SMOOTH TEXTILE REINFORCEMENT FOR PULTRUSION, METHOD AND DEVICE FOR PRODUCING SAME, AND USE THEREOF IN THE MANUFACTURE OF COMPONENTS USING PULTRUSION

Abstract

A textile reinforcement that can be used for the creation of composite components by pultrusion, including a reinforcing layer having lengths of fiberglass oriented randomly and coated in a polyester binder. The reinforcing layer includes at least one reinforcement layer formed of fibers structured as a weave or as a mesh, or as longitudinal and transverse filaments. The reinforcing layer includes at least one thickness layer, adjacent to the reinforcement layer, and based on the lengths of fiberglass oriented randomly and coated in a polyester binder. At least one first surface layer as a web of fibers forms a first external face of the textile reinforcement. A second external face of the textile reinforcement is formed by the reinforcement layer or by a second surface layer as a web of fibers. The polyester binder binds the layers of the textile reinforcement together.

Claims

1-20. (canceled)

21. A textile reinforcement which can be used to make composite parts by pultrusion, comprising a reinforcement layer having segments of glass fiber oriented randomly and coated with a polyester binder, wherein: the reinforcement layer comprises at least one reinforcement layer formed of fibers structured by weaving, or by a grid, or by longitudinal and transverse threads, the reinforcement layer comprises at least one thickness layer, adjacent to the reinforcement layer and based on said segments of glass fiber oriented randomly and coated with a polyester binder, at least one first surface layer of fiber web forms a first external face of the textile reinforcement, a second external face of the textile reinforcement is formed by said at least one reinforcement layer or by a second surface layer of fiber web, the polyester binder bonds together the layers of the textile reinforcement.

22. The textile reinforcement as claimed in claim 21, wherein the glass fiber segments in said at least one thickness layer are pieces of fiber obtained from rovings of glass thread.

23. The textile reinforcement as claimed in claim 21, wherein the glass fiber segments comprise glass threads having a linear weight of 40 to 50 tex (40 to 50 grams per kilometer of thread).

24. The textile reinforcement as claimed in claim 21, wherein the polyester binder that binds together the layers of the textile reinforcement is an unsaturated bisphenol polyester, soluble or insoluble in styrene.

25. The textile reinforcement as claimed in claim 21, wherein the fibers forming said at least one reinforcement layer are continuous glass threads having an individual linear weight of 68 to 272 tex.

26. The textile reinforcement as claimed in claim 21, wherein the fibers forming said at least one reinforcement layer are rovings of continuous glass threads and have a linear weight of the roving of 320 to 1200 tex.

27. The textile reinforcement as claimed in claim 21, comprising the superposition of a first surface layer of fiber web forming a first external face of the textile reinforcement, followed by a first thickness layer based on said segments of glass fiber coated with polyester binder, itself followed by a reinforcement layer forming a second external face of the textile reinforcement.

28. The textile reinforcement as claimed in claim 21, comprising the superposition of a first surface layer of fiber web forming a first external face of the textile reinforcement, followed by a first thickness layer based on said segments of glass fiber coated in polyester resin, itself followed by a first reinforcement layer, followed by a second thickness layer based on said segments of glass fiber coated with polyester binder, itself followed by a second reinforcement layer.

29. The textile reinforcement as claimed in claim 21, wherein the surface layer or layers of fiber web are made of polyester, polyamide, or polypropylene, having a melting point higher than that of said polyester binder.

30. The textile reinforcement as claimed in claim 21, wherein, in the thickness layer or layers, the glass fiber segments have a length of 40 to 120 mm.

31. The textile reinforcement as claimed in claim 21, wherein the glass fiber segments are present in a quantity of 150 to 2000 grams per square meter.

32. The textile reinforcement as claimed in claim 21, wherein in the thickness layer or layers the polyester binder is present in a quantity of 3 to 5% by weight of the glass fibers.

