Method and apparatus for producing fiber-reinforced resin molding material

Abstract

Provided are a method and an apparatus for manufacturing a fiber-reinforced resin molding material by which, when the fiber-reinforced resin molding material is manufactured, separated fiber bundles can be supplied to a cutting machine in stable condition while avoiding the influence of meandering of the fiber bundles or slanting or meandering of filaments occurring in the fiber bundles.

1 . A method for producing a sheet-type fiber-reinforced resin molding material comprising impregnating a resin among filaments of cut fiber bundles,
 wherein the cut fiber bundles are obtained by intermittently separating a continuous fiber bundle in a longitudinal direction and by cutting the fiber bundle at intervals in the longitudinal direction to satisfy the condition specified in formula (1) below:
   1≤ a/L   (1)
 
   in formula (1), “a” is a length of a separated portion of the continuous fiber bundle, and “L” is the interval for cutting the fiber bundle in a longitudinal direction.   
     
     
         2 . The method for producing a fiber-reinforced resin molding material according to  claim 1 , wherein the separation and cutting are conducted to satisfy the condition specified in formula (2) below:
     a/L≤ 10  (2).
   
     
     
         3 . A method for producing a sheet-type fiber-reinforced resin molding material comprising impregnating a resin among filaments of cut fiber bundles,
 wherein the cut fiber bundles are obtained by intermittently separating a continuous fiber bundle in a longitudinal direction and by cutting the fiber bundle at intervals in the longitudinal direction to satisfy the condition specified in formula (3) below:
   0.9≤ a /( a+b )<1  (3)
 
   in formula (3), “a” is a length of a separated portion of the continuous fiber bundle, and “b” is a length of an unseparated portion that is present between portions intermittently separated in the continuous fiber bundle.   
     
     
         4 . The method for producing a fiber-reinforced resin molding material according to  claim 1 , wherein the resin is a thermosetting resin. 
     
     
         5 . The method for producing a fiber-reinforced resin molding material according to  claim 1 , wherein the intermittent separation is conducted by intermittently piercing the continuous fiber bundle with a blade. 
     
     
         6 . The method for producing a fiber-reinforced resin molding material according to  claim 1 , wherein a series of a plurality of blades, aligned at predetermined intervals in a width direction of the continuous fiber bundle, pierce the continuous fiber bundle intermittently so as to form partially unseparated portions among a plurality of separated fiber bundles. 
     
     
         7 . The method for producing a fiber-reinforced resin molding material according to  claim 1 , comprising:
 a step for coating a resin-containing paste on a first sheet transported in a predetermined direction;   a step for separating a continuous fiber bundle into a plurality of fiber bundles;   a step for cutting the separated fiber bundles with a cutter and spreading the cut fiber bundles on the paste; and   a step for impregnating the resin among filaments of the fiber bundles by laminating a second sheet with the coated paste on the first sheet with the fiber bundles spread thereon and by compressing the paste and fiber bundles sandwiched between the first and second sheets.   
     
     
         8 . The method for producing a fiber-reinforced resin molding material according to  claim 7 , wherein in the step for separating a continuous fiber bundle into a plurality of fiber bundles, a plurality of rotary blades, aligned at predetermined intervals in a width direction of a continuous fiber bundle and each having a series of a plurality of teeth in its circumferential direction, are used so that the plurality of teeth intermittently pierce the continuous fiber bundle while the plurality of rotary blades rotate. 
     
     
         9 . The method for producing a fiber-reinforced resin molding material according to  claim 7 , wherein in the step for separating a continuous fiber bundle into a plurality of fiber bundles, saw blades with the plurality of teeth, aligned in a direction the same as the transport direction of the fiber bundle, are used so that the plurality of teeth intermittently pierce the continuous fiber bundle while the saw blades oscillate vertically. 
     
     
         10 . The method for producing a fiber-reinforced resin molding material according to  claim 7 , wherein in the step for separating a continuous fiber bundle into a plurality of fiber bundles, continuous fiber bundles are laminated in a thickness direction and are separated into a plurality of fiber bundles. 
     
     
         11 . The method for producing a fiber-reinforced resin molding material according to  claim 7 , wherein in the step for separating a continuous fiber bundle into a plurality of fiber bundles, the continuous fiber bundle is opened in the width direction, and then the opened fiber bundle is separated into a plurality of fiber bundles. 
     
     
         12 . An apparatus for producing a sheet-type fiber-reinforced resin molding material that is formed by impregnating a resin among filaments of cut fiber bundles, comprising:
 a separation unit for separating a continuous fiber bundle into a plurality of fiber bundles; and   a cutting unit for cutting separated fiber bundles by using a cutter,   wherein the separation unit forms unseparated portions among a plurality of separated fiber bundles by intermittently piercing the continuous fiber bundle with a blade.   
     
