A low aspect ratio strength ratio wood pulp composite forming process

Abstract

The application discloses a low longitudinal-transverse strength ratio wood pulp composite material forming process and belongs to the technical field of wood pulp composite material forming, and comprises the following steps: A, preparing a wood pulp fiber layer: (1) cooking and refining of wood pulp fiber; (2) refining; (3) forming the wood pulp fiber layer by adopting a water jet forming process; B, preparing an intermediate reinforcing layer; C, laying one intermediate reinforcing layer on one wood pulp fiber layer by a carding machine, and then laying one wood pulp fiber layer on the intermediate reinforcing layer; D, reinforcing by a water jet process; E, vacuum drying; and F, heating and bonding. By the above method, in the production process, less toxic and harmful additives are used, and the environmental protection performance of the product production process is improved; the wood pulp composite material prepared by the application has high longitudinal breaking strength, transverse breaking strength, longitudinal tear strength and transverse tear strength, and the longitudinal-transverse strength ratio is within 1:1.2, and the use range of the product is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wood pulp composite material forming, in particular to a low longitudinal and transverse strength ratio wood pulp composite material forming process. BACKGROUND

[0002] The wood pulp composite material can be used as a raw material of spunlace non-woven fabric, and the product can be applied in medical supplies, sanitary products, artificial leather base cloth, clothing lining cloth, decorative cloth and the like.

[0003] At present, the wood pulp composite material forming process still has the following problems:

[0004] 1) In the production process of the wood pulp composite material, too many toxic and harmful additives are used, resulting in poor environmental performance in the product production process;

[0005] 2) The tensile breaking strength of the wood pulp composite material in each direction is low, which affects the application range of the product;

[0006] 3) The physical properties of the wood pulp composite material, such as longitudinal and transverse strength ratio, are large, resulting in small breaking strength.

[0007] Therefore, the present application designs a low longitudinal and transverse strength ratio wood pulp composite material forming process to solve the above problems. SUMMARY

[0008] In view of the above-mentioned shortcomings of the prior art, the present application provides a low longitudinal and transverse strength ratio wood pulp composite material forming process.

[0009] To achieve the above object, the present application realizes the following technical scheme:

[0010] A low longitudinal and transverse strength ratio wood pulp composite material forming process comprises the following steps:

[0011] A, preparing a wood pulp fiber layer:

[0012] (1) Cooking and refining of wood pulp fibers: steam the wood pulp fibers at 122-129 DEG C for 1-3 min, and then place the wood pulp fibers at 80-95 DEG C for 1-2 min;

[0013] (2) Refining: mix the wood pulp fibers and regenerated polyester fibers, and put them into a refining machine for refining treatment, and the refining concentration is 5.3-5.7 w / w %;

[0014] (3) Forming the wood pulp fiber layer by using a spunlace forming process;

[0015] B, preparing an intermediate reinforcing layer:

[0016] (1)mixing graphene, mica and sodium carbonate, and calcining and activating at 200-400℃ for 1-4h; grinding into mixed powder;

[0017] (2)mixing the mixed powder, polypropylene fiber with a melt index of 30-35g / 10min and 3,6,9-trimethyl-1,4,7-triperoxonane, and extruding and granulating, with the extrusion temperature controlled at 225-245℃;

[0018] (3) heating and melting the extruded granules, and spinning to obtain an intermediate reinforcing layer;

[0019] C, laying one layer of intermediate reinforcing layer on one layer of wood pulp fiber layer, and then laying one layer of wood pulp fiber layer on the intermediate reinforcing layer by a carding machine;

[0020] D, reinforcing the two layers of wood pulp fiber layer and one layer of intermediate reinforcing layer by a water jet process to obtain a composite fiber layer;

[0021] E, vacuum drying the composite fiber layer, with the vacuum drying temperature controlled at 85-102℃ and the temperature rising speed controlled at 8-15℃ / min;

[0022] F, heating and bonding the composite fiber layer by a hot calender to bond and reinforce the two layers of wood pulp fiber layer and one layer of intermediate reinforcing layer, thus obtaining a wood pulp composite material with low longitudinal-transverse strength ratio.

[0023] Further, the mass ratio of wood pulp fiber to regenerated polyester fiber is 10-15:5.

[0024] Further, the regenerated polyester fiber is obtained by crushing waste polyester fiber fabric.

[0025] Further, the mass ratio of graphene, mica and sodium carbonate is 8-12:11-22:3-5.

[0026] Further, the graphene and mica are nanoscale.

