阅读说明：本技术 一种混杂纤维经编格栅的制备方法 (Preparation method of hybrid fiber warp-knitted grating ) 是由 梁训美 汪昕 吴智深 张晓非 赵纯锋 于 2020-12-25 设计创作，主要内容包括：本发明公开了一种混杂纤维经编格栅的制备方法,包括以下步骤：配置经向格栅支,所述经向格栅支由高模量纤维和低模量纤维混合而成；配置纬向格栅支,所述纬向格栅支由高模量纤维和低模量纤维混合而成；对经向格栅支和纬向格栅支的低模量纤维纱施加预张力；采用施加预应力后的经向格栅支和纬向格栅支进行正交编织,得到横纵交织的经编格栅；对编织后的经编格栅进行浸渍液浸渍并固化；将固化成型后的格栅进行放张预应力。本发明经编格栅固化成型后低模量纤维中存在初始应力,减少低模量纤维纱的受力滞后,以保证混杂纤维单支格栅受力均匀、变形协调,这样充分利用了不同纤维的优势,解决了单一纤维格栅强度低、延性差的问题。(The invention discloses a preparation method of a warp-knitted hybrid fiber grid, which comprises the following steps: configuring warp-wise grid branches, wherein the warp-wise grid branches are formed by mixing high-modulus fibers and low-modulus fibers; configuring weft-wise grating branches, wherein the weft-wise grating branches are formed by mixing high-modulus fibers and low-modulus fibers; applying pretension to the low-modulus fiber yarns of the warp-wise grid branches and the weft-wise grid branches; carrying out orthogonal weaving by adopting the warp-wise grating branches and the weft-wise grating branches after prestress is applied to obtain warp-knitted gratings which are transversely and longitudinally interwoven; dipping and curing the knitted warp knitted grating by using dipping liquid; and (4) performing relaxation prestress on the cured and formed grating. The low-modulus fiber after the warp knitted grating is solidified and formed has initial stress, so that stress lag of low-modulus fiber yarns is reduced, uniform stress and deformation coordination of the single fiber grating of the hybrid fiber are guaranteed, the advantages of different fibers are fully utilized, and the problems of low strength and poor ductility of the single fiber grating are solved.)

1. A preparation method of a warp-knitted grid of hybrid fibers is characterized by comprising the following steps:

configuring warp-wise grid branches, wherein the warp-wise grid branches are formed by mixing high-modulus fibers and low-modulus fibers;

configuring weft-wise grating branches, wherein the weft-wise grating branches are formed by mixing high-modulus fibers and low-modulus fibers;

applying pretension to the low modulus fiber yarns in the warp and weft grid branches;

carrying out orthogonal weaving by adopting the warp-wise grating branches and the weft-wise grating branches after prestress is applied to obtain warp-knitted gratings which are transversely and longitudinally interwoven;

dipping the knitted warp knitting grid in dipping liquid;

curing the warp-knitted grating impregnated by the impregnation liquid at high temperature;

and (4) performing relaxation prestress on the cured and formed grating.

2. The preparation method according to claim 1, wherein the high-modulus fibers in the warp-wise lattice branches account for 15% -25% of the total volume of the single lattice fibers; the high-modulus fibers in the weft-wise grating branches account for 15% -25% of the total amount of the single grating fibers.

3. The preparation method according to claim 1, wherein the high modulus fiber is carbon fiber, and has a tensile strength of about 4800MPa, a modulus of about 230GPa, and an elongation of 1.8%; the low-modulus fiber is E-glass fiber or basalt fiber, the strength of the E-glass fiber is about 3000MPa, the modulus is about 75GPa, the elongation is 4.1%, the strength of the basalt fiber is 3000MPa, the modulus is 85GPa, and the elongation is 3.1%.

4. The method for preparing the high-modulus fiber reinforced plastic composite material as claimed in claim 2, wherein in the warp direction grating branches and the weft direction grating branches, the high-modulus fiber is arranged in the middle of the grating branches, and the low-modulus fiber is arranged on the side of the grating branches.

5. The method according to claim 1, wherein the high-temperature curing is performed at a temperature of 110 to 180 ℃ for 5 to 20 min.

