Degradable composite non-woven fabric and preparation method and application thereof

Abstract

The invention provides a degradable composite non-woven fabric and a preparation method and application thereof, and relates to the technical field of non-woven fabrics. The degradable composite non-woven fabric comprises a first fiber web layer, a first mixed cellulose fiber layer and a second fiber web layer which are sequentially compounded, wherein the first mixed cellulose fiber layer is mainly prepared from first mixed pulp prepared from wood pulp short fibers and degradable viscose fibers and / or lyocell short fibers through a direct spreading spunlace method. According to the degradable composite non-woven fabric, the water absorbing and locking performance of the degradable composite non-woven fabric is effectively improved through the arrangement of the first mixed cellulose fiber layer, and meanwhile, the first fiber web layer and the second fiber web layer are compounded on the two sides of the first mixed cellulose fiber layer; the problem of hair falling can be effectively avoided; and the tensile breaking strength of the degradable composite non-woven fabric is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of nonwoven fabrics, and in particular to a degradable composite nonwoven fabric and a preparation method and application thereof. Background Art

[0002] Wet wipes are divided into wet wipes for human body and wet wipes for objects. Wet wipes for objects are mainly used for cleaning and disinfection. However, there are certain problems with both wet wipes for human body and wet wipes for objects, as follows: First, when the water content exceeds 4 times the dry weight of the carrier base fabric, liquid will drip without having to squeeze it hard. On the one hand, the consumer experience is very poor. On the other hand, during the production of wet wipes, the base fabric after adding liquid has poor water retention, causing the package to be soaked with liquid, resulting in an increase in the defective rate. Secondly, when producing a large number of wet wipes such as 60, 80, 120 pieces, etc., the wet wipe carrier itself has limited water retention. As production time increases, under the influence of its own weight, transportation, stacking and other stress conditions, taking 60 wet wipes as an example, the water content of the first ten wet wipes under normal conditions is 3.29 times that of the last ten wet wipes at the bottom. For functional wet wipes that rely on liquid medicine, the use effect of the first ten wet wipes is greatly reduced. To address the above-mentioned problem of poor water absorption and water retention, existing solutions also provide some solutions to add wood pulp fibers during hydroentanglement to improve water absorption, but the addition of wood pulp fibers often causes the wet wipes to shed.

[0003] At the same time, the existing market has increasingly higher requirements for various indicators of spunlace non-woven fabrics as carriers of wet wipes, especially the longitudinal and transverse strength of wet wipes. In order to achieve high tensile breaking strength, smaller longitudinal and transverse breaking strength difference ratio, and smaller stretching displacement, various manufacturers have abandoned straight-laid spunlace fabrics and adopted semi-cross spunlace fabrics with higher energy consumption and more complex equipment, which has also led to the high cost of wet wipes.

[0004] Therefore, it is necessary and urgent to research and develop a biodegradable composite nonwoven fabric with high water absorption and water retention, low linting, high tensile strength, and suitable for direct-laid spunlace production to meet market requirements.

[0005] In view of this, the present invention is proposed. Summary of the Invention

[0006] The object of the present invention is to provide a degradable composite nonwoven fabric, which has better water absorption and water retention properties and can also effectively alleviate the problems of linting and low tensile strength of existing degradable composite nonwoven fabrics.

[0007] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are adopted: The present invention provides a degradable composite nonwoven fabric, which comprises a first fiber web layer, a first mixed cellulose fiber layer, and a second fiber web layer, which are composited in sequence; The first mixed cellulose fiber layer is mainly made of a first mixed pulp made of wood pulp short fibers and degradable viscose fibers and / or lyocell short fibers, and is prepared by a direct-laying hydroentanglement method; The wood pulp short fibers account for 70-90% of the first mixed pulp; The weight of the first mixed cellulose fiber layer is 50-80% of the weight of the degradable composite nonwoven fabric.

[0008] Furthermore, the wood pulp short fibers are hardwood pulp short fibers; Preferably, the fiber proportion of the hardwood pulp short fibers in the mixed pulp is 80-90%.

