JP2009269348A - Core for molding - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a core for molding which can prevent a resin from sticking when an FRP is molded, and which has mold releasing properties (non-tacky properties) to be easily drawn out from an molded article. <P>SOLUTION: The core 10 for molding is formed into a narrow shape. the core 10 for molding includes a core body 11 formed of a viscoelastic material, and a surface covering fibrous material 12 integrally molded with the core body 11 and provided so as to cover the surface of the core body 11. The surface covering fibrous material 12 is composed of a plurality of kinds of fiber materials comprising a fluorocarbon fiber and other fibers. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a molding core formed in an elongated shape.

As structural members for aircraft, ships, automobiles, etc., those made of fiber reinforced plastics (FRP) are widely used from the viewpoint of weight reduction. As a method for manufacturing such a structural member, for example, as disclosed in Patent Documents 1 and 2, a fiber laminate in which a reinforcing fiber base material is laminated in advance is shaped into a final product shape to form a preform. An RTM method (Resin Transfer Molding method) in which matrix resin is injected into the reforming and cured, or layers in which fibers and resins are laminated alternately are placed in an autoclave, and a predetermined heat is applied under a predetermined pressure. And an autoclave method for curing the resin.
JP 2007-62150 A JP 2007-118598 A

  By the way, in the case of forming a reinforcing hollow rib on the structural member, a rubber molding core formed in an elongated shape is provided in advance when setting the material to the mold before molding, and molding is performed after molding. For example, the molding core is pulled out from the product.

  However, if the length of the molding core is long, it becomes difficult to pull out the molding core from the molded product.

  An object of the present invention is to provide a molding core that can prevent resin adhesion during FRP molding, has releasability (non-adhesiveness), and can be easily pulled out from a molded product.

The present invention is a molding core formed in an elongated shape,
A core body formed of a viscoelastic material;
A surface-coated fiber material that is integrally formed with the core body and is provided so as to cover the surface of the core body;
With
The surface covering fiber material is composed of a plurality of kinds of fiber materials including fluorine fibers and other fibers.

  According to the present invention, the surface covering fiber material integrally formed with the core body is provided so as to cover the surface of the core body, and the surface covering fiber material includes a plurality of types including fluorine fibers and other fibers. Because it is made of fiber material, it can prevent adhesion of resin during FRP molding by fluorine fiber, and has releasability (non-adhesiveness), and has low surface slip resistance, so it can be easily pulled out from the molded product. In addition, integrity with the core body can be obtained by adhesion of fibers other than fluorine fibers. In addition, since the surface-coated fiber material is provided and reinforced so as to cover the surface of the core body, pressure resistance and dimensional stability can be maintained even when used repeatedly.

  Hereinafter, embodiments will be described in detail based on the drawings.

  FIG. 1 shows a molding core 10 according to the present embodiment. The molding core 10 according to the present embodiment is provided in advance in a mold at the time of material setting before molding when manufacturing FRP components such as aircraft, ships, automobiles, etc. by a method such as RTM method or autoclave method. It is used to form a hollow part in the constituent member by being pulled out from the constituent member which is a molded product after molding.

  The molding core 10 is formed in an elongated shape having a rectangular cross section. The molding core 10 is formed with a hollow portion H having a rectangular outer cross-sectional shape extending in the length direction at the center thereof. The molding core 10 may be formed in a straight line shape or may be formed in a bow shape. The molding core 10 has, for example, a length of 0.5 to 15 m, a width of 50 to 150 mm, a height of 20 to 150 mm, and a vertical diameter of the hollow portion H of 10 to 50 mm and a horizontal diameter of 20 mm. ˜100 mm and the wall thickness is generally 2 to 30 mm.

  In this molding core 10, the core body 11 constituting the outer shape is formed of a material having viscoelasticity, and the sheet-like surface-coated fiber material 12 is wrapped so as to cover and cover the surface of the core body 11. Has a structure provided integrally with the core body 11.

  According to the molding core 10, the surface covering fiber material 12 integrally formed with the core body 11 is provided so as to cover the surface of the core body 11. Because it is composed of multiple types of fiber materials including fibers other than the above, it is possible to prevent resin adhesion during FRP molding with fluorine fibers and to provide releasability (non-adhesiveness), with low surface slip resistance and therefore molding It can be easily pulled out from the product, and can be integrated with the core body by the adhesiveness of fibers other than fluorine fibers.

  In addition, since the molding core is repeatedly used in the manufacture of the structural member, it is difficult to maintain the pressure resistance against the pressurization during the manufacture of the structural member if it is formed only from rubber. In addition, there is a problem that it is difficult to maintain dimensional stability due to shrinkage caused by heating and cooling during the manufacture of the structural member. However, according to the molding core 10, the surface covering fiber material 12 is provided and reinforced so as to cover the surface of the core body 11, so that the pressure resistance and the dimensional stability are maintained even when used repeatedly. Can be maintained.

