JP5590292B2 - Manufacturing method of resin laminate - Google Patents

Description

  The present invention relates to a method for producing a resin laminate, and more particularly, to a method for producing a resin laminate capable of achieving sufficient weight reduction and thinning while ensuring production efficiency and product quality.

Conventionally, so-called resin laminates have been used as interior materials, building materials, logistics and packaging materials for automobiles.
The resin laminate has a resin surface material and a resin back material, and the back material is provided with a recess whose tip is abutted against the inner surface of the surface material. In particular, in the case of automobile interior materials and building materials where the appearance is important, a nonwoven fabric is stuck on the front side of the surface material.
Conventionally, various methods have been adopted as a method for producing the resin laminate.
First, a technique of manufacturing by integral extrusion hollow molding using a molten resin is employed.
According to the resin laminate produced by such a method, compared to a double-walled hollow structure that simply has a hollow portion inside, a concave portion that connects the front surface material and the back surface material provides rigidity, particularly a surface material. On the other hand, it is possible to ensure the compressive rigidity against the load in the vertical direction.

  Secondly, as disclosed in Patent Document 1, two melts extruded individually between a pair of rolls, one of which is a roll having a large number of protrusions arranged on the surface in a staggered pattern. The sheet in the state is passed under a predetermined pressing force to form a recess in one sheet, and the two sheets are welded in such a form that the bottom surface of the recess is abutted against the inner surface of the other sheet. This is a technique in which another sheet is welded to the surface on the side where the opening of the recess is formed, and has a three-layer structure in which the sheet is welded to each of the front side and the back side of the sheet in which the recess is formed.

Thirdly, as disclosed in Patent Document 2, unlike the second method, the extrusion is individually performed between a pair of rolls each having a plurality of protrusions arranged on the surface in a zigzag pattern. The two melted sheets are passed under a predetermined pressing force to form recesses in the respective sheets, and the two sheets in a form in which the bottom surfaces of the corresponding recesses of the respective sheets are welded to each other. It is a technique of welding and further welding another sheet to the opposite surface of each sheet, and has a four-layer structure in which the sheet is welded to the surface of the sheet on which the recess opening is formed.
The following technical problems exist in the technology for producing a resin laminate by extruding a molten sheet as described above.

That is, it is difficult to obtain a resin laminate having sufficient strength without directionality while ensuring manufacturing efficiency. More specifically, as a problem peculiar to extrusion molding common to the first method to the third method, the end portion in the extrusion direction of the sheet is in an open state, so that end surface treatment such as heat sealing treatment is essential. For this reason, an extra step is required, and the overall manufacturing efficiency is lowered. Further, the welding between the sheet having the concave portions formed in a zigzag pattern and another sheet, or the welding between the sheets having the concave portions formed in a zigzag pattern, respectively, passes while being fed by a roller between the pair of rollers. However, it is difficult to ensure a sufficient welding time, and it is difficult to ensure sufficient strength as a resin laminate due to insufficient welding, resulting in quality deterioration.
In this respect, according to blow molding rather than continuous extrusion molding, it is possible to avoid a decrease in manufacturing efficiency due to the end face treatment as described above and a lack of strength due to insufficient welding.
Patent Document 3 discloses a method by such blow molding.
According to Patent Document 3, using a molten cylindrical parison, the back wall is provided with a recess whose front end is butt welded to the inner surface of the front wall, and the outer surface of the front wall is provided with a cover material. The point to stick is disclosed.
However, blow molding using a cylindrical parison and applying blow pressure causes another technical problem.
That is, it is difficult to sufficiently reduce the thickness and thickness of the resin laminate due to molding by applying blowing pressure using a cylindrical parison having a uniform thickness in the circumferential direction.

More specifically, since the cylindrical parison is usually extruded from the annular slit between the die cores, its thickness is substantially uniform in the circumferential direction. On the other hand, when a pair of split molds are clamped Since the pressure applied to the mold of the parison is uniform over the entire surface of the parison because the blowing pressure is applied from the sealed space in the mold, the parison pressed against one mold forming the recess The parison is stretched in relation to the blow ratio according to the depth and the opening diameter, and a locally thin portion is generated. On the other hand, no concave portion is formed in the other mold, so that such a thin portion does not occur. .
From this point, it is necessary to set the thickness of the cylindrical parison according to the thin part on the side of one mold, thereby forming a sheet with an extra thickness on the side of the other mold. become.
As described above, when a cylindrical parison having a substantially uniform thickness in the circumferential direction is used, a difference in thickness inevitably occurs between a wall surface having a plurality of recesses and a wall surface where no recesses are formed after blow molding. As a result, it is impossible to achieve sufficient weight reduction and thinning of the resin laminate.
In this regard, according to Patent Document 4, two sheets in a molten state based on a cylindrical parison are used to have a hollow portion inside, and a plurality of concave portions on the two surfaces facing each other have a bottom surface portion thereof. A method of manufacturing a plate of thermoplastic resin formed so as to face each other is disclosed.
However, in particular, in the case of automobile laminates and building resin laminates for building materials where the appearance of the front surface is important, a decorative material such as a nonwoven fabric is applied to one sheet forming the front surface. Since it is necessary to wear, it is preferable to avoid forming the opening of many recessed parts in the surface by providing the recessed part which forms a recessed part in one sheet | seat.
Japanese Patent No. 4327275 Japanese Patent No. 4192138 JP-A-11-105113 JP-A-7-171877

  In view of the above technical problems, an object of the present invention is to provide a method for producing a resin laminate capable of achieving sufficient weight reduction and thinning while ensuring production efficiency and product quality.