33. A method of fabrication of a textile reinforcement usable in making composite parts by pultrusion, comprising the following consecutive steps: a) on top of a conveyor belt moving in the longitudinal direction (I-I), arranging a first web of fibers made of polyester, polyamide or polypropylene, b) cutting rovings of glass fiber and letting them drop onto a first pin roller at the same time receiving a polyester resin powder, making drop onto said first web placed on the moving conveyor belt a first mixture of segments of glass fiber and polyester resin powder, the polyester resin being chosen so as to have a melting point lower than that of the fibers making up the first web, c) arranging a first reinforcement layer of reinforcing fibers on the first mixture of glass fiber segments and polyester resin powder, f) heating the assemblage by passing through an oven so as to melt the polyester resin and ensure its distribution around the glass fiber segments, yet without melting the fibers of the first web.

34. The method as claimed in claim 33, comprising, prior to step f): d) cutting rovings of glass fiber and letting them drop onto a second pin roller at the same time receiving a polyester resin powder, in order to make drop onto the first reinforcement layer of reinforcing fibers carried by the moving conveyor belt a second mixture of glass fiber segments and polyester resin powder, the polyester resin being chosen so as to have a melting point lower than that of the fibers making up the first web, e) arranging a second reinforcement layer of reinforcing fibers on the second mixture of glass fiber segments and polyester resin powder.

35. The method as claimed in claim 33, wherein the first web is obtained by carding and has a surface density of 20 to 40 grams per square meter.

36. The method as claimed in claim 33, wherein the polyester resin has the property of melting when subjected to a temperature of 100 C. for two minutes.

37. The method as claimed in claim 33, wherein the polyester resin is in the form of a dry powder or in the form of a powder emulsion in water.

38. A device for the fabrication of a textile reinforcement as claimed in claim 21, comprising: a conveyor belt providing movement between an entry roller and an exit roller, near the entry roller, above the conveyor belt, a first web distributor for delivering a first web and for laying it on the conveyor belt, downstream from the first web distributor, a first distributor of glass fiber rovings which can deliver glass fiber rovings to a first chopper, at the exit from the first chopper, a first pin roller for breaking up the pieces of glass fiber rovings to produce glass fiber segments, a first powder distributor for distributing a polyester resin powder on the first pin roller so that the polyester resin powder mixes with the glass fiber segments to form a first mixture during the depositing onto the first web, downstream from the first pin roller, a first reinforcement layer distributor for arranging a first reinforcement layer on the first mixture of fiber segments and powder present on the conveyor belt, downstream from the first reinforcement layer distributor, above the conveyor belt, a second glass fiber roving distributor which can deliver rovings of glass fiber to a second chopper, at the exit from the second chopper a second pin roller for breaking up the pieces of glass fiber rovings and producing glass fiber segments, a second powder distributor for distributing a polyester resin powder on the second pin roller so that the polyester resin powder mixes with the glass fiber segments to form a second mixture which is then arranged on the first reinforcement layer, downstream from the second pin roller a second distributor able, as an operator so chooses, to deliver either a second reinforcement layer or a second web which it arranges on the second mixture coming from the second pin roller, an oven able to heat the elements placed on the conveyor belt, downstream from the oven, one or more pressing rollers able to press the materials moving on the conveyor belt.

39. The device as claimed in claim 38, wherein the second distributor is arranged downstream from the oven.

40. The use of a textile reinforcement as claimed in claim 21 to form a pultruded product, wherein the textile reinforcement taken alone is impregnated with a thermosetting plastic resin, and said impregnated textile reinforcement is drawn through a pultrusion die heated to a temperature that allows the thermosetting plastic resin to cross-link.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Other objects, characteristics and advantages of the present invention will emerge from the following description of particular embodiments, given in regard to the enclosed figures, in which:

[0066] FIG. 1 is a schematic side view in longitudinal section of a textile reinforcement according to a first embodiment of the invention;

[0067] FIG. 2 is a schematic view in transverse section of the textile reinforcement of FIG. 1;

