CN114086397A

CN114086397A - High-density non-woven fiber material and preparation method thereof

Info

Publication number: CN114086397A
Application number: CN202111179667.9A
Authority: CN
Inventors: 赵程波
Original assignee: HANGZHOU NBOND NONWOVENS CO LTD
Current assignee: HANGZHOU NBOND NONWOVENS CO LTD
Priority date: 2021-10-08
Filing date: 2021-10-08
Publication date: 2022-02-25
Anticipated expiration: 2041-10-08
Also published as: CN114086397B

Abstract

The invention relates to the field of non-woven materials, and discloses a high-density non-woven fiber material and a preparation method thereof, wherein the density of the high-density non-woven fiber material is 0.9-1.1 g/cm³The fiber-reinforced composite material is of a multilayer structure and comprises a first sizing material layer, a first fiber layer, a second fiber layer, a third fiber layer and a second sizing material layer which are sequentially attached; first fiber layer and third fiberThe length of the fibers in a layer is greater than the length of the fibers in a second fibrous layer and the fibers in each adjacent fibrous layer are intertwined. The invention uses the non-woven fiber material to replace the traditional woven fabric as the fiber material for printing, and has the advantages of short preparation flow, low production cost and environment-friendly production process; the invention also solves the problems that the conventional non-woven fiber material has poor hand tearability, low density, high elongation at break and poor cloth surface flatness and is not suitable for printing materials.

Description

High-density non-woven fiber material and preparation method thereof

Technical Field

The invention relates to the field of non-woven materials, in particular to a high-density non-woven fiber material and a preparation method thereof.

Background

The fiber material for printing is a flexible fiber material suitable for printing and processing, and is widely applied to the fields of interior decoration, automotive interior decoration, trademark labels, stationery and the like. The label material (trademark cloth) for printing is cut and printed with necessary characters and patterns, and is mainly used for labels of products such as clothes, home textiles, boots, caps, toys and the like. According to the processing and using requirements, the fiber material for printing has higher density and certain dry and wet fracture strength; resistance to dry cleaning and water washing; the printing adaptability is good; the difference between the longitudinal and transverse fracture strengths is small, and the shape stability is good; good opacity. In addition, the printing fiber material should have soft hand, fine appearance and double-sided isotropy.

Patent CN201510019619.1 discloses an easily-torn trademark cloth and a preparation method thereof, relating to the technical field of textile materials. The easy-to-tear trademark cloth comprises a blank cloth layer and a sizing material layer, wherein warp yarns and weft yarns are interwoven into a planar cloth through a loom, the warp yarns and the weft yarns are 70-100 denier acetate fiber yarns, and each denier acetate fiber yarn is composed of 12-36 spun yarns; the density of the warp yarns is 90-110 yarns/cm, and the density of the weft yarns is 60-80 yarns/cm. The easy-tearing trademark cloth is prepared by three steps of weaving a grey fabric layer, dyeing and finishing, desizing and shaping treatment and coating treatment. The invention adopts the cloth woven by the acetate fiber yarn to replace the cloth of artificial fiber on the market, the acetate fiber cloth is easy to tear, thereby being capable of rapidly replacing the trademark of the producing area on the clothes or easily tearing off the unnecessary trademark explaining cloth, and improving the convenience. However, the solution has the disadvantages of high price of the acetate fiber; the process flow of weaving, dyeing and finishing, desizing and coating treatment is long, and the production cost is high; environmental pollution can be caused in dyeing and finishing, desizing and coating processing.

Patent CN201911157382.8 discloses a method for producing a nylon-polyester easy-tearing cloth, which uses nylon-polyester yarn as warp and weft to weave into grey cloth, the nylon-polyester is not limited to 100% nylon, and can be composite yarn, i.e. nylon-polyester and regenerated polyester or other synthetic fibers. Treating the grey cloth with alkali and alcohols (such as ethylene glycol, benzyl alcohol, etc.) in refining and dyeing processes, and then soaping and sizing to obtain the polyester-polyamide easy-to-tear cloth. Through the mode, the easy-to-tear cloth obtained by the production method can be used in the trade mark cloth industry, the tearing strength of the easy-to-tear cloth after being brittle is basically the same as that of the polyester-polyamide composite cloth, and the tearing strength test result is as follows: the warp is 2.5-5.8N, the weft is 3.5-9N, the warp and weft strength is not limited to warp and weft, and the warp and weft strength can be inverted for use, so that the warp and weft limitation of the original polyamide-polyester composite cloth is greatly improved. However, the scheme has the defects that the grey cloth needs to be treated by alkali and alcohols (such as ethylene glycol, benzyl alcohol and the like) in the refining and dyeing processes, and the production and processing processes are not environment-friendly.

Patent CN201610889876.5 discloses a silk easy-to-tear cloth and a preparation method and application thereof, wherein the silk easy-to-tear cloth comprises warp yarns and weft yarns, and the warp yarns and the weft yarns are made of POY (polyester pre-oriented yarn). The invention also provides a preparation method of the silk easy-tearing cloth, which comprises spinning, winding, stretching and warping, grey cloth, refining, acid treatment, alkali treatment and sizing. The silk easy-tearing cloth provided by the invention can be applied to the fields of medical sanitary materials, electronic adhesive tapes, trademark cloth and the like, and the application range of the easy-tearing cloth is greatly expanded. The scheme has the disadvantages of long production process; the grey cloth needs to be refined, treated by acid, treated by alkali and the like, and influences on the environment can be caused.

In summary, the fiber material for printing is mainly woven fabric, which is mostly filament or yarn of acetic acid or other synthetic fiber in warp and weft directions, and is produced by conventional textile weaving, finishing, coating and calendering. The prior fiber material for printing mainly has the following problems in the processing and use processes:

1. the production process of the fiber material for printing produced by the traditional textile technology is longer from fiber (filament) raw materials to final finished products, and the procedures of acid and alkali treatment, coating processing and the like are generally required to be carried out on grey cloth in the production, which can cause certain adverse effects on the environment;

2. for the printing fiber material used as the clothing label, many clothing manufacturers send the clothing to other countries and need to change the brand of the clothing production place, if the brand cloth needs to be cut off and changed piece by piece, the time and the labor are very consumed, so the clothing label material is required to be easy to tear by hand;

3. for some consumers, the option of removing the intimate trademark cloth is often chosen because the trademark cloth will be itchy to the skin, requiring the garment label material to be easily torn by hand.

4. Conventional nonwoven materials are unsuitable for use as printing materials due to their low density, high elongation at break, poor flatness of the fabric surface, and the like.

In view of the above problems of the prior art, there is a need to develop a novel fiber material for printing. The novel fiber material for printing meets the basic requirements of printing materials, and has the characteristics of short preparation process, low production cost, green and environment-friendly production process and the like. Meanwhile, in order to meet the requirement of replacing or removing the trademark of the clothes, the novel fiber material for printing also has high density and tearability, is convenient to tear by hands, and improves the convenience of using the trademark label.

