JP2006123198A - Resin molded panel and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lightweight resin molded panel excellent in sound absorbing properties and heat insulating properties and to provide its manufacturing method relatively inexpensively. <P>SOLUTION: In the resin molded panel P is molded by heating and pressing a base material mat 1 formed by mutually entangling natural fibers and thermoplastic resin fibers, compressed linear pattern parts D1, which are formed by linearly heating and pressing the base material mat 1, and gently compressed pattern parts D2, which are surrounded by the compressed linear pattern parts and heated and pressed under pressure lower than the pressure used for forming the compressed linear pattern parts, are formed continuously. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention is a resin-molded panel suitable for use as a carrier panel (base material panel) for supporting the surface of a decorative panel used as, for example, an automobile interior panel, or as an interior panel itself, and is particularly lightweight. The present invention relates to a resin-molded panel suitably used for members and places where sound absorption performance and heat insulation performance are required, and a method for producing the same.

As a resin molded panel used for a conventional automobile interior panel, an injection molded product using a thermoplastic resin typified by polypropylene is mainly used. Since the conventional injection molded product is in a solid state, it naturally has no sound absorption effect.
The applicant of the present application has proposed a laminate suitable as a base material constituting a carrier layer that supports a decorative surface layer in an automobile interior panel (see, for example, Patent Document 1). However, since this laminate is a flat plate having the same thickness throughout, the sound absorption characteristics (performance) could not be expected.

JP 2000-62062 A

  The present invention has been made in view of such a current situation, and an object of the present invention is to provide a resin-molded panel that is lightweight and excellent in sound absorption performance and heat insulation performance and a method for producing the same at a relatively low cost. is there.

The resin-molded panel according to claim 1 of the present invention that achieves the above object is a resin-molded panel that is molded by hot-pressing a base mat that is formed by intertwining natural fibers and thermoplastic resin fibers. A compression line pattern portion formed by heat-pressing the base mat in a linear shape, and a heat-pressing process surrounded by the compression line pattern portion and at a lower pressure than the compression line pattern portion. The loosely compressed pattern portion is formed continuously.
In such a resin molded panel, a base mat formed by intertwining natural fibers and thermoplastic resin fibers is set between a lower mold for heating and an upper mold for heating, and the molding surface of the upper mold for heating is The lower mold for heating is formed into a flat surface and is formed with a protruding projection that is annularly closed when viewed from the front, and the base mat is heated and pressed with the lower mold for heating and the upper mold for heating. A compression line pattern portion that is heated and pressed in a linear shape at the forming ridge portion and a slowly compressed pattern portion that is surrounded by the forming ridge of the lower mold for heating and heated and pressed at a pressure lower than the compression line pattern portion are formed. (Claim 3).
Further, the resin molded panel according to claim 2 of the present invention is a resin molded product in which a nonwoven fabric is laminated on one side of a base mat formed by intertwining natural fibers and thermoplastic resin fibers, and is integrally molded by a hot press. A compressed line pattern portion formed by heating and pressing the base mat in a linear shape, and being heated and pressed at a pressure lower than that of the compressed line pattern portion. The loosely compressed pattern portion formed by the above is continuously formed.
In such a resin molded panel, a base mat formed by intertwining natural fibers and thermoplastic resin fibers is set between a lower mold for heating and an upper mold for heating, and the molding surface of the upper mold for heating is The heating dies are flat and are formed with protruding protrusions that are annularly closed when viewed from the front, and the base matt is formed on the lower heating mold and the upper heating mold. A semi-molded panel is formed by heat-pressing so that a compressible thickness remains between the flat molding surface, and then a non-woven fabric is laminated on one side of the heating upper mold side of the molded half-molded panel. The nonwoven fabric is laminated and integrated by matching die forming press together, and the compression line pattern portion that is heated and pressed in a linear shape at the forming protrusion portion and the compression protrusion surrounded by the forming protrusion of the lower mold for heating are compressed. The heating process is performed at a lower pressure than the line pattern. It is prepared by forming a gentle compression pattern portion which is scan (claim 4).

