specific gravity so as to be recycled. The separated reinforcing material is ground into powder for reuse.

[48] Further, the sponge can be reused as material for synthetic resin.

Industrial Applicability

[49] As described above, the present invention provides a method of manufacturing bathroom products, such as a bathtub, which does not use asbestos, thus being environmentally friendly, in which a reinforcing material is disposed between first and second synthetic-resin sheets, thus enhancing abrasion resistance and impact resistance, and preventing curved portions from being deformed, in addition to providing a good appearance. Further, since all materials are thermoplastic, dust generated during a finishing operation is absorbed by frictional heat, so that dust is never generated, and thus it is possible to manufacture the bathroom products in an environmentally friendly and hygienic manner. These effects are achieved by the manufacturing method of this invention, which is performed as follows. That is, when the reinforcing material is charged and pressed between the first and second synthetic-re sin sheets, an elastic member, such as sponge, is placed on the first synthetic-resin sheet. In such a state, the second synthetic-resin sheet, provided at an upper position, is pressed against the first synthetic-resin sheet, so that the interior reinforcing member is sealed. At this time, using expansion pressure caused by expansion heat of the re- inforcing member, the first synthetic-resin sheet, the reinforcing material, and the second synthetic-resin sheet are firmly coupled to each other.

[50] Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. In particular, any method of attaching the first synthetic-resin sheet to the second synthetic-resin sheet using the reinforcing material falls within the scope of the present invention regardless of the intended purpose.

Claims

[1] A method of manufacturing bathroom products, such as a finishing material for a ceiling of a bathroom, a washstand, or a bathtub, which are manufactured using a synthetic-resin sheet, comprising: step (Sl) of molding a first synthetic-resin sheet to have a desired shape, thus making a first synthetic -resin sheet molding product having an upwardly protruding protrusion; step (S2) of charging a reinforcing material in the first synthetic-resin sheet molding product; step (S3) of applying a sponge along an edge of the protrusion of the first synthetic-resin sheet molding product to a width of the edge, after the step (S2) has been completed; and step (S4) of placing a second synthetic -resin sheet on the first synthetic-resin sheet molding product, and pressing the second synthetic-resin sheet using a press under a load of 3000 to 4000kg, after step (S3) has been completed. [2] The method according to claim 1, wherein the reinforcing material of step (S2) is a mixture obtained by mixing synthetic resin and calcium carbonate at a weight ratio of 1:1.0 to 1.7. [3] The method according to claim 2, wherein the reinforcing material further comprises phyllite such that a weight ratio of the synthetic resin to the phyllite is

1:0.3 to 1.2. [4] The method according to claim 1, wherein the step (S3) is conducted before the step (S2).