CN109757788B

CN109757788B - Nontoxic sponge brassiere

Info

Publication number: CN109757788B
Application number: CN201910080972.9A
Authority: CN
Inventors: 容轶; 金华; 雷艳; 黄福开
Original assignee: Kaifang Gognchang Shenzhen Technology Co ltd
Current assignee: Kaifang Gognchang Shenzhen Technology Co ltd
Priority date: 2019-01-28
Filing date: 2019-01-28
Publication date: 2023-10-03
Anticipated expiration: 2039-01-28
Also published as: CN109757788A

Abstract

The invention relates to the technical field of bra underwear, in particular to a nontoxic sponge bra. The bra comprises a bra cup, wherein the bra cup comprises two bra cups which are symmetrically arranged, and a lower part which surrounds the bottom and the side part of each bra cup, each bra cup comprises a first cotton cloth layer, a first sterile sponge layer and a second cotton cloth layer which are sequentially connected from outside to inside, and the thicknesses of the first cotton cloth layer and the second cotton cloth layer are all 0.5-1.0mm. The nontoxic sponge bra disclosed by the invention has the advantages that the nontoxic sponge is adopted as the main fabric of the bra, so that the damage of the traditional toxic sponge to the health of a human body is solved, the bra is high in air permeability, soft and comfortable, the sultry feeling of a bra cup is avoided, the breathing of the chest skin is improved, and the practicability is high; and by adopting three layers of nontoxic sponges, the support of the bra cup is improved, and the breast support is improved.

Description

Nontoxic sponge brassiere

Technical Field

The invention relates to the technical field of bra underwear, in particular to a nontoxic sponge bra.

Background

The bra underwear is one of necessary articles for women, has the effects of bearing and gathering the breasts of women, but most of the prior bra cups adopt sponge fabrics, so that people gradually know that the traditional sponge has poor air permeability and is easy to grow bacteria along with the development of society and the improvement of health cognition degree, the health of the breasts of women is greatly adversely affected, the fabrics are toxic, chemical substances adopted in the sponge preparation process have certain volatility, and the breasts of women are extremely easy to cause diseases and even cancers of the breasts of women when the breasts of women are worn by the breasts made of harmful sponge.

Disclosure of Invention

In order to overcome the defects and shortcomings in the prior art, the invention aims to provide the nontoxic sponge bra, which solves the problem that the traditional toxic sponge is harmful to the health of human bodies by adopting the nontoxic sponge as the main fabric of the bra, has high air permeability, is soft and comfortable, avoids the stuffy feel of bra cups, improves the breathing of chest skin and has high practicability; and by adopting three layers of nontoxic sponges, the support of the bra cup is improved, and the breast support is improved.

The aim of the invention is achieved by the following technical scheme: the utility model provides a nontoxic sponge brassiere, includes cup portion, cup portion includes two cup that the symmetry set up, surrounds in the lower of cup bottom and lateral part takes off, every the cup includes from outside to interior first cotton cloth layer, first nontoxic sponge layer and the second cotton cloth layer that connects gradually, the thickness on first cotton cloth layer and second cotton cloth layer is 0.5-1.0mm.

The invention solves the problem that the traditional toxic sponge damages the health of human bodies by adopting the nontoxic sponge as the main fabric of the bra, has high air permeability, is soft and comfortable, avoids the sultry feeling of the bra cup, improves the breathing of the chest skin, and has high practicability. Specifically, the thickness of the first cotton cloth layer and the second cotton cloth layer is 0.5mm, 0.6mm, 0.7mm, 0.8mm or 1.0mm.

Preferably, the cup further comprises a second non-toxic sponge layer and a third non-toxic sponge layer, wherein the outer surface of the second non-toxic sponge layer is connected with the inner surface of the first cotton cloth layer, the inner surface of the second non-toxic sponge layer is connected with the outer surface of the third non-toxic sponge layer, and the inner surface of the third non-toxic sponge layer is connected with the outer surface of the second cotton cloth layer; the second cotton cloth layer is a frosted cotton cloth layer.

According to the bra cup, three layers of nontoxic sponges are adopted, so that the support of the bra cup is improved, and the breast support is improved; and the mill Mao Mianbu is adopted as the fabric of the second cotton layer to be contacted with the skin of a human body, so that the skin-friendly property and softness of the bra cup are improved, friction feeling is not generated, and friction damage to the skin of the chest is not caused.

Preferably, the cup portion further comprises a first glue net layer, and the first glue net layer is arranged between the second non-toxic sponge layer and the third non-toxic sponge layer and extends to the inside of the lower rake; the thickness of the first adhesive net layer is 200-2500 μm, and the mesh density is 20-100 pieces/cm ² 。

The first adhesive net layer is adopted, so that the support and the bearing of the bra cup can be improved, the traditional bra cup basically adopts the backing ring to bear and support the chest, but the backing ring can cause oppression to the chest, blood circulation of the chest is easy to be avoided, the breast is not smooth after long-term wearing, breast hyperplasia, mastitis, breast cancer and other chest diseases are easy to be caused, and the adhesive net layer of the embodiment has better air permeability and flexibility through strictly controlling the thickness and the mesh density of the adhesive net layer, does not cause oppression to the chest, and improves the blood circulation of the chest. In addition, the rubber net layer in the cup extends into the lower part of the cup, so that the rubber net layer is the range of the whole cup part, has supporting and bearing effects on the chest, side walls and other parts, and avoids the phenomena of chest sagging and the like. Specifically, the thickness of the first adhesive net layer is 200 mu m and 700 mu m m, 1200 μm, 1800 μm or 2500 μm, the mesh density is 20 pieces/cm ² 40 pieces/cm ² 60 pieces/cm ² 80 pieces/cm ² Or 100/cm ² 。

Preferably, the cup part further comprises a second adhesive net layer, and the second adhesive net layer is arranged in the lower part; the thickness of the second adhesive net layer is 200-2500 μm, and the mesh density is 20-100 pieces/cm ² 。

The invention can improve the support and the bearing of the bra cup by adopting the second adhesive net layer, the traditional bra cup basically adopts the backing ring to bear and bear the chest, but the backing ring can cause the oppression feeling to the chest, the long-term wearing is easy to cause the chest diseases such as the blood circulation failure and the breast unclean, and the hyperplasia of mammary glands, the mastitis, the breast cancer and the like, and the adhesive net layer has better air permeability and softness by strictly controlling the thickness and the mesh density of the adhesive net layer, can not cause the oppression feeling to the chest, and improves the blood circulation smoothness of the chest. In addition, the rubber net layer in the cup is only arranged in the lower part of the cup, and the supporting and supporting functions on the chest part are realized through the supporting and supporting of the lower part of the cup, so that the phenomena of unsmooth circulation of chest blood and mammary gland and the like caused by the traditional support ring mode are avoided. Specifically, the second adhesive mesh layer has a thickness of 200 μm, 700 μm, 1200 μm, 1800 μm or 2500 μm and a mesh density of 20 pieces/cm ² 40 pieces/cm ² 60 pieces/cm ² 80 pieces/cm ² Or 100/cm ² 。

Preferably, the thickness of the first nontoxic sponge layer is 1.5-2.5mm, the thickness of the second nontoxic sponge layer is 9-11mm, and the thickness of the third nontoxic sponge layer is 2.5-3.5mm.