The resin molded panel according to the present invention includes a compressed line pattern portion formed by linearly heating and pressing a base mat in which natural fibers and thermoplastic resin fibers are entangled with each other, and the compressed line pattern portion. Since the slow compression pattern portion formed by heating and pressing at a pressure lower than the compression line pattern portion is continuously formed, it is lightweight and has excellent sound absorption performance and heat insulation performance, It is optimal as a carrier panel (base material panel) for supporting the decorative surface material in a component member that is lightweight and requires sound absorption performance and heat insulation performance, such as an automobile interior panel.
By heating and pressing a base mat in which natural fibers and thermoplastic resin fibers are intertwined, a compression line pattern part and a slow compression pattern part surrounded by the compression line pattern part are continuously formed and shaped. It is surprising that the compression line pattern part contributes to shape retention as a resin molded panel, and the above-mentioned slow compression pattern part can exhibit excellent sound absorbing performance and heat insulation performance, and the significance of the present invention is here. .

  In addition, according to the resin molded panel according to claim 2, in addition to the above-described effects, the nonwoven fabric is laminated on one side of the base mat and integrally molded by a matched die molding press. Combined with the appearance of the pattern portion having an excellent design (in the illustrated embodiment, a hexagonal continuous pattern, that is, a tortoiseshell pattern), it is used as it is, for example, as an automobile interior panel. It becomes possible.

  In addition, since conventional equipment can be used as it is in the production of the resin molded panel, it can be produced and provided at low cost.

  Hereinafter, specific preferred embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the illustrated embodiments.

The resin-molded panel P according to the present invention is basically formed by hot pressing the base mat 1, but the entire surface of the base mat 1 is not hot pressed uniformly, but is hot pressed linearly. The compression line pattern part D1 formed by the above-mentioned process and the slow compression pattern part D2 surrounded by the compression line pattern part D1 and formed by heating and pressing at a pressure lower than the compression line pattern part D1 are continuously formed. It is characterized by being.
When the molded panel is used as it is, for example, as a carrier panel (base material panel) for supporting a decorative surface material, only the base mat 1 is molded by heating and shaped by pressing. When the material is used as it is as a decorative surface material, the nonwoven fabric 2 as a decorative surface layer is integrally laminated on one side of the base mat 1.

  The base mat 1 has a required size in which a natural fiber and a thermoplastic resin fiber that acts as a matrix material for bonding the natural fiber are intertwined with each other by needle punching, and has a rectangular shape as viewed from above. And a soft soft mat having a thickness.

  Examples of natural fibers that form the base mat 1 include natural fibers such as hemp, flax, cotton, straw, jute, sisal, etc., and those obtained by combining one or more selected from these. used.

  The thermoplastic resin fibers forming the base mat 1 function as a matrix material for binding the natural fibers and as an adhesive with a sheet laminated on the surface of the base mat 1. If there is no particular limitation, a combination of one or more selected from thermoplastic resin fibers such as polypropylene fiber, polyethylene fiber, polyester fiber, and nylon fiber is preferably used.

  The natural fiber and the thermoplastic resin fiber forming the base mat 1 have a blending ratio in the range of 30:70 to 70:30, preferably in the range of 30:70 to 50:50, more preferably in the ratio of 50:50. The natural fibers and the thermoplastic resin fibers are stabbed and knitted to each other, and the thermoplastic resin fibers are at least partially melted by heating to form a matrix, and the natural fibers are bonded to each other.

The non-woven fabric 2 laminated on one side of the base mat 1 serves as a decorative surface layer or a reinforcing surface layer of the molded panel P, and in particular, when it serves as a decorative surface layer. It is preferable that a design including desired coloring is applied.
Moreover, as the nonwoven fabric 2, it is preferable to use the same material as the thermoplastic resin fiber which comprises the base material mat 1, For example, the thing used with a polypropylene single-piece | unit or the combination of a polypropylene and a polyethylene terephthalate is suitable. Used for.