[0009] Furthermore, the first web layer is a hot air nonwoven web composed of biodegradable viscose fiber and polylactic acid fiber; And / or, the second fiber web layer is a hot air nonwoven fiber web composed of degradable viscose fibers and polylactic acid fibers.

[0010] Furthermore, the first fiber web layer has a grammage of 14-50 g / m 2 ; And / or, the weight of the second web layer is 14-50 g / m 2 .

[0011] Furthermore, the second web layer may be replaced with a second mixed cellulose fiber layer; The second mixed cellulose fiber layer is mainly made of a second mixed pulp made of wood pulp short fibers and degradable viscose fibers and / or lyocell short fibers, which is sequentially wet-laid and hydroentangled; Furthermore, the biodegradable viscose fiber and / or lyocell staple fiber accounts for 40-100% of the second mixed pulp.

[0012] Furthermore, a viscose fiber skeleton layer is provided between the first mixed cellulose fiber layer and the second fiber web layer; The preparation method of the viscose fiber skeleton layer comprises: twisting 20-60 mm viscose fiber filaments into filaments, and then weaving the filaments into a yarn mesh structure to obtain the viscose fiber skeleton layer.

[0013] The present invention provides a method for preparing a degradable composite nonwoven fabric, the preparation method comprising: The first fiber web layer, the first mixed cellulose fiber layer and the second fiber web layer are sequentially compounded and then heat-pressed to obtain a degradable composite nonwoven fabric; Alternatively, the first web layer, the first mixed cellulose fiber layer, the viscose fiber skeleton layer and the second web layer are sequentially compounded and then hot-pressed to obtain a degradable composite nonwoven fabric; Alternatively, the first web layer, the first mixed cellulose fiber layer, and the second mixed cellulose fiber layer are sequentially composited and then heat-pressed to obtain a degradable composite nonwoven fabric; Alternatively, the first fiber web layer, the first mixed cellulose fiber layer, the viscose fiber skeleton layer and the second mixed cellulose fiber layer are compounded in sequence and then hot-pressed and bonded to obtain a degradable composite nonwoven fabric.

[0014] Furthermore, the conditions for the thermal compression bonding at least meet at least one of the following: the thermal compression bonding temperature is 110-140° C., the pressure is 0.3-0.6 MPa, and the time is 1-5 s.

[0015] The present invention provides an application of a degradable composite nonwoven fabric in the preparation of degradable wet wipes.

[0016] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a degradable composite nonwoven fabric comprising a first web layer, a first mixed cellulose fiber layer, and a second web layer, which are sequentially laminated. The first mixed cellulose fiber layer is primarily prepared by direct-laying hydroentanglement of a first mixed pulp made primarily of wood pulp staple fibers and degradable viscose fibers and / or lyocell staple fibers. The wood pulp staple fibers comprise 70-90% of the first mixed pulp, and the weight of the first mixed cellulose fiber layer accounts for 50-80% of the weight of the degradable composite nonwoven fabric. The provision of the first mixed cellulose fiber layer effectively improves the water absorption and retention properties of the degradable composite nonwoven fabric. Furthermore, the provision of the first and second web layers laminated to either side of the first mixed cellulose fiber layer effectively prevents linting and improves tensile strength.

[0017] In addition, the second fiber mesh layer of the present application can be replaced with a second mixed cellulose fiber layer, in which the proportion of degradable viscose fiber and / or lyocell staple fiber in the second mixed cellulose fiber layer is 40-100%. By increasing the proportion of viscose fiber and / or lyocell staple fiber in the second mixed cellulose fiber layer, the present application can effectively improve the moisture absorption rate and water lock performance of the entire fiber mesh compared to the first mixed cellulose fiber layer. At the same time, a viscose fiber skeleton layer can be provided between the first mixed cellulose fiber layer and the second fiber mesh layer of the degradable composite non-woven fabric of the present application to increase the longitudinal and transverse strength and make the drafting displacement of the entire non-woven fabric close to consistency; similarly, the viscose fiber skeleton layer can also be provided between the first mixed cellulose fiber layer and the second mixed cellulose fiber layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 A production process flow chart of the first web layer 1 or the second web layer 3 provided in Example 1 of the present invention; Figure 2 This is a flow chart of the production process of the first mixed cellulose fiber layer 2 provided in Example 1 of the present invention; Figure 3 A flow chart of the production process of the degradable composite nonwoven fabric provided in Example 1 of the present invention; Figure 4 A schematic structural diagram of the degradable composite nonwoven fabric provided in Example 1 of the present invention; Figure 5 A flow chart of the production process of the viscose fiber skeleton layer 4 provided in Example 2 of the present invention; Figure 6 A schematic structural diagram of the degradable composite nonwoven fabric provided in Example 2 of the present invention; Figure 7 This is a flow chart of the production process of the second mixed cellulose fiber layer 5 provided in Example 3 of the present invention; Figure 8 A schematic structural diagram of the degradable composite nonwoven fabric provided in Example 3 of the present invention; Figure 9 This is a schematic structural diagram of the degradable composite nonwoven fabric provided in Example 4 of the present invention.