6. The method according to claim 1, wherein the hybrid fiber grid comprises 85 to 92wt% of the fibers and 8 to 15wt% of the dip coating.

7. The preparation method according to claim 6, wherein the content of the dip coating of the hybrid grid is ensured by controlling the dipping time, and the dipping time is 3-5 min.

8. The method according to claim 1, wherein the impregnating solution is styrene-butadiene latex, acrylic emulsion, epoxy resin, vinyl resin or phenolic resin.

Technical Field

The invention relates to the technical field of composite materials, in particular to a preparation method of a warp-knitted hybrid fiber grid.

Background

The fiber warp-knitted grating is widely used in civil engineering due to the excellent mechanical property, and is applied to a cement concrete structure to reinforce concrete and overcome the problems of low tensile strength, poor ductility, poor impact resistance and the like of the concrete; the asphalt mixture is used for enhancing the surface layer of the asphalt mixture in road engineering, improving the stability of the pavement, delaying reflection cracks, improving the fatigue resistance and the like; and the method can also be applied to the reinforcement of roadbeds, embankments, slopes and the like, and the stress stability is improved.

The fiber used by the fiber warp-knitted grating can be carbon fiber, glass fiber, basalt fiber and the like, the carbon fiber has high strength and high modulus, but typical brittle materials have poor deformability and high price, and are easy to generate brittle fracture when used for reinforcing structures; the glass fiber has good ductility and relatively low price, but has low strength and modulus, and is used for reinforcing so that the rigidity and the bearing capacity are low; the mechanical property of the basalt fiber is equivalent to that of glass fiber, and the basalt fiber has better temperature resistance and corrosion resistance. Therefore, in order to fully exert the advantages of different fibers and solve the defect of single fiber, the hybrid fiber composite material is produced. The hybrid fiber warp-knitted grille can give full play to the advantages of fibers with different moduli and different strengths, and the manufactured grille product has the characteristics of high strength, good ductility, coordinated deformation and uniform stress.

The existing preparation method of the hybrid fiber warp-knitted grating mainly comprises the steps that the same fibers are adopted in grating branches, different fibers are adopted between the grating branches alternately, or different fibers are adopted in the warp and weft directions, and the two methods have the advantages that the hybrid fiber warp-knitted grating is not uniformly stressed, and different fibers cannot be fully utilized.

Disclosure of Invention

The invention aims to provide a preparation method of a hybrid fiber warp-knitted grid, and the hybrid fiber warp-knitted grid prepared by the method has the characteristics of high strength, good ductility, uniform stress and coordinated deformation.

In view of the above, the present invention provides a method for preparing a warp-knitted hybrid fiber grid, comprising the following steps:

configuring warp-wise grid branches, wherein the warp-wise grid branches are formed by mixing high-modulus fibers and low-modulus fibers;

configuring weft-wise grating branches, wherein the weft-wise grating branches are formed by mixing high-modulus fibers and low-modulus fibers;

applying pretension to the low-modulus fiber yarns of the warp-wise grid branches and the weft-wise grid branches;

carrying out orthogonal weaving by adopting the warp-wise grating branches and the weft-wise grating branches after prestress is applied to obtain a woven net which is transversely and longitudinally interwoven;

dipping the woven warp and weft yarns in a dipping solution, and curing at high temperature;

and (4) performing relaxation prestress on the cured and formed grating.

Preferably, the fibers are high modulus fibers and low modulus fibers;

preferably, the high modulus fibers are arranged in the middle of the grid branches, the low modulus fibers are arranged on the sides of the grid branches, and the high modulus fibers account for 15% -25% of the total amount of the single grid fibers in the single grid.

Preferably, the high modulus fiber is carbon fiber, the tensile strength of the high modulus fiber is about 4800MPa, the modulus of the high modulus fiber is about 230GPa, the elongation of the low modulus fiber is 1.8%, the low modulus fiber is E-glass fiber or basalt fiber, the E-glass fiber has the strength of about 3000MPa, the modulus of the low modulus fiber is about 72GPa, the elongation of the low modulus fiber is 4.1%, the strength of the basalt fiber is 3000MPa, the modulus of the low modulus fiber is 85Gpa, and the elongation of the low modulus fiber is 3.1%.