Disclosure of Invention

The invention provides a high-density non-woven fiber material and a preparation method thereof, aiming at solving the problems that the existing fiber material for printing has long preparation process, high production cost, no environmental protection in production process, and no possibility of being torn by hands, and the conventional non-woven material has low density, high elongation at break, poor cloth surface flatness and is not suitable for printing materials.

The specific technical scheme of the invention is as follows:

in a first aspect, the invention provides a high-density non-woven fiber material, which is a multilayer structure and comprises a first sizing material layer, a first fiber layer, a second fiber layer, a third fiber layer and a second sizing material layer which are sequentially attached; the fiber length of the first fiber layer and the third fiber layer is larger than that of the second fiber layer, and the fibers of the adjacent fiber layers are mutually entangled; the density of the high-density non-woven fiber material is 0.9-1.1 g/cm³。

The key points of the technical scheme are as follows:

(1) in the research process, the team of the invention finds that the more uniform the fiber distribution of the fiber material is, the more suitable the fiber material is for printing. The size and arrangement of the fibers affects the uniformity of the fiber web, wherein short fiber webs are more uniform than long fiber webs; the random arrangement of webs is more uniform than the directional arrangement of webs. Therefore, the material adopts a multilayer structure, wherein the first fiber layer, the second fiber layer and the third fiber layer are mutually superposed and consolidated, so that fibers of different layers are randomly arranged in the layers, the second fiber layer is positioned in the middle of the material, and the fiber length of the second fiber layer is smaller than that of the upper layer and the lower layer, so that the fiber distribution is more uniform, and the defect that the uniformity of the upper layer and the lower layer is insufficient compared with that of a long fiber net can be overcome. Therefore, the problems that the fiber arrangement of the single-layer structure is not uniform, cloth cover marks caused by fiber web reinforcement influence the surface smoothness of the material, and the printability of the product is reduced can be solved.

(2) In the invention, the second fiber layer adopts shorter fibers, and the first fiber layer (upper layer) and the third fiber layer (lower layer) adopt longer fibers. Because the length of the fibers in the second fiber layer is short and the distribution area is large, the shorter fibers can be partially filled into the longer fiber net, the non-uniformity problem caused by the longer fiber layer is made up, and the density of the material is improved.

(3) As described in the background art, most of the existing fiber materials for printing are woven fabrics, most of the warp and weft fibers are acetate or other synthetic fiber filaments or yarns, the production process from raw materials to final finished products is long, and the fiber materials need to be subjected to a complex post-treatment process, so that the fiber materials are not environment-friendly enough. The invention replaces the woven cloth with the non-woven fiber material, can obviously shorten the preparation process, reduces the production cost and is more environment-friendly. However, the surface of the fiber material for printing is required to be flat and smooth, while the non-woven material is directly formed by fibers, the fiber web is full of pores, and the surface is not smooth, so that the requirements of the material for printing cannot be met. Therefore, the invention is provided with the sizing material layers on the upper surface of the first fiber layer and the lower surface of the third fiber layer, and aims to fill the sizing material into the pores of the surface layer fibers, fix the surface layer fibers, reduce the breaking elongation of the material and improve the hand tearability of the material. In addition, the sizing material layers arranged on the two sides of the fiber material can also make the material have hydrophobicity, thereby meeting the requirement of the material on water washing resistance.

(4) Research and development teams find that the density is a key index influencing the permeability and the mechanical property of the material. Under the same condition, the higher material density can reduce the thickness of the material, improve the surface smoothness of the material, improve the printability of the material and be beneficial to the hand tearing property of the material. Therefore, the team of the invention determines the optimal range of the density of the materials on the basis of a large amount of experimental research.

Preferably, the sum of the mass of the first sizing material layer and the mass of the second sizing material layer accounts for 20-40% of the total mass of the material; the sum of the mass of the first fiber layer and the mass of the third fiber layer accounts for 40-60% of the total mass of the material; the mass of the second fiber layer accounts for 10-30% of the total mass of the material.

Preferably, the fiber fineness in the first fiber layer and the third fiber layer is 0.1-1.2 dtex, and the fiber length is 25-50 mm; the ratio of the fiber length in the first fiber layer and the third fiber layer to the fiber length in the second fiber layer is 6-45.

Adopt the long fiber in first fibrous layer and the third fibrous layer, the second fibrous layer adopts the short fiber, through reasonable control length, two kinds of fiber length's of short proportion, both can guarantee that the material has certain breaking strength, but make the material have hand tear nature again, can make simultaneously in the part short fiber in the second fibrous layer alternates the hole of first fibrous layer and third fibrous layer, increase the density of material, improve the planarization on material surface, be favorable to printing processing.

Preferably, the first fiber layer and the third fiber layer contain superfine fibers accounting for 20-30% of the total mass of the material and artificial cellulose fibers accounting for 20-30% of the total mass of the material; the first fiber layer and the third fiber layer have the same mass.

Preferably, the raw material of the second fiber layer is plant pulp; further, the plant pulp is one or a combination of wood pulp, cotton pulp, bamboo pulp and hemp pulp.

The invention selects plant fiber and superfine fiber, and balances physical index and printability of the material by adjusting the proportion of the fiber.

Preferably, the superfine fibers in the first fiber layer and the third fiber layer are orange-petal split fibers; the orange-peel split fibers are composed of polyester and polyamide, and the fineness after fiber opening is 0.1-0.5 dtex.

The single fiber fineness of the split fibers of the orange petals can reach 0.1-0.5 dtex after fiber splitting, the bending rigidity of the fibers is small, and the fibers have soft and fine handfeel; the superfine fiber has large specific surface area and high compactness, and can improve the uniformity and the cloth surface smoothness of the material and improve the printing performance of the material.

Preferably, the man-made cellulose fibers in the first fiber layer and the third fiber layer are one or more of viscose fibers, bamboo fibers and tencel fibers, the fineness is 0.4-1.2 dtex, and the fiber length is 30-40 mm.

The product of the invention is used as a printing material and needs to have good printability, so the surface of the material is required to be compact, flat and smooth; and the adoption of the fine denier artificial cellulose fiber can improve the density of the material and improve the printing effect of the material.

Preferably, the first and second sizing layers contain aqueous polyurethane and titanium powder.

The thermosetting waterborne polyurethane is selected, does not contain reactive-NCO groups inside, is solidified by purely depending on the cohesive force of polar groups and the crosslinking reaction between carboxyl groups and hydroxyl groups inside, has low smell and toxicity, does not contain an oil solvent, can avoid the problems of hot stickiness and cold brittleness caused by propylene rubber materials as a key, and has a waterproof function while reducing the flexible touch feeling of a product. On the basis, titanium powder with higher scattering degree is mixed, so that the whiteness of the material can be improved while the pores in the fiber web are filled, and the printing performance of the product can be improved.

Preferably, the high-density nonwoven fiber material has a mass per unit area of 80 to 200g/m²The elongation at break in the longitudinal and transverse directions is 0.5-1.8%, and the light transmittance is less than or equal to 10%.