[0068] FIG. 3 is a schematic side view in longitudinal section of a textile reinforcement according to a second embodiment of the invention;

[0069] FIG. 4 is a schematic view in transverse section of the textile reinforcement of FIG. 3;

[0070] FIG. 5 is a schematic side view in longitudinal section of a textile reinforcement according to a third embodiment of the invention;

[0071] FIG. 6 is a schematic top view of the textile reinforcement according to any of the preceding figures; and

[0072] FIG. 7 is a schematic side view illustrating a device and a method for making the textile reinforcement of FIGS. 1 to 6.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0073] In the embodiment illustrated in FIGS. 1 and 2, the textile reinforcement 1 comprises a reinforcing layer 200 and a surface layer 5. The surface layer 5, of fiber web, forms one of the external faces of the textile reinforcement 1, in the present instance, the lower external face.

[0074] The reinforcing layer 200 comprises the combination of a reinforcement layer 6 and a thickness layer 2.

[0075] The thickness layer 2 is based on segments of glass fiber 3 coated in a polyester binder 4. The glass fiber segments 3 are rovings of single-strand thread pieces, having a linear weight of 40 to 50 tex, and oriented in random manner between the longitudinal direction and the transverse direction of the textile reinforcement 1.

[0076] The polyester binder 4 coating the glass fiber segments 3 is an unsaturated bisphenol polyester, whose melting point is on the order of 100 C., lower than the melting point of the synthetic material composing the surface layer 5.

[0077] The surface layer 5 may be made of polyester, polyamide, or polypropylene, reserving the fact that its melting point is higher than that of the polyester making up the thickness layer 2. A melting point of the fibers of the surface layer 5 can be, for example, around 250 C.

[0078] The reinforcement layer 6 is formed of fibers basically oriented in the longitudinal direction and in the transverse direction of the textile reinforcement 1.

[0079] In order to guarantee good mechanical strength under longitudinal traction, the reinforcement layer 6 can basically consist of longitudinal threads. The polyester binder 4 surrounding the glass fibers 3 ensures a good mechanical strength resisting the transverse deformation of the textile reinforcement 1.

[0080] In order to guarantee at the same time a good mechanical strength in the transverse direction of the reinforcement, the reinforcement layer 6 is preferably formed of fibers structured by weaving, or by a grid, thus comprising warp threads and weft threads. The advantage of the grid is that it is more easy and quick to produce than the weaving.

[0081] Preferably, the fibers in the reinforcement layer 6 are secured to each other, by gluing, to facilitate the passage through the pultrusion die when the textile reinforcement 1 is used to make a profiled piece by pultrusion.

[0082] A textile reinforcement 1 according to the invention with reinforcement layer comprising warp threads and weft threads provides a satisfactory mechanical strength not only in the longitudinal direction but also in the transverse direction, allowing such a textile reinforcement 1 to be used to make profiled pieces of greater width.

[0083] It will be noted, in this first embodiment of FIGS. 1 and 2, that the reinforcement layer 6 is the second external face of the textile reinforcement 1. In that way, the thickness layer 2 based on glass fiber segments 3 is enveloped between the first surface layer 5 and the reinforcement layer 6.

[0084] In the second embodiment, illustrated in FIGS. 3 and 4, the elements of the embodiment of FIGS. 1 and 2 are found again. Thus the reinforcing layer 200 and the first surface layer 5 of fiber web are again found. Also found again, in the reinforcing layer 200, are a first reinforcement layer 6 and a first thickness layer 2, said first thickness layer 2 being based on glass fiber segments 3 and polyester binder 4. The difference lies in the additional presence, in the reinforcing layer 200, of a second reinforcement layer 6a and a second thickness layer 2a, these respectively being of the same structure as the first reinforcement layer 6 and the first thickness layer 2.

