Method for manufacturing flooring materials and apparatus for manufacturing flooring materials

Abstract

To make it possible to improve the quality of a flooring material and to suppress deterioration in design.SOLUTION: A method for manufacturing a flooring material by extrusion molding a base material 11A including hygroscopic material in the flooring material, using a manufacturing apparatus equipped with an extrusion mold 20 and a sliding sizing mold 30 positioned with a gap S between the extrusion mold 20 and the sliding sizing mold 30, includes: a process of extruding a material for the base material 11A supplied from an extruder 40 from the extrusion mold 20 to a mold part of the sliding sizing mold 30; a process of cooling the material by passing it through the sliding sizing mold 30; and a process of vacuum suctioning air containing steam from a steam exhaust groove 33 formed on a surface of the sliding sizing mold 30 facing the extrusion mold 20 and through which steam generated by heat of the extrusion mold 20 flows. The steam exhaust groove 33 is arranged on the outer peripheral side of the mold part into which the material of the sliding sizing mold 30 is pushed.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a flooring material and a flooring material manufacturing apparatus.

Background Art

[0002] Conventionally, as a general method for joining flooring materials, there is often a fitting shape such as a mortise and tenon or a tongue-and-groove shape in which the end of a panel material has a concave shape and the opposite end has a convex shape, and adjacent flooring materials are fitted horizontally and laid. However, in such a fitting method with such a fitting shape, when a liquid such as water spills, it seeps into the bottom surface through the gap at the fitting part. Therefore, for example, there is known a flooring material that is fitted vertically with a return shape at the joint part to prevent the spilled liquid from seeping from the fitting part to the bottom surface.

[0003] For manufacturing the base material of such a flooring material, an extrusion die to which a base material material (for example, a material obtained by mixing hygroscopic wood powder, talc, polypropylene resin (PP), an additive, a foaming agent, etc.) is supplied from an extruder, and a sliding sizing die arranged with a gap of about 0.5 mm with respect to the extrusion die are provided, and a molding apparatus that forms the base material by pushing the material from the extrusion die into the sliding sizing die is used (for example, refer to Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In conventional flooring material manufacturing methods, the base material is produced by extruding a material containing hygroscopic wood powder in a self-foaming process, cooling and molding it in a sliding sizing mold, cutting it into a base material of a predetermined length, and then curing it at a warm temperature. During this molding process, as the mixed resin containing wood powder flows from the extrusion mold to the sliding sizing mold, the moisture contained in the wood powder evaporates due to the heat of the extrusion mold. Furthermore, water vapor flows into the gap between the extrusion mold and the sliding sizing mold, and condensation occurs when it convects and comes into contact with the surface of the sliding sizing mold, which has cooled to, for example, 12-13°C. When a certain amount of this condensation accumulates, it drips onto the surface of the resin and hardens rapidly, getting stuck at the entrance of the sliding sizing mold, causing roughness and breakage of the base material surface. Thus, when roughness occurs on the substrate surface during the molding process, the quality of the sheet wrapping deteriorates in the subsequent manufacturing process where the material is attached to the substrate surface. This leads to problems with the design of the decorative layer and a decrease in the peel strength of the decorative layer, indicating room for improvement. Furthermore, since breakage can halt production, there was also room for improvement in this regard.

[0006] This invention has been made in view of the above-mentioned problems, and aims to provide a method for manufacturing flooring materials and a flooring material manufacturing apparatus that can improve the quality of flooring materials and suppress a decline in design quality. [Means for solving the problem]

[0007] (1) Embodiment 1 of the method for manufacturing flooring material according to the present invention is a method for manufacturing flooring material in which a base material containing a hygroscopic material is manufactured by extrusion molding using a manufacturing apparatus comprising an extrusion die and a sliding sizing die arranged with a gap between the extrusion die and the flooring material, comprising the steps of: extruding the base material supplied from the extruder from the extrusion die to the mold portion of the sliding sizing die; cooling the material by passing it through the sliding sizing die; and vacuum sucking air containing the steam from a steam discharge groove formed on the surface of the sliding sizing die facing the extrusion die and through which steam generated by the heat of the extrusion die is passed, wherein the steam discharge groove is arranged on the outer circumference side of the mold portion of the sliding sizing die into which the material is pressed.

