JP3197492B2 - Molded fiberboard - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molded fiberboard used for a door surface material of a flash door mounted on a house.

[0002]

BACKGROUND OF THE INVENTION Flush doors mounted on houses are manufactured by stretching a door panel, which is a molded fiberboard, on both sides of a core. The door panel is hot and humid in summer and low and low in winter. Warping due to large changes in temperature and humidity
Deformation such as swelling is likely to occur, and if such deformation occurs in the door surface material, the degree of sealing of the door may be reduced, or the opening and closing of the door may be hindered.

[0003]

2. Description of the Related Art In order to prevent such a door surface of a flash door from being deformed, a structure in which a water-impermeable and moisture-permeable sheet is bonded to both sides of a door surface of a conventional flash door (Japanese Patent Laid-Open No. 6-272455). And a structure in which a warp member made of metal is applied to a core material (Japanese Patent Laid-Open No. 5-33560).

[0004]

SUMMARY OF THE INVENTION The above-mentioned Japanese Patent Application Laid-Open No. 6-272 is disclosed.
In the structure of No. 455, the influence of humidity on the door surface material can be cut off, but deformation due to temperature change cannot be prevented. In the structure of JP-A-5-33560, deformation of the core material can be prevented, There is a problem that deformation cannot be prevented.

[0005]

According to the present invention, as a means for solving the above-mentioned conventional problems, there is provided a mat (1,2) of a raw material mixture obtained by mixing a fiber mainly composed of wood fibers with a thermosetting resin as a binder. Are laminated on the surface layer and the core layer, and the molded fiberboard obtained by hot-press molding, the mat of the core layer
Another object of the present invention is to provide a molded fiberboard reinforced by providing a threaded portion (2B) in (2). The mat (2) on the back side may be a mat (2A) divided into a plurality of pieces and sewn together with a thread.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to an embodiment shown in FIGS. As shown in FIG. 1, (1,
2) is a fiber mat, and the fiber mat (1, 2) is obtained by drying wood fiber, usually 1 to 15 mm in length, obtained by defibrating wood chips to a water content of 7 to 10% by weight. For example, usually a thermoplastic fiber such as a polyethylene fiber having a fiber length of 2 to 10 mm, a polypropylene fiber, an ethylene-vinyl acetate copolymer fiber, a polyvinylidene chloride fiber, a polyvinyl alcohol fiber, and an acrylic fiber is mixed, and a urethane resin, a melamine resin, A raw material mixture in which a thermosetting resin such as a thermosetting acrylic resin, a urea resin, a phenol resin, an epoxy resin, a thermosetting polyester, or diallyl phthalate is usually mixed at 5 to 20% by weight is formed into a mat by a dry method or a wet method. Manufactured by

[0007] The pair of fiber mats (1, 2) may be made of the same material, but the core layer mat (2) may be made of hemp fiber, palm fiber, palm fiber, bamboo fiber or the like. Rigid fibers may be used. In the present embodiment, a plurality of cuts (2A) of the surface mat (1) are collected as the core layer mat (2), and the mat (1) is cut from the back side at the boundary between the cuts (2A). The cut end (2A) is stitched together with the reinforcing mat (3) with a thread by abutting the cut end of the reinforcing mat (3). As the yarn, for example, a synthetic fiber such as a polyester fiber, a polyamide fiber, an acrylic fiber, a polyvinylidene chloride fiber, or an acetate fiber or a natural fiber yarn such as cotton, silk, or wool is used.

Conventionally, the cut pieces have been defibrated and reused as a part of the raw material. However, since the fibers are not completely loosened and exist as small lumps, the small lumps hinder the forming of the mat. However, if the scraps are used as a back layer mat or a reinforcing mat as in this embodiment, a path for effective reuse of the scraps is opened.

The sewn portion (2B) is provided continuously over substantially the entire length of the mat (2) of the core layer. In the mat (2), the cut pieces (2A) are sewn together and at the same time as the mat (2) is cut.
To prevent deformation of the product such as warpage and swelling, but the sewn portion (2B) may be provided continuously over substantially the entire width.

The pair of fiber mats (1, 2) are superimposed on each other as shown in FIG. 2, are hot-pressed by a press forming machine (5), and have a door face material (FIG. 3) shown in FIGS. Four)
Molded into The door panel (4) has a frame (4A) and a decorative frame (4
An end plate part (4C) surrounded by B) is provided.

As shown in FIG. 5, the door surface material (4) is reinforced by the sewn portion (2B) of the mat (2) of the core layer and the reinforcing mat (3) to change the temperature and humidity. Deformation such as warpage or swelling due to the above is prevented.