[0085] The second reinforcement layer 6a forms the second external face of the textile reinforcement 1. In that way, the thickness layers 2 and 2a based on glass fiber segments 3 are enveloped between the first surface layer 5 and the second reinforcement layer 6a.

[0086] In the third embodiment illustrated in FIG. 5, a reinforcing layer 200 and a first surface layer 5 of fiber web are likewise again found. The difference, in comparison with the first embodiment of FIGS. 1 and 2, lies in the presence of a second surface layer 7 of fiber web, which may be made of the same synthetic material as the first surface layer 5.

[0087] At least one of the two surface layers 5 and 7 can itself be colored in the mass.

[0088] According to a variant of the second embodiment of FIGS. 3 and 4, a second surface layer, similar to the surface layer 7 of the embodiment of FIG. 5 may also be provided, on top of the second reinforcement layer 6a and itself forming the second external face of the textile reinforcement 1.

[0089] As can be seen in FIG. 6 in top view, the textile reinforcement according to the invention can be fabricated in the form of a wide band, extending longitudinally along an elongation axis I-I, and of width L consistent with the manufacturing capacities of the customary apparatus for production of textile reinforcements. For example, the width L may be around 2 to 3 m, while the length along the axis I-I may be much greater, and the reinforcement may be wound on a reel.

[0090] In this figure, the fact is illustrated that the textile reinforcement 1 can then be sliced longitudinally along the dotted lines to form bands 1a, 1b, 1c, 1d, 1e, 1f, 1g, and 1h, each of them constituting a pultrusion reinforcement to make a profiled piece.

[0091] Now considering FIG. 7, which represents schematically a device for the fabrication of a textile reinforcement 1 according to the present invention and at the same time illustrates the method of fabrication of the textile reinforcement 1.

[0092] The device 10 represented in this figure comprises a conveyor belt 11, for example in the form of a conveyor band moving between an entry roller 12 and an exit roller 13 in a longitudinal direction I-I as shown by the arrow 14. Near the entry roller 12, above the conveyor belt 11, there is located a first distributor of glass fiber rovings 15 which can deliver glass fiber rovings 16 to a first chopper 17. The pieces of glass fiber rovings 18 emerging from the first chopper 17 are sent to a first pin roller 19 which breaks up the pieces of glass fiber rovings to produce glass fiber segments. At the same time, a first powder distributor 21 distributes a polyester resin powder on the first pin roller 19, which first pin roller 19 at the same time accomplishes the mixing 20 of the powder with the glass fiber segments.

[0093] Upstream from the first pin roller 19 there is provided a first web distributor 22 to generate a first web 5 and to arrange it on the conveyor belt 11.

[0094] Furthermore, downstream from the first pin roller 19, there is provided a first reinforcement layer distributor 26, which arranges a first reinforcement layer 6 on the first mixture of fiber segments and powder already present on the conveyor belt 11.

[0095] Downstream from the first reinforcement layer distributor 26 there is provided a second glass fiber rovings distributor 28 which can deliver glass fiber rovings 29 to a second chopper 30, which itself can deliver pieces of glass fiber rovings 31 to a second pin roller 32, which itself can break up the pieces of glass fiber rovings and mix them with a polyester resin powder received from a second powder distributor 33 and which then lets them drop onto the first reinforcement layer 6, forming a second mixture.

[0096] Downstream from the second pin roller 32 there is provided a second distributor 34 which can deliver either a second reinforcement layer 6a or a second web 7, and arrange it on the the assemblage of components present on the conveyor belt 11.

[0097] Downstream on the conveyor belt 11 there is provided an oven 24 able to heat the elements placed on the conveyor belt 11, and downstream from the oven 24 there are one or more pressing rollers 25 able to press the materials moving on the conveyor belt 11.

[0098] The oven 24 can be adjusted for example to a temperature of around 180 C., and the speed of movement of the conveyor belt 11 can be such that the heating produced by the oven 24 is sufficient to melt the polyester resin powder, yet low enough to prevent a melting of the other components of the reinforcement.