The thickness of each nontoxic sponge layer is strictly controlled, so that the manufactured bra cup has good air permeability, is soft and comfortable, does not cause stuffy feel and friction feel to the chest, and is high in practicality. Specifically, the thickness of the first nontoxic sponge layer is 1.5mm, 1.8mm, 2.0mm, 2.3mm or 2.5mm, the thickness of the second nontoxic sponge layer is 9mm, 9.5mm, 10mm, 10.5mm or 11mm, and the thickness of the third nontoxic sponge layer is 2.5mm, 2.8mm, 3.0mm, 3.2mm or 3.5mm.

Preferably, the cup further comprises a fourth nontoxic sponge layer, the outer surface of the fourth nontoxic sponge layer is connected with the inner surface of the first nontoxic sponge layer, and the inner surface of the fourth nontoxic sponge layer is connected with the inner surface of the second cotton cloth layer; the thickness of the first nontoxic sponge layer is 4-6mm, and the thickness of the fourth nontoxic sponge layer is 4-8mm. Specifically, the thickness of the first nontoxic sponge layer is 4mm, 4.5mm, 5mm, 5.5mm or 6mm, and the thickness of the fourth nontoxic sponge layer is 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 7mm or 8mm.

Wherein, more preferably, the thickness of the first nontoxic sponge layer and the thickness of the fourth nontoxic sponge layer are both 4.5mm; preferably, the thickness of the first nontoxic sponge layer is 5mm, and the thickness of the fourth nontoxic sponge layer is 7mm.

Preferably, the cup further comprises a third glue net layer, and the third glue net layer is arranged between the first nontoxic sponge layer and the fourth nontoxic sponge layer; the thickness of the third adhesive net layer is 200-2500 μm, and the mesh density is 20-100 pieces/cm ² 。

Preferably, the cup further comprises a fourth adhesive net layer, the outer surface of the fourth adhesive net layer is connected with the inner surface of the first cotton cloth layer, and the inner surface of the fourth adhesive net layer is connected with the outer surface of the first sterile sponge layer; the thickness of the fourth adhesive net layer is 200-2500 μm, and the mesh density is 20-100 pieces/cm ² 。

According to the invention, the third adhesive net layer or the fourth adhesive net layer is arranged, so that the cup can be supported and supported, the supporting and supporting functions of the chest part are realized, the phenomena of unsmooth chest blood circulation, breast circulation and the like caused by adopting a traditional backing ring mode are avoided, the covering effect of the bra on the chest can be improved, the occurrence of the exposure phenomena such as leakage points and the like is avoided, and the wearing safety of the bra is improved.

Preferably, the first non-toxic sponge layer is made of plant fibers, and the plant fibers comprise the following raw materials in parts by weight:

the invention prepares the nontoxic sponge by adopting the raw materials, has no toxicity or side effect on human bodies, can ensure that the prepared nontoxic sponge is harmless to human bodies, has no damage to skin, is safe and environment-friendly, has soft hand feeling, and has better strength, elasticity, hydrophilicity and water diffusivity.

The inorganic filler adopted by the invention can effectively improve the dispersibility of each material, and the powder characteristic of the inorganic filler is utilized to improve the adhesion among the materials, so that the interaction efficiency of the materials is improved, the mechanical strength of polylactic acid is improved, the wear resistance, the breaking strength, the tearing strength and the like of the prepared plant fiber are improved, the shrinkage rate of the plant fiber is reduced, and the use stability of the plant fiber is improved; the antistatic agent is adopted, so that the antistatic effect of the nontoxic sponge can be improved, the prepared nontoxic sponge has excellent antistatic performance, the electrostatic effect generated by fibers can be avoided, and meanwhile, the interference and the influence of static on the subsequent superposition molding process can be avoided; the surfactant is adopted, so that the dispersibility and the mixing uniformity of raw materials in the preparation process of the nontoxic sponge can be effectively improved, and the prepared nontoxic sponge has stable performance; the coupling agent is adopted, so that the interaction of the raw materials can be promoted, the antistatic agent and the antioxidant are promoted to modify the plant fiber, and the antistatic property and the oxidation resistance of the nontoxic sponge are improved; by adopting the silicone oil, the friction coefficient between fibers can be reduced, the stability of plant fibers is improved, and the prepared nontoxic sponge layer has better hand feeling.

Preferably, the inorganic filler comprises 5-6 parts of mica powder, 1-2 parts of calcium carbonate and 2-3 parts of cordierite powder. By adopting the inorganic filler, the invention can effectively promote the adhesiveness between materials by utilizing the powder characteristics, improve the dispersibility and the mixing uniformity among materials, promote the interaction of materials, effectively improve the mechanical strength of polylactic acid, improve the wear resistance, the breaking strength, the tearing strength and other properties of the prepared plant fiber, reduce the shrinkage rate and improve the stability of the plant fiber; the surface of the adopted mica powder is provided with active groups, so that the mica powder is easy to combine and twine with a molecular chain, the polymerizability of the inorganic filler and the polylactic acid can be improved, a compact layer network structure is formed by polymerizing the inorganic filler and the polylactic acid, and the stability and the comprehensive mechanical property of the polylactic acid are improved; in the cordierite powder, six-membered rings forming the structure of the cordierite powder are arranged along the direction of the C axis to form a channel along the C axis, a large space is reserved in the channel, the space can be used for being mixed with a large amount of transition metal (aluminum oxide), the compatibility and the dispersibility of the inorganic filler and polylactic acid are improved, the polylactic acid and other materials are promoted to be uniformly mixed and dispersed, and the calcium carbonate adopted can promote the alkoxy in the siloxane coupling agent and the hydroxyl on the surface of the filler to act to form a layer of coupled monomolecular film, so that long-chain alkane is wound with polylactic acid molecular chains, the strength, tear resistance and other performances of the polylactic acid are further effectively improved, and the mechanical strength of plant fibers is improved.