Next, a method for producing a resin molded panel according to the present invention will be described in detail with reference to FIG.
A raw material of the base mat 1 having a predetermined thickness that is fluffy is formed by needle punching (stitching) natural fibers and thermoplastic resin fibers in advance with a needle punching machine and interlacing the fibers with each other. deep.
The raw material punched to a predetermined thickness is cut into a predetermined shape size to form a base mat 1, and is set between a heating lower mold 3a and a heating upper mold 3b of the heating press machine (FIG. 2 (see (a)).

  On the molding surface (cavity) of the lower mold 3a for heating, an annularly closed molding protrusion 4 is continuously projected and formed on the same plane, and the upper mold 3b for heating basically has no special unevenness. It is formed smoothly.

As shown in FIG. 1, the forming protrusion 4 is for forming the compression line pattern portion D1 on the base mat 1, and is circular or triangular when the lower mold 3a for heating is viewed from the front (cavity). In addition, it is continuously formed in an annularly closed shape having a polygonal shape such as a square shape or a hexagonal shape.
Incidentally, the forming ridge 4 of the illustrated embodiment has a so-called turtle shell pattern that is closed in a substantially regular hexagonal shape continuously protruding.

  Thus, after the base mat 1 is set on the lower heating mold 3a, the upper heating mold 3b is aligned with the lower heating mold 3a of the heating press machine and the base mat 1 is heated and pressed. Then, the base mat 1 is heated and pressed at a pressure higher than that of the other portions at the molding protrusion 4 portion formed in the lower mold 3a for heating.

  As a result, in the portion heated and pressed by the forming ridge 4 of the lower mold 3a for heating, a linear compressed line pattern portion D1 having the same annular shape as the forming ridge 4 is formed and surrounded by the forming ridge 4. In other words, in the portion that is heated and pressed between the lower heating die 3a and the upper heating die 3b other than the molding ridge 4, a planar slow compression pattern portion D2 having the same shape as the molding ridge 4 is formed. A panel P ′ (this is referred to as a semi-formed panel) in which the slow compression pattern portion D2 is continuously formed with the compression line pattern portion D1 as a whole is formed (the state shown in FIG. 2B). ).

  When the panel (semi-molded panel) P ′ formed here is removed from the upper mold 3b for heating and the lower mold 3a for heating, the loosely compressed pattern portion D2 portion is caused by the spring back phenomenon of the base mat 1. It bulges slightly in the front and back both sides, and the boundary between the compression line pattern portion D1 and the slow compression pattern portion D2 becomes conspicuous.

  And, while the thermoplastic resin as the matrix resin is in a molten state, the semi-molded panel P ′ is set on the lower mold 5a of the matched die molding machine and press-molded while being heated. A resin molded panel shaped into a predetermined shape is obtained.

At this time, a spacer 6 is set between the molding lower mold 5a and the molding upper mold 5b so as to be slightly thinner than the thickness of the compression line pattern portion D1 (in the embodiment, it is 1 mm thinner). At this time, a clearance slightly smaller than the thickness H2 of the compression line pattern portion D1 can be maintained between the lower mold 5a and the upper mold 5b.
Incidentally, the thickness of the slowly compressed pattern portion D2 is also shaped by the clearance due to the thickness of the spacer 6, and there is no particular difference in the clearance between the compressed line pattern portion D1 and the slowly compressed pattern portion D2.

After the panels in the matched die molds 5a and 5b are cooled, when the molded upper panel 5b is opened and the molded panel P is removed from the mold, the loosely compressed pattern portion D2 is again turned back and forth due to the spring back phenomenon of the base mat 1. Slightly bulges in both directions, and the boundary between the compression line pattern portion D1 and the slow compression pattern portion D2 becomes conspicuous.
The panel formed here is used as a carrier panel (base material panel) or the like for supporting the decorative surface material.

Next, a method for producing a resin-molded panel that can be used as it is as a decorative surface material after being molded and molded will be described.
The resin-molded panel P is formed by pressing the nonwoven fabric 2 on one side of the semi-molded panel P ′ prepared from the process of FIG. 2 (a) to the process of FIG. 2 (b) while heating. More obtained. That is, while the nonwoven fabric 2 is superimposed on one surface of the semi-molded panel P ′ on the heating upper mold 3b side, the thermoplastic resin that is the matrix resin of the semi-molded panel P ′ is maintained in a molten state. In addition, it is set on a molding lower mold 5a of a matched die molding machine, press-molded while heating, and shaped into a desired shape to form a resin molded panel P ((c) → (d in FIG. 2). )reference).

