A sanitary napkin using a warp knitted absorbent core

Abstract

The invention discloses a sanitary napkin adopting a warp knitted absorption core, comprising an absorption core located between a guide layer and a waterproof bottom film, the upper surface of the guide layer is covered with a surface layer, the absorption core comprises a warp knitted mesh frame, the gaps of the warp knitted mesh frame are filled with SAP particles, the absorption core adopts a woven warp knitted mesh frame, which greatly improves the air permeability of the product, the absorption core will not shift after swelling after absorbing water, the absorption core can completely replace the wood pulp core, and is helpful for forest protection, and the breaking strength of the absorption core exceeds 50N / 15mm, which is much greater than the maximum breaking strength of the wood pulp core, and the problem of breaking after swelling after absorbing water is also avoided. The sanitary napkin adopting the absorption core also has the above advantages.

Description

Technical Field

[0001] The invention relates to a sanitary product, in particular to a sanitary napkin. Background Art

[0002] At present, the absorbent core used in traditional sanitary napkins is mainly a mixture of wood pulp and super absorbent resin (SAP), called wood pulp core. The wood pulp content in the wood pulp core accounts for more than 50%. Wood pulp comes from trees, and trees are increasingly valued and protected as non-renewable materials. At the 2021 United Nations Climate Conference, many countries promised not to cut down forests after 2030, which means that the supply of wood pulp will decrease day by day. Therefore, the industry urgently needs to develop an absorbent core that replaces the wood pulp core to cope with the problem of reduced wood pulp supply.

[0003] In addition, sanitary napkins using wood pulp cores often break and shift after the wood pulp core absorbs water and expands during actual use. Moreover, the air permeability and elasticity of the wood pulp core are also poor after drying and absorbing water. Summary of the invention

[0004] In order to overcome the deficiencies of the prior art, the present invention provides a sanitary napkin using a warp knitted absorbent core that can replace a wood pulp core, improves air permeability, and has good air permeability and elasticity.

[0005] The technical solution adopted by the present invention to solve its technical problem is:

[0006] A sanitary napkin using a warp knitted absorbent core comprises an absorbent core located between a flow guide layer and a waterproof bottom film, wherein the absorbent core weighs 160-300 grams per square meter, the upper surface of the flow guide layer is covered with a surface layer, the absorbent core comprises a warp knitted mesh skeleton, the thickness of the warp knitted mesh skeleton is 1-3 mm, and the weight per square meter is 100-180 grams, and the gaps in the warp knitted mesh skeleton are filled with SAP particles, and the weight of the SAP particles accounts for 25-60% of the weight of the entire absorbent core.

[0007] The warp-knitted mesh skeleton is formed by double-needle bed warp knitting, and comprises an upper surface layer, a lower surface layer and a connecting yarn layer connected between the upper surface layer and the lower surface layer; the upper surface layer is provided with an upper mesh hole, the lower surface layer is provided with a lower mesh hole, the aperture of the upper mesh hole is 1.2-5mm, the aperture of the lower mesh hole is less than 1mm, the aperture of the upper mesh hole is larger than the aperture of the lower mesh hole, so that the connecting yarn layer forms a conical gap with a larger upper part and a smaller lower part at the corresponding part of the upper mesh hole.

[0008] The upper surface layer and the lower surface layer are both formed by warp knitting 50D-200D 12F-72F polyester fibers, and the connecting yarn layer is formed by warp knitting 30D-70D single F polyester fibers.

[0009] The sanitary napkin is a flat sanitary napkin or a trouser-type sanitary napkin, and the sanitary napkin provides three technical solutions for adoption.

[0010] The first technical solution is: the sanitary napkin is a flat sanitary napkin, the surface layer, the guide layer and the two sides of the absorbent core are covered with side non-woven fabrics, the upper side edges of the side non-woven fabrics are bonded to the two side edges of the upper surface of the surface layer, and the lower side edges are bonded to the waterproof bottom film; the waterproof bottom film is provided with a back adhesive layer in the middle, and wing adhesive layers are provided on both sides, the back adhesive layer is affixed with back release paper, and the back adhesive layer is affixed with wing release paper; the upper surface of the absorbent core is covered with an upper covering layer, and the lower surface is covered with a lower covering layer. The covering layer is dust-free paper.

