Warp-knitted multi-axial framework cloth

Abstract

The warp knitting multi-axial framework cloth comprises knitting threads (1) and warp threads (2), the knitting threads (1) are composed of upper-layer knitting threads (1.1) and lower-layer knitting threads (1.2), the upper-layer knitting threads (1.1) and the lower-layer knitting threads (1.2) form a latticed structure, the warp threads (2) are bound at nodes of the latticed structure formed by the knitting threads (1), each strand of warp threads (2) comprises first warp threads (2.1) and second warp threads (2.2), and the first warp threads (2.1) and the second warp threads (2.2) are arranged in a staggered mode. The first warps (2.1) and the second warps (2.2) penetrate through adjacent nodes in an up-down staggered mode, and the first warps (2.1) and the second warps (2.2) penetrate through the two sides of the nodes in an interpenetrating mode.

Description

Technical Field

[0001] The invention relates to a skeleton cloth, in particular to a skeleton plate with a multi-axial structure made by a warp knitting process, which is widely used as a skeleton layer in rubber cloth and belongs to the technical field of rubber. Background Art

[0002] Multi-Axial Warp Knitted Fabric (MAWK) is a high-performance fiber-reinforced material. Especially in the sealing field of the petrochemical industry, the sealing material needs to maintain long-term stability and reliability under extreme working conditions such as high temperature, high pressure, and highly corrosive media. By wrapping special rubber on the outside of the warp knitted multi-axial skeleton fabric, the rubber is used to achieve heat resistance and corrosion resistance, and the warp knitted multi-axial skeleton fabric is used to achieve compression and tear resistance. For example, the Chinese patent 2016101062856 "M-shaped skeleton fabric and sealing tape made of the fabric" obtained by our company.

[0003] After adopting this multi-axial skeleton cloth with a cross-shaped structure, since the warp and weft directions and the fabric layer are all woven, it has extremely high tear resistance in all eight directions; however, when it is used as a sealing material in the petroleum industry, such as when it is used as a seal between the floating roof and the tank body on a gas or oil storage tank, since the rubber sheet needs to float up and down with the floating roof, especially when the oil volume reaches the limit or the oil and gas evaporate, the rubber sheet needs to have a certain elasticity so that it has the ability to stretch, and when the external factors disappear, the rubber sheet can also rebound and reset quickly. These are all things that the skeleton cloth with a cross-shaped structure cannot achieve. The pulling and tearing ability of the skeleton cloth with a cross-shaped structure has become a constraint in this application. During the application, it is easy to cause sealing failure due to the inability to deform, and even cause cracks in the rubber sheet, which seriously affects its service life. For this reason, there is an urgent need for a new warp-knitted multi-axial skeleton cloth that can solve the above problems. Summary of the invention

[0004] The object of the present invention is to overcome the above-mentioned shortcomings and provide a warp knitted multi-axial skeleton fabric which has excellent elasticity and can rebound and reset quickly when the external pressure disappears.

[0005] The object of the present invention is achieved in that: A warp-knitted multi-axial skeleton cloth comprises braiding wires and warp wires, wherein the braiding wires consist of an upper braiding wire and a lower braiding wire, and the upper braiding wire and the lower braiding wire form a grid structure, and the warp wires are bound at the nodes of the grid structure formed by the braiding wires, and each strand of the warp wire comprises a first warp wire and a second warp wire, and the first warp wire and the second warp wire are staggered up and down and pass through adjacent nodes, and the first warp wire and the second warp wire are interlaced with each other on both sides of the node.

[0006] Preferably, the upper layer braided wires are provided with multiple parallel wires, the spacing between adjacent upper layer braided wires is equal, the lower layer braided wires are provided with multiple parallel wires, the spacing between adjacent lower layer braided wires is equal, and the spacing is equal to the spacing between adjacent upper layer braided wires, and the upper layer braided wires are located on the upper layer of the lower layer braided wires.

[0007] Preferably, the upper braided wires and the lower braided wires intersect in staggered layers at 90° or at a certain angle.

