阅读说明：本技术 一种纤维增强复合材料的回收再利用方法 (Recycling method of fiber reinforced composite material ) 是由 杨斌 于 2021-08-24 设计创作，主要内容包括：本发明公开了一种纤维增强复合材料的回收再利用方法,包括以下步骤：将热固性纤维增强复合材料与热塑性纤维增强复合材料分别切割成若干段热固性复材段与热塑性复材段；在裸露出的增强纤维的至少部分表面制备碳纳米材料层以进行改性处理；将每段热固性复材段与相应一段热塑性复材段按照预设的拼接方式拼接在一起以组成单个回收子集；通过压力装置将回收结构压合成统一整体,从热固性复材段中裸露的增强纤维上引出电极,使用外接电源连接电极并通电。根据本发明,其利用热固性纤维增强复合材料与热塑性纤维增强复合材料相结合的方式使得热固性纤维增强复合材料的回收再利用变为可能。(The invention discloses a recycling method of a fiber reinforced composite material, which comprises the following steps: respectively cutting the thermosetting fiber reinforced composite material and the thermoplastic fiber reinforced composite material into a plurality of sections of thermosetting composite material sections and thermoplastic composite material sections; preparing a carbon nano material layer on at least part of the surface of the exposed reinforced fiber for modification treatment; splicing each section of the thermosetting composite material section and a corresponding section of the thermoplastic composite material section together according to a preset splicing mode to form a single recycling subset; the recycling structure is pressed into a unified whole through a pressure device, electrodes are led out from the exposed reinforced fibers in the thermosetting composite material section, and an external power supply is used for connecting the electrodes and electrifying. According to the present invention, it is possible to recycle a thermosetting fiber-reinforced composite material by combining the thermosetting fiber-reinforced composite material with a thermoplastic fiber-reinforced composite material.)

1. A recycling method of a fiber reinforced composite material is characterized by comprising the following steps:

respectively cutting the thermosetting fiber reinforced composite material and the thermoplastic fiber reinforced composite material into a plurality of sections of thermosetting composite material sections and thermoplastic composite material sections, so that each section of thermosetting composite material section is matched with the corresponding section of thermoplastic composite material section in size and shape, and performing surface treatment on the cut thermosetting composite material sections and thermoplastic composite material sections to form a matching structure for improving the combination stability on the contact surface of the thermosetting composite material section and the thermoplastic composite material section;

treating the contact surface of the thermosetting composite material section to enable the thermosetting matrix of the outer layer to fall off and expose at least part of the reinforcing fibers, and preparing a carbon nano material layer on at least part of the surfaces of the exposed reinforcing fibers for modification treatment;

splicing each section of the thermosetting composite material section and a corresponding section of the thermoplastic composite material section together according to a preset splicing mode to form a single recovery subset, and sequentially stacking at least one recovery subset to form a recovery structure;

the recycling structure is pressed into a unified whole through a pressure device, electrodes are led out from the exposed reinforcing fibers in the thermosetting composite material section, an external power supply is used for connecting the electrodes and electrifying, the thermoplastic matrix in contact with the thermosetting composite material section is melted by utilizing the heat generated by electrifying the carbon nano material on the surface of the reinforcing fibers, and at least one recycling subset is bonded and solidified into the unified whole connected with each other after cooling and solidification.

2. The method of recycling the fiber-reinforced composite material according to claim 1, wherein the thermosetting fiber-reinforced composite material and/or the thermoplastic fiber-reinforced composite material is any one of a plate member, a block member, or a column member.

3. The method for recycling fiber-reinforced composite materials according to claim 1 or 2, wherein the carbon nanomaterial is sized with a thermoplastic sizing agent.

4. The method of claim 1 or 2, wherein the mating structure is at least one of a saw-tooth shape, an arc shape, a wave shape, and a mortise and tenon shape.

5. The method for recycling the fiber reinforced composite material according to claim 4, wherein the temperature of the thermoplastic resin is slowly decreased by controlling the current attenuation rate of the external power supply, so as to avoid the cracking and/or warping defects of the thermoplastic resin in the cooling process caused by the excessively high cooling speed, and the recycling operation of the waste fiber reinforced composite material is finished after the thermoplastic resin is cooled and solidified.

6. The method of recycling fiber-reinforced composite materials according to claim 1 or 2, wherein each segment of the thermosetting composite material is adhesively bonded to a corresponding segment of the thermoplastic composite material by an adhesive.