Preferably, the antistatic agent is a mixture of polyoxyethylene alkylamide, alkyl dicarboxymethylammonium acetolide and alkyl bis (alpha-hydroxyethyl amine phosphate) in a weight ratio of 2-3:1-1.5:1.

The invention has no effect on skin, is mild and safe, can lead the prepared nontoxic sponge not to cause stimulation on skin, has good antistatic effect and good thermal stability, and can avoid the aging of plant fibers caused by high temperature in the subsequent hot molding process of the nontoxic sponge, wherein the nontoxic sponge is matched with an anionic antistatic agent (polyoxyethylene alkylamide) for use by adopting alkyl dicarboxylammonium-ethylene lactone as the amphoteric antistatic agent, has higher adhesive force, leads the nontoxic sponge to be easy to absorb and act with polylactic acid, improves the antistatic effect of the nontoxic sponge, can avoid the electrostatic effect generated by fibers, and can also avoid the interference and influence of static on the subsequent superposition molding process.

Preferably, the surfactant is a mixture of polyoxyethylene fatty acid ester and alkylphenol ethoxylate with a weight ratio of 3-4:1.

The surfactant of the type can improve the dispersibility and the mixing uniformity of the raw materials in a nontoxic sponge raw material system, so that the prepared nontoxic sponge has stable performance; the alkylphenol polyoxyethylene ether has excellent dispersibility and antistatic property, and can effectively improve the dispersibility of plant fiber raw materials and the antistatic property of the nontoxic sponge.

Preferably, the coupling agent is a mixture of vinyl triethoxysilane, aniline methyl triethoxysilane and pyrophosphite titanate in a weight ratio of 1-2:1:2.5-3.5.

The invention can promote the interaction of all raw materials by adding the coupling agent, promote the antistatic agent to modify the plant fiber and improve the antistatic property of the nontoxic sponge, and adopts the coupling agent of the type, and the inorganic phase of the coupling agent is utilized to react with the surface groups of the nontoxic sponge to form a molecular film to wrap around powder particles, so that the mutual aggregation of the powder particles is prevented, the interfacial tension between the powder particles and the polymer is reduced, and the dispersibility and the compatibility of the plant fiber raw materials are improved.

Preferably, the solvent is prepared from ethanol and water in a weight ratio of 1: 2.5-3.5.

The invention adopts the above-mentioned types as the solvent, can fully and uniformly dissolve all raw materials, and is easy to recycle, harmless to human body, and traditional solvents such as methyl chloride, methylene dichloride, toluene, etc. are adopted for dissolution, traditional solvents are toxic and difficult to recycle, and residues are harmful to human body; in addition, the solvent adopted in the method is easy to evaporate and remove in the fiber preparation process, so that the processing formability of the plant fiber is improved.

The preparation method of the nontoxic sponge bra comprises the following steps:

step (1): sequentially stacking a first nontoxic sponge layer, a second nontoxic sponge layer, a first adhesive net layer and a third nontoxic sponge layer, and carrying out hot molding for 215-225s at the temperature of 190-200 ℃ under the pressure of 5-6 atmospheres to obtain a composite layer, wherein the thickness of the composite layer is 8-12mm;

step (2): coating the first cotton cloth layer on the outer surface of the composite layer prepared in the step (1), coating the second cotton cloth layer on the inner surface of the composite layer prepared in the step (1), and hot-pressing to prepare the cup part;

step (3): and (3) cutting and sewing the cup obtained in the step (2) to obtain the nontoxic sponge bra.

Or, a preparation method of the nontoxic sponge bra comprises the following steps:

step (1): sequentially stacking a first nontoxic sponge layer, a second adhesive net layer and a third nontoxic sponge layer, wherein the second adhesive net layer is placed at a position of a lower part of the bra, and hot molding is carried out for 215-225s at the temperature of 190-200 ℃ under the pressure of 5-6 atmospheres, so as to prepare a composite layer, and the thickness of the composite layer is 8-12mm;

step (1): sequentially stacking a first nontoxic sponge layer, a third adhesive net layer and a fourth nontoxic sponge layer, wherein the third adhesive net layer is placed at the position of a bra cup, and hot molding is carried out for 130-150s under the pressure of 4-5 atmospheres and the temperature of 188-190 ℃ to prepare a composite layer, and the thickness of the composite layer is 5-9mm;

step (1): sequentially stacking a first nontoxic sponge layer, a third adhesive net layer and a fourth nontoxic sponge layer, wherein the third adhesive net layer is placed at the position of a bra cup of the bra, and hot molding is carried out for 110-130s under the conditions of 5-6 atmospheres and the temperature of 195-205 ℃ to prepare a composite layer, and the thickness of the composite layer is 5-7mm;

step (1): sequentially stacking a fourth adhesive net layer and a first sterile sponge layer, wherein the fourth adhesive net layer is placed at the cup position of the bra, and hot molding is carried out for 110-130s under the conditions that the pressure is 5-6 atmospheres and the temperature is 190-200 ℃ to prepare a composite layer, and the thickness of the composite layer is 4-8mm;

The nontoxic sponge bra prepared by the steps is convenient to operate and control, stable in quality and high in production efficiency, and the first corn cotton layer, the second corn cotton layer, the rubber net layer and the third corn cotton layer are subjected to high-temperature hot die pressing, so that corn fibers in the corn cotton layer can be primarily melted, the bonding connection with other layers is easy, the interlayer stability of a cotton cup is improved, and the interlayer separation phenomenon is not easy to occur; then carrying out low-temperature mould pressing, cooling the heated raw materials of each layer, and simultaneously laminating to improve the formability of the composite layer; then the first surface layer and the second cotton cloth layer are compounded on the two sides of the compound layer, so that the protection of the compound layer is improved, and the softness and the air permeability of the cotton cup are improved; by strictly controlling the temperature, time and pressure in the whole mould pressing preparation process, the structure and performance of the corn fiber or polylactic acid can not be damaged, and the prepared cotton cup has better air permeability, support, softness and antibacterial property.

