阅读说明：本技术 干爽无纺布 (Dry and comfortable non-woven fabric ) 是由 吴晓彪 翁文伟 王伟 于 2021-08-30 设计创作，主要内容包括：本发明公开一种干爽无纺布。所述的无纺布由吸湿纤维制成,所述的吸湿纤维包括皮层和芯层；其中,皮层为聚乙烯和温敏材料；芯层为超吸水树脂或吸水纤维。其中,所述的温敏材料的微孔在33℃以上时处于打开状态；所述的温敏材料在33℃时以下时微孔处于关闭状态。本发明在温度低于33℃时,N-异丙基丙烯酰胺类聚合物发生伸长而将微孔堵住；能较少的吸取空气中的水分。而在33℃以上N-异丙基丙烯酰胺类聚合物发生收缩而将微孔打开,产生的微孔只允许水蒸汽透过,不允许水分子透过,从而避免芯层中的超吸水树脂被尿液所饱和,但能够吸收水蒸汽。有利于芯层的吸水纤维吸取纸尿裤所包围区域的水分,以保持纸尿裤的表面干爽。(The invention discloses a dry and comfortable non-woven fabric. The non-woven fabric is made of moisture absorption fibers, and the moisture absorption fibers comprise a skin layer and a core layer; wherein, the skin layer is made of polyethylene and temperature-sensitive materials; the core layer is made of super absorbent resin or absorbent fiber. Wherein, the micropores of the temperature sensitive material are in an open state at the temperature of more than 33 ℃; the temperature sensitive material is in a closed state when the temperature is below 33 ℃. When the temperature is lower than 33 ℃, the N-isopropyl acrylamide polymer extends to block micropores; can absorb less moisture in the air. And the N-isopropyl acrylamide polymer shrinks at the temperature of more than 33 ℃ to open the micropores, and the generated micropores only allow water vapor to permeate but not allow water molecules to permeate, so that the super absorbent resin in the core layer is prevented from being saturated by urine, but can absorb the water vapor. The water absorption fibers of the core layer can absorb the water in the area surrounded by the paper diaper, so that the surface of the paper diaper is kept dry.)

1. The dry non-woven fabric is characterized in that the non-woven fabric is made of moisture absorption fibers, and the moisture absorption fibers comprise a skin layer and a core layer; the skin layer is prepared from polyethylene, pore-forming materials and temperature-sensitive materials; the core layer is made of super absorbent resin or absorbent fibers;

wherein the micropores of the skin layer are in an open state at a temperature of above 33 ℃; the micropores of the skin layer are closed at a temperature below 33 ℃.

2. The dry nonwoven fabric of claim 1,

the skin layer contains a toughening agent: styrene-butadiene thermoplastic elastomers, methylmethacrylate-butadiene-styrene terpolymers and/or acrylonitrile-butadiene-styrene copolymers.

3. The dry nonwoven fabric of claim 1 wherein the water-absorbent fibers are in a spiral shape and the pitch of the water-absorbent fibers is not less than the diameter of the thread.

4. The dry nonwoven fabric of claim 1 wherein the pore former is a zinc oxide antimicrobial agent.

5. The dry nonwoven fabric of claim 1 wherein said absorbent fibers are prepared by the process of:

70-90 parts of polyethylene, 0.5-3 parts of toughening agent, 1-5 parts of fluorine-containing acrylate resin, 0.5-3 parts of N-isopropyl acrylamide polymer and 10-30 parts of zinc oxide are mixed with 50-150 parts of core layer super absorbent resin material to prepare the moisture absorption fiber through spinning.

Technical Field

The invention relates to a dry and comfortable non-woven fabric.

Background

The surface layer non-woven fabric of the prior paper diaper can control the back permeation of liquid to a very low level, but cannot realize the treatment capacity of gaseous water. The liquid water stored in the absorption core body is evaporated into gaseous water under the action of heat, so that the skin is in a sultry environment, the water content of the skin cuticle is overhigh, and the skin is easily damaged to generate diaper rash.

Disclosure of Invention

In order to overcome the defects, the invention aims to provide the non-woven fabric with the capability of treating the gaseous water, so that the humidity in the microenvironment of the skin and the paper diaper is reduced, and the dryness of the skin is kept.