[0008] (2) Embodiment 2 of the present invention is a method for manufacturing flooring material according to Embodiment 1, characterized in that the steam exhaust groove is provided around the entire circumference of the mold portion.

[0009] (3) Embodiment 3 of the floor material manufacturing apparatus according to the present invention is a floor material manufacturing apparatus for manufacturing a base material containing a hygroscopic material for floor material, comprising: an extrusion die from which the material of the base material is supplied from an extruder; and a sliding sizing die arranged with a gap between it and the extrusion die, which cools the material pushed in from the extrusion die by passing it through, wherein the sliding sizing die has a steam discharge groove on the surface facing the extrusion die, which is arranged on the outer circumference side of the mold portion into which the material of the sliding sizing die is pushed, and through which steam generated by the heat of the extrusion die flows, and the sliding sizing die is provided with a vacuum suction passage for vacuum sucking air containing the steam from the steam discharge groove.

[0010] (4) A fourth aspect of the present invention may be characterized in that, in the floor material manufacturing apparatus of the third aspect, the steam exhaust groove is provided around the entire circumference of the mold.

[0011] (5) Embodiment 5 of the present invention is a floor material manufacturing apparatus according to Embodiment 3 or Embodiment 4, wherein the steam exhaust groove has an upper groove extending in the width direction above the mold portion, and a plurality of the upper grooves are provided at intervals in the vertical direction.

[0012] (6) Aspect 6 of the present invention is a floor material manufacturing apparatus of aspect 3 or aspect 4, wherein the steam exhaust groove has a transverse groove extending in the width direction, the transverse groove has a downward taper that slopes downward from the center in the extension direction toward both sides, and the vacuum suction passage is connected to the center in the extension direction of the transverse groove. [Effects of the Invention]

[0013] According to the flooring material manufacturing method and flooring material manufacturing apparatus of the present invention, it is possible to improve the quality of the flooring material and suppress the deterioration of its design. [Brief explanation of the drawing]

[0014] [Figure 1] This is a perspective view of a flooring material according to an embodiment of the present invention. [Figure 2] This is a perspective view of the flooring material with a section broken. [Figure 3] This is a cross-sectional view of multiple flooring materials arranged in a row, viewed from the longitudinal direction. [Figure 4] Figure 3 is a cross-sectional view of the main part of the flooring material. [Figure 5] This is a side view showing the configuration of a floor material molding machine. [Figure 6] This is a magnified view of the main parts of a floor material molding machine. [Figure 7] This is a plan view of a sliding sizing die, seen from above. [Figure 8] Figure 7 shows a view along line AA, which is a front view of the second connecting end face side of the sliding sizing die. [Figure 9] This is a side view of the upper sliding sizing mold. [Modes for carrying out the invention]

[0015] A method for manufacturing a floor covering and a floor covering manufacturing apparatus according to an embodiment of the present invention will be described with reference to the drawings.

[0016] FIG. 1 is a perspective view of the floor covering of the present embodiment. FIG. 2 is a perspective view in which a part of the floor covering is broken. FIG. 3 is a cross-sectional view of a plurality of arranged floor coverings viewed from the longitudinal direction. FIG. 4 is a cross-sectional view of a main part of the floor covering in FIG. 3. The floor covering molding apparatus 1 (floor covering manufacturing apparatus) of the present embodiment is an apparatus for manufacturing a base material 11A including a hygroscopic material in the floor covering 10 by extrusion molding.

[0017] <Configuration of the entire floor covering> The floor covering 10 has a flat plate shape extending in the longitudinal direction. The floor coverings 10 are connected to each other in the longitudinal direction and the width direction to form a floor surface. The floor covering 10 has a lower engaging portion 10A provided on one of a pair of opposing long side portions, and an upper engaging portion 10B provided on the other side and capable of engaging with the lower engaging portion 10A from above.