The mass per unit area of the material directly affects the thickness of the material. If the mass per unit area is too small, the thickness of the material is too low, so that the material is transparent and the printing definition is influenced; if the mass per unit area is too high, the material is not easy to tear, and the hand-tearing performance of the material is affected. Therefore, after repeated experimental research, the research and development team of the invention determines the appropriate range of the mass per unit area.

The nonwoven material has numerous voids, the amount of which affects the printability of the final product. The higher the porosity, the higher the transmission at the same material density. The research of the invention group finds that the non-woven material as the printing material can obtain better printing effect only by controlling the light transmittance to be below 10%.

Research shows that the higher the elongation at break of the material, the more difficult the material is to be torn by hand; and the lower the elongation at break and the closer the two indexes of elongation at break in the machine direction and elongation at break in the transverse direction, the better the hand tear performance of the material. Therefore, the team of the invention determines the optimal range of the longitudinal and transverse elongation at break on the basis of intensive research.

In a second aspect, the present invention provides a method for preparing the high-density nonwoven fiber material, comprising the following steps:

(1) mixing superfine fibers and artificial cellulose fibers, and carding to prepare thin fiber nets from the fibers; then cross lapping is carried out to prepare a thick fiber net; and drafting the thick fiber web, changing the fiber arrangement direction, disordering the fibers, and respectively preparing the first fiber web and the third fiber web.

(2) And (3) feeding the dry plant pulp material between the first fiber net and the third fiber net for superposition to prepare a three-layer composite fiber net.

(3) Feeding the three-layer composite fiber web into a spunlace unit, and performing spunlace on the front surface and the back surface of the three-layer composite fiber web respectively to consolidate the three-layer fiber web into a whole and remove redundant water in the fiber web; and drying the material to prepare the spunlace substrate.

(4) Sending the spunlace substrate into a coating unit, and respectively applying glue stock to the front surface and the back surface of the spunlace substrate; and curing the glue material on the surface of the spunlace substrate through drying and noise.

(5) The material after coating is subjected to calendaring treatment to enable the surface of the material to be flat; and then the high-density non-woven fiber material for printing which is easy to tear by hands is prepared after being rolled.

Preferably, in step (1), the blended fibers are carded using a roller card.

When a roller carding machine is adopted, the arrangement direction of the fibers after carding is the output direction (longitudinal direction), and the arrangement direction of the fibers is strong; after lapping by a cross lapping machine, the fibers are randomly arranged in the fiber web, the orientation of fiber arrangement is reduced, the difference between the longitudinal and transverse breaking strength and the breaking elongation of the material is reduced, and the hand-tearability of the material is greatly improved.

Preferably, in the step (3), the three-layer composite fiber web is pre-wetted, the front surface of the three-layer composite fiber web is reinforced by a plurality of flat-screen spunlace heads, and the back surface of the three-layer composite fiber web is reinforced by circular drum spunlace.

The thickness of the three-layer composite fiber net is reduced after prewetting, and the composite fiber net is compacted to facilitate subsequent spunlace consolidation. The fiber in the pre-wetted three-layer composite fiber net is not twisted and reinforced, and the layers are still in a separated state. At the moment, the three layers of composite fiber webs are not suitable for being subjected to large-tension drum spunlace so as to avoid deviation and wrinkles among the fiber webs of each layer and cause uneven surfaces of products. When flat net water jet is adopted, the three-layer composite fiber net is in a straight state in the whole conveying process, and the surface of a product is smoother. And the flat net water jet adopts the stepped increasing water pressure arrangement, so that the first fiber net, the third fiber net and the dry plant pulp material have a progressive reinforcing process, the high pressure under the condition of loosening is avoided, the cloth cover is broken by water, and finally the product becomes rough holes to influence the surface effect of the material. The drum spunlace pressure is gradually increased, so that the reverse side of the cloth surface can be stably reinforced, and the conditions that the spunlace holes are serious and the cloth surface is not flat are avoided.

Preferably, the spunlace pressure of the flat-net spunlace heads is 35-65 kg, and the pressure of each flat-net spunlace head gradually increases according to the material advancing direction; the drum spunlace pressure is 35-65 kg; and the water stabbing pressure of the circular drum is gradually increased according to the advancing direction of the material.

Preferably, in step (3), excess water is removed from the web by roll drying.

The adoption of the rolling drying mode is favorable for improving the evenness of the cloth surface, so that the material is favorable for subsequent processing and printing.

Preferably, in the step (3), the consolidated fiber web is dried in a drying cylinder mode; the temperature of the drying cylinder is 100-150 ℃; and the temperature of the drying cylinder is gradually increased according to the advancing direction of the material.

Compared with a hot air penetrating type drying oven, the drying oven has the advantages that the cloth cover is always tightly attached to the wall of the drying oven in a drawing and tensioning state, the cloth cover is not easy to become fluffy and frizzy after being dried, and the surface of the material is smoother and more compact. Because the fiber material for printing has compact structure and smooth cloth surface, if hot air penetration type drying is adopted, the hot air is not easy to penetrate the smooth and compact cloth surface, the drying efficiency is reduced, and the normal production of products is influenced.

Preferably, in the step (4), the sizing material comprises 50-70% of waterborne polyurethane, 10-15% of titanium powder, 0.1-0.2% of defoaming agent, 5-7% of crosslinking agent, 10-15% of water and 1-2% of dispersing agent.

Preferably, in the step (5), the calendering process adopts a multi-zone calendering mode, and the material after hot rolling is cooled by a cooling roll.

During calendering treatment, the progressive multi-region calendering rollers are adopted, the pressure of the calendering rollers is controlled, so that the water-based polyurethane adhesive on two surfaces of the material can be cured to be smoother and smoother, and the titanium powder is matched to further fill and level pores caused by the texture of the spunlace material, so that the flatness of the surface of the material is further improved. The arrangement of the invention can avoid the film formation of the material caused by high rolling pressure and too small thickness, and can also avoid the problem of reduced flatness of the material caused by too large thickness.

The material after calendering is cooled under the rolling state, so that the cloth cover is always in a flat state, the problem of unevenness caused by shrinkage and other reasons on the surface of the material due to natural cooling is avoided, and the flatness of the material after hot rolling is not influenced.

Preferably, in the step (5), the calendering temperature is 100-150 ℃ and the pressure is 0.1-0.4 MPa.

The calendering process is to further flatten and smooth the cloth surface, level and compact filoplume and the like, simultaneously, after continuous multistage calendering, further crosslink and solidify the water-based polyurethane of the cloth surface under the action of a crosslinking agent, fill the water-based polyurethane on the water-pricked lines together with titanium powder, make a smooth and flat surface, and greatly improve the printing performance of the non-woven material.

In a third aspect, the present invention provides a high-density nonwoven fiber material production apparatus, which comprises the following processing steps in sequence: the device comprises a coating unit, a calendaring unit, a cooling unit and a coiling unit.

The coating unit comprises one or more coating subunits connected in series according to the processing procedure in sequence; each coating subunit comprises a coating mechanism and a drying mechanism which are connected in series according to the processing procedure.

The calendering unit comprises a plurality of front calendering mechanisms and back calendering mechanisms which are alternately arranged according to the processing procedure.