  At this time, a spacer 6 set slightly thinner than the compression line pattern portion D1 (in the embodiment, 1 mm thinner) is provided between the lower mold 5a and the upper mold 5b, and the final pressurization is performed. At this time, a clearance slightly smaller than the thickness H2 of the compression line pattern portion D1 can be maintained between the lower mold 5a and the upper mold 5b.

After the panels in the matched die molds 5a and 5b are cooled, the molded upper mold 5b is opened to remove the molded resin molded panel P from the molded upper molds 5a and 5b. Again, it slightly bulges in both the front and back sides, and as a whole, as shown in FIGS. 1A and 1B, the slowly compressed pattern portion D2 is continuously formed with the compressed line pattern portion D1.
However, in this case, since the nonwoven fabric is bonded to one side, the springback is suppressed by the tension of the nonwoven fabric, and the boundary is slightly blurred compared to the panel where the nonwoven fabric is not bonded.

  In addition, the resin molded panel P molded here is the same as the resin molded panel in which the nonwoven fabric 2 described above is not laminated, and the compression line pattern portion D1 is the same as the resin molded panel molded by a normal heating press. When viewed from the side where the nonwoven fabric 2 is laminated, the loosely compressed pattern portion D2 has a felt-like appearance and tactile sensation, and has elasticity.

  The nonwoven fabric 2 is not only laminated and integrated on one side of the semi-molded panel P ′, but a sheet made of the same kind of thermoplastic resin as that of the base mat 1 is further laminated on one side opposite to the nonwoven fabric 2 to form a base. The resin molded panel P may be molded by heating and pressing together with the material mat 1 and the nonwoven fabric 2.

Next, specific examples will be described.
<Example 1>
A base mat in the form of a mat having a basis weight of 1900 g / m ² and a thickness of about 20 mm in which natural fibers and polypropylene fibers are entangled with each other was produced.
This base mat was set in a heating press machine in which the temperature of the lower mold for heating was adjusted to 204 ° C. and the temperature of the upper mold for heating was adjusted to 220 ° C., and the molding ridge formed on the lower mold for heating and the upper A semi-molded panel P ′ was molded by hot pressing so that the compressible thickness (H1) was 6 mm between the molding surface of the mold. At this time, the height of the forming protrusion of the lower mold for heating was set to 6 mm.
Thereafter, the lower mold and upper mold for heating of the heating press machine are opened, and the non-woven fabric having a basis weight of 180 g / m ² produced from polyester fiber by the needle punch method is still on the upper mold for heating. The polypropylene resin, which is the matrix resin of the semi-molded panel P ′, is in a molten state (the resin temperature is set to about 180 ° C.). (Note that the melting point of polypropylene resin is about 160 ° C.) While the temperature is maintained, the molding upper mold is closed and the distance (H2) between the molding lower mold and the molding surface of the molding upper mold is 5 mm. In this way, the nonwoven fabric and the entire semi-formed panel P ′ were pressure-pressed to form a panel in which the compression line pattern portion and the slow compression pattern portion were continuous.
When the molded upper mold and the molded lower mold are opened after the molded product (panel) is cooled, the loosely compressed pattern portion of the molded product (panel) in which the nonwoven fabric and the semi-molded panel P ′ are integrated springs back. The thickness was 7.5 mm, and the thickness of the compressed line pattern portion was 4.8 mm. The thickness of the non-woven fabric was about 1.5 mm, but it was about 0.2 mm when crushed.

  Hereinafter, Examples 2 and 3 and Comparative Examples 1 and 2 were carried out according to Example 1, and resin molded panels were prepared. In Table 1 below, Examples 1 to 3 and Comparative Examples 1 and 2 are posted together.