The preparation method disclosed by the invention is convenient to operate and control, stable in quality and high in production efficiency, the nontoxic sponge layer can be primarily melted by strictly controlling the temperature, time and pressure in the whole mould pressing preparation process, the nontoxic sponge layer is easy to bond and connect with other layers, the interlayer stability of the bra is improved, the interlayer separation phenomenon is not easy to occur, the structure and performance of plant fibers or polylactic acid are not damaged, and the prepared nontoxic sponge bra has better air permeability, support and softness.

The invention has the beneficial effects that: the nontoxic sponge bra disclosed by the invention has the advantages that the nontoxic sponge is adopted as the main fabric of the bra, so that the damage of the traditional toxic sponge to the health of a human body is solved, the bra is high in air permeability, soft and comfortable, the sultry feeling of a bra cup is avoided, the breathing of the chest skin is improved, and the practicability is high; and by adopting three layers of nontoxic sponges, the support of the bra cup is improved, and the breast support is improved.

Drawings

FIG. 1 is a schematic view showing the structure of the inner surface of example 1 of the present invention;

FIG. 2 is a schematic view showing the structure of the inner surface of example 2 of the present invention;

FIG. 3 is a schematic view showing the structure of the inner surface of examples 3-6 of the present invention;

FIG. 4 is a schematic cross-sectional structure of embodiment 1 of the present invention;

FIG. 5 is a schematic cross-sectional structure of embodiment 2 of the present invention;

FIG. 6 is a schematic cross-sectional structure of embodiment 3-4 of the present invention;

FIG. 7 is a schematic cross-sectional structure of examples 5-6 of the present invention.

The reference numerals are: 1-cup part, 11-cup, 111-first cotton cloth layer, 112-first nontoxic sponge layer, 113-second cotton cloth layer, 114-second nontoxic sponge layer, 115-third nontoxic sponge layer, 116-first adhesive net layer, 117-second adhesive net layer, 118-fourth nontoxic sponge layer, 119-third adhesive net layer, 110-fourth adhesive net layer, and 12-lower part.

Detailed Description

The present invention will be further described with reference to examples and fig. 1 to 7, which are not intended to limit the scope of the present invention.

Example 1

Referring to fig. 1 and 4, a nontoxic sponge bra comprises a cup portion 1, wherein the cup portion 1 comprises two cup 11 symmetrically arranged and a lower rake 12 surrounding the bottom and the side of the cup 11, each cup 11 comprises a first cotton cloth layer 111, a first nontoxic sponge layer 112, a second nontoxic sponge layer 114, a third nontoxic sponge layer 115 and a second cotton cloth layer 113 which are sequentially connected from outside to inside, and the thicknesses of the first cotton cloth layer 111 and the second cotton cloth layer 113 are all 0.5-1.0mm.

The outer surface of the second non-toxic sponge layer 114 is connected with the inner surface of the first cotton cloth layer 111, the inner surface of the second non-toxic sponge layer 114 is connected with the outer surface of the third non-toxic sponge layer 115, and the inner surface of the third non-toxic sponge layer 115 is connected with the outer surface of the second cotton cloth layer 113; the second cotton layer 113 is a ground cotton layer.

The cup portion 1 further includes a first adhesive mesh layer 116, the first adhesive mesh layer 116 being disposed between the second non-toxic sponge layer 114 and the third non-toxic sponge layer 115 and extending into the lower rake 12; the first adhesive mesh layer 116 has a thickness of 200-2500 μm and a mesh density of 20-100 pieces/cm ² 。

The thickness of the first non-toxic sponge layer 112 is 1.5-2.5mm, the thickness of the second non-toxic sponge layer 114 is 9-11mm, and the thickness of the third non-toxic sponge layer 115 is 2.5-3.5mm.

step (1): sequentially stacking the first non-toxic sponge layer 112, the second non-toxic sponge layer 114, the first adhesive net layer 116 and the third non-toxic sponge layer 115, and carrying out hot molding for 220s at the temperature of 195 ℃ under the pressure of 5 atmospheres to obtain a composite layer, wherein the thickness of the composite layer is 10mm;

Step (2): coating the first cotton cloth layer 111 on the outer surface of the composite layer prepared in the step (1), coating the second cotton cloth layer 113 on the inner surface of the composite layer prepared in the step (1), and hot-pressing to prepare the cup part 1;

step (3): and (3) cutting and sewing the cup 11 prepared in the step (2) to prepare the nontoxic sponge bra.

In an equivalent alternative, the pressure of the hot molding can also be 5.5 atmospheres or 6 atmospheres; the temperature of the hot molding can also be 190 ℃ or 200 ℃; the time of the thermal molding may also be 215s or 225s.

Example 2

Referring to fig. 2 and 5, a nontoxic sponge bra comprises a cup portion 1, wherein the cup portion 1 comprises two cup 11 symmetrically arranged and a lower rake 12 surrounding the bottom and the side of the cup 11, each cup 11 comprises a first cotton cloth layer 111, a first nontoxic sponge layer 112, a second nontoxic sponge layer 114, a third nontoxic sponge layer 115 and a second cotton cloth layer 113 which are sequentially connected from outside to inside, and the thicknesses of the first cotton cloth layer 111 and the second cotton cloth layer 113 are all 0.5-1.0mm.

The cup part 1 further comprises a second adhesive net layer 117, and the second adhesive net layer 117 is arranged inside the lower part 12; the thickness of the second adhesive net layer 117 is 200-2500 μm, and the mesh density is 20-100 pieces/cm ² 。

step (1): sequentially stacking a first nontoxic sponge layer 112, a second nontoxic sponge layer 114, a second adhesive net layer 117 and a third nontoxic sponge layer 115, wherein the second adhesive net layer 117 is placed at the position of the bra lower rake 12, and hot molding is carried out for 220s under the conditions of 5 atmospheres of pressure and 195 ℃ of temperature to prepare a composite layer, and the thickness of the composite layer is 10mm;

Example 3

See fig. 3 and 6, a nontoxic sponge bra, which comprises a cup portion 1, wherein the cup portion 1 comprises two cup 11 symmetrically arranged and a lower rake 12 surrounding the bottom and the side of the cup 11, each cup 11 comprises a first cotton cloth layer 111, a first nontoxic sponge layer 112, a fourth nontoxic sponge layer 118 and a second cotton cloth layer 113 which are sequentially connected from outside to inside, and the thicknesses of the first cotton cloth layer 111 and the second cotton cloth layer 113 are all 0.5-1.0mm.