The cooling unit comprises cooling rollers which are fixed on the frame and are arranged in pairs.

Several cloth guide rollers for conveying the material are arranged between the units.

Preferably, the coating mechanism comprises an endless rubber belt which can rotate circularly, a plurality of rubber belt guide rollers for driving and conveying the endless rubber belt, a glue applying mechanism arranged above the endless rubber belt and a coating scraper.

Preferably, the coating blade has a circular edge; the drying mechanism is an infrared drying mechanism.

The sizing material has higher viscosity, and when the circular scraper is adopted, the sizing material stays for a longer time under the blade, so that the coating is suitable for the conditions of heavy weight and large coating amount. The infrared drying has the characteristics of high speed, good quality, high efficiency and the like, and is suitable for quickly curing the coating sizing material on the surface of the fiber material.

Preferably, the front-side calender mechanism comprises a front-side heat-conducting roller, a front-side pressure roller matched with the front-side heat-conducting roller and an upper pressurizing mechanism connected above the front-side pressure roller; the reverse side calender mechanism comprises a reverse side heat conduction roller, a reverse side press roller matched with the reverse side heat conduction roller and a lower pressurizing mechanism connected below the reverse side press roller.

Preferably, the calendering mechanism further comprises a heating mechanism connected with the front heat-conducting roller and the back heat-conducting roller.

The production device has the following working procedures and principles: sending the dry spunlace substrate into a coating mechanism, and placing the spunlace substrate on an annular adhesive tape with the front side facing upwards; the glue applying mechanism coats glue stock on the front side of the spunlace base material, and the spunlace base material passes under a scraper under the drive of the annular adhesive tape, so that the glue stock is uniformly distributed on the front side of the spunlace base material; curing the sizing material to the front side of the spunlace substrate by a drying mechanism; then the material is sent into the next coating mechanism, so that the reverse side of the spunlace substrate faces upwards and is placed on the annular adhesive tape; applying glue to the back surface of the spunlace substrate by a glue applying mechanism, and allowing the spunlace substrate to pass under a scraper under the drive of an annular adhesive tape so that the glue is uniformly distributed on the back surface of the spunlace substrate; and (3) passing the sized base material through a drying mechanism, and curing the sizing material to the reverse side of the spunlace base material. Feeding the material into a calendering unit under a tensioned state, allowing the material to pass through the middle of a heat conduction roller and a compression roller, respectively calendering the front side and the back side of the material, and feeding the calendered material into a cooling roller for cooling so as to improve the surface smoothness of the material; and (5) feeding the material into a coiling mechanism to obtain a finished product.

Compared with the prior art, the invention has the beneficial effects that:

(1) according to the invention, through strict optimization and limitation of fiber types, fiber specifications, material structures, material unit area mass and the like, and through the process coordination of fiber carding, sizing material components and the like, the non-woven fiber material which is originally not suitable for printing obtains good printability and hand tearability.

(2) The invention takes superfine fiber, man-made cellulose fiber and plant pulp as raw materials, and directly prepares the fiber into the fiber material for printing through the technical processes of dry-method web forming, spunlace reinforcement, scraper coating, calendering and cooling and the like.

(3) According to the type of the sizing material, a scraper coating is adopted in the preparation process of the product, and the spunlace base cloth is placed on the annular adhesive tape for application, so that the characteristics of the spunlace non-woven material are fully considered, and the problem that the high-viscosity sizing material cannot be applied to the flexible spunlace material is solved.

(4) The production device of the high-density non-woven fiber material can be used for coating the double surfaces of the material at one time, so that the procedures of material changing, transferring and the like in the midway are omitted, and the problem that the one-time double-surface coating cannot be carried out by a scraper in the production of the fiber material for printing in the prior art is solved. And the production device has the advantages of simple structure, convenient operation and high production efficiency, and is suitable for practical popularization.

Drawings

FIG. 1 is a schematic structural view of a high-density nonwoven fibrous material of example 1;

FIG. 2 is a schematic view showing a connection of the production apparatus for a high-density nonwoven fibrous material in example 1;

FIG. 3 is a graph comparing the printing effects of example 2 and comparative example 2.

The reference signs are: the device comprises a first sizing material layer 1, a first fiber layer 2, a second fiber layer 3, a third fiber layer 4, a second sizing material layer 5, a spunlace substrate 6, a coating unit 7, a calendaring unit 8, a cooling unit 9, a coiling unit 10, sizing material 11, a high-density non-woven fiber material 12, a cloth guide roller 13, a sizing mechanism 701, an annular adhesive tape 702, an adhesive tape guide roller 703, a coating scraper 704, a drying mechanism 705, a front side heat conduction roller 801, a front side press roller 802, an upper pressing mechanism 803, a back side heat conduction roller 804, a back side press roller 805, a lower pressing mechanism 806 and a cooling roller 901.

Detailed Description

The present invention will be further described with reference to the following examples.

General examples

A high-density non-woven fiber material is shown in figure 1 and is of a multi-layer structure and comprises a first sizing material layer 1, a first fiber layer 2, a second fiber layer 3, a third fiber layer 4 and a second sizing material layer 5 which are sequentially attached.The fiber length of the first fiber layer and the third fiber layer is larger than that of the second fiber layer, and the fibers of the adjacent fiber layers are mutually entangled; the density of the high-density non-woven fiber material is 0.9-1.1 g/cm³The mass per unit area is 80 to 200g/m²The elongation at break in the longitudinal and transverse directions is 0.5-1.8%, and the light transmittance is less than or equal to 10%.

Wherein the sum of the mass of the first sizing material layer and the mass of the second sizing material layer accounts for 20-40% of the total mass of the material; the sum of the mass of the first fiber layer and the mass of the third fiber layer accounts for 40-60% of the total mass of the material; the mass of the second fiber layer accounts for 10-30% of the total mass of the material. Preferably, the first fiber layer and the third fiber layer contain superfine fibers accounting for 20-30% of the total mass of the material and man-made cellulose fibers accounting for 20-30% of the total mass of the material; the first fiber layer and the third fiber layer have the same mass; the fiber fineness in the first fiber layer and the third fiber layer is 0.1-1.2 dtex, and the fiber length is 25-50 mm; the ratio of the fiber length in the first fiber layer and the third fiber layer to the fiber length in the second fiber layer is 6-45.

Preferably, the raw material of the second fiber layer is plant pulp, and further preferably is one or more of wood pulp, cotton pulp, bamboo pulp and hemp pulp; the superfine fibers in the first fiber layer and the third fiber layer are orange-petal split fibers, the components are polyester and polyamide, and the fineness after fiber splitting is 0.1-0.5 dtex; the artificial cellulose fibers in the first fiber layer and the third fiber layer are one or a combination of viscose fibers, bamboo fibers and tencel fibers, the fineness is 0.4-1.2 dtex, and the fiber length is 30-40 mm.