[0011] The second technical solution is: the sanitary napkin is a flat sanitary napkin, and the two sides of the surface layer, the guide layer and the absorbent core are covered with side non-woven fabrics, the upper edges of the side non-woven fabrics are bonded to the two side edges of the upper surface of the surface layer, and the lower edges are bonded to the waterproof base film; a back glue layer is arranged in the middle of the waterproof base film, and a back release paper is attached to the back glue layer, wing glue layers are arranged on both sides of the back glue layer, and wing release paper is attached to the wing glue layers; the absorbent core is wrapped by the covering layer.

[0012] The third technical solution is: the sanitary napkin is a pants-type sanitary napkin, including a pants body; the absorbent core is wrapped by a covering layer, and the two sides of the surface layer extend downward to cover the sides of the guide layer and the absorbent core and the two sides of the bottom surface of the absorbent core; the bottom and both sides of the surface layer, the guide layer and the absorbent core are covered with a non-woven fabric layer, and the two side edges of the non-woven fabric layer are located at the two side edges of the upper surface of the surface layer, and elastic rubber bands are arranged on the bottom and two side edges of the non-woven fabric layer; the bottom of the non-woven fabric layer is in contact with the pants body.

[0013] The beneficial effects of the present invention are: the absorbent core adopts a woven warp knitted mesh skeleton, which greatly improves the air permeability of the product. The absorbent core will not shift after absorbing water and expanding. The absorbent core can completely replace the wood pulp core, which is helpful for forest protection. The breaking strength of the absorbent core exceeds 50N / 15mm, which is much greater than the maximum breaking strength of the wood pulp core, and also avoids the problem of breakage after absorbing water and expanding. The sanitary napkin using the absorbent core also has the above advantages. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0015] Figure 1 It is a cross-sectional view of the first flat sanitary napkin;

[0016] Figure 2 is a cross-sectional view of the second flat sanitary napkin;

[0017] Figure 3 It is a cross-sectional view of a pant-type sanitary napkin;

[0018] Figure 4 is a schematic diagram of the structure of the absorbent core;

[0019] Figure 5 It is a structural schematic diagram of a warp knitted mesh skeleton;

[0020] Figure 6 It is a structural breakdown diagram of a warp knitted mesh skeleton;

[0021] Figure 7 It is a schematic diagram of the structure of the production equipment of the absorbent core. DETAILED DESCRIPTION

[0022] Reference Figures 1 to 7 A sanitary napkin with a warp knitted absorbent core comprises an absorbent core 3 between a guide layer 1 and a waterproof bottom film 2, wherein the absorbent core 3 weighs 160-300 grams per square meter, the upper surface of the guide layer 1 is covered with a surface layer 4, the absorbent core 3 comprises a warp knitted mesh skeleton 31, the warp knitted mesh skeleton 31 has a thickness of 1-3 mm and a weight of 100-180 grams per square meter, the gaps in the warp knitted mesh skeleton 31 are filled with SAP particles 37, the weight of the SAP particles 37 accounts for 25-60% of the weight of the entire absorbent core 3, and the waterproof bottom film 2 can be a waterproof PE film.

[0023] The warp-knitted mesh skeleton 31 is formed by double-needle bed warp knitting, and has an upper surface layer 32, a lower surface layer 33 and a connecting yarn layer 34 connected between the upper surface layer and the lower surface layer; the upper surface layer 32 is provided with an upper mesh hole 321, and the lower surface layer 33 is provided with a lower mesh hole 331. The aperture of the upper mesh hole 321 is 1.2-5mm, and the aperture of the lower mesh hole 331 is less than 1mm. The aperture of the upper mesh hole 321 is larger than the aperture of the lower mesh hole 331 to prevent SAP particles from leaking out. The upper mesh hole and the lower mesh hole can be circular, elliptical, diamond or rectangular, so that the connecting yarn layer 34 forms a conical gap with a larger upper part and a smaller lower part at the corresponding part of the upper mesh hole 321. The conical gap is easy to be filled with SAP particles. After filling, the SAP particles with smaller particles penetrate into the connecting yarn layer, and the SAP particles with larger particles remain in the conical gap.