[0027] Further, the mixed powder is nanoscale.

[0028] Further, the thickness of the intermediate reinforcing layer is 0.75-1 times the thickness of the wood pulp fiber layer.

[0029] Further, the number of intermediate reinforcing layers is replaced by multiple layers.

[0030] Further, the mass ratio of polypropylene fiber to 3,6,9-trimethyl-1,4,7-triperoxonane is 85-100:1.3-4.

[0031] Further, the wood pulp composite material with a grammage of 80 g / m2 has a longitudinal breaking strength of 318.4 N, a transverse breaking strength of 301.7 N, a longitudinal tear strength of 102 N, a transverse tear strength of 88 N, and a longitudinal to transverse strength ratio within 1:1.2.

[0032] Advantages

[0033] The wood pulp composite material with a grammage of 80 g / m2 has a longitudinal breaking strength of 318.4 N, a transverse breaking strength of 301.7 N, a longitudinal tear strength of 102 N, a transverse tear strength of 88 N, and a longitudinal to transverse strength ratio within 1:1.2.

[0034] In the production process, less toxic and harmful auxiliaries are used, which is beneficial to improve the environmental performance of the product production process.

[0035] The wood pulp composite material prepared has high longitudinal breaking strength, transverse breaking strength, longitudinal tear strength, and transverse tear strength, and a longitudinal to transverse strength ratio within 1:1.2, which is beneficial to improve the use range of the product. DETAILED DESCRIPTION

[0036] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be described below in connection with the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0037] The present application will be further described below in connection with the embodiments.

[0038] Embodiment 1

[0039] The embodiment provides a low longitudinal to transverse strength ratio wood pulp composite material forming process, which comprises the following steps:

[0040] A, preparing a wood pulp fiber layer:

[0041] (1) Cooking and refining of wood pulp fibers: steam the wood pulp fibers at 122 DEG C for 3 min, and then place the wood pulp fibers at 80 DEG C for 2 min;

[0042] (2) Refining: mix the wood pulp fibers and regenerated polyester fibers, and put them into a refining machine for refining treatment, with a refining concentration of 5.3 w / w %;

[0043] The mass ratio of the wood pulp fibers to the regenerated polyester fibers is 10:5, and the regenerated polyester fibers are obtained by crushing waste polyester fabric.

[0044] (3) using a water jet forming process to form a wood pulp fiber layer;

[0045] B, preparing an intermediate reinforcing layer:

[0046] (1) mixing graphene, mica and sodium carbonate, and performing calcination and activation treatment at 200 DEG C for 4h; grinding into a mixed powder;

[0047] The mass ratio of the graphene, mica and sodium carbonate is 8:22:3; the graphene and mica are nanoscale; and the mixed powder is nanoscale;

[0048] (2) mixing the mixed powder, polypropylene fibers with a melt index of 30g / 10min and 3,6,9-trimethyl-1,4,7-triperoxonane, and extruding and granulating, with the extrusion temperature controlled at 245 DEG C;

[0049] The mass ratio of the polypropylene fibers and 3,6,9-trimethyl-1,4,7-triperoxonane is 85:4;

[0050] (3) heating and melting the extruded particles, and spinning to obtain the intermediate reinforcing layer;

[0051] C, laying one layer of the intermediate reinforcing layer on one layer of the wood pulp fiber layer using a carding machine, and then laying one layer of the wood pulp fiber layer on the intermediate reinforcing layer;

[0052] The thickness of the intermediate reinforcing layer is 0.75 times the thickness of the wood pulp fiber layer; and the number of intermediate reinforcing layers is also designed to be multiple layers, and is sandwiched between two layers of wood pulp fiber layers;

[0053] D, using a water jet process to reinforce the two layers of wood pulp fiber layers and the one layer of intermediate reinforcing layer, to obtain a composite fiber layer;

[0054] E, vacuum drying the composite fiber layer, with the vacuum drying temperature controlled at 85 DEG C, and the temperature rising speed controlled at 15 DEG C / min;

[0055] F, heating and bonding the composite fiber layer through a hot calender, so that the two layers of wood pulp fiber layers and the one layer of intermediate reinforcing layer of the composite fiber layer are bonded and reinforced, to obtain the low longitudinal and transverse strength ratio wood pulp composite material.

[0056] Tests show that the wood pulp composite material with a grammage of 80g / m2 has a longitudinal breaking strength of 318.4N, a transverse breaking strength of 301.7N, a longitudinal tear strength of 102N, a transverse tear strength of 88N, and a longitudinal and transverse strength ratio within 1:1.2.

