CN114311944B

CN114311944B - Preparation method of protective clothing moisture-permeable film laminated composite knitted fabric

Info

Publication number: CN114311944B
Application number: CN202111490853.4A
Authority: CN
Inventors: 董旭丽; 郭峻岭; 邵敏华; 施屹
Original assignee: Zhejiang Caidi Industrial Co ltd
Current assignee: Zhejiang Caidi Industrial Co ltd
Priority date: 2021-12-08
Filing date: 2021-12-08
Publication date: 2023-05-30
Anticipated expiration: 2041-12-08
Also published as: CN114311944A

Abstract

The invention discloses a preparation method of a moisture-permeable film laminated composite knitted fabric for protective clothing, which comprises the following steps: drying TPU particles containing polyether polyol, preheating a charging barrel, opening an extruder, adding a small amount of raw materials, adding a normal amount of raw materials after normally extruding molten plastics, introducing compressed air from a core film, and blow molding to form a TPU film; dividing the TPU film into a TPU film surface layer and a TPU film bottom layer, coating first adsorption particles on the TPU film surface layer, and coating second adsorption particles on the TPU film bottom layer; laminating a water-absorbing layer between the TPU film surface layer and the TPU film bottom layer; taking adsorption type fibers as surface yarns, taking breathable fibers as bottom yarns, and taking bamboo joint fibers to hook the surface yarns and the bottom yarns to form a fabric layer; and (3) adopting polyurethane hot melt adhesive as an adhesive to perform hot melt lamination and compounding to obtain a finished product. The invention has the characteristics of good isolation effect on environment and good wearing comfort.

Description

Preparation method of protective clothing moisture-permeable film laminated composite knitted fabric

Technical Field

The invention relates to a film composite fabric, in particular to a preparation method of a moisture permeable film laminated composite knitted fabric for protective clothing.

Background

At present, the medical protective clothing mainly adopts polyethylene/polypropylene spunbonded non-woven fabric and breathable microporous film to be compounded, or adopts water-jet non-woven fabric and breathable microporous film to be compounded, or adopts wood pulp to be compounded with water-jet non-woven fabric. The breathable microporous film is a key component of the disposable protective clothing, and the breathable waterproof principle is that calcium carbonate powder is added into film raw materials before spinning the film, micropores are formed by stretching the film, interfacial peeling occurs between a polymer and calcium carbonate particles during stretching, interconnected tortuous pores or channels are formed around the calcium carbonate particles, and the breathable and moisture permeable functions of the film and the impermeability to liquid are endowed, so that the environments of the two sides of the film are communicated. However, in practical application, the composite fabric is found to be poor in comfort level and not capable of effectively removing sweat generated by a human body in long-time high-strength use, so that the sweat generated by the human body is easy to feel sultry, skin reddening, allergy and the like are caused, the tearing strength of the microporous breathable film is insufficient, the microporous breathable film is broken due to the fact that sharp objects such as a desk corner and a stretcher are touched in the treatment process, the infection risk is increased, and the service life is prolonged.

TPU, also known as thermoplastic polyurethane rubber or thermoplastic polyurethane elastomer, is a linear block copolymer composed of soft segments of oligomeric polyols and hard segments of isocyanates. The TPU film is a compact film and is formed by plasticizing and blowing TPU raw materials. Due to the high tensile strength, elongation, high tear strength, environmental and chemical resistance, wide hardness range, large bearing capacity, and are therefore used in a large number of applications in the textile industry. For the nonporous hydrophilic moisture permeable film TPU, a plurality of chemical groups utilizing the migration of water molecules are arranged on a molecular chain segment, and the sweat of a human body is successfully discharged in the process of moisture absorption, diffusion and moisture release, namely, the hydrophilic chain segment absorbs the sweat emitted by the human body, so that the moisture is rapidly diffused from the inside to the outside, and finally, the moisture is evaporated to the external environment.

The traditional TPU composite fabric is made by directly sticking the TPU film on the common fabric through an adhesive, and the method is simple and efficient, but the formed composite fabric has single functionality, is easy to have water seepage under long-time bearing water, has a strong environmental isolation effect, can not absorb sweat of a human body well, has certain sweat adhesion and stuffiness, has strong wearing comfort, and can not meet the increasing functional requirements of people.

Disclosure of Invention

The invention aims to provide a preparation method of a protective clothing moisture-permeable film laminated composite knitted fabric. The invention has the characteristics of good isolation effect on environment and good wearing comfort.