[0020] Icon: 1-first fiber mesh layer; 2-first mixed cellulose fiber layer; 3-second fiber mesh layer; 4-viscose fiber skeleton layer; 5-second mixed cellulose fiber layer. DETAILED DESCRIPTION

[0021] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the embodiments. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0022] According to one aspect of the present invention, a degradable composite nonwoven fabric comprises a first fiber web layer 1, a first mixed cellulose fiber layer 2, and a second fiber web layer 3, which are composited in sequence; The first mixed cellulose fiber layer 2 is mainly prepared by a first mixed pulp made of wood pulp short fibers and degradable viscose fibers and / or lyocell short fibers through a direct-laying hydroentanglement method; The wood pulp short fibers account for 70-90% of the first mixed pulp; The weight of the first mixed cellulose fiber layer 2 is 50-80% of the weight of the degradable composite nonwoven fabric.

[0023] The present invention provides a degradable composite non-woven fabric, comprising a first fiber web layer 1, a first mixed cellulose fiber layer 2 and a second fiber web layer 3, which are compounded in sequence; wherein, the first mixed cellulose fiber layer 2 is mainly composed of a first mixed pulp made of wood pulp staple fibers and degradable viscose fibers and / or lyocell staple fibers, and is prepared by a direct-laying hydroentanglement method, and the fiber proportion of the wood pulp staple fibers in the first mixed pulp is 70~90%; in addition, the weight of the first mixed cellulose fiber layer 2 of the present application is 50~80% of the weight of the degradable composite non-woven fabric, that is, at least 50% by weight of the cellulose layer in the degradable composite non-woven fabric of the present invention provides good water-locking performance support, and the upper and lower two layers / three layers with a lower limit of 20% by weight provide a constraining mixed cellulose layer for the entire composite non-woven fabric.

[0024] Therefore, the present invention effectively improves the water absorption and water locking performance of the degradable composite non-woven fabric of the present invention by setting the first mixed cellulose fiber layer 2. At the same time, the setting of the first fiber mesh layer 1 and the second fiber mesh layer 3 compounded on both sides of the first mixed cellulose fiber layer 2 can also effectively avoid the problem of hair loss and improve the tensile breaking strength; in addition, the degradable composite non-woven fabric of the present application can be prepared by the direct laying water spunlace method, which has the technical advantages of simple process and low processing cost.

[0025] In a preferred embodiment of the present invention, the wood pulp short fibers are broadleaf wood pulp short fibers.

[0026] As a preferred embodiment, the broadleaf pulp short fiber has a greater cost advantage than the softleaf pulp fiber, and the wood tissue structure is also tighter than that of the softleaf pulp. The composite non-woven fabric material produced therefrom has better absorption performance, water-locking performance and bulky thickness.

[0027] Preferably, the fiber proportion of the hardwood pulp short fibers in the mixed pulp is 80-90%.

[0028] In a preferred embodiment of the present invention, the first web layer 1 is a hot air nonwoven web composed of degradable viscose fiber and polylactic acid fiber; the second web layer 3 is a hot air nonwoven web composed of degradable viscose fiber and polylactic acid fiber.

