Prepreg master rolls and slit tape and method
Thick thermoset prepreg sheets and slit tapes and methods and apparatus for the production thereof.
1 . A method for the production of a continuous sheet or multiple strips of curable, unidirectional thermoset prepreg which method comprises:
A) i) feeding a curable thermoset prepreg component consisting of two or more continuous sheets of conventional curable thermoset prepreg, each with or without a liner or backing material on a surface thereof and each having a continuous length of at least 10 meters and at least one mating surface, said mating surface(s) being free of the liner or backing material, if present, to a mating point; ii) concurrently aligning the two or more continuous sheets of conventional curable thermoset prepreg, one over the other, along their length; iii) and mating the sheets along their mating surfaces to form a single continuous thick curable thermoset prepreg sheet material; and
B) either iv) winding the continuous thick curable thermoset prepreg sheet material into a master roll, v) passing the continuous thick curable thermoset prepreg sheet material on to a manufacturing process for building a composite structure, vi) passing the continuous thick curable thermoset prepreg sheet material through a slitter to form continuous strips of the curable thermoset prepreg material which is then wound, or vii) passing the continuous thick curable thermoset prepreg sheet material through a slitter to form continuous strips of the curable thermoset prepreg material which are then passed on to a manufacturing process for building a composite structure: the conventional curable thermoset prepreg sheets characterized as comprising a plurality of parallel unidirectional fibers/fiber bundles infused with a curable thermosetting matrix resin wherein the fibers/fiber bundles are aligned along the length of the prepreg sheet.
2 . The method of claim 1 wherein the mating surface of at least one of the continuous sheets of conventional curable thermoset prepreg material is heated to a temperature sufficient to enhance or create tackiness of the thermoset resin without curing of the thermoset resin prior to the mating.
3 . The method of claim 2 where the mated sheets are subjected to pressure to press the sheets of the conventional curable thermoset prepreg material to one another.
4 . The method of claim 1 where the mated sheets are subjected to pressure to press the sheets of the conventional curable thermoset prepreg material to one another.
5 . The method of claim 1 wherein the continuous thick curable thermoset prepreg material is wound into a master roll.
6 . The method of claim 1 wherein the continuous thick curable thermoset prepreg material is passed through a slitter to form a plurality of strips of the prepreg material, characterized as slit tape, each of which is then wound.
7 . The method of claim 1 wherein the thickness of the resulting continuous thick curable thermoset prepreg material is reflective of the sum of the thicknesses of the individual sheets of conventional curable thermoset prepreg.
8 . The method of claim 1 wherein the resulting continuous thick curable thermoset prepreg material has less voids and/or better wetting than a single continuous curable thermoset prepreg sheet material of the same thickness and composition made by the same method as used to make the conventional curable thermoset prepreg sheets used in the method of claim 1 .
9 . A master roll of a continuous thick curable thermoset prepreg material formed in accordance with the method of claim 5 .
10 . The master roll of claim 9 wherein the continuous thick curable thermoset prepreg sheet material has less voids and better wetting as compared to a single continuous curable thermoset prepreg master sheet material of the same thickness and composition made by the same method as used to make the conventional curable thermoset prepreg sheets used in the method of claim 5 .
11 . A continuous curable thermoset prepreg slit tape formed in accordance with the method of claim 6 .
12 . The slit tape of claim 11 wherein the continuous curable slit tape has less voids and better wetting as compared to a slit tape of the same thickness and composition made from a continuous curable thermoset prepreg sheet material made by the same method as used to make the conventional curable thermoset prepreg sheets used in the method of claim 6 .
13 . The method of claim 1 wherein the length of the continuous thick curable thermoset prepreg material is at least 25 meters.
14 . The method of claim 1 wherein the thickness of the continuous conventional curable thermoset prepreg materials is from about 0.001″ (25.4 μm) to about 0.015″ (381 μm).
15 . The method of claim 6 wherein the slit tapes have a length of at least 200 meters and are coil wound or transverse wound to form master rolls thereof.
16 . The master roll of claim 9 wherein the thick curable thermoset prepreg is characterized as having upper and lower surfaces of a matrix resin and an inner region comprising a plurality of resin-infused unidirectional fibers or fiber bundle layers each separated by a matrix resin layer.
17 . The method of claim 1 wherein the continuous thick thermoset prepreg material is passed through a slitter to form a plurality of strips of the prepreg material, characterized as slit tape, each of which is then advanced to an ATL apparatus or APP apparatus for production of a product.
18 . The method of claim 1 wherein the curable thermoset prepreg materials are not heated to a temperature whereby cure is initiated.
19 . The method of claim 1 wherein a liner or backing material is on the one or more mating surface(s) and the process further comprises the step of removing the liner or backing material to expose the mating surface(s) prior to the mating point.
20 . The method of claim 1 wherein the thickness of the resulting prepreg material is greater than can be achieved in producing a single prepreg sheet by the same method as used to make the conventional curable thermoset prepreg sheets.
21 . The master roll of claim 9 wherein the thickness of the resulting prepreg material is greater than can be achieved in producing a single prepreg sheet by the same method as used to make the conventional curable thermoset prepreg sheets.
22 . The slit tape of claim 11 wherein the thickness of the resulting prepreg slit tape is greater than can be achieved in producing a single prepreg sheet by the same method as used to make the conventional curable thermoset prepreg sheets.