Preferably, in the hybrid fiber grid, the content of the fibers is 85-92 wt%, and the content of the dip coating is 8-15 wt%.

Preferably, the pretension is applied before the hybrid grid is woven, and the pretension is released after the hybrid grid is woven and impregnated and cured at high temperature.

Preferably, the knitting process is batch section knitting, the longest length of each batch section knitting does not exceed the length of the knitting platform, the widest width does not exceed the width of the knitting platform, and the knitting process can be specifically adjusted according to equipment and requirements.

Preferably, the fiber yarns in the grid branches are continuous fiber yarns, and the thickness of the fiber yarns can be adjusted according to specific requirements.

Preferably, the dipping solution can be styrene-butadiene latex, acrylic emulsion, epoxy resin, vinyl resin, phenolic resin and the like.

The invention provides a preparation method of a warp-knitted grid made of hybrid fibers, which comprises the following steps: the warp and weft grating branches are configured and formed by mixing high-modulus fibers and low-modulus fibers, pretension is applied to low-modulus fiber yarns in the warp and weft grating branches before warp knitting, pretension and tension releasing are carried out on the gratings after high-temperature curing molding, initial stress exists in the low-modulus fibers after curing molding, stress lag of the low-modulus fiber yarns is reduced, so that uniform stress and deformation coordination of a single hybrid fiber grating are guaranteed, the advantages of different fibers are fully utilized, and the problems of low strength and poor ductility of a single fiber grating are solved.

Compared with the prior art, the hybrid fiber warp-knitted grating is formed by a warp-knitting process, the high-modulus fiber grating and the low-modulus fiber grating are mixed in a single grating, the stress is more uniform, the advantages of different fibers can be better utilized, and pretension is applied to the low-modulus fiber bundle to ensure uniform stress and coordinated deformation. The warp-knitted hybrid fiber grid prepared by the method has the characteristics of high strength, good ductility, uniform stress and coordinated deformation.

Detailed Description

For a further understanding of the invention, reference will now be made to the preferred embodiments of the invention by way of example, and it is to be understood that the description is intended to further illustrate features and advantages of the invention, and not to limit the scope of the claims.

The embodiment of the invention discloses a preparation method of a warp-knitted hybrid fiber grid, which comprises the following steps:

configuring warp-wise grid branches, wherein the warp-wise grid branches are formed by mixing high-modulus fibers and low-modulus fibers;

configuring weft-wise grating branches, wherein the weft-wise grating branches are formed by mixing high-modulus fibers and low-modulus fibers;

applying pretension to the low-modulus fiber yarns of the warp-wise grid branches and the weft-wise grid branches;

carrying out orthogonal weaving by adopting the warp-wise grating branches and the weft-wise grating branches after prestress is applied to obtain a woven net which is transversely and longitudinally interwoven;

dipping the woven warp and weft yarns in a dipping solution, and curing at high temperature;

and (4) performing relaxation prestress on the cured and formed grating.

According to the invention, in the process of preparing the warp-knitted grid of the hybrid fiber, firstly, the fiber yarns with high modulus and low modulus are required to be arranged in the grid branches in the warp direction and the weft direction, so that the fiber yarns with low modulus are positioned at the outer side of the grid branches, and the fiber yarns with high modulus are positioned at the inner side of the grid branches. The volume content of the high-modulus fiber yarns in the single-count grid is 15% -25%. The high modulus fiber yarn is carbon fiber, and the low modulus fiber yarn is glass fiber or basalt fiber. The low modulus fiber is pre-tensioned by a pre-stress applying device before warp knitting. The transversely and longitudinally interwoven fiber yarns are knitted by warp knitting yarns, then are soaked by soaking liquid and are cured at high temperature, and the soaking liquid can be styrene-butadiene latex, acrylic emulsion, epoxy resin, vinyl resin, phenolic resin and the like. The specific temperature and time of the high-temperature curing are determined according to the selected impregnation liquid.