[0029] As a preferred embodiment, the first fiber web layer 1 and the second fiber web layer 3 of the present application are both hot air non-woven fiber webs composed of degradable viscose fibers and polylactic acid fibers, which have excellent soft feel and good water absorption speed. At the same time, the first fiber web layer 1 and the second fiber web layer 3 serve as the coating and bearing layers of the first mixed cellulose fiber layer 2, which can effectively prevent the wood pulp fiber layer from shedding and eliminate customer complaints caused by fiber shedding when wiping with wet wipes; in addition, the first fiber web layer 1 and the second fiber web layer 3, as hot air non-woven fiber webs, also have good friction resistance.

[0030] It should be noted that the first fiber web layer 1 and the second fiber web layer 3 of the present application are hot air non-woven fiber webs composed of degradable fiber viscose fiber and polylactic acid fiber. If necessary, a small amount of low-melting point fiber can also be added; the fiber ratio is: polylactic acid fiber 60%-80%, viscose fiber 20-40%, low-melting point fiber 0%-10%.

[0031] In a preferred embodiment of the present invention, the first fiber web layer 1 has a gram weight of 14-50 g / m 2 ; In a preferred embodiment of the present invention, the weight of the second fiber web layer 3 is 14-50 g / m 2 .

[0032] In a preferred embodiment of the present invention, the second web layer 3 can be replaced by a second mixed cellulose fiber layer 5; The second mixed cellulose fiber layer 5 is mainly made of a second mixed pulp made of wood pulp short fibers and degradable viscose fibers and / or lyocell short fibers, which is sequentially wet-laid and hydroentangled; In a preferred embodiment of the present invention, the biodegradable viscose fiber and / or lyocell staple fiber accounts for 40-100% of the second mixed pulp.

[0033] As a preferred embodiment, the second mixed cellulose fiber layer 5 improves the moisture absorption speed and water locking performance of the entire fiber web compared to the first mixed cellulose fiber layer 2 by increasing the proportion of viscose fiber and / or lyocell staple fiber in the second mixed cellulose fiber layer 5.

[0034] In a preferred embodiment of the present invention, a viscose fiber skeleton layer 4 is further provided between the first mixed cellulose fiber layer 2 and the second web layer 3; The preparation method of the viscose fiber skeleton layer 4 includes: twisting 20-60 mm long viscose fiber into filaments, and then weaving the filaments into a yarn mesh structure to obtain the viscose fiber skeleton layer 4.

[0035] As a preferred embodiment, the viscose fiber skeleton layer 4 is a composite nonwoven fabric. Before twisting, the viscose filaments are pretreated with a surface treatment solution containing 0.5-1.5% antistatic agent and 1.0-2.0% softener at a temperature of 40°C ± 2°C for 10-15 minutes. This reduces breakage caused by static electricity and fiber stiffness during twisting and weaving, lubricates the surface of the viscose filaments, facilitates subsequent processing, and improves their flexibility. The woven viscose fiber skeleton layer 4 is heat-set at a temperature of 100°C ± 5°C for 5-10 minutes using hot air circulation or infrared heating. This eliminates internal stress generated in the yarn during weaving and improves dimensional stability. The viscose fiber skeleton layer 4 increases the longitudinal and transverse strength of the composite nonwoven fabric, reduces elongation at break, and facilitates moisture transport along the yarn's axis, forming a moisture-conducting channel.

[0036] According to one aspect of the present invention, a method for preparing a degradable composite nonwoven fabric comprises: The first web layer 1, the first mixed cellulose fiber layer 2 and the second web layer 3 are sequentially compounded and then hot-pressed to obtain a degradable composite nonwoven fabric; Alternatively, the first web layer 1, the first mixed cellulose fiber layer 2, the viscose fiber skeleton layer 4 and the second web layer 3 are sequentially compounded and then hot-pressed to obtain a degradable composite nonwoven fabric; Alternatively, the first web layer 1, the first mixed cellulose fiber layer 2 and the second mixed cellulose fiber layer 5 are sequentially composited and then hot-pressed to obtain a degradable composite nonwoven fabric; Alternatively, the first web layer 1, the first mixed cellulose fiber layer 2, the viscose fiber skeleton layer 4 and the second mixed cellulose fiber layer 5 are compounded in sequence and then hot-pressed to obtain a degradable composite nonwoven fabric.