In order to achieve the aim, the dry and comfortable non-woven fabric is made of moisture absorption fibers, and the moisture absorption fibers comprise a skin layer and a core layer; wherein, the cortex layer is a microporous temperature-sensitive material;

the core layer is made of super absorbent resin or absorbent fiber. Wherein, the micropores of the temperature sensitive material are in an open state at the temperature of more than 33 ℃; the temperature sensitive material is in a closed state when the temperature is below 33 ℃.

Further, the skin layer contains a toughening agent: styrene-butadiene thermoplastic elastomers, methylmethacrylate-butadiene-styrene terpolymers and/or acrylonitrile-butadiene-styrene copolymers. The toughness of the skin layer is improved, the skin layer macrocracks caused by the expansion of the core layer are prevented, and the protective effect of the skin layer on the core layer is damaged.

Furthermore, the water-absorbing fiber is spiral, and the pitch of the water-absorbing fiber is larger than or equal to the diameter of the wire.

Furthermore, the microporous temperature-sensitive material adopts a zinc oxide antibacterial agent as a pore-forming material.

Further, the moisture absorption fiber is prepared by adopting the following process:

70-90 parts of polyethylene, 0.5-3 parts of toughening agent, 1-5 parts of fluorine-containing acrylate resin, 0.5-3 parts of N-isopropyl acrylamide polymer and 10-30 parts of zinc oxide are mixed with 50-150 parts of super-absorbent resin material of the core layer material to prepare the moisture absorption fiber through spinning. The skin layer is added with fluorine-containing acrylate resin. The surface energy of the skin layer is low, the core layer can be automatically spread and coated, the surface energy of the system is reduced, and the core layer at the bonding position is prevented from being exposed when the fibers are bonded by hot air/hot rolling.

In order to achieve the aim, the dry and comfortable non-woven fabric is a pure cotton non-woven fabric doped with 0.5-30% of moisture absorption fibers, and the moisture absorption fibers comprise a skin layer and a core layer; the skin layer is made of polyethylene, pore-forming material and temperature-sensitive material; the core layer is made of super absorbent resin or absorbent fiber; wherein, the micropores of the temperature sensitive material are in an open state at the temperature of more than 33 ℃; the micropores of the temperature-sensitive material are in a closed state at the temperature of below 33 ℃;

the dry and comfortable pure cotton non-woven fabric is prepared by the following steps:

1) preparing an after-finishing agent;

2) adopting the prepared after finishing agent to dip and prick the spunlace pure cotton non-woven fabric;

3) ionizing radiation grafting the soaked spunlace pure cotton non-woven fabric;

4) drying;

wherein the molecular formula of the after-finishing agent is as follows:

wherein R1 and R2 are higher fatty alcohol methacrylate ester or H, and the ester is cetyl ester or stearyl ester.

In order to achieve the purpose, the surface layer of the sanitary product is made of the dry and comfortable non-woven fabric.

Furthermore, the hygienic product also comprises an absorption core body, wherein the absorption core body is prepared by spraying an acrylate foaming material prepared by a high internal phase emulsion method on a working table; the acrylic ester foaming material is formed by mixing a first raw material and a second raw material; the absorption core body is formed by spraying and stacking a spray head with the same width as the absorption core body layer by layer in the depth direction;

wherein, the proportion of the first raw material and the second raw material in the sprayed acrylic ester foam material is continuously adjusted, so that the pore diameter of each layer of the absorption core body is gradually reduced from the middle to two sides in the length direction; and increasing the vacuum degree provided by the working table surface layer by layer in the spraying process so as to gradually reduce the pore diameter of the foam pores of the absorption core body in the depth direction from bottom to top or from top to bottom.

The invention utilizes the separation of the skin zinc oxide and the polyethylene substrate part when preparing the skin-core structure fiber and drafting to generate micropores. But when the temperature is lower than 33 ℃, the N-isopropyl acrylamide polymer extends to block micropores; can absorb less moisture in the air. And the N-isopropyl acrylamide polymer shrinks at the temperature of more than 33 ℃ to open the micropores, and the generated micropores only allow water vapor to permeate but not allow water molecules to permeate, so that the super absorbent resin in the core layer is prevented from being saturated by urine, but can absorb the water vapor. The water absorption fibers of the core layer can absorb the water in the area surrounded by the paper diaper, so that the surface of the paper diaper is kept dry.