The outer surface of the fourth nontoxic sponge layer 118 is connected with the inner surface of the first nontoxic sponge layer 112, and the inner surface of the fourth nontoxic sponge layer is connected with the inner surface of the second cotton cloth layer 113; the second cotton layer 113 is a grinding Mao Mianbu layer; the thickness of the first non-toxic sponge layer 112 and the fourth non-toxic sponge layer 118 are both 4.5mm.

The cup 11 further comprises a third glue layer 119, the third glue layer 119 being arranged between the first and fourth non-toxic sponge layers 112, 118; the thickness of the third adhesive net layer 119 is 200-2500 μm, and the mesh density is 20-100 pieces/cm ² 。

step (1): sequentially stacking a first nontoxic sponge layer 112, a third adhesive net layer 119 and a fourth nontoxic sponge layer 118, wherein the third adhesive net layer 119 is placed at the position of a bra cup 11 of the bra, and hot molding is carried out for 140s at the temperature of 189 ℃ under the pressure of 4.5 atmospheres to prepare a composite layer, and the thickness of the composite layer is 7mm;

In an equivalent alternative, the pressure of the hot molding can also be 4 atmospheres or 5 atmospheres; the temperature of the hot molding can also be 188 ℃ or 190 ℃; the time of the hot molding may be 130s or 150s.

Example 4

The outer surface of the fourth nontoxic sponge layer 118 is connected with the inner surface of the first nontoxic sponge layer 112, and the inner surface of the fourth nontoxic sponge layer is connected with the inner surface of the second cotton cloth layer 113; the rear of the first nontoxic sponge layer 112 is 5mm, and the thickness of the fourth nontoxic sponge layer 118 is 7mm; the second cotton layer 113 is a ground cotton layer.

step (1): sequentially stacking a first nontoxic sponge layer 112, a third adhesive net layer 119 and a fourth nontoxic sponge layer 118, wherein the third adhesive net layer 119 is placed at the position of a bra cup 11 of the bra, and hot molding is carried out for 110-130s under the conditions that the pressure is 5 atmospheres and the temperature is 200 ℃ to prepare a composite layer, and the thickness of the composite layer is 5-7mm;

In an equivalent alternative, the pressure of the hot molding can also be 5.5 atmospheres or 6 atmospheres; the temperature of the hot molding can also be 195 ℃ or 205 ℃; the time of the hot molding may also be 110s or 130s.

Example 5

See fig. 3 and 7, a nontoxic sponge bra, which comprises a cup portion 1, wherein the cup portion 1 comprises two cup 11 symmetrically arranged and a lower rake 12 surrounding the bottom and the side of the cup 11, each cup 11 comprises a first cotton cloth layer 111, a fourth adhesive net layer 110, a first nontoxic sponge layer 112 and a second cotton cloth layer 113 which are sequentially connected from outside to inside, and the thicknesses of the first cotton cloth layer 111 and the second cotton cloth layer 113 are all 0.5-1.0mm.

The outer surface of the fourth adhesive mesh layer 110 is connected with the inner surface of the first cotton cloth layer 111, and the inner surface of the fourth adhesive mesh layer 110 is connected with the first nontoxic sponge layer 112 are connected with the outer surface of the shell; the fourth adhesive mesh layer 110 has a thickness of 200-2500 μm and a mesh density of 20-100 pieces/cm ² 。

The thickness of the first non-toxic sponge layer 112 is 4-6mm.

step (1): sequentially stacking a fourth adhesive net layer 110 and a first sterile sponge layer 112, wherein the fourth adhesive net layer 110 is placed at the position of a cup 11 of the bra, and hot molding is carried out for 120s under the conditions of 5 atmospheres and the temperature of 195 ℃ to prepare a composite layer, and the thickness of the composite layer is 6mm;

In an equivalent alternative, the pressure of the hot molding can also be 5.5 atmospheres or 6 atmospheres; the temperature of the hot molding can also be 190 ℃ or 200 ℃; the time of the hot molding may also be 110s or 130s.

Example 6

The outer surface of the fourth adhesive mesh layer 110 is connected with the inner surface of the first cotton cloth layer 111, and the inner surface of the fourth adhesive mesh layer 110 is connected with the outer surface of the first nontoxic sponge layer 112; the fourth adhesive mesh layer 110 has a thickness of 200-2500 μm and a mesh density of 20-100 pieces/cm ² 。

The thickness of the first non-toxic sponge layer 112 is 7-9mm.

step (1): sequentially stacking a fourth adhesive net layer 110 and a first sterile sponge layer 112, wherein the fourth adhesive net layer 110 is placed at the position of a cup 11 of the bra, and hot molding is carried out for 120s under the conditions of 5 atmospheres and the temperature of 195 ℃ to prepare a composite layer, and the thickness of the composite layer is 8mm;

Example 7

This embodiment differs from embodiment 1 described above in that:

the first non-toxic sponge layer 112 is made of plant fibers, and the plant fibers comprise the following raw materials in parts by weight:

The polylactic acid is prepared by fermenting corn through microorganisms, and comprises the following specific steps:

step (1): crushing corn stalks and corn stems to obtain corn raw materials, adding distilled water and a culture solution, and controlling the mixing ratio of the corn raw materials, the distilled water and the culture solution to be 1:1.5:0.4, preparing a corn mixed material;

step (2): taking rhizopus oryzae spores, adding distilled water, and controlling the feed liquid ratio to be 1:2, preparing rhizopus oryzae spore suspension;

step (3): fixing the rhizopus oryzae spore suspension prepared in the step (2) on an immobilization carrier to obtain immobilized rhizopus oryzae seeds; adding the immobilized rhizopus oryzae seeds into the corn mixed material prepared in the step (1), adding a fermentation culture material, controlling the mixing ratio of the immobilized rhizopus oryzae seeds, the corn mixed material and the fermentation culture material to be 1:15:2 by weight, carrying out immobilized fermentation, and fermenting for 5 days at 25 ℃ to prepare a fermentation product containing lactate;

step (4): adding sulfuric acid with the mass fraction of 15% into the lactate-containing fermented product prepared in the step (3), controlling the mixing ratio of the sulfuric acid and the lactate-containing fermented product to be 1:70 by weight, stirring for 30min at 55 ℃, and filtering to obtain a mixed solution containing lactic acid;

Step (5): heating the mixed solution containing lactic acid prepared in the step (4) to 65 ℃, and then adding 70% ethanol by mass percent, wherein the mixing ratio of the ethanol to the mixed solution containing lactic acid by weight is controlled to be 2:50, stirring and reacting for 30min, evaporating at 80 ℃ to remove ethanol, heating to 105 ℃ to evaporate to remove water, and finally evaporating and purifying at 160 ℃ to obtain ethyl lactate;

step (6): and (3) adding dibutyl tin dilaurate into the ethyl lactate prepared in the step (5), stirring for 70min at 155 ℃, cooling to 40 ℃, adding beta-glucosidase, stirring for 20-40min, heating to 105 ℃, preserving heat for 12min, and cooling to obtain the polylactic acid.