7. The method of claim 3, wherein the carbon nanomaterial layer is applied by at least one of spraying, roll coating, screen printing, and plating.

8. The method for recycling fiber-reinforced composite materials according to claim 1 or 2, wherein the method of surface-treating the cut thermosetting composite material segments and thermoplastic composite material segments is machining.

9. The method for recycling fiber-reinforced composite materials according to claim 1 or 2, wherein the method for surface-treating the cut thermosetting composite material segments and thermoplastic composite material segments is chemical etching.

Technical Field

The invention relates to the field of recycling of fiber reinforced composite materials, in particular to a recycling method of a fiber reinforced composite material.

Background

The fiber reinforced composite material has excellent properties of light weight, high strength and the like, and is widely applied to the fields of aerospace, transportation, marine ships, sports goods and the like. While the continued growth of carbon fiber reinforced Composites (CFRP) has led to a dramatic growth in discarded CFRP articles. About 60-70 kg carbon fibers are contained in every 100kg of carbon fiber composite waste, and if the carbon fiber value in 6.2 million tons of waste CFRPs is calculated according to 200 yuan/kg, the carbon fiber value can reach more than 74 million yuan. Therefore, from an economic perspective, the recovery of high value carbon fibers facilitates a reduction in overall costs, and is of significant commercial value.

Although the recovery value of other types of fibers such as glass fibers is inferior to that of carbon fibers, the amount of the fibers used is increasing year by year because of their excellent mechanical properties and low cost, but the waste products are also rapidly growing. With the increasing environmental protection of countries in the world, a proper utilization way for waste products such as glass fiber and the like must be found to solve the problem of environmental pollution, otherwise, the method is a great burden for production enterprises and causes environmental pollution and harm to the society.

Recycling of fibre-reinforced composites is generally dependent on the matrix material, with thermosetting resins being the predominant matrix material in fibre-reinforced composites, accounting for about 80% of the total content, the remaining 20% being predominantly thermoplastic resins. In the case of thermosetting resins, the curing process of the thermosetting resins belongs to irreversible crosslinking reaction, so that the processing performance of the thermosetting resins is not repeatable, and in the past decades, the waste fiber reinforced thermosetting composite materials are mainly treated by the traditional methods of landfill and incineration, so that the recycling of resources is seriously hindered, and the environmental pollution is also caused. In the case of thermoplastic resin, the curing process is only a physical change process, so the recycling process does not involve a complex separation process of the fiber residual resin matrix, and has a wide application prospect in the aspect of recycling, but still has the problem of poor recycling economy.

From the growing trend of the whole composite material market and the sustainable development of the industry, the recycling of the composite material has important practical significance in the aspects of transportation, aerospace, building and the like. In the current recycling technology, the mechanical method and the heat treatment method are only suitable for recycling fiber materials, but can not recycle matrix materials; the chemical method belongs to a novel recovery technology, but is still in a test stage at present, and still has a great technical problem and an industrial recovery cost problem. Therefore, how to realize the recycling of the fiber reinforced composite material under mild conditions, and the recycling of large-size members, especially the whole structure, and the improvement of recycling economy are problems to be solved.

In view of the above, it is necessary to develop a recycling method of fiber reinforced composite material to solve the above problems.

Disclosure of Invention

The embodiment of the application provides a recycling method of a fiber reinforced composite material, which makes recycling of the thermosetting fiber reinforced composite material possible by combining the thermosetting fiber reinforced composite material and the thermoplastic fiber reinforced composite material, improves recycling economy of the fiber reinforced composite material, is suitable for industrial application, and has a great application prospect.

In order to solve the above technical problem, an embodiment of the present application discloses the following technical solutions:

provided is a recycling method of a fiber reinforced composite material, comprising the following steps:

respectively cutting the thermosetting fiber reinforced composite material and the thermoplastic fiber reinforced composite material into a plurality of sections of thermosetting composite material sections and thermoplastic composite material sections, so that each section of thermosetting composite material section is matched with the corresponding section of thermoplastic composite material section in size and shape, and performing surface treatment on the cut thermosetting composite material sections and thermoplastic composite material sections to form a matching structure for improving the combination stability on the contact surface of the thermosetting composite material section and the thermoplastic composite material section;

treating the contact surface of the thermosetting composite material section to enable the thermosetting matrix of the outer layer to fall off and expose at least part of the reinforcing fibers, and preparing a carbon nano material layer on at least part of the surfaces of the exposed reinforcing fibers for modification treatment;

splicing each section of the thermosetting composite material section and a corresponding section of the thermoplastic composite material section together according to a preset splicing mode to form a single recovery subset, and sequentially stacking at least one recovery subset to form a recovery structure;

the recycling structure is pressed into a unified whole through a pressure device, electrodes are led out from the exposed reinforcing fibers in the thermosetting composite material section, an external power supply is used for connecting the electrodes and electrifying, the thermoplastic matrix in contact with the thermosetting composite material section is melted by utilizing the heat generated by electrifying the carbon nano material on the surface of the reinforcing fibers, and at least one recycling subset is bonded and solidified into the unified whole connected with each other after cooling and solidification.