     
         13 . The apparatus for producing a fiber-reinforced resin molding material according to  claim 12 , wherein the blade is set to be a series of a plurality of blades aligned at predetermined intervals in a width direction of the continuous fiber bundle. 
     
     
         14 . The apparatus for producing a fiber-reinforced resin molding material according to  claim 12 , comprising:
 a coating unit for coating a resin-containing paste on a first sheet transported in a predetermined direction;   the separation unit;   a cutting unit for cutting the separated fiber bundles with a cutter and spreading the cut fiber bundles on the paste; and   an impregnation unit for impregnating the resin among filaments of the fiber bundles by laminating a second sheet with the coated paste on the first sheet with the fiber bundles spread thereon and by compressing the paste and fiber bundles sandwiched between the first and second sheets.   
     
     
         15 . The apparatus for producing a fiber-reinforced resin molding material according to  claim 12 , wherein the separation unit comprises rotary blades with a plurality of teeth aligned in its circumferential direction, and the plurality of teeth pierce the continuous fiber bundle intermittently when the rotary blades rotate. 
     
     
         16 . The apparatus for producing a fiber-reinforced resin molding material according to  claim 12 , wherein the separation unit comprises saw blades with a plurality of teeth aligned in a direction the same as the transport direction of the fiber bundle and the plurality of teeth intermittently pierce a continuous fiber bundle while the saw blades oscillate vertically. 
     
     
         17 . The apparatus for producing a fiber-reinforced resin molding material according to  claim 12 , further comprising paired guide members positioned on both sides of the blade in the transport direction, and from the side opposite where the paired guide members are positioned, the blade pierces the continuous fiber bundle transported between the paired guide members. 
     
     
         18 . The apparatus for producing a fiber-reinforced resin molding material according to  claim 13 , further comprising a spacer member positioned between the plurality of blades aligned in a width direction, wherein the plurality of blades pierce the continuous fiber bundle up to the point where the spacer member makes contact with the bundle. 
     
     
         19 . The method for producing a fiber-reinforced resin molding material according to  claim 3 , wherein the resin is a thermosetting resin. 
     
     
         20 . The method for producing a fiber-reinforced resin molding material according to  claim 19 , wherein the intermittent separation is conducted by intermittently piercing the continuous fiber bundle with a blade. 
     
     
         21 . The method for producing a fiber-reinforced resin molding material according to  claim 19 , wherein a series of a plurality of blades, aligned at predetermined intervals in a width direction of the continuous fiber bundle, pierce the continuous fiber bundle intermittently so as to form partially unseparated portions among a plurality of separated fiber bundles. 
     
     
         22 . The method for producing a fiber-reinforced resin molding material according to  claim 19 , comprising:
 a step for coating a resin-containing paste on a first sheet transported in a predetermined direction;   a step for separating a continuous fiber bundle into a plurality of fiber bundles;   a step for cutting the separated fiber bundles with a cutter and spreading the cut fiber bundles on the paste; and   a step for impregnating the resin among filaments of the fiber bundles by laminating a second sheet with the coated paste on the first sheet with the fiber bundles spread thereon and by compressing the paste and fiber bundles sandwiched between the first and second sheets.   
     
     
         23 . The method for producing a fiber-reinforced resin molding material according to  claim 22 , wherein in the step for separating a continuous fiber bundle into a plurality of fiber bundles, a plurality of rotary blades, aligned at predetermined intervals in a width direction of a continuous fiber bundle and each having a series of a plurality of teeth in its circumferential direction, are used so that the plurality of teeth intermittently pierce the continuous fiber bundle while the plurality of rotary blades rotate. 
     
     
         24 . The method for producing a fiber-reinforced resin molding material according to  claim 22 , wherein in the step for separating a continuous fiber bundle into a plurality of fiber bundles, saw blades with the plurality of teeth, aligned in a direction the same as the transport direction of the fiber bundle, are used so that the plurality of teeth intermittently pierce the continuous fiber bundle while the saw blades oscillate vertically. 
     
     
         25 . The method for producing a fiber-reinforced resin molding material according to  claim 22 , wherein in the step for separating a continuous fiber bundle into a plurality of fiber bundles, continuous fiber bundles are laminated in a thickness direction and are separated into a plurality of fiber bundles. 
     
     
         26 . The method for producing a fiber-reinforced resin molding material according to  claim 22 , wherein in the step for separating a continuous fiber bundle into a plurality of fiber bundles, the continuous fiber bundle is opened in the width direction, and then the opened fiber bundle is separated into a plurality of fiber bundles.