The inorganic filler comprises 5 parts of mica powder, 1 part of calcium carbonate and 2 parts of cordierite powder; the antistatic agent is a mixture composed of polyoxyethylene alkylamide, alkyl dicarboxymethylammonium acetolide and alkyl bis (alpha-hydroxyethyl amine phosphate) in a weight ratio of 2:1:1; the surfactant is a mixture composed of fatty acid polyoxyethylene ester and alkylphenol polyoxyethylene ether in a weight ratio of 3:1.

The coupling agent is a mixture composed of vinyl triethoxysilane, aniline methyl triethoxysilane and pyrophosphite titanate in a weight ratio of 1:1:2.5; the solvent is prepared from ethanol and water in a weight ratio of 1: 2.5.

In an equivalent alternative, the above plant fibers are also used to make the second, third and fourth non-toxic sponge layers 114, 115 and 118 of the present invention, and are applicable to the first, second, third and fourth non-toxic sponge layers 112, 114, 115 and 118 mentioned in examples 1-6 above.

Example 8

This embodiment differs from embodiment 1 described above in that:

the antistatic agent is a mixture composed of polyoxyethylene alkylamide, alkyl dicarboxymethylammonium acetolide and alkyl bis (alpha-hydroxyethyl amine phosphate) in a weight ratio of 2:1:1.8; the antioxidant is a mixture of beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) octadecyl propionate and tris (nonylphenyl) phosphite in a weight ratio of 2:1; the surfactant is a mixture composed of fatty acid polyoxyethylene ester and alkylphenol polyoxyethylene ether in a weight ratio of 3:1.

The coupling agent is vinyl triethoxysilane or/and aniline methyl triethoxysilane; the solvent is prepared from ethanol and water in a weight ratio of 1:2, and a mixture of the same.

step (1): crushing corn stalks and corn stems to obtain corn raw materials, adding distilled water and a culture solution, and controlling the mixing ratio of the corn raw materials, the distilled water and the culture solution to be 1:2:0.8, preparing a corn mixed material;

step (2): taking rhizopus oryzae spores, adding distilled water, and controlling the feed liquid ratio to be 1:4, preparing rhizopus oryzae spore suspension;

step (3): fixing the rhizopus oryzae spore suspension prepared in the step (2) on an immobilization carrier to obtain immobilized rhizopus oryzae seeds; adding the immobilized rhizopus oryzae seeds into the corn mixed material prepared in the step (1), adding a fermentation culture material, controlling the mixing ratio of the immobilized rhizopus oryzae seeds, the corn mixed material and the fermentation culture material to be 1:16:2.5 by weight, carrying out immobilized fermentation, and fermenting for 4 days at 32 ℃ to prepare a fermentation product containing lactate;

step (4): adding 18% sulfuric acid into the lactate-containing fermented product prepared in the step (3), controlling the mixing ratio of the sulfuric acid to the lactate-containing fermented product to be 1:80 in parts by weight, stirring at 58 ℃ for 25min, and filtering to obtain a mixed solution containing lactic acid;

Step (5): heating the mixed solution containing lactic acid prepared in the step (4) to 70 ℃, then adding 73% ethanol by mass, and controlling the mixing ratio of the ethanol and the mixed solution containing lactic acid to be 2.3 by weight: 55, stirring and reacting for 35min, evaporating at 87 ℃ to remove ethanol, heating to 110 ℃ to evaporate to remove water, and finally evaporating and purifying at 163 ℃ to obtain ethyl lactate;

step (6): and (3) adding dibutyl tin dilaurate into the ethyl lactate prepared in the step (5), stirring for 60min at 160 ℃, then cooling to 50 ℃, adding beta-glucosidase, stirring for 30min, finally heating to 108 ℃, preserving heat for 11min, and cooling to obtain the polylactic acid.

The inorganic filler comprises 5.5 parts of mica powder, 1.5 parts of calcium carbonate and 2.5 parts of cordierite powder; the antistatic agent is a mixture composed of polyoxyethylene alkylamide, alkyl dicarboxymethylammonium acetolide and alkyl bis (alpha-hydroxyethyl amine phosphate) in a weight ratio of 2.5:1.3:1; the surfactant is a mixture composed of fatty acid polyoxyethylene ester and alkylphenol polyoxyethylene ether in a weight ratio of 3.5:1.

The coupling agent is a mixture composed of vinyl triethoxysilane, aniline methyl triethoxysilane and pyrophosphite titanate in a weight ratio of 1.5:1:3; the solvent is prepared from ethanol and water in a weight ratio of 1: 3.

Example 9

This embodiment differs from embodiment 1 described above in that:

step (1): crushing corn stalks and corn stems to obtain corn raw materials, adding distilled water and a culture solution, and controlling the mixing ratio of the corn raw materials, the distilled water and the culture solution to be 1:2.5:1.2, preparing a corn mixed material;

step (2): taking rhizopus oryzae spores, adding distilled water, and controlling the feed liquid ratio to be 1:6, preparing rhizopus oryzae spore suspension;

step (3): fixing the rhizopus oryzae spore suspension prepared in the step (2) on an immobilization carrier to obtain immobilized rhizopus oryzae seeds; adding the immobilized rhizopus oryzae seeds into the corn mixed material prepared in the step (1), adding a fermentation culture material, controlling the mixing ratio of the immobilized rhizopus oryzae seeds to the corn mixed material to be 1:18:3 by weight, carrying out immobilized fermentation, and fermenting for 3 days at 40 ℃ to prepare a fermentation product containing lactate;

Step (4): adding sulfuric acid with the mass fraction of 20% into the lactate-containing fermented product prepared in the step (3), controlling the mixing ratio of the sulfuric acid and the lactate-containing fermented product to be 1:90 by weight, stirring for 20min at 60 ℃, and filtering to obtain a mixed solution containing lactic acid;

step (5): heating the mixed solution containing lactic acid prepared in the step (4) to 75 ℃, then adding ethanol with the mass fraction of 75%, and controlling the mixing ratio of the ethanol and the mixed solution containing lactic acid to be 2.5 in parts by weight: 60, stirring and reacting for 40min, evaporating at 95 ℃ to remove ethanol, heating to 115 ℃ to evaporate to remove water, and finally evaporating and purifying at 165 ℃ to obtain ethyl lactate;

step (6): and (3) adding dibutyl tin dilaurate into the ethyl lactate prepared in the step (5), stirring for 50min at 165 ℃, then cooling to 60 ℃, adding beta-glucosidase, stirring for 40min, finally heating to 110 ℃, preserving heat for 10-min, and cooling to obtain the polylactic acid.