In order to achieve the above object, the method for producing a resin laminate of the present invention comprises:
A pair of split molds having a plurality of protrusions projecting toward the other mold is provided in the cavity of one mold, and two melted heats each adjusted in thickness are provided. Preparing a plastic resin sheet; and
Positioning two molten thermoplastic resin sheets between a pair of split molds in a form that protrudes around an annular pinch-off portion at a predetermined interval from each other;
Forming a sealed space between one sheet and the cavity of one mold facing the outer surface of the one sheet;
The step of sucking the sealed space from the side of one mold and pressing the outer surface of the one sheet against the cavity of the one mold to shape one sheet and form a recess When,
Clamping a pair of molds and welding the peripheral edges of two molten thermoplastic resin sheets and the tops of the recesses formed in one sheet to the inner surface of the other sheet, respectively And having
Thereby, it is set as the structure which manufactures the resin laminated board in which the thickness of both sheets is substantially equal.

According to the method for manufacturing a resin laminate having the above-described configuration, after positioning two thermoplastic resin sheets each having a thickness adjusted between the molds of the split type, one resin sheet is opposed to the resin sheet. A sealed space is formed between the mold cavity and the inside of the sealed space is sucked from the mold side. According to conventional blow molding, a cylindrical parison is used to blow the cavity along the cavity. When a shape is formed, a plurality of protrusions are provided only in the cavity of one mold, so the parison is greatly stretched on the cavity side with the protrusions, but on the cavity side without the protrusions The problem was that the parison would not be stretched and there would be a difference in the thickness of each wall. By solving such a problem, the required strength was increased. It is possible to reduce the thickness of each of the two resin sheets to the maximum as long as they are maintained, thereby achieving sufficient weight reduction and thinning while ensuring manufacturing efficiency and product quality. It is.
In addition, after the mold clamping step, by applying blowing pressure from a sealed space formed in the pair of molds clamped, two molten thermoplastic resin sheets respectively correspond to the mold cavities. To form both sheets.
Furthermore, you may have a step which extrudes between a pair of division | segmentation type | mold metal mold | die by the form which hangs down the sheet-like parison of a molten state downward.
Further, the protrusions are provided in a plurality of rows on the surface of the cavity at predetermined intervals in the vertical direction, and at least a part of the protrusions in each row has a strip shape extending in the horizontal direction on the surface of the cavity. It should be made.
The protrusions may be arranged in a staggered pattern on the cavity.
Furthermore, it is preferable that the protrusion has a regular hexagonal truncated pyramid shape that is tapered toward the other mold.
In addition, the other sheet may be a sheet having a decorative material attached to the outer surface thereof.
Further, the suction step includes a step of moving an outer frame that is fitted around a peripheral edge of the one mold so as to be movable in a mold clamping direction toward an outer surface of the one sheet, It is preferable that a sealed space is constituted by the outer surface, the inner peripheral surface of the outer frame, and the cavity of the one mold.
Furthermore, through clamping the pair of molds, the respective pinch-off portions are brought into contact with each other, thereby welding the peripheral edges of two molten thermoplastic resin sheets to form a parting line, It is preferable to form a sealed hollow portion between two molten thermoplastic resin sheets.

An embodiment of a method for producing a resin laminate 100 according to the present invention will be described below in detail with reference to the drawings.
As shown in FIGS. 1 to 3, the resin laminate 100 includes a front surface sheet 120A, a back surface sheet 120B, and a decorative material sheet 140 bonded to the outer surface 150 of the front surface sheet 120A. The resin laminate 100 has a three-layer laminated structure of a decorative material sheet 140, a front side sheet 120A, and a back side sheet 120B. In FIG. 1, in order to clearly show the internal structure of the resin laminate 100, the periphery of the peripheral portion of the resin laminate 100 is omitted.

Each thickness (thickness) of the front side sheet 120 </ b> A and the back side sheet 120 </ b> B and the overall thickness (plate thickness) as the vehicle interior product 100 may be appropriately determined according to the use of the vehicle interior product 100. Good. From the viewpoint of lightness, the wall thickness is 1.5 mm or less, preferably 1.0 mm or less, and the plate thickness is 15 mm or less, preferably 10 mm or less.
The back side sheet 120B has a large number of recesses 200 bonded to the inner surface 170, which is the surface opposite to the outer surface 150 to which the decorative material sheet 140 of the front side sheet 120A is bonded. And the depth of many recessed parts 200 comprises the thickness of the laminated structure board 100 substantially. Each of the plurality of recesses 200 is tapered inward so as to protrude on the inner surface side by a rib 122 extending between the inner surface 180 of the back side sheet 120B and the inner surface 170 of the front side sheet 120A. Each of the plurality of recesses 200 is bottomed and has a butting surface 240 at the foremost detail so that the butting surface 240 is bonded to the inner surface 170 of the front side sheet 120A.
The number of the plurality of recesses 200 may be set as appropriate depending on the application of the resin laminate 100, but the higher the number, the higher the rigidity compared to the weight.