[0024] The upper surface layer 32 and the lower surface layer 33 are both formed by warp knitting 50D-200D 12F-72F polyester fibers, and the connecting yarn layer 34 is formed by warp knitting 30D-70D single F polyester fibers (D represents fineness, and F represents the number of fine fibers).

[0025] The sanitary napkin is a flat sanitary napkin or a trouser-type sanitary napkin, and the sanitary napkin provides three technical solutions for adoption.

[0026] The first technical solution is: the sanitary napkin is a flat sanitary napkin, and the two sides of the surface layer 4, the guide layer 1 and the absorbent core 3 are covered with side non-woven fabrics 5, the upper edges of the side non-woven fabrics 5 are bonded to the two side edges of the upper surface of the surface layer 4 by hot melt adhesive, and the lower edges are bonded to the waterproof base film 2; a back glue layer 21 is arranged in the middle of the waterproof base film 2, and wing glue layers 22 are arranged on both sides, the back glue layer 21 is affixed with a back release paper 211, and the wing glue layer 22 is affixed with a wing release paper 221; the upper surface of the absorbent core 3 is covered with an upper covering layer 35, and the lower surface is covered with a lower covering layer 36, and the entire sanitary napkin is completely wrapped by the envelope.

[0027] The upper covering layer is toilet paper, dust-free paper, or toilet paper and dust-free paper. The upper covering layer and the woven mesh skeleton are bonded with hot melt adhesive, and the amount of hot melt adhesive per square meter is between 3-8 grams; the lower covering layer is toilet paper, dust-free paper, or toilet paper and dust-free paper. The upper covering layer and the woven mesh skeleton are bonded with hot melt adhesive, and the amount of hot melt adhesive per square meter is between 3-8 grams.

[0028] The second technical solution is: the sanitary napkin is a flat sanitary napkin, and the two sides of the surface layer 4, the guide layer 1 and the absorbent core 3 are coated with side non-woven fabrics 5, the upper edges of the side non-woven fabrics 5 are bonded to the two side edges of the upper surface of the surface layer 4 by hot melt adhesive, and the lower edges are bonded to the waterproof base film 2; a back adhesive layer 21 is arranged in the middle of the waterproof base film 2, and a back release paper 211 is attached to the back adhesive layer, and wing adhesive layers 22 are arranged on both sides of the back adhesive layer 21, and wing release paper 221 is attached to the wing adhesive layer 22; the absorbent core 3 is wrapped by a covering layer 6, and the covering layer can be dust-free paper or toilet paper, and the entire sanitary napkin is completely wrapped by the covering film.

[0029] The third technical solution is: the sanitary napkin is a pants-type sanitary napkin, including a pants body 7; the absorbent core 3 is wrapped by a covering layer 6, which can be dust-free paper or toilet paper, and the two sides of the surface layer 4 extend downward to cover the sides of the guide layer 1 and the absorbent core 3 and the two sides of the bottom surface of the absorbent core; the bottom and both sides of the surface layer 4, the guide layer 1 and the absorbent core 3 are covered with a non-woven fabric layer 8, and the two side edges of the non-woven fabric layer 8 are located at the two side edges of the upper surface of the surface layer 4, and elastic rubber bands 81 are arranged at the bottom and both side edges of the non-woven fabric layer 8; the bottom of the non-woven fabric layer 8 is in contact with the pants body 8.

[0030] Reference Figure 7The production equipment of the warp knitted absorbent core includes a front laminating mechanism 94 and a rear laminating mechanism 99. A skeleton unwinding mechanism 91 and a lower surface unwinding mechanism 90 are arranged in front of the process of the front laminating mechanism 94. A lower surface glue spraying mechanism 92 is arranged between the lower surface unwinding mechanism 90 and the front laminating mechanism 94; a SAP unwinding mechanism 95 is arranged between the front laminating mechanism 94 and the rear laminating mechanism 99, a negative pressure suction mechanism 96 is arranged below the SAP unwinding mechanism 95, an upper surface unwinding mechanism 98 is arranged between the SAP unwinding mechanism 95 and the rear laminating mechanism 99, an upper surface glue spraying mechanism 97 is arranged between the upper surface unwinding mechanism 98 and the rear laminating mechanism 99, a slitting mechanism 100 is arranged behind the rear laminating mechanism 99, and a rewinding mechanism 101 is arranged behind the slitting mechanism 100. For the parts that need to be turned or tensioned, a guide roller 93 can be used. The winding mechanism 101 is powered, and the front pressing mechanism 94 , the rear pressing mechanism 99 , the upper surface unwinding mechanism 98 , the skeleton unwinding mechanism 91 , and the lower surface unwinding mechanism 90 may not be powered, or the front pressing mechanism 94 and the rear pressing mechanism 99 may be powered.