[0018] As shown in FIG. 4, the floor covering 10 has a base material layer 11 and a buffer layer 12 provided on the lower surface 11b of the base material layer 11. A decorative layer 13 is provided on the upper surface 11a of the base material layer 11. In the floor covering 10, the base material layer 11 and the buffer layer 12 are bonded together by a first adhesive layer 14, the base material layer 11 and the decorative layer 13 are bonded together by the first adhesive layer 14, the base material layer 11 and the buffer layer 12 are bonded together by a second adhesive layer 15, and a third adhesive layer 16 is provided on the lower surface 12b of the buffer layer 12. That is, the floor covering 10 is laminated in the order of the third adhesive layer 16, the buffer layer 12, the second adhesive layer 15, the base material layer 11, the first adhesive layer 14, and the decorative layer 13 from the lower side to the upper side.

[0019] Here, in the following description, based on the base material layer 11, the direction on the floor surface F side where the floor covering 10 is installed will be described as "lower side, downward", and the opposite direction will be described as "upper side, upward". That is, based on the base material layer 11, the surface of the base material layer 11 on the side where the buffer layer 12 is provided (laminated) will be described as the "lower surface (back surface)", and the opposite surface will be described as the "upper surface (front surface)".

[0020] <Base material layer> As shown in Figure 2, the base material layer 11 has a flat plate-shaped main body portion 110, a first fitting portion 111 provided on one end (short side portion) of the main body portion 110 in the longitudinal direction, and a second fitting portion 112 provided on the other end (short side portion) of the main body portion 110 in the longitudinal direction. Furthermore, the base material layer 11 has an upper engaging portion 10A provided on one side portion (long side portion) in the direction perpendicular to the longitudinal direction (width direction), and a lower engaging portion 10B provided on the other side portion (long side portion) in the direction perpendicular to the longitudinal direction.

[0021] The upper engaging portion 10B engages with the lower engaging portion 10B of another flooring material 10 installed adjacent to it. The upper engaging portion 10A forms an engaging groove that extends in the direction of the long side and opens downward. The lower engaging portion 10B forms an engaging projection that extends in the direction of the long side and protrudes upward.

[0022] The upper engaging portion 10A and the lower engaging portion 10B may be provided simultaneously with the main body portion 110 during the molding of the base material layer 11, or they may be provided by machining the main body portion 110 after molding. Alternatively, the upper engaging portion 10A and the lower engaging portion 10B and the rectangular main body portion 110 may be molded separately and then joined together by heat fusion or adhesive bonding.

[0023] The base material 11A of the base layer 11 is manufactured from a wood-based resin foam material M using the floor material molding apparatus 1 shown in Figure 3.

[0024] <Flooring material molding machine> Figure 5 is a side view showing the configuration of the floor material molding apparatus 1. Figure 6 is an enlarged view of the main part of the floor material molding apparatus 1. Figure 7 is a plan view of the sliding sizing die 30 seen from above. Figure 8 is a front view of the sliding sizing die 30, seen from the second connecting end face 32a side, as seen from the line AA shown in Figure 7. Figure 9 is a side view of the upper sliding sizing die 30A.

[0025] As shown in Figure 5, the floor molding apparatus 1 includes an extrusion die 20 from which the material for the base material 11A of the base layer 11 of the floor material 10 (wood-based resin foam material M, described later) is supplied from the extruder 40, and a sliding sizing die 30 positioned with a gap S between it and the extrusion die 20, which cools the wood-based resin foam material M pushed in from the extrusion die 20. The wood-based resin foam material M is, for example, a material mixed with hygroscopic wood powder, talc, polypropylene resin (PP), additives, foaming agents, etc.

[0026] <Extrusion die> As shown in Figures 5 and 6, the extrusion die 20 is mounted at the tip of the extruder 40 and has a mechanism for continuously extruding molten thermoplastic resin. Examples of extrusion dies 20 include T-dies and die-type dies. A heater (not shown) is incorporated into the extrusion die 20 to maintain the die temperature at a predetermined temperature (for example, a high temperature of about 180°C).

[0027] The extrusion die 20 is precisely manufactured so that the cross-sectional shape of its inner wall surface 21 matches the cross-sectional shape of the molded body to be manufactured (in this case, the base material 11A). On the extrusion side end face 20a of the extrusion die 20, which faces the sliding sizing die 30 downstream, a fitting recess 22 is formed, which is horizontally elongated and roughly rectangular in shape when viewed from the front in the extrusion direction X1. The fitting projection 32 (described later) of the sliding sizing die 30 is fitted into this fitting recess 22.