  Examples of the viscoelastic material forming the core body 11 include a crosslinked polymer composition such as a rubber material or a resin material. The polymer composition is obtained by crosslinking an uncrosslinked polymer composition in which a raw material polymer is blended with a curing agent, a pigment, or the like, by heating and pressing. The molding core 10 has a durometer type A spring-type surface hardness measured according to JIS K6253, for example, 50 to 80, and the uncrosslinked polymer composition is blended and designed so that such surface hardness is realized. ing.

  The polymer composition is preferably a silicone rubber composition from the viewpoint of heat resistance. In this case, examples of the raw material polymer include polydimethyl silicone rubber (MQ), methyl vinyl silicone rubber (VMQ), methyl phenyl silicone rubber (PMQ), and fluorosilicone rubber (FVMQ). Examples of the curing agent include organic peroxides such as alkyl organic peroxides. In addition, the silicone rubber composition may contain a reinforcing agent (silica), a pigment, an internal mold release agent, and the like.

  The surface covering fiber material 12 is composed of a plurality of types of fiber materials including fluorine fibers and other fibers.

  Examples of the fluorine fiber include polytetrafluoroethylene (PTFE) fiber, tetrafluoroethylene / ethylene copolymer (ETFE) fiber, tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA) fiber, and tetrafluoroethylene / hexa. Examples include fluoropropylene copolymer (FEP) fibers. The fluorine fiber may be composed of a single species or a plurality of species.

  Examples of fibers other than fluorine fibers include organic fibers such as polyester fibers, nylon fibers, vinylon fibers, acrylic fibers, and aramid fibers, inorganic fibers such as glass fibers, carbon fibers, and metal fibers, or natural fibers such as cotton. Fiber. Of these, polyester fibers and nylon fibers are preferred from the viewpoint of adhesion to the core body. Fibers other than fluorine fibers may be composed of a single species, or may be composed of a plurality of species.

  The surface covering fiber material 12 may be composed of a woven fabric, may be composed of a braid, may be composed of a knitted fabric, and may be composed of a nonwoven fabric.

  As the woven fabric, for example, a woven fabric having a basic structure such as plain weave, oblique woven fabric, or satin weaving; Woven double woven fabrics, warp double woven fabrics, double woven fabrics and other laminated fabrics; twisted woven fabrics; weft pile fabrics, warp pile woven fabric fabrics; .

  The warp and the weft constituting the surface covering fiber material 12 of the woven fabric are not particularly limited as long as the surface covering fiber material 12 is composed of a plurality of types of fiber materials including fluorine fibers and other fibers. The yarn may be composed of only fibers other than fluorine fibers, or may be composed of a mixture of fluorine fibers and other fibers. May be. The warp and weft have a thickness of, for example, 300 to 1500 dtex, and the crossing angle is generally 90 °. The diameter of the single yarn fiber constituting the warp and the weft is, for example, 10 to 300 μm.

  The surface covering fiber material 12 of the woven fabric may be provided on the core body so that the warp and the weft extend in any direction. For example, one of them extends in the length direction of the core body. Or one of them may be provided so as to extend in the width direction of the core body, and any one of them may extend in the length direction or width direction of the core body. And may be provided inclined.

  Examples of the braid include, for example, a flat strut braid; a round strut braid; a vertical stripe braid, a cross-jointed braid, a double braid, and a braid lace rugged hammer strut.

  The yarn constituting the surface covering fiber material 12 of the braid is not particularly limited as long as the surface covering fiber material 12 is composed of a plurality of types of fiber materials including fluorine fibers and other fibers. The yarn may be composed of only fibers other than fluorine fibers, or may be composed of a mixture of fluorine fibers and other fibers. Also good. The yarn has a thickness of, for example, 200 to 1500 dtex, and a yarn crossing angle of 10 to 90 °. The diameter of the single yarn fiber constituting the yarn is, for example, 5 to 50 μm.

  The surface covering fiber material 12 of the braid may be provided on the core body so that the thread extending in two directions extends in any direction, for example, one of them is in the length direction of the core body. They may be provided so as to extend, or one of them may be provided so as to extend in the width direction of the core body, and any of them may be provided in the length direction or width direction of the core body. It may be provided to be inclined.