The technical scheme of the invention is as follows: the preparation method of the moisture-permeable film laminated composite knitted fabric for the protective clothing comprises the following steps:

s1, preparing TPU film

a. Drying TPU particles containing polyether polyol, and staying in a dryer for 2-5h to obtain a product A;

b. preheating a charging barrel, and preserving heat for 20-30min;

c. opening an extruder, running at a low speed, adding a small amount of product A, adding a normal amount of product A after normally extruding molten plastics, introducing compressed air from a core film, and pulling a pipe blank to a pulling roll through a cooling air ring to form a TPU film with a flat surface and no micropores, wherein the TPU film is a product B;

d. dividing the product B into a TPU film surface layer and a TPU film bottom layer, and coating first adsorption particles on the bottom of the TPU film surface layer to obtain a product C1; coating second adsorption particles on the top layer of the TPU film bottom layer to obtain a C2 product;

e. laminating a water absorption layer between the C1 product and the C2 product to obtain a D product;

s2, preparing fabric

Taking adsorption type fibers as surface yarns, taking breathable fibers as bottom yarns, taking bamboo joint fibers as connecting yarns, and hooking the surface yarns and the bottom yarns to form a fabric layer;

s3, preparing hot melt adhesive

Taking polyether glycol and MDI, and synthesizing a reactive moisture-curing polyurethane hot melt adhesive through a bulk polymerization reaction;

s4, lamination compounding

And (3) adopting a reactive moisture-curing polyurethane hot melt adhesive as an adhesive, and carrying out hot melt lamination and compounding on the D product and the fabric layer through a compounding unit to obtain a finished product.

In the preparation method of the protective clothing moisture-permeable film laminated composite knitted fabric, the water absorbing layer comprises water absorbing particles distributed in a wave shape, the upper parts of the water absorbing particles are wrapped with a diversion layer formed by antistatic fibers, and the diversion layer is provided with straight flow holes and tree-shaped holes; the lower part of the water absorbing particles is wrapped with a ventilation layer composed of hydrophobic fibers, and the ventilation layer is provided with conical holes with small upper parts and large lower parts.

In the preparation method of the protective clothing moisture-permeable film laminated composite knitted fabric, the tree-shaped holes comprise main holes communicated with water absorbing particles at the lowest position and branch holes communicated with the water absorbing particles at two sides of the lowest position; the direct current hole is communicated with the water absorbing particles at the highest position.

In the preparation method of the moisture-permeable film laminated composite knitted fabric for the protective clothing, the first adsorption particles and the second adsorption particles adopt nano-scale activated carbon particles, diatom mineral balls or fullerene C60.

In the preparation method of the moisture-permeable film laminated composite knitted fabric for the protective clothing, the adsorption type fiber is formed by blending a plurality of cross-section fibers and Y-section fibers; the air-permeable fiber is composed of a plurality of hollow fibers with bean-shaped cross sections, and air flow gaps are formed between adjacent hollow fibers.

In the preparation method of the moisture-permeable film laminated composite knitted fabric for the protective clothing, the bamboo joint fiber comprises a central fiber and a thick node positioned on the central fiber, a plurality of cavities surrounding the central fiber are arranged on the thick node, and a plurality of antibacterial particles are filled in the cavities.

In the preparation method of the moisture-permeable film laminated composite knitted fabric for the protective clothing, the central fiber comprises a plurality of flame-retardant fibers and bamboo fibers which are distributed in parallel, and two polyethylene fibers are alternately and alternately wound between the flame-retardant fibers and the bamboo fibers.

Compared with the prior art, the polyether TPU film is adopted, so that the affinity of the polymer to water is improved, the flexibility is better, the barrier property is better, the comfort is strong, the film strength and thickness uniformity are improved, and the quality stability of the same batch is improved by improving the preparation method; the invention adopts double-layer TPU film, has good waterproof and moisture permeability and harmful microorganism isolation performance, and establishes a barrier with effective protection between the wearer and the environment; the first adsorption particles, the water absorption layer and the second adsorption particles are arranged between the two layers of TPU films, so that multiple adsorption can be effectively carried out on air passing through the TPU films, peculiar smell, bacteria and other harmful substances are removed, and the permeated water is absorbed, so that the waterproof performance is further improved; the adopted hot melt adhesive has stable quality and strong adhesion;

the sweat that the surface of precoat produced through absorption formula fibre when keeping apart external moisture effectively absorbs human body to play good impurity adsorption, clean, dry skin, sweat that produces the human body through ventilative formula fibre is discharged, avoids the sultry, improves the travelling comfort, and the setting of connecting yarn improves the structural stability and the physical mechanical properties of precoat.

Therefore, the invention has the characteristics of good isolation effect on environment and good wearing comfort.