[0057] 1) In the production process of the present application, fewer toxic and harmful auxiliaries are used, which is conducive to improving the environmental performance of the product production process;

[0058] 2) The longitudinal breaking strength, transverse breaking strength, longitudinal tear strength, and transverse tear strength are high, and the longitudinal to transverse strength ratio is within 1:1.2, which is beneficial to improve the use range of the product.

[0059] Embodiment 2

[0060] The embodiment provides a low longitudinal to transverse strength ratio wood pulp composite forming process, comprising the following steps:

[0061] A, preparing a wood pulp fiber layer:

[0062] (1) Cooking and refining of wood pulp fibers: steam the wood pulp fibers at 129 DEG C for 1 min, and then place the wood pulp fibers at 95 DEG C for 1 min;

[0063] (2) Refining: mix the wood pulp fibers and the regenerated polyester fibers, and put them into a refining machine for refining treatment, and the refining concentration is 5.7 w / w %;

[0064] The mass ratio of the wood pulp fibers to the regenerated polyester fibers is 15:5; and the regenerated polyester fibers are obtained by crushing waste polyester fabric;

[0065] (3) Forming the wood pulp fiber layer by using a water jet forming process;

[0066] B, preparing an intermediate reinforcing layer:

[0067] (1) Mix graphene, mica and sodium carbonate, and calcine and activate at 400 DEG C for 1 h; and grind into a mixed powder;

[0068] The mass ratio of the graphene, mica and sodium carbonate is 12:11:5; the graphene and mica are nanoscale; and the mixed powder is nanoscale;

[0069] (2) Mix the mixed powder, polypropylene fibers with a melt index of 35 g / 10 min, and 3,6,9-trimethyl-1,4,7-triperoxonane, and extrude and granulate, and the extrusion temperature is controlled at 225 DEG C;

[0070] The mass ratio of the polypropylene fibers to 3,6,9-trimethyl-1,4,7-triperoxonane is 100:1.3;

[0071] (3) The extruded particles are heated and melted, and spun to obtain the intermediate reinforcing layer;

[0072] C, the carding machine lays one intermediate reinforcing layer on one wood pulp fiber layer, and then lays one wood pulp fiber layer on the intermediate reinforcing layer;

[0073] The thickness of the intermediate reinforcing layer is 1 times the thickness of the wood pulp fiber layer;

[0074] D, the two layers of wood pulp fiber layer and one layer of intermediate reinforcing layer are reinforced by using a water jet process to obtain a composite fiber layer;

[0075] E, the composite fiber layer is vacuum dried, the vacuum drying temperature is controlled at 102℃, and the temperature rising speed is controlled at 8℃ / min;

[0076] F, the composite fiber layer is heated and bonded by a hot calender to bond and reinforce the two layers of wood pulp fiber layer and one layer of intermediate reinforcing layer of the composite fiber layer, thereby obtaining a low longitudinal-transverse strength ratio wood pulp composite material.

[0077] Example 3

[0078] The embodiment provides a low longitudinal-transverse strength ratio wood pulp composite material forming process, which comprises the following steps:

[0079] The embodiment provides a low longitudinal-transverse strength ratio wood pulp composite material forming process, which comprises the following steps:

[0080] A, preparing a wood pulp fiber layer:

[0081] (1) Cooking and refining of wood pulp fibers: steam the wood pulp fibers at 125℃ for 2min, and then place the wood pulp fibers at 85℃ for 1.6min;

[0082] (2) Refining: mix the wood pulp fibers and the regenerated polyester fibers, and put them into a refining machine for refining treatment, and the refining concentration is 5.4w / w%;

[0083] The mass ratio of the wood pulp fibers to the regenerated polyester fibers is 12:5; the regenerated polyester fibers are obtained by crushing waste polyester fabric;

[0084] (3) Forming the wood pulp fiber layer by using a water jet forming process;

[0085] B, preparing an intermediate reinforcing layer:

[0086] (1) Mix graphene, mica and sodium carbonate, and calcine and activate at 300℃ for 3h; grind into a mixed powder;

[0087] The mass ratio of the graphene, mica and sodium carbonate is 9:18:4; the graphene and mica are nanoscale; and the mixed powder is nanoscale;

[0088] (2) Mix the mixed powder, polypropylene fibers with a melt index of 32g / 10min and 3,6,9-trimethyl-1,4,7-triperoxonane, and extrude and granulate, and the extrusion temperature is controlled at 232℃;