  As the knitted fabric, knitted fabrics with basic structures such as flat knitting, rubber knitting, double-sided knitting, pearl knitting; tack knitting, welt knitting, lace stitching, eyelet knitting, splicing knitting, reverse splicing knitting, pile knitting, inlay knitting, Jacquard edition, Blister edition (change organization common to all basic organizations), Kanoko edition, back hair edition, semi-transfer edition, sinker fish net, accordion edition, boss neck pattern, spiral mesh (above, flat knitting type) (Change organization), teleco knitting, one-sided knitting, two-sided knitting, swing knitting, rope knitting, stitch knitting, milan rib, double picke (more than rubber knitting type knitting structure), mock milan rib, eight lock, three-step double knitting, single Examples thereof include knitted fabrics having a changed structure such as picket (above, double-sided knitted pattern changing structure).

  The yarn constituting the surface covering fiber material 12 of the knitted fabric is not particularly limited as long as the surface covering fiber material 12 is composed of a plurality of types of fiber materials including fluorine fibers and other fibers. The yarn may be configured, may be a yarn composed only of fibers other than fluorine fibers, or may be a yarn composed of a mixture of fluorine fibers and other fibers. Good. The yarn has a thickness of, for example, 100 to 1500 dtex. The diameter of the single yarn fiber constituting the yarn is, for example, 5 to 100 μm.

  The surface covering fiber material 12 of the braid may be provided on the core body so that the wale and the course extend in any direction. For example, one of them extends in the length direction of the core body. Or one of them may be provided so as to extend in the width direction of the core body, and any one of them may extend in the length direction or width direction of the core body. And may be provided inclined.

  On the front side, the surface-coated fiber material 12 has an exposed area of fluorine fibers larger than an exposed area of fibers other than fluorine fibers, and on the back side, an exposed area of fluorine fibers is smaller than an exposed area of fibers other than fluorine fibers. It is preferable to be configured. In this way, the sliding resistance of the surface of the molding core can be further lowered by the fluorine fibers exposed to a large amount on the surface, and higher than the core body by fibers other than the fluorine fibers exposed to the back side. Unity can be obtained. As such a surface covering fiber material 12, for example, a double-layered fabric whose surface is composed of a woven fabric mainly composed of fluorine fibers, and whose lining is composed of a woven fabric mainly composed of fibers other than fluorine fibers. Examples thereof include satin fabrics in which one of the textured fabric, the warp and the weft is a fluorine fiber and the other is a fiber other than the fluorine fiber.

  The surface covering fiber material 12 is formed in a sheet shape, and is provided so as to wrap the core body 11. The presence of wrinkles on the surface of the molding core 10 means that the wrinkles are transferred to the component that is the molded product, and resistance when the molding core 10 is pulled out from the component that is the molded product. This is not preferable. However, since the surface-coated fiber material 12 is formed in a sheet shape and is provided so as to wrap the core body 11 in this way, an excess portion of the surface-coated fiber material 12 is produced when the molding core 10 is manufactured. Is extended toward the end, whereby the generation of wrinkles of the surface-coated fiber material 12 on the surface of the molding core 10 is suppressed.

  Moreover, the surface covering fiber material 12 is provided so that it may face | match at the top part of the corner | angular part 11a of the core main body 11. FIG. Thereby, the butted portion where the surface-coated fiber material 12 becomes discontinuous is not arranged on the planar portion of the component to be molded, and its transfer is prevented, and when the core 10 for molding is manufactured, the core body The surplus portion of the material forming 11 flows out from the butted portion of the surface-coated fiber material 12, thereby forming the core body 11 with less internal distortion.

  The surface covering fiber material 12 has a thickness of, for example, 0.3 to 1.5 mm.

  Next, the manufacturing method of the molding core 10 according to the present embodiment will be described with reference to FIGS. 2 (a) to 2 (c) and FIGS. 3 (a) to 3 (c).

  The core molding die 20 includes a lower mold 21 and an upper mold 22, and the lower mold 21 is provided with a lower concave groove 23 that constitutes a cavity and a guide pin 24 that protrudes upward. 22 is provided with a guide hole 25 corresponding to the guide pin 24.

  First, as shown in FIG. 2A, the surface-coated fiber material 12 is provided so as to cover the bottom and side surfaces of the lower recess 23 of the lower mold 21 and extend to the upper surface of the lower mold 21, and the lower recess 23 from above is provided. The uncrosslinked polymer composition R is provided in a layered manner corresponding to the bottom surface and the side surface. At this time, you may use the topping sheet | seat which topped the uncrosslinked polymer composition R on the surface covering fiber material 12 previously in the layer form.

  Next, as shown in FIG. 2B, a cored bar 26 is prepared. At this time, the cored bar 26 may be provided so as to cover the uncrosslinked polymer composition.

  Next, as shown in FIG. 2C, the cored bar 26 is provided so as to be fitted onto the uncrosslinked polymer composition R in the lower recess 23 of the lower mold 21.