In the present embodiment, the reinforcing mat (3) is used, but the reinforcing mat (3) is not essential in the present invention and may be omitted. In addition, the mat (2) of the core layer may be provided with only the sewn portion in the longitudinal direction and / or the width direction in one piece instead of the end cut sewn with the sewn portion. The sewn portion is desirably provided over substantially the entire length and / or substantially the entire width.

[Example 1] As a surface mat, a fiber length of 2 to 2 was used.
15 mm, 88% by weight of wood fiber and 7% by weight of wood fiber and 12% by weight of powdered phenol resin were uniformly mixed and formed into a mat having a thickness of about 10 mm by a felt machine.
49% by weight of hemp fiber having a fiber length of 50 to 100 mm and a water content of 10% by weight, 40% by weight of wood fiber having a fiber length of 2 to 15 mm and a water content of 7% by weight, and 5% by weight of polyethylene fiber having a fiber length of 7 mm as a core layer mat % And powdered phenolic resin 11% by weight
And a uniform thickness of about 15 with a felt machine.
Formed mm mat. A continuous sewn portion was provided in the center of the core layer mat using the # 20 cotton thread over the entire length, and the surface layer mat was superposed on the front side and hot-press molded to a length of 600 mm, a width of 300 mm, and a thickness of 3.2 mm. Was produced.

Embodiment 2 A reinforcing mat made of the same material as the backing mat and having a thickness of 10 mm is brought into contact with the back side of the core mat (single piece) of the embodiment 1, and the reinforcing mat and the core mat are connected to each other. Was sewn at the sewn portion using the same cotton thread as in Example 1 and then overlaid with a surface mat, and hot-pressed as in Example 1 to obtain a flat plate having a length of 600 mm, a width of 300 mm, and a thickness of 3.0 mm. A shaped fiberboard was produced.

Example 3 Two pieces of the same width as the core layer mat of Example 1 were used, and a reinforcing mat having a thickness of 10 mm and the same material as the core layer mat was used on the back side of the joint between the ends. , And the cut ends are sewn together with a reinforcing mat using a sewn portion using the same cotton thread as in Example 1 and then superimposed on the surface layer mat. A 300-mm-wide, 3.3-mm-thick, flat molded fiberboard was produced.

Comparative Example 1 A flat molded fiberboard having a thickness of 2.9 mm was produced in the same manner as in Example 1 except that the core layer mat was not provided with a sewn portion.

[Comparative Example 2] In Example 3, the cut ends of the back layer mat were not sewn together by a sewn portion.
Other than that produced the flat molded fiberboard similarly to Example 3.

Examples 1, 2 and 3 and Comparative Examples 1 and 2
Table 1 shows the results of measuring the bending strength of the formed fiberboard.

[Table 1]

Comparison between Example 1 and Example 2 in Table 1 shows that Example 2 using the reinforcing mat has improved strength compared to Example 1 not using the reinforcing mat. Also, comparing Example 2 and Example 3, the bending strength of Example 3 using the cut-off sutures in the core layer mat is also superior to Example 2 using one piece of the core layer mat. Almost equivalent. Comparative Example 1 is obtained by omitting the sewn portion in Example 1. By omitting the sewn portion, Comparative Example 1 has a lower bending strength than Example 1, and Comparative Example 2 has a sewn portion in Example 3. Since the cut ends were not sewn and the sewn portion was not present, the bending strength of Comparative Example 2 was significantly reduced compared to Example 2.

[0020]

According to the present invention, a molded fiberboard which is hardly deformed such as warpage or swelling even by a large change in temperature or humidity can be obtained, and the molded fiberboard is useful, for example, as a door face material.

[Brief description of the drawings]

 1 to 5 show an embodiment of the present invention.

FIG. 1 is a perspective view of a surface mat and a core layer mat.

FIG. 2 is an explanatory view of a molding state.

FIG. 3 is a perspective view of a door surface material.

FIG. 4 is a sectional view taken along line AA in FIG. 3;

FIG. 5 is a partial sectional view of a sewn portion.

[Explanation of symbols]

 1 Surface mat (fiber mat) 2 Core layer mat (fiber mat) 2A Cut off 2B Sewing part 3 Reinforcement mat 4 Door face material

Claims (4)

(57) [Claims] 1. A molded fiberboard obtained by arranging and laminating a mat of a raw material mixture obtained by mixing a fiber mainly composed of wood fibers with a thermosetting resin as a binder on a surface layer and a core layer, and hot-press molding. Characterized in that a threaded portion is provided on the mat of the core layer and reinforced by providing a thread portion. 2. The molded fiberboard according to claim 1, wherein the mat of the core layer is composed of a plurality of mats, and the mats are stitched to each other by a threaded portion. 3. The molded fiberboard according to claim 2, wherein the mat constituting the mat of the core layer is a cut end of a surface layer mat. 4. The molded fiberboard according to claim 1, wherein a reinforcing mat is lined with a sewn portion of the mat of the core layer.