[0008] Preferably, the binding structure of warp line 1 and warp line 2 at the node is as follows: warp line 1 is located below the node, and warp line 1 is located above the next node, warp line 2 passes through warp line 1 upward from below the warp line, then passes over the node from above the node, and then passes through warp line 1 downward again from above the warp line 1, so that warp line 2 is located below the next node, thereby making warp line 1 and warp line 2 staggered above and below adjacent nodes.

[0009] Preferably, at the four nodes of each grid formed by the upper braided wires and the lower braided wires, two adjacent warp threads are respectively used to bind two grid nodes located on the diagonal line.

[0010] Compared with the prior art, the present invention has the following beneficial effects: The present invention forms a three-dimensional space structure in which the upper and lower sides are not woven together through the upper and lower wefts (i.e., warp one and warp two) through the upper and lower wefts, and the binding is carried out in an upper and lower staggered manner, thereby achieving less constraints and making the dimensional direction have telescopic ductility, and through the existence of the warp without elasticity (or with weak elasticity), when external factors such as force causing dimensional deformation disappear, the designed skeleton cloth can be quickly reset under the action of the warp, so it can be safely and reliably used in petrochemical and other industries where a certain elastic deformation is required. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a structural schematic diagram of a warp knitted multi-axial skeleton cloth of the present invention.

[0012] Figure 2 This is a partial enlarged view of a warp-knitted multi-axial skeleton fabric of the present invention.

[0013] Figure 3 This is a partial magnified view of a physical product of a warp-knitted multi-axial skeleton fabric of the present invention under a microscope.

[0014] in: Braided wire 1, upper braided wire 1.1, lower braided wire 1.2; Latitude 2, longitude 1 2.1, longitude 2 2.2. DETAILED DESCRIPTION

[0015] See also Figures 1 to 3 The present invention relates to a warp-knitted multi-axial skeleton cloth, comprising a braiding wire 1 and a warp wire 2, wherein the braiding wire 1 comprises an upper braiding wire 1.1 and a lower braiding wire 1.2, wherein the upper braiding wire 1.1 is provided with a plurality of parallel upper braiding wires, and the spacing between adjacent upper braiding wires 1.1 is equal, and the lower braiding wire 1.2 is also provided with a plurality of parallel lower braiding wires, and the spacing between adjacent lower braiding wires 1.2 is equal, and the spacing is equal to the spacing between adjacent upper braiding wires 1.1, and the lower braiding wire 1.2 is located in the lower layer, and the upper braiding wire 1.1 is located in the upper layer, and the upper braiding wire 1.1 is located on the lower braiding wire 1.2 and is close to each other, and the upper braiding wire 1.1 and the lower braiding wire 1.2 are at 90° or a certain angle and intersect in upper and lower layers.

[0016] Each strand of warp 2 also includes a warp 1 2.1 and a warp 2 2.2, that is, one warp 1 2.1 and one warp 2 2.2 constitute one strand of warp, and the multiple warp strands are parallel to each other and have equal spacing; the nodes where the upper braided wire 1.1 and the lower braided wire 1.2 intersect in staggered layers are tied by warp threads, that is, the warp 1 2.1 is located below the node, and the warp 1 2.1 is located above the next node, the warp 2.2 passes through the warp 1 2.1 upward from the bottom of the warp 1 2.1, then passes over the node from above the node, and then passes through the warp 1 2.1 downward again, so that the warp 2.2 is located below the warp 2.1, and then the warp 2.1 is located below the next node, so that the warp 1 2.1 and the warp 2.2 are staggered and interspersed above and below adjacent nodes, thereby binding each node.

[0017] Preferably, at the four nodes of each grid formed by the upper weaving wire 1.1 and the lower weaving wire 1.2, two adjacent warp threads 2 are respectively used to bind two grid nodes located on the diagonal line, and the other two nodes do not need to be bound, so that the woven warp knitted multi-axial skeleton cloth has the ability to stretch and extend in the weft direction. At the same time, due to the presence of the warp threads 2, when the external force causing the warp knitted multi-axial skeleton cloth disappears, the warp knitted multi-axial skeleton cloth can be quickly reset under the tension of the warp threads 2.