Detailed Description

The invention aims to provide a dry and comfortable non-woven fabric, which is made of moisture absorption fibers, wherein the moisture absorption fibers comprise a skin layer and a core layer; wherein, the cortex layer is a microporous temperature-sensitive material;

the core layer is made of super absorbent resin or absorbent fiber. Wherein, the micropores of the temperature sensitive material are in an open state at the temperature of more than 33 ℃; the temperature sensitive material is in a closed state when the temperature is below 33 ℃.

Specifically, 70-90 parts of polyethylene, 0.5-3 parts of toughening agent, 1-5 parts of fluorine-containing acrylate resin, 0.5-3 parts of N-isopropyl acrylamide polymer and 10-30 parts of zinc oxide are mixed with 50-150 parts of super-absorbent resin material of the core layer material to prepare the moisture absorption fiber through spinning.

The fluorine-containing acrylate resin is added into the skin layer, so that the skin layer has low surface energy, and the core layer is automatically spread and coated, so that the surface energy of a system is reduced, and the core layer is prevented from being exposed at a bonding position when fibers are bonded by hot air/hot rolling. The core layer is made of super absorbent resin and has high moisture absorption effect. The core layer is hollow and is designed with a reserved expansion space; the core layer can be spiral, and the pitch of the water-absorbing fiber is larger than or equal to the diameter of the wire, so that more expansion spaces are reserved.

As a further improvement of the embodiment, the microporous temperature-sensitive material adopts a zinc oxide antibacterial agent as a pore-forming material, so that the antibacterial effect of the surface of the non-woven fabric can be increased.

As a further improvement of the above embodiment, the skin layer comprises a toughening agent: styrene-butadiene thermoplastic elastomers, methylmethacrylate-butadiene-styrene terpolymers and/or acrylonitrile-butadiene-styrene copolymers. Therefore, the toughness of the skin layer can be improved, the skin layer macrocracks caused by the expansion of the core layer are prevented, and the protective effect of the skin layer on the core layer is damaged.

As a further improvement of the embodiment, the water-absorbing fiber is in a spiral shape, the thread pitch of the water-absorbing fiber is larger than or equal to the thread diameter, the process is that the water-absorbing fiber reserves an expansion space, and the production process is simpler.

The above embodiments can be applied to various types of diapers, sanitary napkins and the like, for example, the surface layer of the diaper is made of the above dry non-woven fabric.

Water absorption rate test 1

Placing the non-woven fabric in a constant temperature and humidity box with the concentration of 80 RH% for 1h under different temperature conditions, centrifuging for 10min under the centrifugal force of 250g, and testing the water absorption multiplying power.

Water absorption rate

Temperature/. degree.C	24	26	28	30	32	33	34	36	37
										Water absorption Rate/%	4	4	4	8	30	190	220	230	230

Water absorption multiplying power test 2

Soaking the non-woven fabric in deionized water at 37 ℃ for 1h, centrifuging for 10min under the centrifugal force of 250g, and testing the water absorption rate. The nonwoven fabric was placed in a constant temperature and humidity chamber at 37 ℃ and 80 RH% for 1 hour, centrifuged at 250g for 10min, and the water absorption rate was measured.

Water absorption multiplying power test III

The nonwoven fabric was placed in a 37 ℃ 80 RH% constant temperature and humidity cabinet for 1 hour, and then in a 37 ℃ 20 RH% constant temperature and humidity cabinet for 4 hours. And then testing according to the second testing method.

Water absorption multiplying power test four

A constant-temperature doll (37 ℃) is adopted to wear the paper diaper, 80mL of artificial urine at 37 ℃ is injected after 30min, and the skin humidity and the temperature between the doll skin and the paper diaper are tested after 60 min.