[0099] Thus, during the fabrication of the textile reinforcement 1 by the device 10, a first polyester web 5 is arranged on top of the conveyor belt 11 moving in the longitudinal direction I-I. With the first chopper 17, rovings of glass fiber 16 are chopped and made to drop onto the first pin roller 19, which at the same time receives the polyester resin powder coming from the first powder distributor 21. The mixture 20 of glass fiber segments mixed with the polyester resin powder drops onto the first web 5, itself having been placed on the moving conveyor belt 11, forming a first mixture. The reinforcement layer distributor 26 arranges the reinforcement layer 6 on the first mixture. The device allows one or other of the embodiments of textile reinforcement to be fabricated, as chosen by an operator.

[0100] According to a first mode of operation, the operator inhibits the operation of the second chopper 30, of the second powder distributor 33 and of the second pin roller 32, and the operation of the second distributor 34. During the passage through the oven 24, the polyester resin powder melts and is distributed around the glass fiber segments. The pressing rollers 25 encourage the formation of a sheet of constant thickness by pressing the melted resin powder on the glass fiber segments. The result at the exit of the device 10 is a textile reinforcement 1 according to the embodiment of FIG. 1.

[0101] According to a second mode of operation, the operator inhibits the operation of the second chopper 30, of the second powder distributor 33 and of the second pin roller 32 but uses the second distributor 34, adapting it to deliver a second web 7 and to arrange same on the first reinforcement layer 6. During the passage through the oven 24, the polyester resin powder melts and is distributed around the glass fiber segments. The pressing rollers 25 encourage the formation of a sheet of constant thickness by pressing the melted resin powder on the glass fiber segments. The result of the exit of the device 10 is a textile reinforcement 1 according to the embodiment of FIG. 5.

[0102] According to a third mode of operation, the operator uses all the components of the device, adapting the second distributor 34 to deliver a second reinforcement layer 6a. In this case, the second chopper 30, the second powder distributor 33 and the second pin roller 32 produce and apply to the first reinforcement layer 6 a second mixture of pieces of glass fiber rovings and polyester powder, and the second distributor 34 arranges the second reinforcement layer 6a on this second mixture. During the passage through the oven 24, the polyester resin powder melts and is distributed around the glass fiber segments. The pressing rollers 25 encourage the formation of a sheet of constant thickness by pressing the melted resin powder on the glass fiber segments. The result of the exit of the device 10 is a textile reinforcement 1 according to the embodiment of FIGS. 3 and 4.

[0103] As an alternative, the invention provides for the device to be designed for the fabrication of just one of the embodiments of textile reinforcement which are defined hereinabove.

[0104] Thus, to fabricate the textile reinforcement according to the embodiment of FIG. 1, there is no need to provide the means for producing the second mixture of fibers leaving the second pin roller 32 or to provide the second distributor 34.

[0105] In order to fabricate the textile reinforcement according to the embodiment of FIG. 5, the second distributor 34 is added and is then suited to delivering a second web 7.

[0106] In order to fabricate the textile reinforcement according to the embodiment of FIGS. 3 and 4, use is made of the device as illustrated in FIG. 7, adapting the second distributor 34 to deliver a second reinforcement layer 6a.

[0107] As a preferred example, the polyester powder may be an unsaturated bisphenol polyester resin. Such a powder is a commercially available product, for example, from C.O.I.M. S.p.A. with the reference FILCO 661.

[0108] Alternatively, the polyester powder may be an unsaturated bisphenol polyester resin used in an aqueous emulsion, such as the ones commercially available from C.O.I.M. S.p.A with the references FILCO 657 or FILCO 659. Its drying temperature is 170 to 200 C. for 40 to 70 seconds. After cross linking, it becomes insoluble in styrene and acquires its bonding ability.

[0109] The present invention is not limited to the embodiments which have been explicitly described, and instead it includes the different variants and generalizations thereof contained in the scope of the following claims.