Example 1

Preparing a carbon fiber and glass fiber hybrid grid, configuring warp and weft hybrid grid supports of carbon fibers and glass fibers, wherein each hybrid grid of the warp and weft comprises three bundles of fiber yarns, the high-modulus carbon fiber yarn is positioned in the middle of the grid support, the two bundles of low-modulus glass fiber yarns are positioned at the side positions of the grid support, the content of the carbon fiber yarn accounts for 25 percent of the total volume content of a single grid fiber yarn, after the warp and weft fiber yarns are laid, 20 percent of the theoretical bearing capacity of the bundle of fibers is applied to the two bundles of low-modulus glass fiber yarns in the warp and weft grid supports as pretension, then weaving the transversely and longitudinally interwoven fiber yarn bundles through warp-wise fiber warp knitting yarns, dipping the woven grid through styrene-butadiene latex, curing at the temperature of 120 ℃ for 10min, releasing and rolling the cured and molded grid, and then the low-modulus fiber yarns in the grid prestress have initial stress, so as to ensure the coordinated deformation when stressed and carry out the grid weaving of the next batch of sections after the rolling is finished. The elongation of the mixed grid is 2.9%, and compared with the elongation of the original carbon fiber grid of 1.5%, the ductility of the mixed grid is improved by 93%; compared with the strength of 1800MPa and the modulus of 75GPa of the original glass fiber grid, the strength of the hybrid grid is improved by 50 percent, the modulus is improved by 52 percent, and the performance of the original grid is fully improved.

Example 2

Preparing a carbon fiber and basalt fiber hybrid grid, configuring warp and weft hybrid grid branches of carbon fibers and basalt fibers, wherein each hybrid grid in the warp and weft comprises four bundles of fiber yarns, two bundles of high-modulus carbon fiber yarns are positioned in the middle of each grid branch, two bundles of low-modulus glass fiber yarns are positioned at the side positions of each grid branch, the content of the carbon fiber yarns accounts for 15 percent of the total amount of a single grid fiber yarn, after the warp and weft fiber yarns are laid, applying 20 percent of the theoretical bearing capacity of the bundles of basalt fiber yarns to the two bundles of low-modulus basalt fiber yarns in the warp and weft grid branches as pretension, weaving the transversely and longitudinally interwoven fiber yarn bundles through warp-direction fiber warp knitting yarns, impregnating the woven grid with epoxy resin, curing for 10min at 165 ℃, releasing and pre-stressing the cured and molded grid, and then pre-stressing the low-modulus fiber yarns in the grid branches, so as to ensure the coordinated deformation when stressed and carry out the grid weaving of the next batch of sections after the rolling is finished. The strength of the hybrid grid is 2900MPa, the modulus is 98GPa, compared with the strength 1900MPa and the modulus of the original basalt fiber grid, the strength of the hybrid grid is improved by 53 percent, the modulus is improved by 15 percent, and the performance of the original grid is fully improved.

Example 3

Preparing a carbon fiber and basalt fiber hybrid grid, configuring warp and weft hybrid grid branches of carbon fibers and basalt fibers, wherein each hybrid grid in the warp and weft comprises four bundles of fiber yarns, two bundles of high-modulus carbon fiber yarns are positioned in the middle of each grid branch, two bundles of low-modulus glass fiber yarns are positioned at the side positions of each grid branch, the content of the carbon fiber yarns accounts for 20 percent of the total amount of a single grid fiber yarn, after the warp and weft fiber yarns are laid, applying 20 percent of the theoretical bearing capacity of the bundles of basalt fiber yarns to the two bundles of low-modulus basalt fiber yarns in the warp and weft grid branches as pretension, weaving the transversely and longitudinally interwoven fiber yarn bundles through warp-direction fiber warp knitting yarns, impregnating the woven grid with epoxy resin, curing for 10min at 165 ℃, releasing and pre-stressing the cured and molded grid, and then pre-stressing the low-modulus fiber yarns in the grid branches, so as to ensure the coordinated deformation when stressed and carry out the grid weaving of the next batch of sections after the rolling is finished. The elongation of the mixed grid is 2.5%, and compared with the elongation of the original carbon fiber grid of 1.5%, the ductility of the mixed grid is improved by 67%; the strength of the hybrid grid is 3100MPa, the modulus is 114GPa, compared with the strength 1900MPa and the modulus of the original basalt fiber grid, the strength of the hybrid grid is improved by 63 percent, the modulus is improved by 34 percent, and the performance of the original grid is fully improved.