[0089] The mass ratio of the polypropylene fibers to 3,6,9-trimethyl-1,4,7-triperoxonane is 90:2.5;

[0090] (3) extruding the granules to melt, spin and obtain the intermediate reinforcing layer;

[0091] C. The carding machine lays one layer of the intermediate reinforcing layer on one layer of the wood pulp fiber layer, and then lays one layer of the wood pulp fiber layer on the intermediate reinforcing layer;

[0092] The thickness of the intermediate reinforcing layer is 0.9 times the thickness of the wood pulp fiber layer; the number of the intermediate reinforcing layer is also designed to be multiple layers, which are sandwiched between two layers of the wood pulp fiber layer;

[0093] D. The water jet process is used to reinforce the two layers of the wood pulp fiber layer and the one layer of the intermediate reinforcing layer to obtain the composite fiber layer;

[0094] E. The composite fiber layer is vacuum dried, the vacuum drying temperature is controlled at 95℃, and the temperature rising speed is controlled at 11℃ / min;

[0095] F. The composite fiber layer is heated and bonded by the hot calender to bond and reinforce the two layers of the wood pulp fiber layer and the one layer of the intermediate reinforcing layer, thereby obtaining the low longitudinal-transverse strength ratio wood pulp composite material.

[0096] Example 4

[0097] The embodiment provides a low longitudinal-transverse strength ratio wood pulp composite material forming process, which comprises the following steps:

[0098] A. Preparing the wood pulp fiber layer:

[0099] (1) Cooking and refining the wood pulp fiber: steam the wood pulp fiber at 125℃ for 1.3min, and then place the wood pulp fiber at 82℃ for 1.3min;

[0100] (2) Refining: mix the wood pulp fiber and the regenerated polyester fiber, and put them into the refiner for refining treatment, the refining concentration is 5.4w / w%;

[0101] The mass ratio of the wood pulp fiber to the regenerated polyester fiber is 11:5; the regenerated polyester fiber is obtained by crushing the waste polyester fabric;

[0102] (3) Forming the wood pulp fiber layer by using the water jet forming process;

[0103] B. Preparing the intermediate reinforcing layer:

[0104] (1) Mix the graphene, mica and sodium carbonate, and calcine and activate them at 220℃ for 1.5h; grind them into a mixed powder;

[0105] The mass ratio of the graphene, mica and sodium carbonate is 9.5:16:3.5; the graphene and the mica are nanoscale; the mixed powder is nanoscale;

[0106] (2) mixing the mixed powder, polypropylene fiber with a melt index of 31 g / 10 min, and 3,6,9-trimethyl-1,4,7-triperoxonane, and extruding and granulating, with the extrusion temperature controlled at 228°C;

[0107] wherein the mass ratio of the polypropylene fiber and the 3,6,9-trimethyl-1,4,7-triperoxonane is 95:2.8;

[0108] (3) melting the extruded particles by heating, and spinning to obtain an intermediate reinforcing layer;

[0109] C. The carding machine lays one layer of the intermediate reinforcing layer on one layer of the wood pulp fiber layer, and then lays one layer of the wood pulp fiber layer on the intermediate reinforcing layer;

[0110] The thickness of the intermediate reinforcing layer is 0.88 times the thickness of the wood pulp fiber layer; the number of the intermediate reinforcing layers is also designed to be multiple layers, which are all sandwiched between two layers of the wood pulp fiber layer;

[0111] D. The two layers of the wood pulp fiber layer and the one layer of the intermediate reinforcing layer are reinforced by using a water jet process to obtain a composite fiber layer;

[0112] E. The composite fiber layer is vacuum dried, with the vacuum drying temperature controlled at 100°C and the temperature rising speed controlled at 13°C / min;

[0113] F. The composite fiber layer is subjected to heating and bonding treatment by a hot calender to bond and reinforce the two layers of the wood pulp fiber layer and the one layer of the intermediate reinforcing layer of the composite fiber layer, thereby obtaining the low longitudinal-transverse strength ratio wood pulp composite material.