As shown in FIG. 1, in each of the plurality of recesses 200, the opening 260 in the outer surface 220 of the back sheet 120 </ b> B is a regular hexagonal pyramid, and the openings 260 are arranged in a honeycomb shape on the outer surface 220. Is preferred. That is, on the outer surface 220, the opposing sides of the adjacent openings 260 are arranged so as to be parallel to each other. Thereby, it is possible to arrange the plurality of concave portions 200 on the outer surface 220 most densely. Further, on the outer surface 200, it is also possible to arrange so that the corners of the adjacent regular hexagonal pyramidal frustum-shaped openings 260 are close to each other. By arranging evenly so that the corners of the opening 260 are close to each other, cutting is facilitated in manufacturing such a mold. Regarding the size of the opening 260 of each of the plurality of recesses 200, the depth of the recesses 200, and the interval between the adjacent recesses 200, the size of the opening 260 is small, the depth of the recesses 200 is deep, and the interval between the adjacent recesses 200 is The smaller the is, the higher the rigidity can be obtained as compared with the weight of the laminate 100 as a whole.
As shown in FIG. 3, a sealed hollow portion 280 is formed between the front surface side sheet 120 </ b> A and the back surface side sheet 120 </ b> B, and the sealed hollow portion 280 is formed on the back surface of the laminated structural plate 100. It is closed by the outer peripheral wall of the side sheet 120B.
As a modified example, the plurality of recesses 200 are preferably distributed evenly on the outer surface 220, but the shapes thereof are various shapes such as a cone shape, a truncated cone shape, a cylindrical shape, a prism shape, a pyramid shape, and a hemispherical shape. May be selected as appropriate.

As will be described later, the back-side sheet 120B is clamped on the two divided molds 50 with the two sheet-like parisons P in a molten state positioned between the two divided molds 50. In the case of being molded, it is formed so as to have a sealed hollow portion 280 at a desired position between the front sheet 120A and the back sheet 120B and to exhibit a desired surface shape according to the use of the laminated plate 100. On the other hand, it is possible to provide the laminate 100 capable of realizing the outer shape or the surface shape and the internal structure according to the use of the laminate 100 by welding the front side sheet 120A and the back side sheet 120B. It is. In particular, the parting line PL is formed by the peripheral surfaces of the front side sheet 120A and the back side sheet 120B being welded to each other.

Next, an apparatus for forming such a laminated plate 100 will be described below.

  As shown in FIG. 4, the molding device 10 for the laminated plate 100 includes an extrusion device 12 and a mold clamping device 14 disposed below the extrusion device 12, and is a molten sheet extruded from the extrusion device 12. The parison P is fed to the mold clamping device 14, and the mold-like clamping device 14 forms the molten sheet parison P. Here, since the apparatuses for extruding each of the two thermoplastic resins and sending them to the mold clamping device 14 are the same, only one of them will be described, and the other will be given the same reference number for the description. Omitted.

  The extruding device 12 is a conventionally known type, and a detailed description thereof is omitted. However, a cylinder 18 provided with a hopper 16, a screw (not shown) provided in the cylinder 18, and a screw are connected to the screw 18. The hydraulic motor 20, an accumulator 22 that communicates with the inside of the cylinder 18, and a plunger 24 provided in the accumulator 22, and a resin pellet introduced from the hopper 16 is screwed into the cylinder 18 by the hydraulic motor 20. The molten resin is melted and kneaded by the rotation of the resin, and the molten resin is transferred to the accumulator chamber 22 and stored in a certain amount. The plunger 24 is driven to feed the molten resin toward the T-die 28 and through the extrusion slit 34 to a predetermined length. A pair of continuous sheet-like parisons P are extruded and spaced apart While being clamped by Ra 30 is fed downward is suspended between the split mold blocks 32. Thereby, as will be described in detail later, the sheet-like parison P is disposed between the split molds 32 in a state having a uniform thickness in the vertical direction (extrusion direction).

The extrusion capability of the extrusion device 12 is appropriately selected from the viewpoint of the size of the resin molded product to be molded, the draw-down of the sheet parison P, or the prevention of neck-in occurrence. More specifically, from a practical point of view, the extrusion amount of one shot in intermittent extrusion is preferably 1 to 10 kg, and the extrusion rate of the resin from the extrusion slit 34 is several hundred kg / hour or more, more preferably 700 kg / hour or more. In addition, from the viewpoint of preventing the draw-down or neck-in of the sheet-like parison P, the extrusion process of the sheet-like parison P is preferably as short as possible and generally depends on the type of resin, MFR value, and melt tension value. The extrusion process should be completed within 40 seconds, more preferably within 10 to 20 seconds. For this reason, the unit area and the amount of extrusion per unit time from the extrusion slit 34 of the thermoplastic resin are 50 kg / hour cm ² or more, more preferably 150 kg / hour cm ² or more.