Optionally, the thermosetting fiber-reinforced composite material and/or the thermoplastic fiber-reinforced composite material is any one of a plate member, a block member, or a column member.

Optionally, the carbon nanomaterial is sized with a thermoplastic sizing agent.

Optionally, the matching structure is at least one of a zigzag shape, an arc shape, a wave shape and a mortise and tenon shape.

Optionally, the temperature of the thermoplastic resin is reduced at a slow rate by controlling the current attenuation rate of the external power supply, so that the cracking and/or warping defects of the thermoplastic resin in the cooling process caused by the excessively high cooling speed are avoided, and the recovery operation of the waste fiber reinforced composite material is finished after the thermoplastic resin is cooled and solidified.

Optionally, each section of thermosetting composite material is adhesively bonded to a corresponding section of thermoplastic composite material by an adhesive.

Optionally, the sizing method of the carbon nanomaterial layer is at least one of spraying, roll coating, screen printing and coating.

Optionally, the surface treatment of the cut thermosetting composite material segment and thermoplastic composite material segment is machining.

Optionally, the surface treatment of the cut thermosetting composite material section and thermoplastic composite material section is chemical corrosion processing.

One of the above technical solutions has the following advantages or beneficial effects: the mode of combining the thermosetting fiber reinforced composite material and the thermoplastic fiber reinforced composite material makes the recycling of the thermosetting fiber reinforced composite material possible, improves the economical efficiency of recycling the fiber reinforced composite material, is suitable for industrial application, and has a wide application prospect.

Another technical scheme in the above technical scheme has the following advantages or beneficial effects: the sizing agent is coated on the surface of the thermosetting fiber reinforced fiber, so that the molten thermoplastic resin reacts with the sizing agent on the surface of the fiber to form hydrogen bonds so as to enhance the bonding performance between the thermoplastic resin and the sizing agent.

Another technical scheme in the above technical scheme has the following advantages or beneficial effects: because the carbon nano material is used for preparing the surface of the reinforced fiber, on one hand, the excellent electrical property of the carbon nano material is utilized, the electric heating effect can be formed after the carbon nano material is externally connected with current, the temperature can be controlled by adjusting the input power, and the thermoplastic resin can be melted and bonded with the thermosetting fiber reinforced composite material by utilizing the electric heating effect; on the other hand, by utilizing the excellent mechanical property of the carbon nano material, a bridging effect can be formed by implanting the carbon nano material between layers, and the carbon nano material can fully transfer the stress on the matrix to the reinforced fiber under the action of external load, so that the interface property of the composite material is effectively enhanced.

Drawings

In order to more clearly illustrate the technical solution of the embodiments of the present invention, the drawings of the embodiments will be briefly described below, and it is apparent that the drawings in the following description relate only to some embodiments of the present invention and are not limiting thereof, wherein:

FIG. 1 is a schematic view of a surface treatment process of a composite material in a recycling method of a fiber reinforced composite material according to an embodiment of the present invention;

FIG. 2 is a diagram illustrating a process of combining a thermosetting fiber-reinforced composite material and a thermoplastic fiber-reinforced composite material in a recycling method of a fiber-reinforced composite material according to an embodiment of the present invention;

FIG. 3 is a cross-sectional view of a hybrid structure of a thermosetting/thermoplastic fiber-reinforced composite material with a planar contact surface according to an embodiment of the present invention;

FIG. 4 is a cross-sectional view of a hybrid structure of thermosetting/thermoplastic fiber-reinforced composite material with a sawtooth-shaped contact surface according to an embodiment of the present invention;

fig. 5 is a cross-sectional view of a hybrid structure of an arc-shaped plate of a thermosetting/thermoplastic fiber-reinforced composite material, in which a contact surface is a plane, in the recycling method of the fiber-reinforced composite material according to an embodiment of the present invention;

fig. 6 is a cross-sectional view of a hybrid structure of a plurality of layers of thermosetting/thermoplastic fiber reinforced composite materials in a recycling method of the fiber reinforced composite materials according to an embodiment of the present invention.