[0031] The preparation method of the warp knitted absorbent core is as follows:

[0032] (1) Gluing the lower surface layer: Spray glue (hot melt adhesive FL5766) on the upper side of the lower surface layer 33, the glue temperature is 160°C, and the glue spraying amount is 3-8g / m2.

[0033] (2) Roller bonding: The lower surface layer 33 is bonded to the lower surface of the warp knitted mesh skeleton 31 and sent to the front bonding mechanism 94 for roller bonding at a pressure of 3-4 kg / cm2 and a line speed of 60-70 m / min (the line speed of the entire production line is the same).

[0034] (3) Filling with SAP particles: The SAP feeding mechanism 95 sprays SAP particles at a spraying amount of 40-180 g / m2; the negative pressure suction mechanism 96 maintains a negative pressure of 30-50 KPa; and the SAP particles are sucked into the gaps of the warp knitted mesh skeleton 31. The negative pressure of the negative pressure suction mechanism 96 can be constant or fluctuating, so that the SAP particles penetrate into the gaps of the warp knitted mesh skeleton 31.

[0035] (4) Gluing the upper surface layer: Spray glue (hot melt adhesive FL5766) on the lower side of the upper surface layer 32, the glue temperature is 160°C, and the glue spraying amount is 2-8g / m2.

[0036] (5) Rolling synthesis: The upper surface layer 32 is bonded to the upper surface of the warp knitted mesh skeleton 31 and sent to the rear pressing mechanism 99 for rolling synthesis at a pressure of 3.5-4.5 kg / cm2.

[0037] (6) Cutting and forming: The synthesized material is fed into the cutting mechanism 100 and cut into the desired shape. The cutting mechanism 100 is composed of two die-cutting rollers that are in contact with each other.

[0038] (7) Rewinding: The rewinding mechanism 101 rewinds the cut materials for later use.

[0039] The test results of the absorbent core of this embodiment, the thin type of traditional wood pulp core, and the thick type of traditional wood pulp core are as follows:

[0040]

[0041]

[0042] Note 1-Test method: In a laboratory environment with a temperature of 20-25℃ and a humidity of 50-70% RH, cut the sample length L150mm and width 65mm, and the test material thickness T1, then place it on the platform, use a 1.5 kg 100mm diameter press block, and press for 2 hours. Measure the thickness T2 after pressing, and calculate, resistance to deformation = (T1-T2) / T1*100%.

[0043] Note 2-Test method: In a laboratory environment with a temperature of 20-25℃ and a humidity of 50-70% RH, cut the sample length L150mm and width 65mm, put the sample into a low-speed centrifuge, set the speed to 4000 rpm, and keep it for 30 minutes after turning it on. Use a high-light lamp to check the proportion of discrete fracture displacement in the absorbent core.

[0044] It can be seen from the test results that the absorbent core is significantly better than the traditional wood pulp core in terms of breaking strength and deformation resistance tests.

[0045] The test results of the sanitary napkins in this embodiment and the traditional sanitary napkins are as follows:

[0046]

[0047]

[0048] Note 3-Test method: Use the BTY-B2P air permeability tester customized by Labthink. Take a whole piece of sanitary napkin and unfold it flat on the bottom of the upper cavity of the instrument and fix it to seal. The upper cavity is overlapped with the lower cavity and positioned and sealed. Turn on the compressed air at a pressure of 1.5kp from the upper cavity through the middle of the sample to the lower cavity. The instrument will automatically measure and verify the amount of gas that penetrates the product under a certain unit of time and pressure.

[0049] Note 4-Test method: In a laboratory environment with a temperature of 20-25℃ and a humidity of 50-70% RH, take a whole piece of sanitary napkin and unfold it flat on the table. At the center of the product, test the material thickness T1, then use a 1.5 kg 100mm diameter press block and press for 2 hours. Measure the thickness T2 after pressing, and calculate, resistance to deformation = (T1-T2) / T1*100%.