And (3) testing environment: temperature (23 + -2 deg.C), humidity (50 + -5) RH%

	Temperature/. degree.C	humidity/RH%
			Conventional paper diaper	35.0	90
Example paper diaper	33.5	60

Production of diapers

The surface layer non-woven fabric, the waistline non-woven fabric and the basement membrane non-woven fabric of the paper diaper are all made by the same process, and only the hydrophilic and water repellent treatment modes are different. And bonding the surface layer non-woven fabric, the waist line non-woven fabric and the bottom film non-woven fabric together by adopting an ultrasonic or thermal bonding mode. Because the humidity in basement membrane non-woven fabrics and the waistline non-woven fabrics outside is lower, the non-woven fabrics waist of surface course non-woven fabrics turns the non-woven moisture that by inboard absorption can transmit basement membrane non-woven fabrics and waistline non-woven fabrics to release in the atmosphere, thereby avoid absorbing the problem appearance of saturation.

In order to adapt to different requirements, the dry and comfortable non-woven fabric is prepared by doping 0.5-30% of moisture absorption fiber in the preparation process of pure cotton non-woven fabric, and the moisture absorption fiber comprises a skin layer and a core layer; wherein, the skin layer is made of polyethylene, pore-forming material and temperature-sensitive material;

the core layer is made of super absorbent resin or absorbent fiber. Wherein, the micropores of the temperature sensitive material are in an open state at the temperature of more than 33 ℃; the micropores of the temperature-sensitive material are in a closed state at the temperature of below 33 ℃;

the dry and comfortable pure cotton non-woven fabric is prepared by the following steps:

1) preparing an after-finishing agent;

2) adopting the prepared after finishing agent to dip and prick the spunlace pure cotton non-woven fabric;

3) ionizing radiation grafting the soaked spunlace pure cotton non-woven fabric;

4) drying;

wherein the molecular formula of the after-finishing agent is as follows:

wherein R1 and R2 are higher fatty alcohol methacrylate ester or H, and the ester is cetyl ester or stearyl ester.

The after-finishing agent is prepared by adding trihydroxyethyl ethane, higher fatty alcohol methacrylate and fatty alcohol-polyoxyethylene ether into a composite emulsifying system consisting of water, hexadecyl trimethyl ammonium bromide and tween 80, introducing nitrogen for protection, stirring at a constant temperature of 60-80 ℃, and adding an initiator (azodiisobutyronitrile and persulfate composite initiation system) to prepare the emulsion containing the system with the structural formula, wherein the emulsion contains polyalcohol, higher fatty alcohol methacrylate water repellent groups and polyoxyethylene ether hydrophilic groups.

Examples

1) Preparing an after-finishing agent;

adding 5 parts of trihydroxyethyl ethane, 5 parts of higher fatty alcohol methacrylate and 5 parts of fatty alcohol-polyoxyethylene ether into a composite emulsification system consisting of water, hexadecyl trimethyl ammonium bromide and tween 80, introducing nitrogen for protection, stirring at a constant temperature of 60-80 ℃, and adding an initiator (azodiisobutyronitrile and persulfate composite initiation system) to prepare an emulsion containing polyalcohol, a higher fatty alcohol methacrylate water repellent group and a polyoxyethylene ether hydrophilic group; the structural formula is as follows:

2) placing the pure cotton non-woven fabric doped with 10% of moisture absorption fibers into the prepared after-finishing agent for dipping and binding;

3) ionizing radiation grafting is carried out on the spunlaced pure cotton non-woven fabric after being soaked and bound;

4) drying;

through the treatment, the hydroxyl of the polyhydric alcohol and the cellulose is crosslinked and grafted, the hydroxyl end group is sealed, the hydrophilicity is reduced, and meanwhile, the water repellent group, namely the higher aliphatic acrylate or the siloxane acrylate, forms a net to cover the surface of the cellulose, so that the hydrophilicity of the fiber is further reduced. Meanwhile, the polyoxyethylene ether group realizes the hydrophilic performance of the material and realizes the unification of the infiltration and the rewet of the liquid. Then ionizing radiation is assisted to depolymerize the hydroxyl hydrogen bonds of the cellulose fibers by utilizing the ionizing radiation, so that the structure is loose, and the activity of the cellulose is increased; p-toluenesulfonic acid is used as a catalyst, ionizing radiation is used as an initiating system, and hydroxyl is dehydrated and condensed into ether, so that the finishing agent system is fixed on the cellulose fiber.