Reference numerals:

1-a thermoset fiber reinforced composite; 2-a sizing agent;

3-carbon nanomaterial suspension; a layer of 4-carbon nanomaterial;

5-thermoplastic fiber reinforced composite; 6-an electrode;

7-pressure head; 8-external power supply.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

In the drawings, the shape and size may be exaggerated for clarity, and the same reference numerals will be used throughout the drawings to designate the same or similar components.

Unless defined otherwise, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention belongs. The use of "first," "second," and similar terms in the description and claims of the present application do not denote any order, quantity, or importance, but rather the terms are used to distinguish one element from another. Also, the use of the terms "a," "an," or "the" and similar referents do not denote a limitation of quantity, but rather denote the presence of at least one. The word "comprise" or "comprises", and the like, means that the element or item listed before "comprises" or "comprising" covers the element or item listed after "comprising" or "comprises" and its equivalents, and does not exclude other elements or items. "upper", "lower", "left", "right", and the like are used merely to indicate relative positional relationships, and when the absolute position of the object being described is changed, the relative positional relationships may also be changed accordingly.

In the following description, terms such as center, thickness, height, length, front, back, rear, left, right, top, bottom, upper, lower, etc., are defined with respect to the configurations shown in the respective drawings, and in particular, "height" corresponds to a dimension from top to bottom, "width" corresponds to a dimension from left to right, "depth" corresponds to a dimension from front to rear, which are relative concepts, and thus may be varied accordingly depending on the position in which it is used, and thus these or other orientations should not be construed as limiting terms.

Terms concerning attachments, coupling and the like (e.g., "connected" and "attached") refer to a relationship wherein structures are secured or attached, either directly or indirectly, to one another through intervening structures, as well as both movable or rigid attachments or relationships, unless expressly described otherwise.

Example one

Referring to fig. 1 to 3, fig. 1 is a schematic view illustrating a surface treatment process of a composite material in a recycling method of a fiber reinforced composite material according to an embodiment of the present invention; FIG. 2 is a diagram illustrating a process of combining a thermosetting fiber-reinforced composite material and a thermoplastic fiber-reinforced composite material in a recycling method of a fiber-reinforced composite material according to an embodiment of the present invention; FIG. 3 is a cross-sectional view of a hybrid structure of a thermosetting/thermoplastic fiber-reinforced composite material with a planar contact surface according to an embodiment of the present invention; the method provided by the embodiment is used for enabling the recycling of the thermosetting fiber reinforced composite material, and comprises the following steps:

respectively cutting the thermosetting fiber reinforced composite material 1 and the thermoplastic fiber reinforced composite material 5 into a plurality of sections of thermosetting composite material sections and thermoplastic composite material sections, so that each section of thermosetting composite material section is matched with a corresponding section of thermoplastic composite material section in size and shape, and performing surface treatment on the cut thermosetting composite material sections and thermoplastic composite material sections to form a matching structure for improving the combination stability on the contact surface of the thermosetting fiber reinforced composite material section and the thermoplastic composite material section;

treating the contact surface of the thermosetting composite material section to enable the thermosetting matrix of the outer layer to fall off to expose at least part of the reinforcing fibers, preparing a carbon nano material layer on at least part of the surfaces of the exposed reinforcing fibers for modification treatment, wherein the process of spraying carbon nano material suspension 3 on the surfaces of the reinforcing fibers to prepare the carbon nano material is shown in fig. 1;

splicing each section of thermosetting composite material section and a corresponding section of thermoplastic composite material section together according to a preset splicing mode to form a single recovery subset, wherein at least one recovery subset is sequentially laminated to form a recovery structure, the step shown in figure 3 is that the thermosetting composite material section and the corresponding section of thermoplastic composite material section are spliced together according to a laminating mode, and the contact surface between the thermosetting composite material section and the corresponding section of thermoplastic composite material section is subjected to frosting treatment to improve the combination stability of the thermosetting composite material section and the corresponding section of thermoplastic composite material section;

the recycling structures are pressed into a unified whole through a pressure device, electrodes are led out from the exposed reinforcing fibers in the thermosetting composite material section, an external power supply is used for connecting the electrodes and electrifying, the thermoplastic matrix in contact with the thermosetting composite material section is melted by utilizing the heat generated by electrifying the carbon nano materials on the surface of the reinforcing fibers, and after cooling and solidification, at least one recycling subset is bonded and solidified into the unified whole connected with each other, wherein in the embodiment shown in fig. 2, the pressure device comprises a pressure head 7 and a pressure head driving device (not shown) for driving the pressure head 7 to selectively compress.