Drawings

FIG. 1 is a schematic diagram of the structure of the present invention;

FIG. 2 is a schematic structural view of an adsorbent fiber;

FIG. 3 is a schematic structural view of a breathable fiber;

FIG. 4 is a schematic structural view of a bamboo joint fiber;

fig. 5 is a schematic structural view of the central fiber.

The marks in the drawings are: 1. a TPU film surface layer; 2. a TPU film bottom layer; 3. a water-absorbing layer; 31. water-absorbing particles; 32. a flow guiding layer; 33. a straight flow hole; 34. tree-shaped holes; 35. a ventilation layer; 36. a tapered bore; 41. a first adsorbent particle; 42. a second adsorbent particle; 5. a fabric layer; 51. an adsorption type fiber; 511. a cross-section fiber; 512. y-shaped cross-section fiber; 52. breathable fibers; 521. hollow fiber; 522. an air flow gap; 53. bamboo joint fibers; 531. a central fiber; 532. coarse nodes; 533. a cavity; 534. antibacterial particles; 535. flame retardant fibers; 536. bamboo fiber; 537. polyethylene fibers.

Detailed Description

The invention is further illustrated by the following examples, which are not intended to be limiting.

Examples:

as shown in fig. 1 to 5, the preparation method of the protective clothing moisture permeable film laminated composite knitted fabric comprises the following steps:

s1, preparing TPU film

a. Drying TPU particles containing polyether polyol, and staying in a dryer for 2-5h to obtain a product A; the polyether type TPU film is adopted, the moisture permeability effect is 5-6 times that of the common TPU film, the water permeability is improved, the affinity of the polymer to water is improved, the permeability of water vapor is improved, the flexibility is better, the barrier property is better, and the comfort is strong; drying is carried out in the early stage of blow molding, so that the influence on the subsequent operation and the molding effect caused by the moisture absorption of TPU particles is avoided;

b. preheating a charging barrel, and preserving heat for 20-30min;

c. opening an extruder, running at a low speed, adding a small amount of product A, heating to a melting temperature, adding a normal amount of product A after normally extruding molten plastics, introducing compressed air from a core film, and pulling a pipe blank to a pulling roll through a cooling air ring to form a TPU film with a flat surface and no micropores, wherein the TPU film is a product B; the TPU film formed by the method is smooth, film breakage is not easy to occur when the TPU film is compounded with the fabric in the later period, the water pressure test of the film is normal, the film forming property is good, and the TPU film has good mechanical property and moisture permeability;

d. dividing the product B into a TPU film surface layer 1 and a TPU film bottom layer 2, and coating first adsorption particles 41 on the bottom of the TPU film surface layer 1 to obtain a product C1; coating second adsorption particles 42 on the top layer of the TPU film bottom layer 2 to obtain a C2 product;

e. laminating a water absorption layer 3 between the C1 product and the C2 product to obtain a D product;

s2, preparing fabric

Taking the adsorption type fiber 51 as a surface yarn, taking the ventilation type fiber 52 as a bottom yarn, taking the bamboo joint fiber 53 as a connecting yarn, and hooking the surface yarn and the bottom yarn to form a fabric layer 5;

s3, preparing hot melt adhesive

s4, lamination compounding

Carrying out plasma treatment on the fabric layer 5 by using air containing a small amount of ozone; and (3) adopting a reactive moisture-curing polyurethane hot melt adhesive as an adhesive, and carrying out hot melt lamination and compounding on the D product and the fabric layer 5 through a compounding unit to obtain a finished product. The production process of compounding is carried out after the air containing a small amount of ozone is subjected to plasma treatment, so that the mechanical property of the compound fabric is effectively improved, and the adverse phenomena of curling, deformation and the like generated after the TPU compound fabric is stored for a long time are avoided.

When the hot melt adhesive is transferred onto the film from the engraving roll, the hot melt adhesive is low in viscosity and high in fluidity, so that the wire drawing phenomenon is avoided, the transfer difficulty is reduced, the separation efficiency is improved, the waste is reduced, and the cost is reduced; in lamination compounding, the hot melt adhesive is low in fluidity and high in viscosity, so that the fabric and the film are compounded together instantly under certain pressure, the laminated fabric is prevented from being possibly separated after leaving a lamination point, the penetration of the hot melt adhesive through the fabric is avoided, and the appearance, the hand feeling, the adhesive strength, the washing resistance and the like are improved.

Finally, the finished product is subjected to ultraviolet irradiation treatment, so that the firmness and durability of the composite are improved.