The above embodiments can be applied to various types of diapers, sanitary napkins and the like, for example, the surface layer of the diaper is made of the above pure cotton nonwoven fabric.

The invention relates to a hygienic product, which comprises a surface layer and an absorption core body, wherein the surface layer is made of the pure cotton non-woven fabric; the absorption core body is prepared by spraying an acrylic ester foaming material prepared by a high internal phase emulsion method on a working table; the acrylic ester foaming material is formed by mixing a first raw material and a second raw material; the absorption core body is formed by spraying and stacking layer by utilizing a spray head with the same width as the absorption core body in the depth direction;

wherein, the proportion of the first raw material and the second raw material in the sprayed acrylic ester foam material is continuously adjusted, so that the pore diameter of each layer of the absorption core body is gradually reduced from the middle to two sides in the length direction; and increasing the vacuum degree provided by the working table surface layer by layer in the spraying process so as to gradually reduce the pore diameter of the foam pores of the absorption core body in the depth direction from bottom to top or from top to bottom.

The vacuum degree can be provided by a negative pressure fan or a vacuum device.

The spray head is a controlled spray head and is used for continuously adjusting the proportion and the spraying amount of the first raw material and the second raw material in the sprayed acrylic ester foaming material; the controlled spray head and the working platform move relatively to complete the spraying of each layer, the controlled spray head can be fixed, and the working platform moves relatively to the controlled spray head continuously; or the working platform can be fixed, and the controlled spray head continuously moves relative to the working platform. The working platform can be a flat plate type platform and is driven to reciprocate by a reciprocating driving device; or a die wheel, which is driven to rotate by a rotating device to realize relative motion.

In the production process, a system containing a low emulsifier can be mixed with the emulsifier by a double-screw extrusion mode, and the proportion of the emulsifier in the length direction of the high internal phase emulsion can be continuously regulated and controlled by continuously regulating and controlling the mixing proportion of the first raw material and the second raw material; a layer of absorbing core body can be formed on the working table surface by continuously spraying the absorbing core body with a spray head with the same width as the absorbing core body at a constant speed according to a preset proportion value. When the absorption core is stacked layer by layer in the depth direction, the pore diameter of each layer of absorption core body positioned below is larger than the pore diameter of each layer of absorption core body positioned above due to the existence of vacuum provided by the working table; the ratio of the first raw material to the second raw material of the two adjacent layers of absorption cores and/or the vacuum degree corresponding to each layer of absorption core are adjusted, so that the pore diameter above the lower layer of absorption core in the two adjacent layers of absorption cores is the same as (or close to) the pore diameter below the upper layer of absorption core, and the interface between the two layers is eliminated; the pore diameter of the whole absorbing core body is gradually reduced from bottom to top along the depth direction (when in actual use, the pores are large and close to the surface layer of the sanitary product); the absorption core body with the structure between layers manufactured by the method has the following advantages: the pore diameters of the pores on the two sides are small, the capillary action is strong, the liquid can be favorably absorbed towards the two sides, and the utilization rate of the absorption core body on the sanitary articles is improved. The pore diameter of the lower layer of the foam pore is large, so that the foam pore can realize quick liquid infiltration when being used as an upper layer of an absorption core body and has low reverse osmosis; the pore diameter of the lower layer pores is small, so that the liquid can be quickly infiltrated when the lower layer is used as an absorption core body, and the high liquid retention capacity can be realized by utilizing the capillary action.

The raw materials of the acrylic ester foaming material comprise acrylic ester, a cross-linking agent, an initiator, an emulsifier and salt.

Wherein the acrylate is one or two of isooctyl acrylate and isooctyl methacrylate.

The cross-linking agent is ethylene glycol dimethacrylate, the emulsifier is Tween 80, the salt is calcium chloride, and the initiator is an oxidation-reduction initiation system and can be sodium persulfate, potassium persulfate, ammonium persulfate and the like.

The acrylate, the cross-linking agent, the initiator, the emulsifier and the water are emulsified by an emulsifying kettle to obtain stable emulsion as a first raw material. The second raw material is emulsifier Tween 80.