  By feeding the sheet-like parison P sandwiched between the pair of rollers 30 by the rotation of the pair of rollers 30 downward, the sheet-like parison P can be stretched and thinned, and the extruded sheet-like parison P is extruded. By adjusting the relationship between the speed and the delivery speed of the sheet-like parison P by the pair of rollers 30, it is possible to prevent the occurrence of drawdown or neck-in, so the type of resin, particularly the MFR value and melt tension. It is possible to reduce the restriction on the value or the extrusion amount per unit time.

  As shown in FIG. 4, the extrusion slit 34 provided in the T-die 28 is arranged vertically downward, and the sheet-like parison P extruded from the extrusion slit 34 is suspended from the extrusion slit 34 as it is vertically downward. I am trying to send it. The extrusion slit 34 can change the thickness of the sheet-like parison P by making the interval variable.

  The pair of rollers 30 will be described. In the pair of rollers 30, the rotation axes of the pair of rollers 30 are arranged substantially horizontally in parallel with each other, one is the rotation drive roller 30A, and the other is driven to rotate. The roller 30B. More specifically, as shown in FIG. 3, the pair of rollers 30 are arranged so as to be line-symmetric with respect to the sheet-like parison P extruded in a form that hangs downward from the extrusion slit 34.

The diameter of each roller and the axial length of the roller may be appropriately set according to the extrusion speed of the sheet-like parison P to be molded, the length and width of the sheet in the extrusion direction, and the type of resin. As will be described, from the viewpoint of smoothly feeding the sheet-like parison P downward by rotation of the roller with the sheet-like parison P sandwiched between the pair of rollers 30, the diameter of the rotation drive roller 30A is the rotation-driven roller. It is preferably slightly larger than the diameter of 30B. The diameter of the roller is preferably in the range of 50 to 300 mm. If the curvature of the roller is too large or too small in contact with the sheet-like parison P, the sheet-like parison P may be wound around the roller. Become.
On the other hand, the mold clamping device 14 is also a conventionally known type like the extrusion device 12, and detailed description thereof will be omitted, but the two divided molds 32A and 32B and the molds 32A and 32B are melted. A mold driving device that moves between an open position and a closed position in a direction substantially orthogonal to the supply direction of the sheet-like parison P.

As shown in FIG. 4, the two divided molds 32 </ b> A and 32 </ b> B are arranged with the cavities 116 facing each other, and the cavities 116 are arranged along the substantially vertical direction. Projections 119 are provided on the surfaces of the respective cavities 116 in accordance with the outer shape of the molded product molded based on the melted sheet-like parison P and the surface shape.
More specifically, a protrusion 119 complementary to the recess 200 is formed on the surface of the cavity 116A of one mold 32A for molding the back sheet 120B so as to form the recess 200 on the outer surface of the back sheet 120B. Is provided so as to protrude toward the cavity 116B of the other mold 32B.
As the arrangement of the plurality of protrusions 119 on the surface of the cavity 116A, a plurality of rows are provided on the surface of the cavity 116A at predetermined intervals in the vertical direction, and the protrusions 119 in each row are arranged in the horizontal direction on the surface of the cavity 116A. You may make the strip | belt shape extended over. Thereby, the recessed part 200 is formed as a recessed groove. The plurality of protrusions 119 may be arranged in a staggered pattern on the surface of the cavity 116A.

  In each of the two divided molds 32A and 32B, a pinch-off part 118 is formed around the cavity 116. The pinch-off part 118 is formed in an annular shape around the cavity 116, and the opposing molds 32A and 32B are formed. Protrusively toward. As a result, when the two divided molds 32A and 32B are clamped, the tip portions of the pinch-off portions 118 come into contact with each other, and the two sheet-like parisons P1 and P2 in the molten state are parted around the periphery. A line PL is welded to form an outer peripheral wall that closes the hollow portion.

  A mold 33A is slidably fitted on the outer periphery of the mold 32A so as to be slidable in a sealed state, and the mold 33A can be moved relative to the mold 32A by a mold moving device (not shown). . More specifically, the mold frame 33A can contact the side surface of the sheet-like parison P1 disposed between the molds 32A and 32B by projecting toward the mold 32B with respect to the mold 32A.

The mold driving device is the same as the conventional one, and the description thereof is omitted. However, the two divided molds 32A and 32B are respectively driven by the mold driving device and are divided into two in the open position. Two melted sheet parisons P can be placed between the molds 32A and 32B, and the pinch-off portions 118 of the two split molds 32A and 32B are in contact with each other at the closed position, When the pinch-off portions 118 are in contact with each other, a sealed space is formed in the two divided molds 32A and 32B. Regarding the movement of the molds 32A and 32B from the open position to the closed position, the closed position, that is, the position where the pinch-off portions 118 abut each other is between the two sheet-like parisons P1 and P2 in the molten state. The molds 32A and 32B are driven by a mold driving device so as to move toward the positions at equal positions from the parisons P1 and P2.
Note that the extrusion device and the pair of rollers for one sheet-like parison P1 and the extrusion device and the pair of rollers for the other sheet-like parison P2 are arranged symmetrically with respect to this closed position.