[0037] In a preferred embodiment of the present invention, the heat-compression bonding conditions satisfy at least one of the following: heat-compression bonding temperature is 110-140° C., pressure is 0.3-0.6 MPa, and time is 1-5 s.

[0038] According to one aspect of the present invention, a degradable composite nonwoven fabric is used in the preparation of degradable wet wipes.

[0039] The degradable composite nonwoven fabric provided by the present invention can be widely used in the preparation process of degradable wet wipes.

[0040] The technical solution of the present invention will be further described below with reference to embodiments.

[0041] Example 1 Figure 1This is a production process flow chart of the first web layer 1 or the second web layer 3 provided in Example 1 of the present invention.

[0042] Figure 2 This is a flow chart of the production process of the first mixed cellulose fiber layer 2 provided in Example 1 of the present invention.

[0043] Figure 3 This is a flow chart of the production process of the degradable composite nonwoven fabric provided in Example 1 of the present invention.

[0044] Figure 4 This is a schematic structural diagram of the degradable composite nonwoven fabric provided in Example 1 of the present invention.

[0045] like Figure 4 As shown, this embodiment provides a degradable composite nonwoven fabric, which comprises a first fiber web layer 1, a first mixed cellulose fiber layer 2, and a second fiber web layer 3 that are composited in sequence; The first mixed cellulose fiber layer 2 is mainly prepared by a first mixed pulp made of wood pulp short fibers and degradable viscose fibers and / or lyocell short fibers through a direct-laying hydroentanglement method; The first mixed cellulose fiber layer 2 undergoes only pre-hydroentanglement, achieving initial entanglement at low pressure to stabilize the fiber web and achieve initial fiber entanglement. After the carded mixed fiber web is laid directly onto the pre-entanglement zone, the hydroentanglement parameters are: pressure of 0.5-1.5 MPa, water needle hole diameter of 0.1-0.2 mm (small hole diameter to ensure dense water flow), and water needle hole spacing of 0.5-0.6 mm to ensure uniform entanglement of the fiber web. The number of hydroentanglement nozzles ranges from 1 to 3.

[0046] The fiber composition of the first mixed pulp is: 70%-90% of hardwood pulp short fibers and 10%-30% of degradable viscose fibers.

[0047] The degradable composite non-woven fabric of this embodiment includes a first fiber mesh layer 1, a first mixed cellulose fiber layer 2 and a second fiber mesh layer 3 which are compounded in sequence; wherein, the provision of the first mixed cellulose fiber layer 2 effectively improves the water absorption and water locking performance of the degradable composite non-woven fabric of the present invention. At the same time, the provision of the first fiber mesh layer 1 and the second fiber mesh layer 3 compounded on both sides of the first mixed cellulose fiber layer 2 can also effectively avoid the problem of hair loss and improve the tensile breaking strength.

[0048] In an optional technical solution of this embodiment, the first web layer 1 and the second web layer 3 are air-through nonwoven webs composed of biodegradable viscose fibers and polylactic acid fibers. These air-through nonwoven webs have an excellent soft feel and good water absorption rate. They also effectively prevent the wood pulp fiber layer from shedding, eliminating customer complaints caused by fiber shedding during wiping with wet wipes. Furthermore, the first web layer 1 and the second web layer 3, as air-through nonwoven webs, also have excellent friction resistance.

[0049] In this embodiment, the first web layer 1 and the second web layer 3 are hot air nonwoven webs composed of biodegradable viscose fiber and polylactic acid fiber, and the fiber ratio is: polylactic acid fiber 70%, viscose fiber 20%, and low melting point fiber 10%.

[0050] In the optional technical solution of this embodiment, the weight of the first fiber web layer 1 is 30g / m 2 The second web layer 3 has a gram weight of 30 g / m 2 .

[0051] The method for preparing the degradable composite nonwoven fabric of this embodiment comprises: The first web layer 1, the first mixed cellulose fiber layer 2 and the second web layer 3 are sequentially compounded and then hot-pressed to obtain a degradable composite nonwoven fabric; The thermal compression bonding temperature is 120° C., the pressure is 0.5 MPa, and the time is 3 seconds.