Usually, the amount of the cross-linking agent is 20-65% (wt, mass fraction, the same below) of the amount of the monomer, the amount of the initiator is 0.5-5% of the reactant, the amount of the emulsifier is 4-16% of the reactant, the emulsion concentration, i.e., the ratio of the water phase to the oil phase, is 10: 1-36: 1, and the emulsification temperature is 60-80 ℃.

As a further development of the invention, the absorbent core is produced by spraying on a die wheel: the die wheel is provided with an air vent communicated with vacuum equipment; a layer of polytetrafluoroethylene breathable film is coated on the die wheel corresponding to the air holes; the absorption core body is sprayed on the polytetrafluoroethylene breathable film, so that the finished absorption core body is favorably taken off from the die wheel; the absorbing core body can be sprayed one layer each time the absorbing core body rotates one circle, and a plurality of spray heads can be arranged above the peripheral side of the die wheel, and each spray head is sprayed one layer; in the spraying process of each layer, the vacuum equipment provides vacuum with preset vacuum degree for each absorption core body; thus, the absorption core body can be adsorbed on the die wheel by utilizing vacuum, which is beneficial to production; and adjusting the degree of vacuum as required can affect the thickness of each layer of the absorbent core, the formation of pores, and the like. For example, since the absorption core is sprayed layer by layer, under the condition of a certain vacuum degree, the vacuum has the largest influence on the absorption core in the spraying process of the lowest layer, and the influence is smaller as the absorption core goes upwards; meanwhile, due to the fact that the effects of the fan forces on the air flow in different depth directions are different, the air volume of the emulsion closer to the polytetrafluoroethylene breathable film is larger, the pore size is larger, and the pore size is gradually reduced from bottom to top. By combining with layer-by-layer accumulation, the aperture can be continuously changed in the depth direction and the adjustable range is large.

The embodiment of the preparation method of the sanitary product absorbing core body of the invention comprises the following steps:

the invention discloses a preparation method of an absorption core body of a hygienic product, which comprises the following steps:

the absorption core body is prepared by spraying an acrylic ester foaming material prepared by a high internal phase emulsion method on a working table; the acrylic ester foaming material is formed by mixing a first raw material and a second raw material; the absorption core body is formed by spraying and stacking layer by utilizing a spray head with the same width as the absorption core body in the depth direction;

wherein, the proportion of the first raw material and the second raw material in the sprayed acrylic ester foam material is continuously adjusted, so that the pore diameter of each layer of the absorption core body is gradually reduced from the middle to two sides in the length direction; and increasing the vacuum degree provided by the working table surface layer by layer in the spraying process so as to gradually reduce the pore diameter of the foam pores of the absorption core body in the depth direction from bottom to top or from top to bottom.

The method specifically comprises the following steps:

21) reading a preset value table, wherein the preset value table records the continuous change value of the ratio of the first raw material to the second raw material in each layer of the acrylate foaming material of the absorption core body along the length direction of the core body, the initial spraying amount of the corresponding spray head, the thickness value of each layer of the absorption core body and the vacuum degree of each layer;

22) spraying layer by layer according to a preset value table, and providing a preset vacuum degree through a working table;

23) monitoring whether the thickness of the current-layer absorption core body exceeds a preset threshold value in real time:

if the spraying amount of the next layer of the absorption core body is exceeded, the next layer is sprayed after the spraying amount of the next layer of the absorption core body is proportionally reduced or increased;

if not, spraying the next layer according to the preset spraying amount;

24) whether the current layer is the last layer or not, if not, returning to the step 22);

if the last layer is selected, detecting whether the thickness of the current absorption core body exceeds a preset threshold value;

if the spraying amount of the first layer of spray heads of the next absorption core in the preset value table is exceeded, the spraying amount of the first layer of spray heads of the next absorption core in the preset value table is proportionally reduced or increased, and a new preset value table is formed; returning to step 21);

if not, recording the spraying amount of each spray head of each path of each layer of the current absorption core body to form a new preset value table; return to step 21).

In this embodiment, the thickness of each layer is monitored to achieve product consistency.