[0028] The first connecting end face 22a, which forms the bottom surface of the fitting recess 22, is positioned in close proximity to the second connecting end face 32a of the fitting projection 32 of the sliding sizing die 30 in the extrusion direction X1 when fitted to the fitting projection 32. That is, the first connecting end face 22a is positioned with a gap S of, for example, about 0.5 mm in the extrusion direction X1 relative to the second connecting end face 32a. In this way, the extrusion die 20 is configured to prevent heat exchange between the extrusion die 20 and the sliding sizing die 30 by providing a gap S between them.

[0029] <Sliding sizing mold> As shown in Figures 5 to 9, the sliding sizing mold 30 is provided in a manner that allows it to be divided vertically into an upper sliding sizing mold 30A and a lower sliding sizing mold 30B. The sliding sizing mold 30 has a mold section 31 into which the wood-based resin foam material M is pressed from the extrusion mold 20. The cross-sectional shape of this mold section 31 is precisely manufactured to match the cross-sectional shape of the molded body to be produced (in this case, the base material 11A). As the wood-based resin foam material M is pressed into this mold section 31 by its own foaming pressure and cools and solidifies, a wood-based resin foam molded body (described 11A in the base material layer 11) with a cross-sectional shape exactly as designed, accurately replicating the cross-sectional shape of the mold section 31 of the sliding sizing mold 30, can be stably manufactured.

[0030] Existing design methods are also used for the sliding sizing mold 30. Generally, materials with high thermal conductivity, such as brass or aluminum, are used, and a flow path is provided for circulating a coolant such as water. This flow path is positioned close to the resin flow surface and its dimensions are appropriately adjusted according to the Reynolds number, etc., to create turbulence in order to enhance the cooling effect. In other words, the sliding sizing mold 30 becomes a low-temperature body, for example, at around 12-13°C.

[0031] As shown in Figure 5, a fitting projection 32 is formed on the sizing side end face 30a of the sliding sizing die 30, which faces the extrusion die 20 on the upstream side, and is horizontally elongated and roughly rectangular in shape when viewed from the front in the extrusion direction X1. The front shape of the fitting projection 32 is substantially the same as the front shape of the fitting recess 22 of the extrusion die 20. This fitting projection 32 is fitted into the fitting recess 22 of the extrusion die 20.

[0032] The second connecting end face 32a, which is the tip surface of the fitting projection 32, is positioned in close proximity to the first connecting end face 22a of the fitting recess 22 of the extrusion die 20 in the extrusion direction X1 when fitted into the fitting recess 22. That is, the second connecting end face 32a is positioned with the aforementioned gap S in the extrusion direction X1 relative to the first connecting end face 22a. In this way, the sliding sizing die 30 is structured so as not to be affected by the heat of the extrusion die 20 because a gap S is provided between it and the extrusion die 20.

[0033] <Steam exhaust channel> The second connecting end face 32a is provided with a steam discharge groove 33 located on the outer circumference of the mold portion 31, through which steam generated in the extrusion die 20 flows. The sliding sizing die 30 is provided with a vacuum suction passage 34 that vacuum-suctions steam-containing air E (see Figure 8) from the steam discharge groove 33. Here, the arrow E shown in Figure 8 indicates the direction in which the steam-containing air E flows during vacuum suction.

[0034] The steam discharge groove 33 is, for example, a groove with a width of about 5 mm, opening on the first connecting end face 22a side and extending around the entire circumference on the outside of the mold part 31. The steam discharge groove 33 has a pair of upper grooves 331 and 332 (lateral grooves) that extend in the width direction X2 (lateral direction) on the upper side of the mold part 31, a lower groove 333 (lateral groove) that extends in the width direction X2 on the lower side of the mold part 31, and a vertical groove 334 that connects the ends of the upper grooves 331 and 332 and the lower groove 333 in the width direction X2. The upper grooves 331 and 332 and the lower groove 333 extend to the outside in the width direction of the mold part 31. In other words, the mold part 31 is surrounded all around by the steam discharge groove 33.

