CN-116583393-B - Method and apparatus for producing composite material from multifilament fibres

CN116583393BCN 116583393 BCN116583393 BCN 116583393BCN-116583393-B

Abstract

A method of manufacturing an elongated composite element comprising bundles (20) of multifilament fibres embedded in a composition made of a polymerizable material is disclosed, the method comprising the steps of-creating an arrangement of multifilament fibres in the form of several individual strands such that a first strand (20 a) is located in the centre of the bundles and the other strands are arranged around the first strand, -moving the arrangement of multifilament fibres such that it is in the direction of movement, subjecting the arrangement of multifilament fibres to a process of-degassing the arrangement of fibres by vacuum, -impregnating the arrangement of fibres with the composition, -passing the first impregnated strands through a first mould (10 a) which partly polymerizes them, -passing all strands through a second mould (10 f) which aggregates them into individual strands (20 f), -exposing the individual strands (20 f) to a radiation source for additional polymerization, thereby obtaining an elongated composite element.

Inventors

D. Olsemar
A. Delphino

Assignees

米其林集团总公司

Dates

Publication Date: 20260512
Application Date: 20211126
Priority Date: 20201207

Claims (7)

1. A method of continuously manufacturing an elongated composite element comprising bundles (20) of multifilament fibers embedded in a composition based on a polymerizable substance, the method comprising the steps of: Arranging the multifilament fibres of the bundle in the form of several individual strands, each strand comprising several multifilament fibres, such that a first strand (20 a) is located in the centre of the bundle and the other strands are located around the first strand, -Carrying said arrangement of multifilament fibres so that, in the direction of advancement, it is subjected to: -degassing said arrangement of fibres by vacuum action; Impregnating said arrangement of fibres with said composition to obtain an impregnated strand, Passing the first impregnated strand through a first mould (10 a), said first mould (10 a) carrying out a partial polymerization of the composition, Passing all strands through a final die (10 f), said final die (10 f) gathering all strands into a single strand (20 f), Exposing the single strand (20 f) to a radiation source for additional polymerization to obtain the elongated composite element, The arrangement of strands and the successive passing through at least a first die and a last die are performed such that the strands converge from the impregnation chamber (3) towards the last die (10 f), the arrangement being most expanded at the outlet of the impregnation chamber (3), the arrangement shrinking to form the single strand (20 f) at the last die (10 f), and The arrangement of multifilament fibers comprises a center strand and several intermediate strands arranged to form at least one intermediate layer around the center strand and at least one outer layer of peripheral strands, wherein each intermediate layer of intermediate strands passes through an intermediate die where the partial polymerization of the composition takes place.
2. The method of claim 1, wherein the composite element is circular in cross-section.
3. A method according to any of the preceding claims, wherein the multifilament fibres are selected from glass fibres, carbon fibres, silicon fibres, ceramic fibres and mixtures of such fibres.
4. The method according to claim 1, wherein the polymerizable substance is of the thermosetting type.
5. An apparatus (1) for continuously manufacturing an elongated composite element comprising a bundle (20) of multifilament fibres embedded in a composition based on a polymerizable substance, the apparatus (1) comprising means capable of producing an arrangement of multifilament fibres of the bundle in the form of several individual strands, each strand comprising several fibres such that a first strand (20 a) is located in the centre of the bundle, means for degassing the arrangement and means for impregnating the arrangement with a composition based on a polymerizable material, a first mould (10 a) capable of receiving the first strand (20 a) to partially polymerize it and at least one final mould (10 f) capable of receiving all strands to form a single strand (20 f), and means for polymerizing the single strand using radiation means (50) to obtain the elongated composite element, The apparatus comprises at least one intermediate mould (10 b-10 e) located between the first mould (10 a) and the last mould (10 f), The first die (10 a) and the intermediate dies (10 b-10 e) comprise an annular UV radiation lamp (30), a guiding tube (40) for the strands is included in the central part of the annular UV radiation lamp (30), and The internal section of each guide tube (40) gradually increases from upstream to downstream between the first die (10 a) and the last die (10 f), Wherein the first strand (20 a) passes through the first die (10 a), the intermediate strands pass through the intermediate dies (10 b-10 e) and are gradually gathered until all strands are combined together through the last die (10 f) and form a single strand (20 f).
6. The apparatus according to claim 5, characterized in that the ring-shaped UV radiation lamp (30) comprises a disc (32) for supporting several light emitting diodes and provided with a central opening through which the guide tube (40) passes, and a reflector (33) capable of directing the radiation emitted by the light emitting diodes in the direction of the outlet of the guide tube, means for cooling the lamp and means for powering the lamp.
7. The apparatus according to claim 6, characterized in that the means for cooling the lamp comprise a water cooling circuit and/or means for generating a flow of air or nitrogen.