[0050] Note 5-Test method: In a laboratory environment with a temperature of 20-25℃ and a humidity of 50-70% RH, use a dynamic simulation tester to set the step frequency to 90 steps / minute. Take a whole piece of sanitary napkin to simulate the human body and fit it on the underwear, and then wear the underwear on the dynamic simulation tester to simulate the human body. After starting, keep simulating human walking for 1 hour. After stopping, take out the test product and use a high-light light to check the proportion of discrete break displacement in the absorbent core of the sanitary napkin.

[0051] Note 6-Test method: According to the test method of water absorption multiple in 4.4 of national standard GB8939-2018. The sample is immersed in pure water for 1 minute, and the mass before and after water absorption is weighed after draining for 90 seconds. The water absorption multiple is calculated.

[0052] It can be seen from the test results that this sanitary napkin is significantly superior to the traditional wood pulp core in terms of product air permeability, deformation resistance, deformation resistance, and product water absorption multiples.

[0053] The absorbent core adopts a woven warp knitted mesh skeleton, which greatly improves the breathability of the product. The absorbent core will not shift after absorbing water and expanding. The absorbent core can completely replace the wood pulp core, which is helpful for forest protection. The breaking strength of the absorbent core exceeds 50N / 15mm, which is much greater than the maximum breaking strength of the wood pulp core of 10N / 15mm. It also avoids the problem of breakage after absorbing water and expanding. Sanitary napkins using this absorbent core also have the above advantages.

[0054] It can be seen from the test results of the sanitary napkin of this embodiment and the traditional sanitary napkin that the product of the present invention is obviously superior to the traditional wood pulp core in terms of breaking strength, deformation resistance and air permeability tests.

[0055] The above implementation modes cannot limit the protection scope of the present invention. The equivalent modifications and changes made by those skilled in the art without departing from the overall concept of the present invention are still within the scope of the present invention.

Claims

1. A sanitary napkin using a warp knitted absorbent core, comprising an absorbent core (3) located between a guide layer (1) and a waterproof base film (2), wherein the upper surface of the guide layer (1) is covered with a surface layer (4), characterized in that The absorbent core (3) comprises a warp-knitted mesh frame (31), the gaps of which are filled with SAP particles (37), and the warp-knitted mesh frame (31) is formed by double-needle bed warp knitting, and comprises an upper surface layer (32), a lower surface layer (33), and a connecting yarn layer (34) connected between the upper surface layer and the lower surface layer; the upper surface layer (32) is provided with an upper mesh hole (321), and the lower surface layer (33) is provided with a lower mesh hole (331), and the aperture of the upper mesh hole (321) is larger than the aperture of the lower mesh hole (331), so that the connecting yarn layer (34) forms a cone with a larger upper portion and a smaller lower portion at the corresponding portion of the upper mesh hole (321). The aperture of the upper mesh hole (321) is 1.2-5 mm, the aperture of the lower mesh hole (331) is less than 1 mm, the upper surface layer (32) and the lower surface layer (33) are both formed by warp knitting of 50D-200D 12F-72F polyester fibers, the connecting yarn layer (34) is formed by warp knitting of 30D-70D single F polyester fibers, the weight of the SAP particles (37) accounts for 25-60% of the weight of the entire absorbent core (3), and the preparation method of the warp knitted absorbent core is as follows: (1) gluing the lower surface layer: spraying glue on the upper side of the lower surface layer (33), the glue temperature is 160°C, and the glue spraying amount is 3-8g / m 2 (2) Roller lamination: Lay the lower surface layer (33) with the lower surface of the warp knitted mesh frame (31) and send it to the front lamination mechanism (94) for roller lamination at a pressure of 3-4kg / cm 2 , the line speed is 60-70m / min; (3) filling SAP particles: the SAP feeding mechanism (95) sprays SAP particles, and the spraying amount is 40-180g / m 2 ; The negative pressure suction mechanism (96) maintains a negative pressure of 30-50 KPa, so that the SAP particles are sucked into the gaps of the warp-knitted mesh skeleton (31); (4) Gluing the upper surface: Spray glue on the lower side of the upper surface (32) at a temperature of 160°C and a spraying amount of 2-8 g / m 2 ; (5) Rolling synthesis: The upper surface layer (32) is bonded to the upper surface of the warp knitted mesh frame (31), and then sent to the rear pressing mechanism (99) for rolling synthesis at a pressure of 3.5-4.5 kg / cm 2 ; (6) Cutting and forming: the synthesized material is fed into the cutting mechanism (100) and cut into the desired shape; (7) Rolling: the rolling mechanism (101) rolls up the cut material.