[0035] The steam discharge groove 33 is provided on the fitting projection 32. The groove depth of the steam discharge groove 33 is set to be less than the thickness of the fitting projection 32. The upper grooves 331 and 332 have a downward taper that slopes downward from the center in the extending direction toward both sides. The angle of inclination of the taper can be set arbitrarily. Furthermore, the taper does not need to be provided along the entire length of the upper grooves 331 and 332, but may be provided only in part.

[0036] The vacuum suction passages 34 are provided in pairs, spaced apart in the width direction X2. Each vacuum suction passage 34 opens into the center in the width direction of the upper upper groove 331 of a pair of upper and lower upper grooves 331 and 332, and communicates with the vacuum pump 42 located outside the sliding sizing mold 30 through this opening 34a. The vacuum suction passage 34 extends downstream from the opening 34a in the extrusion direction X1, then bends upward at a right angle to a connection portion 34b that opens onto the upper surface 30b of the sliding sizing mold 30. A pipe 43 connected to the vacuum pump 42, as shown in Figure 5, is connected to the connection portion 34b. In the floor material molding apparatus 1, steam-containing air E circulating in the gap S between the extrusion die 20 and the sliding sizing die 30 is drawn into the steam discharge groove 33, and this air E is discharged or forcibly condensed by being sucked out by the vacuum pump 42.

[0037] The Selka method is employed as the foam extrusion molding method for such floor material molding apparatus 1. In this Selka method, an extrusion die 20 has mold dimensions that are almost the same as the dimensions of the molded body (base material 11A) to be manufactured, and a torpedo (also called a mandrel or core) is installed inside it. The wood-based resin foam material M is extruded in a hollow state, and when the foaming has hardly progressed, it is introduced into a sliding sizing die 30, where it is allowed to foam mainly toward the inner cavity. According to this method, the extruded wood-based resin foam material M foams toward the inner cavity inside the sliding sizing die 30, and as a reaction, a strong pressure is generated that presses the surface layer toward the mold part 31 of the sliding sizing die 30.

[0038] <Wood-based resin foam material> The thermoplastic resin constituting the wood-based resin foam molded article can be appropriately selected from polyolefin-based materials such as polyethylene, polypropylene, polybutene, polyisoprene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ethylene-α-olefin copolymer, propylene-α-olefin copolymer, ethylene-ethyl acrylate copolymer, or acid-modified versions thereof for improved adhesion, or ionomers, and can be used as a single material or a mixture of multiple materials.

[0039] Among these, polypropylene resins such as homopolypropylene, random polypropylene, block polypropylene, and propylene-α-olefin copolymer are the most suitable in terms of rigidity, surface hardness, and dimensional stability required for the base material 11A.

[0040] While there are no particular restrictions on the material of the wood-based filler contained in the wood-based resin composition, it is generally made by cutting wood with a cutter mill and then crushing it into a fine powder (wood powder) with a ball mill or impeller mill. Furthermore, wood-based fillers are hygroscopic materials that contain moisture.

[0041] The average particle size of the wood-based filler is preferably 1 to 200 μm, and more preferably 10 to 150 μm. Fillers with an average particle size of less than 1 μm are difficult to handle, and especially when the amount of wood-based filler is large, poor dispersion in the resin can occur during manufacturing, leading to a decrease in the mechanical strength of the resulting wood-based resin foam molded article. Furthermore, if the particle size is greater than 200 μm, the homogeneity, flatness, and mechanical strength of the molded product tend to decrease.

[0042] Furthermore, while the amount of wood-based filler can be appropriately selected from 10 to 300 parts by weight per 100 parts by weight of thermoplastic resin, it is desirable to use 20 to 200 parts by weight, more preferably 30 to 150 parts by weight, of wood-based filler per 100 parts by weight of thermoplastic resin, in order to improve moldability and homogeneity. If the amount of wood-based filler is too high, the bending modulus of the flooring material increases, and its flexibility is lost, resulting in poor workability (especially when installing in corners or replacing individual tiles, it becomes difficult to flex the flooring material during installation) and it becomes more prone to cracking when bent. On the other hand, if the amount is too low, the coefficient of linear expansion increases, reducing dimensional stability, which can cause gaps between flooring tiles or lifting due to buckling of flooring tiles due to temperature changes.