As shown in FIG. 6, a vacuum suction chamber 80 is provided inside the divided mold 32 </ b> A, and the vacuum suction chamber 80 communicates with the cavity 116 </ b> A through the suction hole 82, and the suction hole 82 is opened from the vacuum suction chamber 80. The sheet-like parison P1 is adsorbed toward the cavity 116A by being sucked through, and shaped into a shape along the outer surface of the cavity 116A. More specifically, the recesses 200 are formed on the outer surface 117 of the sheet-like parison P1, which is the material of the back sheet 120B, by the protrusions 119 provided on the outer surface of the cavity 116A.
On the other hand, a conventionally known blow pin (not shown) is applied to the divided mold 32B so that when the molds 32A and 32B are clamped, blowing pressure can be applied from within the sealed space formed by both molds. ) Is installed.

  The sheet-like parisons P1 and P2 which are materials of the front side sheet 120A and the back side sheet 120B are made of an olefinic resin such as polyethylene or polypropylene, or an amorphous resin. More specifically, the sheet-like parisons P1 and P2 are preferably made of a resin material having a high melt tension from the viewpoint of preventing a variation in thickness due to drawdown, neck-in, etc. It is preferable to use a resin material with high fluidity in order to improve the transferability and followability.

  More specifically, it is a polyolefin (for example, polypropylene, high density polyethylene) which is a homopolymer or copolymer of an olefin such as ethylene, propylene, butene, isoprene pentene, methyl pentene, etc., and has an MFR (JIS) at 230 ° C. According to K-7210, measured at a test temperature of 230 ° C. and a test load of 2.16 kg) of 3.0 g / 10 min or less, more preferably 0.3 to 1.5 g / 10 min, or acrylonitrile butadiene Amorphous resin such as styrene copolymer, polystyrene, high impact polystyrene (HIPS resin), acrylonitrile / styrene copolymer (AS resin), MFR at 200 ° C. (test temperature 200 according to JIS K-7210) ℃, measured at a test load of 2.16 kg) is 3.0 to 60 g / 10 min More preferably, the melt tension at 30 to 50 g / 10 min and at 230 ° C. (using a melt tension tester manufactured by Toyo Seiki Seisakusho Co., Ltd., preheating temperature 230 ° C., extrusion speed 5.7 mm / min, diameter 2.095 mm, A strand is extruded from an orifice having a length of 8 mm, and a tension when the strand is wound around a roller having a diameter of 50 mm at a winding speed of 100 rpm) is 50 mN or more, preferably 120 mN or more.

In addition, in order to prevent the sheet-like parisons P1 and P2 from cracking due to impact, it is preferable that a hydrogenated styrene-based thermoplastic elastomer is added in a range of less than 30 wt%, preferably less than 15 wt%. Specifically, a styrene-ethylene / butylene-styrene block copolymer, a styrene-ethylene / propylene-styrene block copolymer, a hydrogenated styrene-butadiene rubber and a mixture thereof are suitable as the hydrogenated styrene-based thermoplastic elastomer. The styrene content is less than 30 wt%, preferably less than 20 wt%, and the MFR at 230 ° C. (measured at a test temperature of 230 ° C. and a test load of 2.16 kg according to JIS K-7210) is 1.0 to 10 g / 10. Minute, preferably 5.0 g / 10 min or less and 1.0 g / 10 min or more.
Further, the sheet-like parisons P1 and P2 may contain an additive. Examples of the additive include inorganic fillers such as silica, mica, talc, calcium carbonate, glass fiber, and carbon fiber, plasticizer, and stability. Agents, colorants, antistatic agents, flame retardants, foaming agents and the like.
Specifically, silica, mica, glass fiber or the like is added in an amount of 50 wt% or less, preferably 30 to 40 wt%, based on the molding resin.

  In the case where the decorative material sheet 140 is provided on the surface of the sheet-like parison P2 that is the material of the front surface sheet 120A, the decorative material sheet 140 is an object that improves appearance, decoration, and contacts with the molded product (for example, In the case of a cargo floor board, the cargo floor board is configured for the purpose of protecting a load placed on the upper surface of the board. The material of the decorative material sheet 140 is a fiber skin material, a sheet-like skin material, a film-like skin material, or the like. As the material of such a fiber skin material, synthetic fibers such as polyester, polypropylene, polyamide, polyurethane, acrylic and vinylon, semi-synthetic fibers such as acetate and rayon, regenerated fibers such as viscose rayon and copper ammonia rayon, cotton, hemp, Examples thereof include natural fibers such as wool and silk, or blended fibers thereof.

  Among these, polypropylene or polyester is preferable and polyester is more preferable from the viewpoints of touch, durability, and moldability. The yarn used for the fiber skin material is, for example, polyester: (3-5) denier × (50-100) mm or other fineness of 3-15 denier, and a staple spun yarn having a fiber length of about 2-5 inches Polyester in a bundle of thin flexible filaments: about 150 to 1000 denier / 30 to 200 filaments = about 5 denier × 30 to 200 multifilaments, or polyester: 400 to 800 deniers per filament -It is preferable to use in combination with a filament.