A method of making a high density nonwoven fibrous material comprising the steps of:

(1) mixing the superfine fibers and the artificial cellulose fibers, and carding the mixed fibers by a roller carding machine to prepare a thin fiber web; then cross lapping is carried out to prepare a thick fiber net; the thick fiber web is drafted, the fiber arrangement direction is changed, the fibers are arranged in a disorderly way, and the first fiber web and the third fiber web are respectively manufactured.

(3) The three-layer composite fiber web is sent into a spunlace unit, pre-wetting is carried out, and then the front side of the three-layer composite fiber web is reinforced by adopting a plurality of flat-net spunlace heads (the spunlace pressure is 35-65 kg, and the pressure of the spunlace heads gradually increases according to the material advancing direction); then, reinforcing the back surface of the three-layer composite fiber web by adopting circular drum spunlace (the spunlace pressure is 35-65 kg, and the spunlace pressure is gradually increased according to the material advancing direction); finally, removing redundant water in the fiber web by adopting a rolling drying mode; drying the material in a drying cylinder mode (the cylinder temperature is 100-150 ℃, and the drying cylinder temperature gradually increases according to the material advancing direction); drying to obtain the spunlace substrate.

(4) Sending the spunlace substrate into a coating unit, and respectively applying sizing materials (50-70% of waterborne polyurethane, 10-15% of titanium powder, 0.1-0.2% of defoaming agent, 5-7% of cross-linking agent, 10-15% of water and 1-2% of dispersing agent) to the front side and the back side of the spunlace substrate; and curing the glue material on the surface of the spunlace substrate through drying and noise.

(5) Carrying out calendering treatment on the coated material in a multi-zone calendering mode (the calendering temperature is 100-150 ℃, and the pressure is 0.1-0.4 Mpa) to enable the surface of the material to be flat; cooling the hot-rolled material by a cooling roll; and then the high-density non-woven fiber material is prepared after being rolled.

The above process is processed by a high-density nonwoven fiber material production device, as shown in fig. 2, the production device sequentially comprises the following processing procedures: the coating unit 7, the calendering unit 8, the cooling unit 9 and the coiling unit 10; between the units are arranged several cloth guide rolls 13 for the transport of the material. Wherein:

the coating unit comprises one or more coating subunits connected in series according to the processing procedure in sequence; each of the coating subunits comprises a coating mechanism and a drying mechanism 705 connected in series according to the processing procedure. The coating mechanism comprises a circular adhesive tape 702 capable of circularly rotating, a plurality of adhesive tape guide rollers 703 for driving and conveying the circular adhesive tape, a sizing mechanism 701 arranged above the circular adhesive tape and a coating scraper 704; the blade of the coating scraper is round; the drying mechanism is an infrared drying mechanism.

The calendering unit comprises a plurality of front calendering mechanisms and back calendering mechanisms which are alternately arranged according to the processing procedure. The front-side finishing mechanism comprises a front-side heat-conducting roller 801, a front-side pressing roller 802 matched with the front-side heat-conducting roller and an upper pressurizing mechanism 803 connected above the front-side pressing roller. The reverse side calender mechanism comprises a reverse side heat-conducting roller 804, a reverse side press roller 805 matched with the reverse side heat-conducting roller and a lower pressurizing mechanism 806 connected below the reverse side press roller; in addition, the front side heat guide roller and the reverse side heat guide roller are connected with a heating system which is configured separately.

The cooling unit includes a pair of cooling rollers 901 fixed to the frame.

The production device has the following working procedures and principles: sending the dry spunlace substrate 6 into a coating mechanism, and placing the spunlace substrate on an annular adhesive tape with the right side facing upwards; the glue applying mechanism coats glue stock on the front side of the spunlace base material, and the spunlace base material passes under a scraper under the drive of the annular adhesive tape, so that the glue stock is uniformly distributed on the front side of the spunlace base material; curing the sizing material to the front side of the spunlace substrate through a drying mechanism; then the material is sent into the next coating mechanism, so that the reverse side of the spunlace substrate faces upwards and is placed on the annular adhesive tape; the glue applying mechanism applies glue material 11 to the reverse side of the spunlace substrate, and the spunlace substrate passes under a scraper under the drive of the annular adhesive tape, so that the glue material is uniformly distributed on the reverse side of the spunlace substrate; and (3) passing the sized base material through a drying mechanism, and curing the sizing material to the reverse side of the spunlace base material. Feeding the material into a calendering unit under a tensioned state, allowing the material to pass through the middle of a heat conduction roller and a compression roller, respectively calendering the front side and the back side of the material, and feeding the calendered material into a cooling roller for cooling so as to improve the surface smoothness of the material; the material is fed into a roll forming mechanism to produce a finished high density nonwoven fibrous material 12.

Example 1

A high-density non-woven fiber material, the mass per unit area is 80g/m²The density of the material is 0.9g/cm³(ii) a As shown in fig. 1, the fabric comprises a first sizing layer 1, a first fiber layer 2, a second fiber layer 3, a third fiber layer 4 and a second sizing layer 5 from top to bottom. First glue material layer1 is attached to the surface of the first fiber layer 2, and a second sizing material 5 layer is attached to the surface of the third fiber layer 4; the first fiber layer 2, the second fiber layer 3 and the third fiber layer 4 are mutually connected; the fiber length in the first fiber layer 2 and the third fiber layer 4 is larger than that in the second fiber layer 3.

Wherein the mass sum of the first sizing material layer 1 and the second sizing material layer 5 accounts for 30 percent of the total mass of the material; the sum of the mass of the first fiber layer 2 and the third fiber layer 4 accounts for 40 percent of the total mass of the material; the mass of the second fiber layer 3 accounts for 30 percent of the total mass of the material.

The first sizing material layer 1 and the second sizing material layer 5 contain waterborne polyurethane and titanium powder; the second fiber layer 4 is wood pulp; the first fiber layer and the third fiber layer contain superfine fibers accounting for 20 percent of the total mass of the material and artificial cellulose fibers accounting for 20 percent of the total mass of the material. The first fiber layer and the third fiber layer have the same mass; wherein the superfine fiber is orange petal type split fiber, the components are polyester and polyamide, and the fineness after fiber opening is 0.1 dtex. The man-made cellulose fiber in the first fiber layer and the third fiber layer is fine denier viscose fiber, the fiber fineness is 0.4dtex, and the fiber length is 25 mm.

(1) mixing superfine fiber and man-made cellulose fiber in proportion, and making the fiber into a thin fiber web by a roller carding machine; then cross lapping is carried out to prepare a thick fiber net; and drafting the thick fiber web, changing the fiber arrangement direction, disordering the fibers, and respectively preparing the first fiber web and the third fiber web.

(2) And unwinding the dry wood pulp paper coiled material, and then feeding the unwound dry wood pulp paper coiled material between the first fiber net and the third fiber net for superposition to prepare the three-layer composite fiber net.