The water absorbing layer 3 includes water absorbing particles 31 distributed in a wave shape, and the water absorbing particles 31 may be polymer water absorbing resin. The upper part of the water absorbing particles 31 is wrapped with a diversion layer 32 formed by antistatic fibers, and the diversion layer 32 is provided with a straight hole 33 and a tree-shaped hole 34; the water absorbing particles 31 are arranged into a wavy distribution structure, so that on one hand, the water absorbing area is increased, the water absorbing performance is improved, and on the other hand, the compactness and the water absorbing effect of the water absorbing particles 31 can be ensured even if the film stretches and stretches. The antistatic fiber absorbs water in the environment to cause most of generated static electricity to leak, and the antistatic fiber is matched with the high-humidity environment constructed by the water absorption of the water absorption particles 31 to form a water film, so that the static electricity leakage amount is increased; the tree-shaped holes 34 comprise main holes communicated with the water absorbing particles 31 at the lowest position and branch holes communicated with the water absorbing particles 31 at two sides of the lowest position; the direct current hole 33 is communicated with the water absorbing particles 31 at the highest position; the straight flow holes 33 and the tree-shaped holes 34 effectively drain and split the water body permeated into the water absorbing layer 3, fully utilize the water absorbing particles 31 to absorb, and improve the water absorbing efficiency.

The lower part of the water absorbing particles 31 is wrapped with a ventilation layer 35 formed by hydrophobic fibers, and the ventilation layer 35 is provided with conical holes 36 with small upper parts and large lower parts. The ventilation layer 35 is provided to allow free release of moisture and to prevent internal swelling and stuffiness from affecting the wearability.

The first adsorption particles 41 and the second adsorption particles 42 are nano-scale activated carbon particles, diatom mineral spheres or fullerene C60. Effectively absorbs bacteria, peculiar smell and the like penetrating through the PTU film, and inhibits bacteria from growing in a humid environment after the water absorption layer 3 absorbs water. The first and

second adsorption particles

41 and 42 may be made of the same material or different materials.

The adsorption type fiber 51 is formed by blending a plurality of cross-section fibers 511 and Y-shaped section fibers 512, and the adsorption type fiber 51 is made of cotton fibers, and has the advantages of large specific surface area, strong adsorptivity and good skin friendliness; the air-permeable fiber 52 is composed of a plurality of hollow fibers 521 with bean-shaped cross sections, air flow gaps 522 are formed between adjacent hollow fibers 521, and the air-permeable fiber 52 is made of polyester fiber and has good shape retention. Sweat discharged from a human body is absorbed by the adsorption type fibers 51 through the ventilation type fibers 52, so that the inside of a wearer is kept dry, and the ventilation type fibers 52 are composed of a plurality of hollow fibers 521 with bean-shaped cross sections, so that the warmth retention property and the comfort of the fabric are improved, and the fabric is not easy to deform.

The bamboo joint fiber 53 comprises a central fiber 531 and a thick node 532 positioned on the central fiber 531, wherein a plurality of cavities 533 surrounding the central fiber 531 are arranged on the thick node 532, and a plurality of antibacterial particles 534 are filled in the cavities 533. The slub fiber 53 is used as a connecting yarn for hooking the surface yarn and the bottom yarn, so that a capillary channel between the yarns is increased, the moisture absorption and drainage performance and the contact area between the antibacterial particles 534 and the environment are improved, the antibacterial capacity is improved, the strength of the slub fiber 53 is also improved due to the arrangement of the antibacterial particles 534, the structural stability of the fabric layer 5 is improved, and the yarn is not easy to break and take off.

The central fiber 531 includes a plurality of flame retardant fibers 535 and bamboo fibers 536 which are distributed in parallel, and two polyethylene fibers 537 are alternately and alternately wound between the flame retardant fibers 535 and the bamboo fibers 536. By utilizing the matching of the flame-retardant fiber 535 and the bamboo fiber 536, good antibacterial, deodorant and flame-retardant effects are achieved, the polyethylene fiber 537 is wound on the outer parts of the flame-retardant fiber 535 and the bamboo fiber 536 in a crossing way, the strength of the central fiber 531 and the tightness of the inner flame-retardant fiber 535 and the bamboo fiber 536 are improved, and the loose filament falling of the fibers is prevented.