  Examples of the structure of the decorative material sheet 140 include non-woven fabrics, woven fabrics, knitted fabrics, and fabrics obtained by raising them. The woven fabric includes not only a plain structure in which the woven structure is tangled up and down in order, but also various changed woven forms in which some yarns are entangled and jumped. Among these, since there is no directionality with respect to elongation, a non-woven fabric is preferable because it can be easily formed into a three-dimensional shape and has excellent surface feel and texture. Here, the non-woven fabric means a cloth-like product in which fibers are stacked in parallel or alternately or are randomly dispersed to form a web, and then the fibers that become the web are joined. Among these, it is preferable that it is a nonwoven fabric manufactured by the needle punch method from a viewpoint of the three-dimensional shape reproducibility of a molded article, and an external appearance characteristic. In addition, since the nonwoven fabric obtained by the needle punch method has lower strength and higher elongation than the woven fabric and has a large degree of deformation in any direction, it improves the strength of the nonwoven fabric and stabilizes its dimensions. For this reason, it is more preferable to attach a binder to the woven fabric or to punch the web and the nonwoven fabric with overlapping needles. From these things, it is more preferable that the decorative material sheet 140 is a polypropylene nonwoven fabric or a polyester nonwoven fabric. In this case, since the decorative material sheet 140 itself is thermoplastic, it can be used for another purpose by being heated and deformed after separation and collection. For example, if the main resin layer is made of polypropylene and the decorative material sheet 140 is made of a polypropylene nonwoven fabric, the main resin layer and the decorative material sheet 140 of the molded product are the same material, which facilitates recycling.

On the other hand, if the decorative material sheet 140 is a polyester non-woven fabric, the melting point of the main resin layer composed of polypropylene and the fiber skin material are different, so that when the decorative material sheet 140 is bonded to a molded product, it is altered or deformed by heat. Or problems such as failure to adhere to the correct position can be suppressed. In this case, the moldability, rigidity, appearance and durability are also excellent. The tensile strength of the decorative material sheet 140 is 15 kg / cm from the viewpoint of three-dimensional shape reproducibility and moldability.
It is preferably ² or more, and the elongation is preferably 30% or more. In addition, the value of this tensile strength and elongation is measured based on JIS-K-7113 at the temperature of 20 degreeC. As the sheet-like skin material and film-like skin material, thermoplastic elastomer, embossed resin layer, resin layer with printed layer attached to the outer surface, synthetic leather, non-slip mesh-shaped skin layer, etc. can be used. .

A method for manufacturing the laminated plate 100 using the molding apparatus 10 for the laminated plate 100 having the above configuration will be described below with reference to the drawings.
First, in FIG. 4, a predetermined amount of the melt-kneaded thermoplastic resin is stored in the accumulator 22, and the stored thermoplastic resin is discharged from the extrusion slits 34 provided at predetermined intervals on the T die 28. In this case, the thermoplastic resin swells and is extruded at a predetermined extrusion speed with a predetermined thickness so as to hang downward into a molten sheet.

Next, the pair of rollers 30 is moved to the open position, and the gap between the pair of rollers 30 disposed below the extrusion slit 34 is widened from the thickness of the sheet-like parison P, so that the molten sheet is pushed downward. The lowermost part of the parison P is smoothly supplied between the pair of rollers 30. In addition, the timing which makes the space | interval of the rollers 30 wider than the thickness of the sheet-like parison P may be performed after the end of the secondary molding for each one shot, not after the start of extrusion.
Next, the pair of rollers 30 are moved closer to each other and moved to the closed position, the sheet-like parison P is sandwiched by narrowing the interval between the pair of rollers 30, and the sheet-like parison P is sent downward by the rotation of the rollers.
Next, as shown in FIG. 4, the sheet-like parison P having a uniform thickness in the extrusion direction is disposed between the divided molds 32 </ b> A and 32 </ b> B disposed below the pair of rollers 30. Thereby, the sheet-like parison P is positioned in a form that protrudes around the pinch-off portion 118.
The above process is performed for each of the two sheet-like parisons P1 and P2, and the sheet-like parison P2 that is the material of the front side sheet 120A and the sheet-like parison P1 that is the material of the back side sheet 120B are mutually connected. It arrange | positions between the split molds 32A and 32B in the state which separated the space | interval.
In this case, the two sheet-like parisons P1 and P2 are arranged between the divided molds 32A and 32B by adjusting the interval between the extrusion slits 34 or the rotation speed of the pair of rollers 30 independently of each other. The thickness at the time can be adjusted.