[0043] In the floor molding apparatus 1, the wood-based resin composition used for the wood-based resin foam material M is foamed during the molding process by adding a foaming agent in addition to the thermoplastic resin and wood-based filler. Thermoplastic resins may also contain, as needed, heat stabilizers, acid neutralizers, UV absorbers, anti-blocking agents, dehydrating agents, light scattering agents for semi-transparency, gloss modifiers, and the like. Among these additives, heat stabilizers include hindered phenols, sulfurs, and phosphorus-based compounds; acid neutralizers include metal stearates and hydrotalcite; UV absorbers include benzotriazoles, benzoates, benzophenones, and triazines; and light stabilizers include hindered amines.

[0044] Furthermore, the foaming method is not particularly limited, and any known method can be used. Generally, foaming can be classified into chemical foaming, which generates gas through thermal decomposition or chemical reactions, and physical foaming, which vaporizes a low-boiling point liquid by applying heat. As chemical foaming agents, inorganic types such as sodium bicarbonate, ammonium carbonate, ammonium nitrite, sodium boride, light metals, and azide compounds can be used, while as organic foaming agents, azo, nitroso, and hydrazide compounds can be used in any combination.

[0045] Furthermore, for foaming at high expansion ratios, especially those exceeding 2x, physical foaming is primarily used, with carbon dioxide and aliphatic hydrocarbons being the main foaming agents. Chemical foaming agents are also often used in conjunction with physical foaming to maintain the cell shape of the foam.

[0046] Next, the method for manufacturing the flooring material 10 using the flooring material molding apparatus 1 described above will be explained in detail with reference to the drawings. First, as shown in Figure 5, the base material 11A of the flooring material 10 is manufactured using the flooring material molding apparatus 1. A wood-based resin foam material M, which consists of a thermoplastic resin mixed with wood powder, talc, polypropylene resin (PP), additives, and a foaming agent, is placed in the hopper 41 of the extruder 40, and kneaded while being heated and plasticized inside the extruder 40. The resulting heated and plasticized wood-based resin foam material M is then extruded from the extrusion die 20 attached to the tip of the extruder 40 by Celca foaming and introduced into the sliding sizing die 30.

[0047] Then, as shown in Figures 5 to 9, the wood-based resin foam material M, which has been cooled and solidified to the extent that it does not deform under its own weight within the sliding sizing mold 30, is demolded from the sliding sizing mold 30, and after being sufficiently cooled by passing it through a cooling water tank (not shown), it is sent to a cutting table (not shown) and cut to a predetermined dimension (for example, 1.8 m), and then subjected to warm curing. In this way, a wood-based resin foam molded body, which is the base material layer 11 of the target object, is obtained by using the floor material molding apparatus 1.

[0048] During cooling in the sliding sizing mold 30, the steam-containing air E generated between the extrusion mold 20 and the sliding sizing mold 30 is discharged by vacuum suction from the steam discharge groove 33 and vacuum suction passage 34 processed in the sliding sizing mold 30 using a vacuum pump 42. Furthermore, since the moisture that condenses upon contact with the sliding sizing mold 30 flows into the steam discharge groove 33, it is prevented from dripping onto the substrate 11A (wood-based resin foam molded body) being molded.

[0049] Next, as shown in Figure 4, the surface (top surface 11a) of the manufactured substrate 11A is corona-treated, and then a PUR adhesive (moisture-curing type) is applied. After application, a decorative sheet such as a polyolefin resin sheet is wrapped to create a decorative layer 13, and the substrate 11A is cut in half and cured. Subsequently, the shorter side of the halved base material 11A is processed using a specially shaped circular saw to create the upper engaging portion 10A and the lower engaging portion 10B shown in Figure 3.