2. The sanitary napkin using a warp knitted absorbent core according to claim 1, characterized in that The warp-knitted mesh skeleton (31) has a thickness of 1-3 mm and a weight of 100-180 g per square meter.

3. The sanitary napkin using a warp knitted absorbent core according to claim 1, characterized in that The absorbent core (3) has a weight of 160-300 grams per square meter.

4. The sanitary napkin using a warp knitted absorbent core according to any one of claims 1 to 3, characterized in that The sanitary napkin is a flat sanitary napkin, wherein the surface layer (4), the guide layer (1) and the two sides of the absorbent core (3) are covered with side non-woven fabrics (5), the upper side edges of the side non-woven fabrics (5) are bonded to the two side edges of the upper surface of the surface layer (4), and the lower side edges are bonded to the waterproof base film (2); a back adhesive layer (21) is arranged in the middle of the waterproof base film (2), and wing adhesive layers (22) are arranged on both sides, the back adhesive layer (21) is bonded with a back release paper (211), and the wing adhesive layer (22) is bonded with a wing release paper (221); the upper surface of the absorbent core (3) is covered with an upper covering layer (35), and the lower surface is covered with a lower covering layer (36).

5. The sanitary napkin using a warp knitted absorbent core according to claim 1, characterized in that The sanitary napkin is a flat sanitary napkin, wherein both sides of the surface layer (4), the guide layer (1) and the absorbent core (3) are coated with side non-woven fabrics (5), the upper side edges of the side non-woven fabrics (5) are bonded to the two side edges of the upper surface of the surface layer (4), and the lower side edges are bonded to the waterproof base film (2); a back adhesive layer (21) is arranged in the middle of the waterproof base film (2), a back release paper (211) is attached to the back adhesive layer, wing adhesive layers (22) are arranged on both sides of the back adhesive layer (21), and wing release paper (221) is attached to the wing adhesive layer (22); the absorbent core (3) is wrapped by a coating layer (6).

6. The sanitary napkin using a warp knitted absorbent core according to claim 1, characterized in that The sanitary napkin is a trouser-type sanitary napkin, comprising a trouser body (7); the absorbent core (3) is wrapped by a covering layer (6), and the two sides of the surface layer (4) extend downward to cover the side surfaces of the guide layer (1) and the absorbent core (3) and the two sides of the bottom surface of the absorbent core; the bottom and both sides of the surface layer (4), the guide layer (1) and the absorbent core (3) are covered with a non-woven fabric layer (8), the two side edges of the non-woven fabric layer (8) are located at the two side edges of the upper surface of the surface layer (4), and elastic rubber bands (81) are arranged at the bottom and both side edges of the non-woven fabric layer (8); the bottom of the non-woven fabric layer (8) is in contact with the trouser body.

7. The sanitary napkin using a warp knitted absorbent core according to claim 1, characterized in that The production equipment of the warp knitted absorbent core comprises a front pressing mechanism (94) and a rear pressing mechanism (99); a skeleton unwinding mechanism (91) and a lower surface layer unwinding mechanism (90) are arranged in front of the process of the front pressing mechanism (94); a lower surface layer glue spraying mechanism (92) is arranged between the lower surface layer unwinding mechanism (90) and the front pressing mechanism (94); a SAP unloading mechanism (95) is arranged between the front pressing mechanism (94) and the rear pressing mechanism (99); A negative pressure suction mechanism (96) is arranged below the unloading mechanism (95); an upper surface layer unwinding mechanism (98) is arranged between the SAP unwinding mechanism (95) and the rear lamination mechanism (99); an upper surface layer glue spraying mechanism (97) is arranged between the upper surface layer unwinding mechanism (98) and the rear lamination mechanism (99); a slitting mechanism (100) is arranged behind the rear lamination mechanism (99); and a winding mechanism (101) is arranged behind the slitting mechanism (100).

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