Further, the thermosetting fiber-reinforced composite material and/or the thermoplastic fiber-reinforced composite material is any one of a plate member, a block member, or a column member. Fig. 2 and 3 show embodiments in which the thermosetting fiber-reinforced composite material and/or the thermoplastic fiber-reinforced composite material is a plate-type member or a block-type member.

Further, the sizing agent 2 adopted by the carbon nano material is a thermoplastic sizing agent.

Furthermore, the matching structure is at least one of a saw-tooth shape, an arc shape, a wave shape and a mortise and tenon shape. In the embodiment shown in fig. 3, the mating structure is a generally planar frosted structure.

Further, the current attenuation rate of the external power supply 8 is reduced, so that the temperature of the thermoplastic resin is reduced at a slow rate, the defects of cracking and/or warping of the thermoplastic resin in the cooling process caused by the excessively high cooling speed are avoided, and the recovery operation of the waste fiber reinforced composite material is finished after the thermoplastic resin is cooled and solidified.

Further, each section of the thermosetting composite material is in adhesive bonding with the corresponding section of the thermoplastic composite material through an adhesive.

Further, the sizing mode of the carbon nano material layer is at least one of spraying, roll coating, screen printing and film coating.

Furthermore, the surface treatment mode of the thermosetting composite material section and the thermoplastic composite material section after cutting is mechanical cutting processing or chemical corrosion processing.

Example two

Fig. 4 shows a second embodiment of the present invention, which is different from the first embodiment in that:

the thermosetting composite material section and the corresponding thermoplastic composite material section are spliced together in a laminating mode, and the contact surface between the thermosetting composite material section and the corresponding thermoplastic composite material section is cut to form a serrated joint surface so as to improve the joint stability of the thermosetting composite material section and the corresponding thermoplastic composite material section.

In the embodiment shown in fig. 4, the functions/steps of the recycling method of the fiber reinforced composite material provided in this embodiment correspond to the functions realized in the first embodiment, so that reference may be made to the contents in the first embodiment for other functions/steps of this embodiment, and details are not repeated here.

EXAMPLE III

Fig. 5 shows a third embodiment of the present invention, which is different from the first embodiment/the second embodiment in that:

the solid composite material section and the corresponding section of thermoplastic composite material section are spliced together in a laminating mode, and the contact surface between the arc-shaped thermosetting composite material section and the corresponding section of arc-shaped thermoplastic composite material section is polished to form a frosted joint surface so as to improve the joint stability of the two sections.

In the embodiment shown in fig. 5, the functions/steps of the recycling method of the fiber reinforced composite material provided in this embodiment correspond to the functions realized in the first embodiment, so that reference may be made to the contents in the first embodiment for other functions/steps of this embodiment, and details are not repeated here.

Example four

Fig. 6 shows a fourth embodiment of the present invention, which is different from the first embodiment/the second embodiment/the third embodiment in that:

the two thermosetting fiber reinforced composite materials/sheets 1 and the single thermoplastic fiber reinforced composite material/sheet 5 are combined and recycled, so that the problem of easy warping in the combining process is solved, and the possibility of combining and recycling the multilayer thermosetting/thermoplastic fiber reinforced composite materials is solved.

In the embodiment shown in fig. 6, the functions/steps of the recycling method of the fiber reinforced composite material provided in this embodiment correspond to the functions realized in the first embodiment, so that reference may be made to the contents in the first embodiment for other functions/steps of this embodiment, and details are not repeated here.

The number of apparatuses and the scale of the process described herein are intended to simplify the description of the present invention. Applications, modifications and variations of the present invention will be apparent to those skilled in the art.

The features of the different implementations described herein may be combined to form other embodiments not specifically set forth above. The components may be omitted from the structures described herein without adversely affecting their operation. Further, various individual components may be combined into one or more individual components to perform the functions described herein.

Furthermore, while embodiments of the invention have been described above, it is not limited to the applications set forth in the description and the embodiments, which are fully applicable in a variety of fields of endeavor to which the invention pertains, and further modifications may readily be made by those skilled in the art, it being understood that the invention is not limited to the details shown and described herein without departing from the general concept defined by the appended claims and their equivalents.