[0052] The thickness of the first fiber web layer 1 is 0.2 mm.

[0053] The thickness of the first mixed cellulose fiber layer 2 is 0.6 mm.

[0054] The thickness of the second fiber web layer 3 is 0.2 mm.

[0055] Example 2 This embodiment is the same as the first embodiment except that a viscose fiber skeleton layer 4 is provided between the first mixed cellulose fiber layer 2 and the second fiber web layer 3 .

[0056] The preparation method of the viscose fiber skeleton layer 4 includes: twisting 20-60 mm long viscose fiber into filaments, and then weaving the filaments into a yarn mesh structure to obtain the viscose fiber skeleton layer 4.

[0057] Figure 5 This is a flow chart of the production process of the viscose fiber skeleton layer 4 provided in Example 2 of the present invention.

[0058] Figure 6 This is a schematic structural diagram of the degradable composite nonwoven fabric provided in Example 2 of the present invention.

[0059] The method for preparing the degradable composite nonwoven fabric of this embodiment comprises: The first web layer 1, the first mixed cellulose fiber layer 2, the viscose fiber skeleton layer 4, and the second web layer 3 are sequentially compounded and then hot-pressed to obtain a degradable composite nonwoven fabric; The hot pressing process parameters are the same as those in Example 1.

[0060] The thickness of the first fiber web layer 1 is 0.2 mm.

[0061] The thickness of the first mixed cellulose fiber layer 2 is 0.5 mm.

[0062] The thickness of the viscose fiber skeleton layer 4 is 0.1 mm.

[0063] The thickness of the second fiber web layer 3 is 0.2 mm.

[0064] Example 3 This embodiment is the same as the first embodiment except that the second web layer 3 is replaced by a second mixed cellulose fiber layer 5 .

[0065] The second mixed cellulose fiber layer 5 is a spunlace fabric prepared from hardwood pulp short fibers and degradable viscose fibers by a semi-cross method. The fiber composition of the second mixed cellulose fiber layer 5 is: The hardwood pulp staple fiber and biodegradable viscose fiber are mixed at a ratio of 60:40, and the mixed fibers are conveyed to the lapping machine using a semi-cross-lapping process. The fibers are arranged longitudinally in the main lapping direction, and the cross-lapping device lays some fibers at an angle of 30°~60° to interweave the longitudinal and transverse fibers of the fiber web, enhance the anisotropy of the fiber web, and control the fiber web weight to 25-50g / ㎡ and the thickness to 0.2-0.5mm. Only the pre-hydroentanglement reinforcement stage is carried out subsequently. In the pre-entanglement area, the hydroentanglement head pressure is 2-5MPa, the water needle hole diameter is 0.1-0.2mm, the hole spacing is 0.5-1.0mm, and the distance between the hydroentanglement head and the fiber web is 5-10mm, so that the fibers are initially entangled at a relatively low pressure.

[0066] Figure 7 This is a flow chart of the production process of the second mixed cellulose fiber layer 5 provided in Example 3 of the present invention.

[0067] Figure 8 This is a schematic structural diagram of the degradable composite nonwoven fabric provided in Example 3 of the present invention.

[0068] The method for preparing the degradable composite nonwoven fabric of this embodiment comprises: The first web layer 1, the first mixed cellulose fiber layer 2, and the second mixed cellulose fiber layer 5 are sequentially compounded and then hot-pressed to obtain a degradable composite nonwoven fabric; The hot pressing process parameters are the same as those in Example 1.

[0069] The thickness of the first fiber web layer 1 is 0.2 mm.

[0070] The thickness of the first mixed cellulose fiber layer 2 is 0.8 mm.

[0071] The thickness of the second mixed cellulose fiber layer 5 is 0.2 mm.

[0072] Example 4 This embodiment is the same as the embodiment 3 except that a viscose fiber skeleton layer 4 is provided between the first mixed cellulose fiber layer 2 and the second mixed cellulose fiber layer 5 .

[0073] The preparation method of the viscose fiber skeleton layer 4 is the same as that of Example 2.

[0074] Figure 9 This is a schematic structural diagram of the degradable composite nonwoven fabric provided in Example 4 of the present invention.