(3) The three-layer composite fiber web is sent into a spunlace system, the three-layer composite fiber web is pre-wetted, the front side of the three-layer composite fiber web is subjected to spunlace reinforcement by adopting a plurality of flat-screen spunlace heads (wherein the spunlace pressure of the flat-screen spunlace heads is 25kg, 30kg and 35kg in sequence), the back side of the composite fiber web is subjected to spunlace reinforcement by adopting a round-drum spunlace head (wherein the spunlace pressure of the round-drum spunlace heads is 25kg, 30kg and 35kg in sequence, so that the three-layer fiber web is consolidated into a whole, excessive moisture in the fiber web is removed by adopting a dry rolling mode, and the material is dried by adopting a drying cylinder mode (wherein the drying cylinder temperature is 80 ℃, 90 ℃ and 100 ℃ in sequence) to prepare the spunlace base material 6.

(4) Feeding the spunlace substrate into a coating system, and respectively applying glue stock to the front side and the back side of the spunlace substrate; curing the glue material on the surface of the spunlace substrate through drying; wherein the sizing material comprises the following components: 60% of waterborne polyurethane, 15% of titanium powder, 0.1% of defoaming agent, 7% of crosslinking agent, 15% of water and 3% of dispersing agent.

(5) Subjecting the coated material to multi-zone calendering treatment (wherein the calendering temperature is 100 ℃ and the pressure is 0.1Mpa), and cooling the material by a cooling roller to enable the surface of the material to be flat; coiling the mixture to obtain a product of 80g/m²A high density nonwoven fibrous material.

A high-density nonwoven fiber material production apparatus, as shown in fig. 2, comprising in order of processing steps: the coating unit 7, the calendering unit 8, the cooling unit 9 and the coiling unit 10; between the units are arranged several cloth guide rollers 13 for conveying the material. Wherein:

the coating unit sequentially comprises two coating subunits which are connected in series according to a processing procedure; each of the coating subunits comprises a coating mechanism and a drying mechanism 705 connected in series according to the processing procedure. The coating mechanism comprises a circularly rotatable annular adhesive tape 702, a plurality of adhesive tape guide rollers 703 for driving and conveying the annular adhesive tape, an adhesive applying mechanism 701 arranged above the annular adhesive tape and a coating scraper 704; the blade of the coating scraper is round; the drying mechanism is an infrared drying mechanism.

The calendering unit comprises a plurality of front calendering mechanisms and a plurality of back calendering mechanisms which are alternately arranged (two each) according to the processing procedure. The front-side calender mechanism includes a front-side heat-conductive roller 801, a front-side pressure roller 802 fitted to the front-side heat-conductive roller, and an upper pressing mechanism 803 attached above the front-side pressure roller. The reverse side calender mechanism comprises a reverse side heat-conducting roller 804, a reverse side pressure roller 805 matched with the reverse side heat-conducting roller and a lower pressurizing mechanism 806 connected below the reverse side pressure roller; the front heat-conducting roller and the reverse heat-conducting roller are connected to a heating system which is additionally provided.

The cooling unit includes a pair of cooling rollers 901 fixed to the frame.

Example 2

A high-density non-woven fiber material with the mass per unit area of 100g/m²The density of the material is 1.0g/m³(ii) a As shown in fig. 1, the fabric comprises a first sizing material layer 1, a first fiber layer 2, a second fiber layer 3, a third fiber layer 4 and a second sizing material layer 5 from top to bottom in sequence; the first sizing material layer 1 is attached to the surface of the first fiber layer 2, and the second sizing material layer 5 is attached to the surface of the third fiber layer 4; the first fiber layer 2, the second fiber layer 3 and the third fiber layer 4 are mutually connected; the fiber length in the first fiber layer 2 and the third fiber layer 4 is larger than that in the second fiber layer 3.

Wherein the mass sum of the first sizing material layer 1 and the second sizing material layer 5 accounts for 30 percent of the total mass of the material; the sum of the mass of the first fiber layer 2 and the third fiber layer 4 accounts for 50 percent of the total mass of the material; the mass of the second fiber layer 3 accounts for 20 percent of the total mass of the material; the first sizing material layer 1 and the second sizing material layer 5 contain waterborne polyurethane and titanium powder; the second fiber layer 4 is plant pulp; the components are two combinations of wood pulp and cotton pulp; the first fiber layer and the third fiber layer contain superfine fibers accounting for 25 percent of the total mass of the material and man-made cellulose fibers accounting for 25 percent of the total mass of the material; the first fiber layer and the third fiber layer have the same mass; the superfine fibers in the first fiber layer and the third fiber layer are orange petal type split fibers; the components are polyester and polyamide, and the fineness after fiber opening is 0.3 dtex; the artificial cellulose fibers in the first fiber layer and the third fiber layer are fine-denier bamboo fibers; the fineness is between 0.6dtex, and the fiber length is 38 mm.

(1) mixing superfine fiber and fine denier bamboo fiber in proportion, and making the fiber into a thin fiber net by a roller carding machine; then cross lapping is carried out to prepare a thick fiber net; drafting the thick fiber web, changing the fiber arrangement direction, arranging the fibers in a disorderly way, and respectively manufacturing a first fiber web and a third fiber web;

(2) unwinding the dry plant pulp material, and then feeding the unwound dry plant pulp material between a first fiber mesh and a third fiber mesh for superposition to prepare a three-layer composite fiber mesh;

(3) the three-layer composite fiber web is sent into a spunlace system, the three-layer composite fiber web is prewetted, the front side of the three-layer composite fiber web is subjected to spunlace reinforcement by adopting a plurality of flat-screen spunlace heads (wherein the spunlace pressure of the flat-screen spunlace heads is 40kg, 45kg and 50kg in sequence), and the back side of the composite fiber web is subjected to spunlace reinforcement by adopting a round-drum spunlace head (wherein the spunlace pressure of the round-drum spunlace heads is 40kg, 45kg and 50kg in sequence), so that the three-layer fiber web is consolidated into a whole; removing redundant water in the fiber web by adopting a rolling drying mode; drying the material by a drying cylinder (wherein the drying cylinder temperature is 120kg, 130kg and 135 ℃ to prepare the spunlace base material;

(4) feeding the spunlace substrate into a coating system, and respectively applying glue stock to the front side and the back side of the spunlace substrate; curing the glue material on the surface of the spunlace substrate through drying; wherein the sizing material comprises the following components: 70% of waterborne polyurethane, 13% of titanium powder, 0.15% of defoaming agent, 6% of crosslinking agent, 10% of water and 1.85% of dispersing agent;

(5) subjecting the coated material to multi-zone calendering treatment (wherein the calendering temperature is 125 ℃ and the pressure is 0.3Mpa), and cooling the material by a cooling roller to enable the surface of the material to be flat; coiling the mixture to obtain a 100g/m²A high density nonwoven fibrous material.

A high-density nonwoven fiber material production apparatus, the same as in example 1.

Example 3

A high-density non-woven fiber material with the mass per unit area of 200g/m²The density of the material is 1.1g/cm^3，；(ii) a As shown in fig. 1, the fabric comprises a first sizing material layer 1, a first fiber layer 2, a second fiber layer 3, a third fiber layer 4 and a second sizing material layer 5 from top to bottom in sequence; the first sizing material layer 1 is attached to the surface of the first fiber layer 2, and the second sizing material layer 5 is attached to the surface of the third fiber layer 4; the first fiber layer 2, the second fiber layer 3 and the third fiber layer 4 are mutually connected; the fiber length in the first fiber layer 2 and the third fiber layer 4The degree is greater than the fiber length in the second fiber 3 layer.