The inorganic filler comprises 6 parts of mica powder, 2 parts of calcium carbonate and 3 parts of cordierite powder; the antistatic agent is a mixture composed of polyoxyethylene alkylamide, alkyl dicarboxymethylammonium acetolide and alkyl bis (alpha-hydroxyethyl amine phosphate) in a weight ratio of 3:1.5:1; the surfactant is a mixture composed of fatty acid polyoxyethylene ester and alkylphenol polyoxyethylene ether in a weight ratio of 4:1.

The coupling agent is a mixture composed of vinyl triethoxysilane, aniline methyl triethoxysilane and pyrophosphite titanate in a weight ratio of 2:1:3.5; the solvent is prepared from ethanol and water in a weight ratio of 1: 3.5.

Comparative example 1

This comparative example differs from example 1 described above in that:

the utility model provides a sponge brassiere, includes cup portion 1, cup portion 1 includes two cup 11 that the symmetry set up, surrounds in the lower of cup 11 bottom and lateral part takes off 12, every cup 11 includes from outside to interior first cotton cloth layer 111, first sponge layer, second sponge layer, third sponge layer and second cotton cloth layer 113 that connect gradually, the thickness of first cotton cloth layer 111 and second cotton cloth layer 113 is 0.5-1.0mm.

Similarly, the bras of examples 2-6 all use commercially available sponge materials, rather than the nontoxic sponge materials of the present invention.

Comparative example 2

This comparative example differs from example 7 above in that:

the corn fiber is prepared from polylactic acid master batches sold in the market, such as REVODE101 type polylactic acid sold by Hai Zheng Biol.

The nontoxic sponge bras prepared in the above examples 1 to 6 and the sponge bras prepared in comparative example 1 were subjected to the tests for properties such as breathability, softness, supportability, water resistance and the like, and the test methods and results are as follows:

(1) Air permeability test

The testing method comprises the following steps: the inner side of the cotton cup is downwards, steam is continuously sprayed to the inner side of the cotton cup (the temperature of the steam at the inner side of the cotton cup is 115 ℃), the speed of water vapor or water drops penetrating out of the outer side of the cotton cup is observed, and the temperature of the steam at the outer side of the cotton cup is measured.

(2) Softness test

The testing method comprises the following steps: the cotton cups prepared in examples 2-6 and comparative examples 1-2 were tested for softness using an M508 swing fabric softness tester, the cotton cups were clamped to a sample clamp in the tester that had a sample bar that was capable of swinging sufficiently, the sample was bent by increasing the pendulum load that resisted swinging of the sample bar until the sample left the pendulum, and the force used when the sample left the pendulum was measured.

(3) Support test

The testing method comprises the following steps: the cups prepared in examples 2 to 6 and comparative examples 1 to 2 were tested for supportability by using an LLY-01 electronic stiffness meter, and flexural modulus at flexural deformation was tested by using the longitudinal line of the cups as a cantilever.

(4) Test of Water washing resistance

The testing method comprises the following steps: soaking cotton cup in 35-40deg.C warm water for 20-30min, adding 7.5-8.5 pH liquid, washing for 10-15min, and naturally air drying to obtain a machine washing process; and repeatedly carrying out the machine washing process for 20-60 times on the cotton cup, and then checking the deformation condition of the cotton cup after washing for multiple times.

(5) Test results

From the data, the nontoxic sponge bras prepared in examples 1-6 can clearly see that water vapor rapidly escapes from the outer side of the cotton cup, and the temperature difference is less than 8 ℃, so that the nontoxic sponge bras in examples 1-6 have good air permeability, do not generate smoldering feel when being worn at the body temperature, and are breathable and comfortable; the steam temperature at two sides of the cotton cup of the sponge bra prepared in the comparative example 1 is 18 ℃, which indicates that the sponge bra prepared in the comparative example 1 has relatively weak air permeability and is easy to generate stuffy feel after being worn for a long time, and further indicates that the nontoxic sponge bra prepared by the plant fiber of the invention has stable structure of ventilation micropores in the nontoxic sponge bra, high air permeability and wearing comfort.

The plant fibers prepared in examples 7 to 9 and comparative example 2 were subjected to tests for properties such as fiber strength, elongation at break, breaking strength, abrasion resistance, boiling water shrinkage and the like, and the test methods and results are shown below:

(1) Abrasion resistance test

The fibers are held in a fixture on a fixed support and mounted to a disk of test material. The other end of the fiber was suspended with an 8g weight, the disc was rotated at 75m/min, the portion of the fiber yarn in contact with the disc was abraded and the surface was continuously abraded until the fiber was abraded to break, and the time from the start of abrasion to break of the fiber was recorded.

(2) Shrinkage in boiling water

Boiling the fiber in boiling water for 30min, testing the length of the fiber before and after boiling water treatment, and calculating to obtain the boiling water shrinkage.

From the data, the plant fibers prepared in examples 7-9 have the advantages of better fiber strength, elongation at break, breaking strength, wear resistance and the like, and the shrinkage rate of boiling water is low, and the shrinkage phenomenon of the fibers after the treatment of boiling water is not obvious, so that the plant fibers have the advantages of high strength, good stability, difficult breaking and shrinkage, and capability of ensuring that the prepared nontoxic sponge material has better air permeability and stability and is difficult to deform or damage after repeated machine washing.