[0075] The method for preparing the degradable composite nonwoven fabric of this embodiment comprises: The first web layer 1, the first mixed cellulose fiber layer 2, the viscose fiber skeleton layer 4 and the second mixed cellulose fiber layer 5 are sequentially compounded and then hot-pressed to obtain a degradable composite nonwoven fabric; The hot pressing process parameters are the same as those in Example 1.

[0076] The thickness of the first fiber web layer 1 is 0.2 mm.

[0077] The thickness of the first mixed cellulose fiber layer 2 is 0.6 mm.

[0078] The thickness of the viscose fiber skeleton layer 4 is 0.1 mm.

[0079] The thickness of the second mixed cellulose fiber layer 5 is 0.2 mm.

[0080] Experimental Example 1 In order to demonstrate the technical effect of the degradable composite nonwoven fabric of the present application, the performance of the degradable composite nonwoven fabrics prepared in Examples 1 to 4 above was tested.

[0081] (1) The specific groups are as follows: Group 1: the degradable composite nonwoven fabric prepared in Example 1 (a first fiber web layer 1, a first mixed cellulose fiber layer 2, and a second fiber web layer 3); Group 2: the degradable composite nonwoven fabric prepared in Example 2 (a first fiber web layer 1, a first mixed cellulose fiber layer 2, a viscose fiber skeleton layer 4, and a second fiber web layer 3); Group 3: the degradable composite nonwoven fabric prepared in Example 3 (a first web layer 1, a first mixed cellulose fiber layer 2, and a second mixed cellulose fiber layer 5); Group 4: the degradable composite nonwoven fabric prepared in Example 4 (a first web layer 1, a first mixed cellulose fiber layer 2, a viscose fiber skeleton layer 4, and a second mixed cellulose fiber layer 5); Group 5: meltblown-wood pulp-meltblown double-spinning composite nonwoven fabric.

[0082] The specific preparation process of Group 5 is as follows: 1. Raw material preparation Meltblown fiber raw material: Polypropylene (PP) is a biodegradable material. Wood pulp raw material: virgin wood pulp fiber with a length of 1-3mm.

[0083] 2. Fiber preparation: Meltblown fiber preparation: After drying, the polymer chips are fed into a twin-screw extruder, melt-extruded at 200°C-300°C, and ejected through a meltblown nozzle to form ultrafine fibers. Wood pulp fiber opening and carding: The wood pulp fibers pass through the pulp opening mechanism and, driven by a conveying fan, enter the carding machine. The carding machine generally rotates at 3000-3200 rpm, combing the wood pulp fibers into a uniform fiber web.

[0084] 3. Mixed web formation: The meltblown head sprays polymer fibers toward the mixing zone, and the wood pulp fibers are sprayed into the mixing zone through the discharge nozzle on the carding machine. The two fibers intersect and mix in the mixing zone. The polymer fibers on both sides of the meltblown head that have not entered the mixing zone form the bottom layer and the upper layer respectively. The mixed fibers fall onto the web-forming mechanism to form the middle layer. The web-forming mechanism carries the composite fiber web and runs at a speed of generally 40-100 m / min.

[0085] 4. Thermal bonding: Thermal bonding method: hot rolling or hot air bonding is used to bond the meltblown fibers and wood pulp fibers in the composite web to form a stable nonwoven fabric structure.

[0086] Thermal bonding parameters: During hot rolling bonding, the hot rolling roller temperature is generally 100℃-150℃, and the pressure is 5-20kN / m; during hot air bonding, the hot air temperature is 80℃-120℃, and the wind speed is 0.5-2m / s.

[0087] 5. Winding and slitting: The bonded nonwoven fabric is wound into a roll and then slit according to different uses to obtain products of the required specifications.

[0088] Group 6: 4r / 6t spunlace fabric.

[0089] Group 7: 2r / 8t spunlace fabric.

[0090] The weight of each group of fabrics mentioned above is controlled to be 80±5g.