Wherein, the mass percentage of the first sizing material layer 1 and the second sizing material layer 5 in the total mass of the material is 40 percent; the mass of the first fiber layer 2 and the third fiber layer 4 accounts for 50 percent of the total mass of the material; the mass of the second fiber layer 3 accounts for 10 percent of the total mass of the material; the first sizing material layer 1 and the second sizing material layer 5 contain waterborne polyurethane and titanium powder; the second fiber layer 4 is plant pulp; the plant pulp is the combination of wood pulp and hemp pulp; the first fiber layer and the third fiber layer contain superfine fibers accounting for 30 percent of the total mass of the material and man-made cellulose fibers accounting for 30 percent of the total mass of the material; the first fiber layer and the third fiber layer have the same mass; the superfine fibers in the first fiber layer and the third fiber layer are orange petal type split fibers; the components are polyester and polyamide, and the fineness after fiber opening is 0.5 dtex; the man-made cellulose fibers in the first fiber layer and the third fiber layer are fine tencel fibers; the fineness was 1.2dtee and the fiber length was 50 mm.

(1) mixing superfine fiber and fine denier tencel fiber in proportion, and making the fiber into a thin fiber net by a roller carding machine; then cross lapping is carried out to prepare a thick fiber net; drafting the thick fiber web, changing the fiber arrangement direction, arranging the fibers in a disorderly way, and respectively manufacturing a first fiber web and a third fiber web;

(3) the three-layer composite fiber web is sent into a spunlace system, the three-layer composite fiber web is prewetted, the front side of the three-layer composite fiber web is subjected to spunlace reinforcement by adopting a plurality of flat-screen spunlace heads (wherein the spunlace pressure of the flat-screen spunlace heads is 35kg, 45kg, 55kg and 65kg in sequence), and the back side of the composite fiber web is subjected to spunlace reinforcement by adopting round-drum spunlace (wherein the spunlace pressure of the round-drum spunlace heads is 35kg, 50kg and 65kg in sequence, and the spunlace pressure is gradually increased), so that the three-layer fiber web is consolidated into a whole; removing redundant water in the fiber web by adopting a rolling drying mode; drying the material by adopting a drying cylinder mode (wherein the drying cylinder temperature is 130, 140 and 150 ℃) to prepare a spunlace base material;

(4) feeding the spunlace substrate into a coating system, and respectively applying glue stock to the front side and the back side of the spunlace substrate; curing the glue material on the surface of the spunlace substrate through drying; wherein the sizing material comprises the following components: 50% of waterborne polyurethane, 15% of titanium powder, 0.2% of defoaming agent, 7.8% of cross-linking agent, 25% of water and 2% of dispersing agent;

(5) subjecting the coated material to multi-zone calendering treatment (wherein the calendering temperature is 150 ℃ and the pressure is 0.4Mpa), and cooling the material by a cooling roller to enable the surface of the material to be flat; coiling the mixture to obtain a 200g/m mixture²A high density nonwoven fibrous material.

Comparative example 1

A fiber material for printing with a gram weight of 100g/m²The difference from example 2 is that the calendering temperature is 155 ℃, the pressure is 0.5MPa, and the density is 1.2g/cm³。

Comparative example 2

A fiber material for printing with a gram weight of 100g/m²The difference from example 2 is that the calendering temperature is 90 ℃, the pressure is 0.05MPa, and the density is 0.8g/cm³。

Comparative example 3

A fiber material for printing with a gram weight of 100g/m²The difference from example 2 is that the first and second sizing layers use an acrylic resin adhesive.

Comparative example 4

A fiber material for printing with a gram weight of 100g/m²The difference from example 2 is that the content of the middle second fiber layer is 0, the content of the first fiber layer and the third fiber layer is 70%, and the content of the third size layer is 30%.

Comparative example 5

A fiber material for printing with a gram weight of 100g/m²The difference from example 2 is that the first and second size layers are present in an amount of 0 and the first and third fiber layersThe ply content was 70% and the second fibrous ply content was 30%.

Comparative analysis of Performance test

Description of test items:

(1) material density: the density of a material is the ratio of its weight to its apparent volume (g/cm)³) Directly influences the permeability and mechanical property of the material. The formula for calculating the density (R) of the material is R-W/T1000, wherein W is the mass per unit area (g/m) of the material²) And T is the material thickness (mm).

(2) Tearing strength: the tear properties of the textile fabric were tested according to GB/T3917.2-2009 (trouser test specimen-Single slit). According to the summary of relevant documents and practical tests, the tearing strength of the material is generally about 15N, the material is easily torn by hands, the tearing is difficult after the tearing strength exceeds the tearing strength, and the tearing is easier when the tearing strength is lower.

(3) Printability: and printing the same segment of manuscript by adopting a digital printer, and judging by comparing the font outline definition.

(4) Washing fastness: and (5) evaluating the simulated washing mode by using a washing machine. The method comprises the following steps: taking 25 samples (size: 350mm x 600mm), adding 1ml of liquid detergent and 160ml of bleaching agent, and performing quick washing once at normal temperature and water temperature and at 800rpm for 30 min. Evaluation basis: after washing by a washing machine, the surface of the material is qualified without obvious cracks and damages.

(5) Elongation at break: according to GB/T24218.3/ISO 9073-3 (strip sample method), the width of a test sample is 50mm, the pretension is 0.00, the clamping distance is 100mm, and the moving speed is 100 mm.

Performance test results List

And (3) analyzing a test result:

(1) it can be seen from examples 1 to 3 that the tear strength increases progressively with increasing density of the material, the material becomes more and more difficult to tear by hand, and the lower the elongation at break, the higher the washfastness and the better the printability. In summary, the performance indexes of embodiment 2 are optimal.

(2) As can be seen from comparative examples 1 and 2, when the calendering process limit is exceeded, the tearability of comparative example 1 becomes poor as not tearable by hand, the printability of comparative example 2 becomes poor as print blur (fig. 3 is a comparison graph of the print effect of example 2 and comparative example 2), the washability also becomes poor as 8 times, the elongation at break increases, and the material stiffness decreases, resulting in easy deformation.

(3) As can be seen from comparative example 3, when the coating resin was changed from the aqueous polyurethane to the acrylic resin under the same other conditions, the washing resistance and printability were greatly reduced, the elongation at break was increased, and the material was easily deformed.

(4) From comparative example 4, it can be seen that when the second fiber layer in the middle is removed, the long fiber content and the coating content of the material are increased, the tearing strength of the material is increased, and the material is difficult to tear by hand, and meanwhile, due to the absence of the filling effect of the ultrashort fibers, the porosity of the material is increased, the material is easy to transmit light, so that the printability is reduced, and the printing is blurred.