Compared with the example 7, the comparative example 2 adopts the common commercial polylactic acid raw material, the prepared fiber strength is obviously lower, the breaking elongation, breaking strength and wear resistance are also obviously reduced, the boiling water shrinkage rate is higher, the fiber is easy to break and damage after the boiling water treatment, further shows that the plant fiber prepared by adopting the polylactic acid disclosed by the invention can effectively improve the mechanical strength and stability of the plant fiber, has strong hydrolysis resistance, is not easy to break or shrink after the boiling water treatment, and further ensures that the prepared nontoxic sponge material has better air permeability and stability and is not easy to deform or damage after repeated machine washing.

The above embodiments are preferred embodiments of the present invention, and besides, the present invention may be implemented in other ways, and any obvious substitution is within the scope of the present invention without departing from the concept of the present invention.

Claims

1. The utility model provides a nontoxic sponge brassiere, includes cup portion, cup portion is including two cups of symmetry setting, enclose in cup bottom and lateral part's lower taking off, its characterized in that: each cup comprises a first cotton cloth layer, a first non-toxic sponge layer and a second cotton cloth layer which are sequentially connected from outside to inside, wherein the thickness of each of the first cotton cloth layer and the second cotton cloth layer is 0.5-1.0mm;

The cup further comprises a second non-toxic sponge layer and a third non-toxic sponge layer, the outer surface of the second non-toxic sponge layer is connected with the inner surface of the first non-toxic sponge layer, the inner surface of the second non-toxic sponge layer is connected with the outer surface of the third non-toxic sponge layer, and the inner surface of the third non-toxic sponge layer is connected with the outer surface of the second cotton cloth layer;

the first non-toxic sponge layer is made of plant fibers, and the plant fibers comprise the following raw materials in parts by weight:

40-60 parts of polylactic acid

10-15 parts of inorganic filler

1-3 parts of antistatic agent

0.8-1.2 parts of surfactant

2-3 parts of coupling agent

0.3 to 0.8 part of silicone oil

30-50 parts of solvent.

2. A non-toxic sponge bra as claimed in claim 1 wherein: the second cotton cloth layer is a frosted cotton cloth layer.

3. A non-toxic sponge bra as claimed in claim 1 wherein: the cup part further comprises a first glue net layer, wherein the first glue net layer is arranged between the second non-toxic sponge layer and the third non-toxic sponge layer and extends to the inside of the lower part; the thickness of the first adhesive net layer is 200-2500 μm, and the mesh density is 20-100 pieces/cm ² 。

4. According to claimThe nontoxic sponge bra of claim 1, wherein the bra is characterized in that: the cup part further comprises a second adhesive net layer, and the second adhesive net layer is arranged in the lower part; the thickness of the second adhesive net layer is 200-2500 μm, and the mesh density is 20-100 pieces/cm ² 。

5. A non-toxic sponge bra as claimed in claim 2 wherein: the thickness of the first nontoxic sponge layer is 1.5-2.5mm, the thickness of the second nontoxic sponge layer is 9-11mm, and the thickness of the third nontoxic sponge layer is 2.5-3.5mm.

6. A non-toxic sponge bra as claimed in claim 1 wherein: the cup further comprises a fourth nontoxic sponge layer, the outer surface of the fourth nontoxic sponge layer is connected with the inner surface of the first nontoxic sponge layer, and the inner surface of the fourth toxic sponge layer is connected with the inner surface of the second cotton cloth layer; the thickness of the first nontoxic sponge layer is 4-6mm, and the thickness of the fourth nontoxic sponge layer is 4-8mm.

7. A non-toxic sponge bra as claimed in claim 6 wherein: the cup further comprises a third glue net layer, and the third glue net layer is arranged between the first nontoxic sponge layer and the fourth nontoxic sponge layer; the thickness of the third adhesive net layer is 200-2500 μm, and the mesh density is 20-100 pieces/cm ² 。

8. A non-toxic sponge bra as claimed in claim 1 wherein: the cup further comprises a fourth adhesive net layer, the outer surface of the fourth adhesive net layer is connected with the inner surface of the first cotton cloth layer, and the inner surface of the fourth adhesive net layer is connected with the outer surface of the first sterile sponge layer; the thickness of the fourth adhesive net layer is 200-2500 μm, and the mesh density is 20-100 pieces/cm ² 。

9. A non-toxic sponge bra as claimed in claim 1 wherein: the polylactic acid is prepared by fermenting corn through microorganisms, and comprises the following specific steps:

step (1): crushing corn stalks and corn stems to obtain corn raw materials, adding distilled water and a culture solution, and controlling the mixing ratio of the corn raw materials, the distilled water and the culture solution to be 1:1.5-2.5:0.4-1.2, and preparing a corn mixed material;

step (2): taking rhizopus oryzae spores, adding distilled water, and controlling the feed liquid ratio to be 1:2-6, preparing rhizopus oryzae spore suspension;

step (3): fixing the rhizopus oryzae spore suspension prepared in the step (2) on an immobilization carrier to obtain immobilized rhizopus oryzae seeds; adding the immobilized rhizopus oryzae seeds into the corn mixed material prepared in the step (1), adding a fermentation culture material, controlling the mixing ratio of the immobilized rhizopus oryzae seeds, the corn mixed material and the fermentation culture material to be 1:15-18:2-3 by weight, carrying out immobilized fermentation, and fermenting for 3-5 days at 25-40 ℃ to prepare a fermentation product containing lactate;

step (4): adding 15-20% sulfuric acid into the lactate-containing fermented product prepared in the step (3), controlling the mixing ratio of the sulfuric acid to the lactate-containing fermented product to be 1:70-90 in parts by weight, stirring for 20-30min at 55-60 ℃, and filtering to obtain a lactic acid-containing mixed solution;

Step (5): heating the mixed solution containing lactic acid prepared in the step (4) to 65-75 ℃, then adding 70-75% ethanol by mass percent, and controlling the mixing ratio of the ethanol and the mixed solution containing lactic acid to be 2-2.5 by weight: 50-60, stirring and reacting for 30-40min, evaporating at 80-95deg.C to remove ethanol, heating to 105-115deg.C to evaporate and remove water, and evaporating and purifying at 160-165 deg.C to obtain ethyl lactate;

step (6): adding dibutyl tin dilaurate into the ethyl lactate prepared in the step (5), stirring for 50-70min at 155-165 ℃, cooling to 40-60 ℃, adding beta-glucosidase, stirring for 20-40min, heating to 105-110 ℃, preserving heat for 10-12min, and cooling to obtain polylactic acid.