  Next, as shown in FIG. 3 (a), the uncrosslinked polymer composition R is provided in layers so as to cover the core metal 26 fitted in the lower concave portion 23 of the lower mold 21, and the upper part is covered therewith. The surface covering fiber material 12 is provided so as to extend to the upper surface of the lower mold 21. Therefore, a pair of surface covering fiber materials 12 are provided on the upper surface of the lower die 21 so as to overlap each other. At this time, you may use the topping sheet | seat which topped the uncrosslinked polymer composition R on the surface covering fiber material 12 previously in the layer form.

  Next, as shown in FIG. 3B, the upper die 22 is lowered, and the guide pin 24 is inserted into the guide hole 25 and guided to clamp the die. At this time, the mold temperature is, for example, 150 to 180 ° C., the mold clamping pressure is 0.2 to 1 MPa, and the holding time is 5 to 60 minutes. As a result, the crosslinking reaction of the uncrosslinked polymer composition R proceeds and the core body 11 is molded, and the surface-coated fiber material 12 is bonded to the core body 11 and integrally molded, so that the surface of the core body 11 is formed. It is provided to cover. Further, the surplus of the polymer composition flows from between the pair of surface-coated fiber materials 12 between the lower mold 21 and the upper mold 22 to the mold-matching portion to form burrs B. As a result, the core body 11 with less internal distortion is formed. Further, the surplus portion of the surface covering fiber material 12 is also extended toward the end and similarly flows to the die-matching portion to form the burrs B. Thereby, generation | occurrence | production of the wrinkle of the surface covering fiber material 12 in the surface of the core 10 for shaping | molding will be suppressed.

  Then, as shown in FIG. 3C, the mold is opened, the molded body is taken out from the core molding die 20, the core metal 26 is pulled out from the molded body, and the burrs B are cut to form the molding core 10. Get. At this time, by cutting the burrs B, the molding core 10 is configured such that the surface covering fiber material 12 is abutted on the top of the corner portion 11 a of the core body 11.

  The obtained molding core 10 may be subjected to a secondary curing heat treatment with a heating temperature of 200 ° C. to 250 ° C. and a heating time of 1 to 16 hours. Thereby, the shrinkage resistance at the time of FRP molding can be improved.

  In the present embodiment, the molding core 10 has a rectangular cross-sectional shape, but is not particularly limited thereto, and may be other polygonal shapes such as a triangle and a trapezoid, Further, it may be oval or circular.

  Moreover, in this embodiment, although it was set as the molding core 10 which has the hollow part H, it is not specifically limited to this, A solid thing may be sufficient.

  Moreover, in this embodiment, it was set as the structure by which the sheet-like surface covering fiber material 12 was provided so that the core main body 11 may be wrapped, but it is not limited to this in particular so that the core main body 11 may be covered. The structure provided with the cylindrical surface covering fiber material may be sufficient, and the structure provided with the strip | belt-shaped surface covering fiber material so that it may wind around the core main body 11 helically may be sufficient.

  INDUSTRIAL APPLICATION This invention is useful about the core for shaping | molding formed in the elongate shape used in the case of manufacture of the structural member made from FRP.

It is a perspective view of the molding core which concerns on embodiment. (A)-(c) is explanatory drawing which shows the first half of the manufacturing method of the molding core which concerns on embodiment. (A)-(c) is explanatory drawing which shows the second half of the manufacturing method of the molding core which concerns on embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Molding core 11 Core main body 11a Corner | angular part 12 Surface covering fiber material

Claims (5)

A molding core formed in an elongated shape,
A core body formed of a viscoelastic material;
A surface-coated fiber material that is integrally formed with the core body and is provided so as to cover the surface of the core body;
With
The core for molding is characterized in that the surface covering fiber material is composed of a plurality of kinds of fiber materials including fluorine fibers and other fibers. In the molding core according to claim 1,
In the surface-coated fiber material, on the front side, the exposed area of the fluorine fiber is larger than the exposed area of the fiber other than the fluorine fiber, while on the back side, the exposed area of the fluorine fiber is smaller than the exposed area of the fiber other than the fluorine fiber. A molding core characterized in that it is configured. In the molding core according to claim 2,
The surface covering fiber material is characterized in that the outer fabric is a double-woven fabric composed of a woven fabric mainly composed of fluorine fibers and the lining is composed of a woven fabric mainly composed of fibers other than fluorine fibers. Molding core to be used. In the molding core according to any one of claims 1 to 3,
A molding core, wherein the fibers other than the fluorine fibers are polyester fibers or nylon fibers. In the molding core according to any one of claims 1 to 4,
The core body has a corner extending along the length direction,
The core for molding is characterized in that the surface covering fiber material is provided so as to be abutted at the top of the corner of the core body.

Images