[0050] Next, corona treatment is performed on the lower surface 11b of the base material 11, a two-component curing epoxy resin (second adhesive layer 15) is applied, and then a cushioning material (e.g., PE-based 10x foam) is bonded and pressed down for curing. This forms a buffer layer 12 on the underside of the base material layer 11. After that, double-sided tape (third adhesive layer 16) is attached to the lower surface 12b of the cushioning material (buffer layer 12). This results in the manufacture of flooring material 10.

[0051] Next, the manufacturing method of the flooring material and the operation of the flooring material manufacturing apparatus described above will be explained in detail based on the drawings. In this embodiment, as shown in Figures 5 to 9, the side of the sliding sizing mold 30 facing the extrusion mold 20 (second connecting end face 32a) is provided with a steam discharge groove 33, which is located on the outer circumference side of the mold portion 31 into which the wood-based resin foam material M of the sliding sizing mold 30 is pressed, and through which steam generated by the heat of the extrusion mold 20 flows. The sliding sizing mold 30 is also provided with a vacuum suction passage 34 that vacuum-suctions air E containing steam from the steam discharge groove 33. In this embodiment, during molding, air E containing steam is vacuum-suctioned from the steam discharge groove 33. The steam discharge groove 33 is located on the outer circumference side of the mold portion 31 into which the wood-based resin foam material M of the sliding sizing mold 30 is pressed.

[0052] As described above, in this embodiment, a steam discharge groove 33 is provided on the second connecting end face 32a of the sliding sizing mold 30, so that the steam generated in the extrusion mold 20 can be discharged to the outside of the floor material molding apparatus 1 by vacuum suction through this steam discharge groove 33. Steam can be discharged from at least the gap S between the first connecting end face 22a and the second connecting end face 32a, and condensation that occurs between the extrusion mold 20 and the sliding sizing mold 30 can be prevented. As a result, it is possible to prevent water from dripping onto the resin surface before it is pressed into the mold portion 31 of the sliding sizing mold 30, thereby preventing roughness and breakage of the molded substrate surface. In this embodiment, the deterioration of the quality of the sheet wrapping of the decorative layer 13 provided on the upper surface 11a of the substrate layer 11 due to roughness of the substrate surface can be suppressed, improving the design, and sufficient strength can be ensured without reducing the peel strength of the decorative layer 13.

[0053] Moreover, since the steam exhaust groove 33 and vacuum suction passage 34 are provided on the sliding sizing mold 30 side, the heater is positioned near the inner wall surface 21, and they can be positioned more efficiently compared to when they are provided on the extrusion mold 20 where there is no space to place the steam exhaust groove 33, thus having less impact on vacuum suction. Furthermore, this embodiment is applicable to conventionally used extruders, does not require a special structure, and can reduce manufacturing costs.

[0054] Furthermore, in this embodiment, the steam discharge groove 33 is provided around the entire circumference of the mold portion 31, and the steam can be guided to the vacuum suction port (opening 34a) along the steam discharge groove 33, bypassing the mold portion 31. This reduces the amount of steam passing through the gap S, and allows for efficient vacuum suction of the steam.

[0055] Furthermore, in this embodiment, the steam discharge groove 33 extends in the width direction X2 above the mold portion 31 and has multiple (in this case, two) upper grooves 331 and 332 spaced apart in the vertical direction. Therefore, the capacity of the steam discharge channel 33 into which the steam generated and rising in the gap S enters can be increased, suppressing the amount of steam overflowing outside the channel and enabling more reliable vacuum suction.

[0056] Furthermore, in this embodiment, the steam discharge groove 33 has lateral grooves (here, upper grooves 331 and 332) that extend in the width direction X2. These upper grooves 331 and 332 have a downward taper that slopes downward from the center in the direction of extension toward both sides. The vacuum suction passage 34 is connected to the center of the upper groove 331 in the direction of extension. In this case, the steam generated in the gap S, entering the steam discharge groove 33 and rising is guided along the tapered section toward the vacuum suction passage 34 located in the widthwise center of the upper groove 331, thus enabling more reliable vacuum suction. Furthermore, in this embodiment, even if water droplets form in the steam discharge groove 33, since the upper grooves 331 and 332 have downward tapers, the water droplets can be moved along the tapers to both sides in the width direction, bypassing the mold section 31 and thus preventing the water droplets from coming into contact with the resin.