For the outside, the outside air is doubly protected through the TPU film surface layer 1 and the TPU film bottom layer 2, so that the outside harmful microorganisms can be effectively isolated, the waterproof moisture permeability is good, and a barrier with effective protection is established between a wearer and the environment; the first adsorption particles 41, the water absorption layer 3 and the second adsorption particles 42 are arranged between the TPU film surface layer 1 and the TPU film bottom layer 2, so that filtered air can be subjected to multiple adsorption, peculiar smell, bacteria and other harmful substances are removed, permeated water is absorbed, and the waterproof performance is effectively improved;

for the inside, the fabric layer 5 is pressed at the bottom of the TPU film bottom layer 2 through a hot melt adhesive layer, sweat generated by a human body is discharged onto the adsorption type fiber 51 through the ventilation type fiber 52 by the fabric layer 5, so that the stuffiness is avoided, the wearing comfort is improved, and the structural stability and the physical and mechanical properties of the fabric layer 5 are improved by the arrangement of the bamboo joint fiber 53; the adsorption fiber 51 can absorb sweat generated by human body, clean and dry skin.

Through the arrangement, the prepared composite knitted fabric has good waterproof property, air permeability, antibacterial property and antistatic property, and various performance indexes of the fabric are shown in the following table 1.

Table 1 performance index of composite knitted fabric

Performance index	Measurement value
		Hydrostatic pressure resistance	≥1.67kPa
Moisture permeability	≥2500g/m2·d
		Penetration resistance to synthetic blood	≥1.75kPa
Surface moisture resistance	Grade			3 or more
		Elongation at break	≥30％
Breaking strength	≥45N

Claims

1. The preparation method of the moisture-permeable film laminated composite knitted fabric for the protective clothing is characterized by comprising the following steps of: the method comprises the following steps:

s1, preparing TPU film

b. preheating a charging barrel, and preserving heat for 20-30min;

d. dividing the product B into a TPU film surface layer (1) and a TPU film bottom layer (2), and coating first adsorption particles (41) on the TPU film surface layer (1) to obtain a product C1; coating second adsorption particles (42) on the TPU film bottom layer (2) to obtain a C2 product;

e. laminating a water absorption layer (3) between the C1 product and the C2 product to obtain a D product;

the water absorption layer (3) comprises water absorption particles (31) which are distributed in a wave shape, a diversion layer (32) formed by antistatic fibers is wrapped on the upper part of the water absorption particles (31), and a straight flow hole (33) and a tree-shaped hole (34) are arranged on the diversion layer (32); the lower part of the water absorbing particles (31) is wrapped with a ventilation layer (35) formed by hydrophobic fibers, and the ventilation layer (35) is provided with conical holes (36) with small upper parts and large lower parts;

s2, preparing fabric

Taking the adsorption type fiber (51) as a surface yarn, taking the ventilation type fiber (52) as a bottom yarn, taking the bamboo joint fiber (53) as a connecting yarn, and hooking the surface yarn and the bottom yarn to form a fabric layer (5);

s3, preparing hot melt adhesive

s4, lamination compounding

And (3) adopting a reactive moisture-curing polyurethane hot melt adhesive as an adhesive, and carrying out hot melt lamination and compounding on the D product and the fabric layer (5) through a compounding unit to obtain a finished product.

2. The method for producing a protective clothing moisture-permeable film laminated composite knitted fabric according to claim 1, characterized in that: the tree-shaped holes (34) comprise main holes communicated with the water absorbing particles (31) at the lowest position and branch holes communicated with the water absorbing particles (31) at two sides of the lowest position; the straight hole (33) is communicated with the water absorbing particles (31) at the highest position.

3. The method for producing a protective clothing moisture-permeable film laminated composite knitted fabric according to claim 1, characterized in that: the first adsorption particles (41) and the second adsorption particles (42) adopt nano-scale activated carbon particles, diatom mineral spheres or fullerene C60.

4. The method for producing a protective clothing moisture-permeable film laminated composite knitted fabric according to claim 1, characterized in that: the adsorption type fiber (51) is formed by blending a plurality of cross-shaped section fibers (511) and Y-shaped section fibers (512); the air-permeable fiber (52) is composed of a plurality of hollow fibers (521) having a bean-shaped cross section, and air flow gaps (522) are formed between adjacent hollow fibers (521).

5. The method for producing a protective clothing moisture-permeable film laminated composite knitted fabric according to claim 1, characterized in that: the bamboo joint fiber (53) comprises a central fiber (531) and a thick node (532) positioned on the central fiber (531), a plurality of cavities (533) surrounding the central fiber (531) are arranged on the thick node (532), and a plurality of antibacterial particles (534) are filled in the cavities (533).

6. The method for producing a protective clothing moisture-permeable film laminated composite knitted fabric according to claim 5, characterized in that: the central fiber (531) comprises a plurality of flame-retardant fibers (535) and bamboo fibers (536) which are distributed in parallel, and two polyethylene fibers (537) are alternately and alternately wound between the flame-retardant fibers (535) and the bamboo fibers (536).