[0091] (2) Performance testing items include: a- the average of five qualified data of wet longitudinal breaking strength; b- the average of five qualified data of longitudinal elongation displacement at break in wet state; c- average of five qualified data of wet transverse breaking strength; d-mean value of five qualified data of transverse fracture elongation displacement in wet state; e- Water retention of 80 simulated wet wipes placed for one month at 3.5 times the dry cloth weight and liquid content - Difference between the lowest and highest liquid content in 80 wipes: (3) The test results are as follows:

[0092] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A degradable composite nonwoven fabric, characterized in that: The degradable composite nonwoven fabric comprises a first fiber web layer (1), a first mixed cellulose fiber layer (2), and a second fiber web layer (3) which are composited in sequence; The first mixed cellulose fiber layer (2) is mainly made of a first mixed pulp made of wood pulp short fibers and degradable viscose fibers and / or lyocell short fibers, and is prepared by a direct-laying hydroentanglement method; The wood pulp short fibers account for 70-90% of the first mixed pulp; The weight of the first mixed cellulose fiber layer (2) is 50-80% of the weight of the degradable composite non-woven fabric.

2. The degradable composite nonwoven fabric according to claim 1, characterized in that: The wood pulp short fibers are broadleaf wood pulp short fibers; Preferably, the fiber proportion of the hardwood pulp short fibers in the mixed pulp is 80-90%.

3. The degradable composite nonwoven fabric according to claim 1, characterized in that: The first fiber web layer (1) is a hot air nonwoven fiber web composed of biodegradable fiber viscose fiber and polylactic acid fiber; And / or, the second fiber web layer (3) is a hot air nonwoven fiber web composed of degradable viscose fibers and polylactic acid fibers.

4. The degradable composite nonwoven fabric according to claim 3, characterized in that: The first fiber web layer (1) has a gram weight of 14-50 g / m 2 ; And / or, the second fiber web layer (3) has a gram weight of 14-50 g / m 2 .

5. The degradable composite nonwoven fabric according to claim 3, characterized in that: The second fiber web layer (3) may be replaced by a second mixed cellulose fiber layer (5); The second mixed cellulose fiber layer (5) is mainly made of a second mixed pulp made of wood pulp short fibers and degradable viscose fibers and / or lyocell short fibers, which is successively made by wet-laid web forming and hydroentanglement.

6. The degradable composite nonwoven fabric according to claim 5, characterized in that: The biodegradable viscose fiber and / or lyocell staple fiber account for 40-100% of the second mixed pulp.

7. The degradable composite nonwoven fabric according to claim 1, characterized in that: A viscose fiber skeleton layer (4) is further provided between the first mixed cellulose fiber layer (2) and the second fiber web layer (3); The preparation method of the viscose fiber skeleton layer (4) comprises: twisting 20-60 mm viscose fiber filaments into filaments, and then weaving the filaments into a yarn mesh structure to obtain the viscose fiber skeleton layer (4).

8. A method for preparing the degradable composite nonwoven fabric according to any one of claims 1 to 7, characterized in that: The preparation method comprises: The first fiber web layer (1), the first mixed cellulose fiber layer (2), and the second fiber web layer (3) are sequentially composited, and then heat-pressed and bonded to obtain a degradable composite nonwoven fabric; Alternatively, the first fiber web layer (1), the first mixed cellulose fiber layer (2), the viscose fiber skeleton layer (4) and the second fiber web layer (3) are sequentially composited and then hot-pressed to obtain a degradable composite nonwoven fabric; Alternatively, the first fiber web layer (1), the first mixed cellulose fiber layer (2), and the second mixed cellulose fiber layer (5) are sequentially composited and then heat-pressed to obtain a degradable composite nonwoven fabric; Alternatively, the first fiber web layer (1), the first mixed cellulose fiber layer (2), the viscose fiber skeleton layer (4) and the second mixed cellulose fiber layer (5) are sequentially composited and then hot-pressed to obtain a degradable composite nonwoven fabric.

9. The method for preparing the degradable composite nonwoven fabric according to claim 8, wherein: The conditions for thermal compression bonding at least meet at least one of the following: The hot pressing bonding temperature is 110~140℃, the pressure is 0.3~0.6 MPa, and the time is 1~5s.

10. Use of the degradable composite nonwoven fabric according to any one of claims 1 to 7 in the preparation of degradable wet wipes.

Images