[0057] Thus, the method for manufacturing the flooring material 10 and the flooring material manufacturing apparatus according to this embodiment can improve the quality of the flooring material 10 and suppress a decline in its aesthetic appeal.

[0058] Although one embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and modifications and combinations of the configuration that do not depart from the spirit of the present invention are also included.

[0059] For example, in this embodiment, the steam discharge groove 33 is provided so as to surround the entire circumference of the mold portion 31, but it is not limited to this, and it may be configured to be located in the upper half of the mold portion 31, for example. Furthermore, in this embodiment, a pair of upper grooves 331 and 332 are provided spaced apart in the vertical direction, but it is not limited to a pair; there may be only one upper groove.

[0060] Furthermore, although the steam discharge groove 33 is configured with a downward taper extending from the center in the extending direction toward both sides in the lateral grooves (upper grooves 331 and 332 in this embodiment), it is not limited to this configuration, and the lateral grooves may be horizontal and without a taper.

[0061] Furthermore, the configuration of the vacuum suction passages 34 in the sliding sizing mold 30, including their position, number, and length, is not limited to the embodiments described above and can be appropriately changed to suit the configuration, shape, size, and other piping of the sliding sizing mold 30. [Explanation of symbols]

[0062] 1. Flooring material molding machine (flooring material manufacturing machine) 10 Flooring 11 Base material layer 11A Base material 20 Extrusion molds 21 Interior wall surface 22 Fitting recess 22a First connecting end face 30 Sliding sizing molds 31 Mold section 32 Fitting protrusion 32a Second connecting end face 33 Steam discharge channel 331, 332 Upper groove (horizontal groove) 333 Lower groove (horizontal groove) 334 Longitudinal grooves 34 Vacuum suction path 40 Extruders 41 Hopper 42 Vacuum pump E. Air containing vapor M Wood-based resin foam material X1 Extrusion direction X2 Width direction

Claims

1. A method for manufacturing flooring materials, comprising a manufacturing apparatus equipped with an extrusion die and a sliding sizing die positioned with a gap between it and the extrusion die, wherein a base material containing a hygroscopic material for flooring materials is manufactured by extrusion molding, A step of extruding the material of the base material supplied from the extruder from the extrusion die into the mold portion of the sliding sizing die, A step of passing the material through the sliding sizing mold and cooling it, The process includes a step of vacuum-suctioning air containing steam from a steam discharge groove formed on the surface of the sliding sizing mold facing the extrusion mold, through which steam generated by the heat of the extrusion mold flows, A method for manufacturing flooring material, wherein the steam discharge groove is located on the outer circumference side of the mold portion into which the material of the sliding sizing mold is pressed.

2. The method for manufacturing flooring material according to claim 1, wherein the steam discharge groove is provided around the entire circumference of the mold portion.

3. A flooring material manufacturing apparatus for manufacturing a base material containing a hygroscopic material for flooring materials, An extrusion die from which the material for the base material is supplied from the extruder, The system includes a sliding sizing die, which is positioned with a gap between it and the extrusion die, and which allows the material pushed from the extrusion die to pass through and be cooled, On the surface of the sliding sizing die facing the extrusion die, a steam discharge groove is provided, which is located on the outer circumference side of the mold portion into which the material of the sliding sizing die is pressed, and through which steam generated by the heat of the extrusion die flows. A flooring material manufacturing apparatus, wherein the sliding sizing die is provided with a vacuum suction passage for vacuum-suctioning air containing the steam from the steam discharge groove.

4. The floor material manufacturing apparatus according to claim 3, wherein the steam exhaust groove is provided around the entire circumference of the mold portion.

5. The steam discharge groove has an upper groove that extends in the width direction on the upper side of the mold portion, The floor material manufacturing apparatus according to claim 3 or 4, wherein the upper grooves are provided in multiple locations at intervals in the vertical direction.

6. The steam discharge groove has transverse grooves extending in the width direction, The aforementioned transverse groove has a downward taper that extends downward from the center in the direction of extension toward both sides. The floor material manufacturing apparatus according to claim 3 or 4, wherein the vacuum suction passage is connected to the center in the extending direction of the transverse groove.

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