(5) It can be seen from comparative example 5 that when the material is 100% made of fibers, the flatness of the material surface is low because no sizing layer is present on the upper and lower surfaces of the material, the printability of the material is seriously reduced, the printing is unclear, and the tearing strength is increased and the material is difficult to tear by hand. In addition, as the surface of the material is not protected by sizing materials, the material is uneven and has hydrophobicity, the washing fastness degree is greatly reduced, and the material fails the washing fastness test.

The raw materials and equipment used in the invention are common raw materials and equipment in the field if not specified; the methods used in the present invention are conventional in the art unless otherwise specified.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and all simple modifications, alterations and equivalents of the above embodiments according to the technical spirit of the present invention are still within the protection scope of the technical solution of the present invention.

Claims

1. A high density nonwoven fibrous material characterized by: is of a multilayer structure and comprises a first sizing material layer (1) and a second sizing material layer,A first fiber layer (2), a second fiber layer (3), a third fiber layer (4) and a second sizing material layer (5); the fiber length of the first fiber layer and the third fiber layer is larger than that of the second fiber layer, and the fibers of the adjacent fiber layers are mutually entangled; the density of the high-density non-woven fiber material is 0.9-1.1 g/cm³。

2. The high density nonwoven fibrous material of claim 1, wherein:

the mass sum of the first sizing material layer and the second sizing material layer accounts for 20-40% of the total mass of the material;

the sum of the mass of the first fiber layer and the mass of the third fiber layer accounts for 40-60% of the total mass of the material;

the mass of the second fiber layer accounts for 10-30% of the total mass of the material.

3. The high density nonwoven fibrous material of claim 2, wherein:

the fiber fineness in the first fiber layer and the third fiber layer is 0.1-1.2 dtex, and the fiber length is 25-50 mm;

the ratio of the fiber length in the first fiber layer and the third fiber layer to the fiber length in the second fiber layer is 6-45.

4. The high density nonwoven fibrous material of claim 3, wherein:

the first fiber layer and the third fiber layer contain superfine fibers accounting for 20-30% of the total mass of the material and artificial cellulose fibers accounting for 20-30% of the total mass of the material;

the first fiber layer and the third fiber layer have the same mass;

the raw material of the second fiber layer is plant pulp.

5. The high density nonwoven fibrous material of claim 4, wherein:

the superfine fibers in the first fiber layer and the third fiber layer are orange petal type split fibers; the orange petal-shaped split fiber comprises polyester and polyamide, and the fineness after fiber opening is 0.1-0.5 dtex;

the artificial cellulose fibers in the first fiber layer and the third fiber layer are one or more of viscose fibers, bamboo fibers and tencel fibers, the fineness of the artificial cellulose fibers is 0.4-1.2 dtex, and the fiber length of the artificial cellulose fibers is 30-40 mm.

6. The high density nonwoven fibrous material of claim 1, wherein: the first sizing material layer and the second sizing material layer contain waterborne polyurethane and titanium powder.

7. The high density nonwoven fibrous material of claim 1, wherein: the high-density non-woven fiber material has a mass per unit area of 80-200 g/m²The elongation at break in the longitudinal and transverse directions is 0.5-1.8%, and the light transmittance is less than or equal to 10%.

8. A method for preparing a high-density nonwoven fibrous material as claimed in any of claims 1 to 7, characterized by comprising the steps of:

(1) mixing superfine fibers and artificial cellulose fibers, and carding to prepare thin fiber nets from the fibers; then cross lapping is carried out to prepare a thick fiber net; drafting the thick fiber web, changing the fiber arrangement direction, arranging the fibers in a disorderly way, and respectively manufacturing a first fiber web and a third fiber web;

(2) feeding dry plant pulp material between the first fiber net and the third fiber net for superposition to prepare a three-layer composite fiber net;

(3) sending the three-layer composite fiber web into a spunlace unit, and spunlacing the front surface and the back surface of the three-layer composite fiber web respectively to consolidate the three-layer fiber web into a whole and remove redundant water in the fiber web; drying the material to prepare a spunlace substrate;

(4) sending the spunlace substrate into a coating unit, and respectively applying glue stock to the front surface and the back surface of the spunlace substrate; curing the glue material on the surface of the spunlace substrate through drying;

(5) the material after coating is subjected to calendaring treatment to enable the surface of the material to be flat; and then the high-density non-woven fiber material is prepared after being rolled.

9. The method of claim 8, wherein:

in the step (1), carding the mixed fiber by a roller carding machine;

in the step (3), the three-layer composite fiber net is pre-wetted, the front side of the three-layer composite fiber net is reinforced by adopting a plurality of flat-net spunlace heads, and the back side of the three-layer composite fiber net is reinforced by adopting round drum spunlace; the spunlace pressure of the flat-net spunlace heads is 35-65 kg, and the pressure of each flat-net spunlace head gradually increases according to the advancing direction of the material; the drum spunlace pressure is 35-65 kg; and the drum hydroentangling pressure is gradually increased according to the material advancing direction;

in the step (3), removing redundant water in the fiber web by adopting a rolling drying mode;

in the step (3), the consolidated fiber web is dried in a drying cylinder mode; the temperature of the drying cylinder is 100-150 ℃; and the temperature of the drying cylinder is gradually increased according to the advancing direction of the material;

in the step (4), the sizing material comprises 50-70% of waterborne polyurethane, 10-15% of titanium powder, 0.1-0.2% of defoaming agent, 5-7% of cross-linking agent, 10-15% of water and 1-2% of dispersing agent;

in the step (5), the calendering treatment adopts a multi-zone calendering mode, and the hot rolled material is cooled by a cooling roll; the calendering temperature is 100-150 ℃, and the pressure is 0.1-0.4 Mpa.

10. The method of claim 8, wherein: the fabric is processed by a high-density non-woven fiber material production device;

the production device comprises the following steps in sequence according to the processing procedures: the device comprises a coating unit (7), a calendaring unit (8), a cooling unit (9) and a coiling unit (10);

the coating unit comprises one or more coating subunits connected in series according to the processing procedure in sequence; each coating subunit comprises a coating mechanism and a drying mechanism (705) which are connected in series according to the processing procedure;

the calendering unit comprises a front calendering mechanism and a back calendering mechanism which are alternately arranged according to the processing procedure;

the cooling unit includes cooling rollers (901) arranged in pairs;

a plurality of cloth guide rollers (13) for conveying materials are arranged among the units;

the coating mechanism comprises a circular adhesive tape (702) which can circularly rotate, a plurality of adhesive tape guide rollers (703) which are used for driving and conveying the circular adhesive tape, an adhesive applying mechanism (701) which is arranged above the circular adhesive tape and a coating scraper (704);

the front-side calendering mechanism comprises a front-side heat-conducting roller (801), a front-side pressing roller (802) matched with the front-side heat-conducting roller and an upper pressurizing mechanism (803) connected above the front-side pressing roller;

the reverse side calender mechanism comprises a reverse side heat conduction roller (804), a reverse side pressing roller (805) matched with the reverse side heat conduction roller and a lower pressurizing mechanism (806) connected below the reverse side pressing roller.