[0018] When in use, the rubber sheet is formed by compounding the upper and lower surfaces of the warp-knitted multi-axial skeleton cloth of the present invention with a rubber layer. When it is applied to industries such as petrochemicals, the rubber layer realizes corrosion resistance, and the braided layer and the warp of the warp-knitted multi-axial skeleton cloth provide tear resistance. The double-layer braided layer designed with upper and lower staggered layers, and the warp that is interlaced and interspersed up and down to achieve the binding of the braided layer, enable the rubber sheet to have a certain extension and deformation ability in the weft direction. When affected by the outside world, it can better match the sealing structure to deform synchronously, thereby ensuring the sealing effect. At the same time, under the pulling action of the warp, when the external factors disappear, the warp can pull the braided layer that is extended and deformed outward, and combined with the certain elasticity of the rubber sheet itself, the rubber sheet can be quickly reset, thereby ensuring the sealing effect.

[0019] The preparation process of the warp knitted multi-axial skeleton fabric of the present invention is as follows: Step 1: Material selection and pretreatment: The braided wire 1 is made of high-strength, low-elongation synthetic fiber, such as polyester fiber, aramid fiber or glass fiber, with a single fiber diameter of 0.05-0.2 mm and a tensile strength of ≥800 MPa.

[0020] The warp 2 is made of high modulus fiber (such as carbon fiber or ultra-high molecular weight polyethylene) with an elastic modulus of ≥50 GPa to provide a reset tension.

[0021] The fiber needs to be plasma surface treated or coated with a wetting agent to improve adhesion to rubber.

[0022] Step 2: laying of multi-axial braided layers; The upper braided wire 1.1 and the lower braided wire 1.2 are laid at one or two angles of 0°, ±45°, 90°, with an interlayer spacing of 0.5-2 mm, to form a three-dimensional grid structure staggered up and down.

[0023] Step 3: Warp Binding Process A double needle bed warp knitting machine is used to interweave the warp thread 1 2.1 and the warp thread 2.2 in the aforementioned path to tie the nodes. The tying density is 5-15 needles / cm², and the warp tension is controlled at 5-15N, so that an elastic hinge structure is formed at the node, and a reset force is provided while ensuring the hinge freedom of the node.

[0024] Step 4: Post-processing The woven skeleton fabric is heat-set at a temperature of 150-220°C (adjusted according to the fiber type) for 30-120 seconds to eliminate internal stress and stabilize the structure.

[0025] After cooling and winding, the surface of the sheet can be coated with an epoxy resin coupling agent (thickness ≤ 10 μm) to enhance the interfacial bonding with the rubber.

[0026] A rubber sheet preparation process based on the busy warp knitted multi-axial skeleton fabric is as follows: Step 1: Rubber mixing The rubber matrix is ​​made of fluororubber (FKM) or hydrogenated nitrile rubber (HNBR), etc., and corrosion-resistant fillers (such as graphite, carbon black) and vulcanizing agents are added. The mixing temperature is 80~120℃ and the mixing time is 20~40min to make the rubber compound.

[0027] Step 2: Pretreatment of skeleton fabric The warp knitted multi-axial skeleton fabric obtained in the above steps is immersed in RFL (resorcinol-formaldehyde-latex) adhesive solution for 3-10 seconds and dried at 100-150°C to form an adhesive transition layer. Through the double coating design of the adhesive transition layer and the aforementioned epoxy resin coupling agent, the peel strength of the rubber-skeleton fabric is ≥8kN / m (ASTM D903 standard); Dynamic durability optimization: The segmented vulcanization process reduces thermal stress, and combined with gradient cooling, the product life is increased by more than 3 times under -40-200°C working conditions.

[0028] Step 3: Composite molding The mixed rubber is rolled into sheets using a multi-roll calender, with the thickness of the upper and lower rubber layers being 0.5-3mm respectively, and a skeleton cloth is embedded in the middle, with a total thickness controlled at 1.5-8mm. During compounding, a pressure of 0.5-2MPa is applied at a temperature of 80-100℃ to ensure that the rubber penetrates into the gaps between the braided wires.