More specifically, the sheet-like parison P1 that is the material of the back-side sheet 120B is stretched along the protrusions of the mold cavity during molding because the plurality of recesses 200 are formed, and the recesses 200 are not provided. The surface side sheet 120A tends to be thinner than the sheet-like parison P2, which is a material of the front side sheet 120A. As will be described later, the back side sheet 120B can be obtained by clamping the divided molds 32A and 32B. When the laminated sheet 100 is completed by welding the front side sheet 120A and the front side sheet 120B, the thickness of the rear side sheet 120B and the thickness of the front side sheet 120A are substantially the same. As for the sheet-like parison P1 which is the material of, for example, by making the interval of the extrusion slit 34A wider than the interval of the extrusion slit 34B It is possible to make thicker.
Next, as shown in FIG. 5, the outer surface 117 of the sheet-like parison P1 facing the mold 32A is directed toward the sheet-shaped parison P1 that is the material of the back-side sheet 120B with respect to the mold 32A. Move until it hits.
The decorative material sheet 14 may be appropriately suspended above the mold and suspended in advance along the cavity surface. The timing of disposing the decorative material sheet 14 may be performed before the mold 32 is clamped.

  Next, as shown in FIGS. 5 and 6, a first hermetic seal formed by the cavity 116A of the mold 32A, the inner peripheral surface 102 of the mold 33A, and the outer surface 117 of the sheet-like parison P1 facing the mold 32A. By sucking from the vacuum suction chamber 80 through the suction hole 82 through the space 84, the sheet-like parison P1 is pressed against the cavity 116A, and the sheet-like parison P1 is shaped into a shape along the uneven surface of the cavity 116A. To do. Thereby, the several recessed part 200 is formed as the back surface side sheet | seat 120B.

Next, as shown in FIG. 7, each annular pinch-off portion 118A, while holding the sheet-like parison P1 in a state where the mold 33A that contacts the outer surface 117 of the sheet-like parison P1 is held at the position as it is. The molds 32A and 32B are moved in a direction approaching each other until B come into contact with each other. In this case, the contact position in the mold clamping direction between the pinch-off portions 118A and 118B is between two sheet-like parisons P1 and P2 that are separated from each other. As shown in FIG. The two sheet-like parisons P1 and P2 are welded and fixed to each other at the peripheral edges, and the abutting flat surface portions 240 of the many concave portions 200 formed on the surface of the back surface side sheet 120B are mainly used. And is welded to the inner surface of the surface side sheet 120A.
Thereby, the sealed hollow portion 280 is formed between the back surface side sheet 120B and the front surface side sheet 120A.
Next, as shown in FIG. 8, the split molds 32A and B are opened, the molded laminate 100 is taken out, the burr portions B outside the pinch-off portions 118A and B are cut, and the molding is completed with this. To do.

  As described above, each time the molten sheet-like parison P is extruded intermittently, the sheet-like laminated plate 100 can be formed one after another by repeating the above-described steps. It is possible to extrude the thermoplastic resin intermittently as a melted sheet-like parison P, and shape the sheet-like parison P extruded by vacuum forming or pressure forming into a predetermined shape using a mold.

  According to the manufacturing method of the resin laminate 100 having the above configuration, when it is difficult to adjust the circumferential thickness of the cylindrical parison as in the prior art, for example, blow molding using the cylindrical parison. In addition, if the blowing pressure is applied in the parison after the mold is clamped, the problem that the thickness of the sheet after molding is locally thinned according to the blow ratio can be solved. It is. That is, after positioning two thermoplastic resin sheets whose thicknesses are adjusted independently between the molds 32A and 32B of the split type, the one resin sheet and the mold cavity 116 facing the resin sheet are arranged. By forming a sealed space between them and sucking the sealed space from the mold side, the required strength and moldability are ensured according to the degree to which the thermoplastic resin sheet is stretched along each cavity shape It is possible to reduce the thickness of each of the two resin sheets to the maximum as much as possible, thereby achieving sufficient weight reduction and thinning while ensuring manufacturing efficiency and product quality. is there.

  Although the embodiments of the present invention have been described in detail above, various modifications or changes can be made by those skilled in the art without departing from the scope of the present invention. For example, in the present embodiment, it has been described that it is formed by suction before mold clamping of the divided mold, but is not limited thereto, for example, depending on the mode of the pattern to be formed on the surface of the sheet, Blowing pressure may be applied after the molds of the divided molds are clamped, and the sheet-like parisons P1 and P2 are pressurized through the second sealed space 86 formed inside by the mold 32A and the mold 32B, and the first sealing is performed. The sheet-like parison P1 may be continuously sucked from the mold 32A side through the space 84.

  Moreover, in this embodiment, although demonstrated as what shape | molds and shape | molds directly as the laminated sheet 100 using the extruded sheet-like parison of a molten state, it is not limited to it, and shaping | molding and shaping | molding As long as the melted state necessary for this is realized, shaping and molding may be performed using a material that has been once extruded and then heated again to a molten thermoplastic resin sheet.

  Further, in the present embodiment, when the front side sheet 120A is disposed between the pair of molds, the front side sheet 120A is described as being held above the molds and suspended along the cavity surface. The mold may be clamped in a state where the decorative sheet 140 is placed in the cavity 116B by sucking the decorative sheet 140 from the mold B, for example, or the decorative sheet 140 is placed on the front side sheet 120A. It is good also as what is arrange | positioned in the state adhere | attached beforehand.