Moreover, the sound absorption performance of the molded panel which concerns on Example 1 and Comparative Example 1 is shown in FIG. 3, and the heat insulation performance is shown in FIG. 4, respectively.
This time, the sound absorption performance of the molded panel is measured in accordance with “JIS A 1405: 98”, the vertical entry sound absorption rate (back air layer is 10 mm), and the heat insulation performance is based on “JIS A 1412-1: 96”. The thermal resistance value was measured from the thermal conductivity.

  The broken lines (1) to (3) in FIG. 3 relate to the resin molded panel prepared based on the embodiment of the present invention, and the broken line (4) is disclosed in Japanese Patent Laid-Open No. 2000-62062. The present invention relates to a resin molded panel created by technology. As is apparent from this graph, it is understood that the resin molded panel according to the present invention exhibits a specific sound absorbing performance from around 700 Hz as compared with the conventional resin molded panel.

Moreover, in FIG. 4, the result of having measured the heat insulation effect about the resin molding panel which concerns on this invention is shown.
As is clear from the graph shown in FIG. 4, it is understood that the resin molded panel according to the present invention exhibits an excellent heat insulating effect as compared with other resin molded panels.

An example of implementation of the resin molding panel which concerns on this invention is shown, (a) is a front view, (b) is sectional drawing which follows the (X)-(X) line. The manufacturing process figure explaining the manufacturing method of the resin molding panel which concerns on this invention. The graph which shows the sound absorption performance of the shape | molded panel. The graph which shows the heat insulation performance of the shape | molded panel.

Explanation of symbols

1: Substrate mat 2: Non-woven fabric 3a: Lower mold for heating 3b: Upper mold for heating 4: Molding protrusion P: Molded panel 5a: Molded lower mold 5b: Molded upper mold 6: Spacer P ': Semi-molded panel D1: Compressed line pattern part D2: Slowly compressed pattern part

Claims (4)

    A resin molded panel formed by heat-pressing a base mat formed by intertwining natural fibers and thermoplastic resin fibers, and formed by heat-pressing the base mat linearly A compressed line pattern part and a slowly compressed pattern part surrounded by the compressed line pattern part and formed by heating and pressing at a pressure lower than that of the compressed line pattern part are continuously formed. Resin molded panel.     A resin-molded panel in which a nonwoven fabric is laminated on one side of a base mat that is formed by intertwining natural fibers and thermoplastic resin fibers, and is integrally molded by a hot press, and the base mat is linearly hot-pressed The compression line pattern part formed by the process and the slow compression pattern part surrounded by the compression line pattern part and formed by heating and pressing at a pressure lower than the compression line pattern part are continuously formed. A resin-molded panel characterized by     A base mat that is formed by intertwining natural fibers and thermoplastic resin fibers is set between the lower mold for heating and the upper mold for heating, and the molding surface of the upper mold for heating is flat and the lower mold for heating. Is formed with protrusions that are annularly closed when viewed from the front, and the base mat is heated and pressed with a lower mold for heating and an upper mold for heating, thereby forming a linear shape at the portion of the molded protrusion. A method for producing a resin-molded panel, comprising: forming a heat-pressed compressed line pattern portion and a slowly compressed pattern portion surrounded by the forming protrusions and heated and pressed at a lower pressure than the compression line pattern portion.     A base mat that is formed by intertwining natural fibers and thermoplastic resin fibers is set between the lower mold for heating and the upper mold for heating, and the molding surface of the upper mold for heating is flat and the lower mold for heating. Is formed so as to protrude in a ring shape when viewed from the front, and between the forming ridge formed on the lower mold for heating the base mat and the flat molding surface of the upper mold for heating. Further, by heating and pressing so that a compressible thickness remains, a half-molded panel is formed, and then a non-woven fabric is overlapped on one side of the upper mold side for heating in the molded half-molded panel and a matched die forming press is performed. The nonwoven fabric is laminated and integrated, and a compressed line pattern portion linearly heated and pressed at the molding ridge portion, and a loose line that is surrounded by the molding ridge and heated and pressed at a lower pressure than the compression line pattern portion. To form a compression pattern Method for producing a resin molded panel to symptoms.

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