Description

Method and apparatus for producing composite material from multifilament fibres Technical Field The present invention relates to a continuous manufacturing process of an elongated composite material produced by impregnating multifilament fibres with a polymerizable composition, and more particularly to a process of manufacturing a composite material in the form of individual strands, for example of the GRC (glass-resin composite) type comprising continuous unidirectional multifilament glass fibres embedded in a polymerizable resin. Background Document EP1 174 250 describes a method and a plant for the continuous impregnation of ultra-long fibres with a resin to manufacture ultra-elongated composite elements, these composite materials comprising reinforcing fibres embedded in a matrix of a cured resin. The described method comprises the steps of carrying a bundle of reinforcing fibres from a fibre storage reel through a vacuum hood, then through an impregnation chamber where the fibres are impregnated with resin, and then passing the impregnated fibres through a calibration mould after the shape of the prepreg material has been stabilised beforehand by at least partial polymerisation of the resin of the prepreg material. There is also a calibration mould of a predetermined shape and a predetermined size at the inlet of the vacuum hood and before the impregnation chamber. The facility includes a pull roll carrying the fibers from a fiber storage spool and a spool for receiving the prepreg material. Although functioning satisfactorily, it has proved difficult to increase the diameter of composite materials manufactured with such facilities beyond a certain limit. Thus, the need to make larger diameter composite materials emerges. One solution to this problem is to place a resin-impregnated fiber bundle (obtained with a continuous manufacturing plant for fibers of the type described above) in an oven so as to obtain polymerization in the core of the bundle. However, this approach can be time and effort consuming. Documents EP 1,506,085 A1 and US 2015/318080 A1 describe different methods of manufacturing a composite material in the form of a cord. Another solution to this problem is described in document EP 0 290 849. According to this document, a resin-impregnated fiber bundle is produced by a pultrusion method by passing the fiber bundle through a resin bath, then passing it through a die and exposing it to UV radiation. The polymerization of the beam proceeds stepwise from the outside to the inside of the beam as the beam travels over the length of the transparent mold or through a liquid medium defined by two watertight nozzles while being exposed to UV radiation. While it is accepted that better polymerization can be carried out in the core of the bundle, this process proves to be quite slow, not suitable for the manufacturing speed of the industrial process. Disclosure of Invention The object of the present invention is to overcome the drawbacks of the above-mentioned documents by providing an original solution to a process and apparatus for the polymerization of multifilament fibres for a plant for the continuous manufacture of elongated composite materials, enabling composite materials with a cross section of larger dimensions to be obtained with high productivity. This object is achieved by the present invention, which provides a method for continuously manufacturing an elongated composite element comprising bundles of multifilament fibres embedded in a composition based on a polymerizable substance, comprising the steps of: arranging the multifilament fibres of the bundle in the form of several individual strands, each strand comprising several multifilament fibres, such that a first strand is located in the centre of the bundle and the other strands are located around the first strand, -Carrying said arrangement of multifilament fibres so that, in the direction of advancement, it is subjected to: -degassing said arrangement of fibres by vacuum action; Impregnating said arrangement of fibres with said composition to obtain an impregnated strand, Passing the first impregnated strand through a first die, the first die performing a partial polymerization of the composition, -Passing all strands through a final die which aggregates them into individual strands; -exposing said individual strands to a radiation source for additional polymerization, thereby obtaining said elongated composite element. An elongated composite element comprising bundles of multifilament fibres embedded in a composition based on a polymerizable substance is understood to mean a composite element of great length, which is continuously manufactured from one or more reels supplied with multifilament fibres to form bundles, which bundles are carried to continuously carry out impregnation of their fibres with a polymerizable organic substance and polymerization of the substance as the bundles move through. In other words, in the method