It is a perspective view of the resin laminated board which concerns on embodiment of this invention. It is sectional drawing which follows the line AA of FIG. 1 is an overall view of a resin laminate according to an embodiment of the present invention. It is a side view which shows the state by which the molten resin sheet was arrange | positioned between the division molds with the shaping | molding apparatus which concerns on embodiment of this invention. In the molding apparatus which concerns on embodiment of this invention, it is a schematic side view which shows the state which is making the outer frame of a division mold contact | abut to the side surface of a molten resin sheet. In the shaping | molding apparatus which concerns on embodiment of this invention, it is a general | schematic fragmentary sectional view which shows the condition which is shaping the molten resin sheet. It is a figure which shows the state which clamped the division mold in the shaping | molding apparatus which concerns on embodiment of this invention. In the molding apparatus which concerns on embodiment of this invention, it is a figure which shows the state which opened the split mold.

P sheet parison P
PL parting line 10 molding device 12 extrusion device 14 mold clamping device 16 hopper 18 cylinder 20 hydraulic motor 22 accumulator 24 plunger 28 T die 30 roller 32 split mold 33 mold 34 extrusion slit 80 vacuum suction chamber 82 vacuum suction hole 84 First sealed space 86 Second sealed space 100 Laminated plate
102 Inner peripheral surface 116 Cavity 117 Outer surface 118 Pinch-off portion 119 Projection body 120 Sheet 140 Cosmetic material sheet 150 Outer surface of front side sheet 170 Inner surface of front side sheet 180 Inner surface 200 of back side sheet Recess 220 Outer surface 240 of back side sheet Abutting surface 260 Opening 280 Sealed hollow part

Claims (10)

A pair of split molds provided with a plurality of protrusions projecting toward the other mold only in the cavity of one mold, and extrusion of the pair of molds downstream in the extrusion direction of the extrusion die A pair of rollers provided on the upstream side in the direction, each having a pair of rollers in which the respective rotation axes are arranged in parallel to each other, and two molten thermoplastic resin sheets each having a adjusted thickness And the stage of preparing
Each of the two molten thermoplastic resin sheets extruded from the corresponding extrusion dies and passed between the corresponding pair of rollers protrudes around the annular pinch-off portion at a predetermined interval from each other. Positioning between a pair of molds;
Forming a sealed space between one sheet and the cavity of one mold facing the outer surface of the one sheet;
By sucking the sealed space from the side of one mold and pressing the outer surface of one sheet against the cavity of one mold, one sheet is shaped so that it follows the projection The stage of stretching to,
A pair of molds are clamped, and the peripheral edges of two molten thermoplastic resin sheets are welded to the inner surface of the other sheet, and the tops corresponding to the protrusion tips of one sheet are welded to each other. And having a stage
In the stage of preparing two molten thermoplastic resin sheets, the two sheets were melted so as to reduce the difference in thickness between the two sheets after production due to the relative difference in the blow ratio between the two thermoplastic resin sheets. About the thermoplastic resin sheet in a state, the distance between the extrusion slits of the extrusion die and / or the rotation speed of the pair of rollers is adjusted, and the resin laminate is manufactured by independently adjusting the thickness. A method for manufacturing a resin laminate. After the mold clamping step, by applying blowing pressure from a sealed space formed in the pair of molds clamped, the two molten thermoplastic resin sheets are respectively applied to the corresponding mold cavities. The method for producing a resin laminate according to claim 1, wherein the two sheets are shaped by pressing together. The manufacturing method of the resin laminated board of Claim 1 which has a step which extrudes between a pair of division | segmentation type | mold metal mold | die in the form which hangs down the sheet-like parison of a molten state downward. The protrusions are provided in a plurality of rows on the surface of the cavity at predetermined intervals in the vertical direction, and at least a part of the protrusions in each row has a strip shape extending in the horizontal direction on the surface of the cavity. The manufacturing method of the resin laminated board of Claim 1. The method of manufacturing a resin laminate according to claim 4, wherein the protrusions are arranged in a staggered pattern on the cavity. 6. The method for manufacturing a resin laminate according to claim 4, wherein the protrusion has a regular hexagonal truncated pyramid shape toward the other mold. The said other sheet | seat is a manufacturing method of the resin laminated board of Claim 1 which is a sheet | seat with which the decorative material was stuck on the outer surface. The suction step includes a step of moving an outer frame that is externally fitted to a peripheral edge of the one mold in a mold clamping direction toward the outer surface of the one sheet, and the outer surface of the one sheet The method for producing a resin laminated board according to claim 1, wherein a sealed space is constituted by an inner peripheral surface of the outer frame and a cavity of the one mold. A pair of molds are clamped to bring the pinch-off portions into contact with each other, thereby welding the peripheral edges of two molten thermoplastic resin sheets to form a parting line and The manufacturing method of the resin laminated board of Claim 1 which forms a sealed hollow part between the sheets made from a thermoplastic resin of a molten state. The occurrence of drawdown or neck-in is prevented by adjusting the relationship between the extrusion speed from the extrusion slit and the rotation speed of the pair of rollers for the molten thermoplastic resin sheet. A method for producing a resin laminate.

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