[0029] Step 4: Vulcanization Use flat plate vulcanizing machine for segmented vulcanization: The first stage: temperature 140~160℃, pressure 5~10MPa, time 10~20min, to complete the initial cross-linking; The second stage: temperature 180~200℃, pressure 8~15MPa, time 20~40min, to achieve complete vulcanization.

[0030] After vulcanization, the temperature should be gradually lowered (cooling rate ≤ 5℃ / min) to avoid internal stress cracking.

[0031] Step 5: Post-processing and testing Cut to design specifications and laser-sealed at the edges to prevent delamination.

[0032] Finally, elasticity test (ASTM D412 standard), medium immersion resistance test (ASTM D471 standard) and fatigue cycle test (≥10^5 deformations without cracks) are carried out.

[0033] In addition: It should be noted that the above specific implementation is only an optimization scheme of this patent. Any changes or improvements made by technicians in this field based on the above concept are within the scope of protection of this patent.

Claims

1. A warp-knitted multi-axial skeleton fabric, comprising a braiding thread (1) and a warp thread (2), characterized in that: The braided wire (1) comprises an upper braided wire (1.1) and a lower braided wire (1.2), and the upper braided wire (1.1) and the lower braided wire (1.2) form a grid structure, and the warp threads (2) are bound at the nodes of the grid structure formed by the braided wire (1), and each strand of the warp threads (2) comprises a first warp thread (2.1) and a second warp thread (2.2), and the first warp thread (2.1) and the second warp thread (2.2) are staggered up and down through adjacent nodes, and the first warp thread (2.1) and the second warp thread (2.2) are interlaced with each other on both sides of the node.

2. The warp knitted multi-axial skeleton fabric according to claim 1, characterized in that: The upper layer braided wires (1.1) are provided in a plurality and are parallel to each other, and the spacing between adjacent upper layer braided wires (1.1) is equal; the lower layer braided wires (1.2) are provided in a plurality and are parallel to each other, and the spacing between adjacent lower layer braided wires (1.2) is equal, and the spacing is equal to the spacing between adjacent upper layer braided wires (1.1); the upper layer braided wires (1.1) are located above the lower layer braided wires (1.2).

3. The warp knitted multi-axial skeleton fabric according to claim 1, characterized in that: The upper braided wire (1.1) and the lower braided wire (1.2) intersect each other in staggered layers at an angle of 90° or a certain angle.

4. The warp knitted multi-axial skeleton fabric according to claim 1, characterized in that: The binding structure of the warp line 1 (2.1) and the warp line 2 (2.2) at the node is as follows: the warp line 1 (2.1) is located below the node, and the warp line 1 (2.1) is located above the next node, the warp line 2 (2.2) passes through the warp line 1 (2.1) from below, then passes over the node from above, and then passes through the warp line 1 (2.1) from above to below again, so that the warp line 2 (2.2) is located below the next node, so that the warp line 1 (2.1) and the warp line 2 (2.2) are interlaced above and below adjacent nodes.

5. The warp knitted multi-axial skeleton fabric according to claim 1, characterized in that: At the four nodes of each grid formed by the upper braided wire (1.1) and the lower braided wire (1.2), two adjacent warp threads (2) are respectively used to bind two grid nodes located on the diagonal line.

6. The process for preparing the warp knitted multi-axial skeleton fabric according to any one of claims 1 to 5, characterized in that: The method includes the steps of laying of multi-axial braided layers, interlacing and binding of warp threads, heat setting and surface coupling agent treatment, wherein the binding density is 5-15 needles / cm² and the heat setting temperature is 150-220°C.

7. A rubber sheet based on the warp knitted multi-axial skeleton fabric according to any one of claims 1 to 5, characterized in that: It is made through calendering compound-segmented vulcanization process, with the rubber layer thickness of 0.5~3mm, vulcanization pressure of 5~15MPa, and vulcanization temperature of 140~200℃.

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