[0114] Example 5

[0115] The present embodiment provides a low longitudinal-transverse strength ratio wood pulp composite material forming process, which comprises the following steps:

[0116] A. Preparing a wood pulp fiber layer:

[0117] (1) Cooking and refining of the wood pulp fiber: the wood pulp fiber is steamed at 128°C for 2.4 min, and then the wood pulp fiber is placed at 93°C for 1.8 min;

[0118] (2) Refining: the wood pulp fiber is mixed with the regenerated polyester fiber, and is put into a refining machine for refining treatment, with the refining concentration being 5.6 w / w%;

[0119] The mass ratio of the wood pulp fiber and the regenerated polyester fiber is 14:5; the regenerated polyester fiber is obtained by crushing waste polyester fabric;

[0120] (3) Forming the wood pulp fiber layer by using a water jet forming process;

[0121] B, preparation of intermediate reinforcing layer:

[0122] (1) Mix graphene, mica and sodium carbonate, and perform calcination and activation treatment at 380℃ for 3.4h; grind into a mixed powder;

[0123] The mass ratio of the graphene, mica and sodium carbonate is 11.5:21:4.5; the graphene and mica are nanoscale; and the mixed powder is nanoscale;

[0124] (2) Mix the mixed powder, polypropylene fiber with a melt index of 33.5g / 10min and 3,6,9-trimethyl-1,4,7-triperoxonane, and extrude and granulate, with the extrusion temperature controlled at 240℃;

[0125] The mass ratio of the polypropylene fiber and 3,6,9-trimethyl-1,4,7-triperoxonane is 99:2.3;

[0126] (3) The extruded granules are heated and melted, and spun to obtain the intermediate reinforcing layer;

[0127] C, the carding machine lays one layer of the intermediate reinforcing layer on one layer of wood pulp fiber layer, and then lays one layer of wood pulp fiber layer on the intermediate reinforcing layer;

[0128] The thickness of the intermediate reinforcing layer is 0.8 times the thickness of the wood pulp fiber layer; the number of the intermediate reinforcing layers is also designed to be multiple layers, which are sandwiched between two layers of wood pulp fiber layers;

[0129] D, the water jet process is used to reinforce the two layers of wood pulp fiber layers and one layer of the intermediate reinforcing layer to obtain a composite fiber layer;

[0130] E, the composite fiber layer is vacuum dried, with the vacuum drying temperature controlled at 100℃ and the temperature rising speed controlled at 10℃ / min;

[0131] F, the composite fiber layer is heated and bonded by a hot calender to bond and reinforce the two layers of wood pulp fiber layers and one layer of the intermediate reinforcing layer, thereby obtaining the low longitudinal-transverse strength ratio wood pulp composite material.

[0132] Example 6

[0133] The embodiment provides a low longitudinal-transverse strength ratio wood pulp composite material forming process, which comprises the following steps:

[0134] A, preparation of wood pulp fiber layer:

[0135] (1) Cooking and refining of wood pulp fiber: steam the wood pulp fiber at 127℃ for 1.9min, and then place the wood pulp fiber at 94℃ for 1.2min;

[0136] (2) Refining: wood pulp fibers and regenerated polyester fibers are mixed and put into a refiner for refining treatment, and the refining concentration is 5.5 w / w %;

[0137] The mass ratio of wood pulp fibers to regenerated polyester fibers is 11.5:5; the regenerated polyester fibers are obtained by crushing waste polyester fabric;

[0138] (3) The wood pulp fiber layer is formed by using a spunlace forming process;

[0139] B, preparation of the intermediate reinforcing layer:

[0140] (1) The graphene, mica and sodium carbonate are mixed and subjected to calcination and activation treatment at 285°C for 1.4h; and are ground into a mixed powder;

[0141] The mass ratio of the graphene, mica and sodium carbonate is 10:20:3; the graphene and mica are nanoscale; and the mixed powder is nanoscale;

[0142] (2) The mixed powder, polypropylene fibers with a melt index of 32g / 10min and 3,6,9-trimethyl-1,4,7-triperoxonane are mixed and extruded to form granules, and the extrusion temperature is controlled at 241°C;

[0143] The mass ratio of the polypropylene fibers to 3,6,9-trimethyl-1,4,7-triperoxonane is 93:3.3;

[0144] (3) The extruded granules are heated and melted, and are spun to obtain the intermediate reinforcing layer;

[0145] C, the carding machine lays one layer of the intermediate reinforcing layer on one layer of the wood pulp fiber layer, and then lays one layer of the wood pulp fiber layer on the intermediate reinforcing layer;

[0146] The thickness of the intermediate reinforcing layer is 0.85 times the thickness of the wood pulp fiber layer; and the number of the intermediate reinforcing layers is also designed to be multiple layers, which are all sandwiched between two layers of wood pulp fiber layers;

[0147] D, the two layers of wood pulp fiber layers and one layer of the intermediate reinforcing layer are reinforced by using a spunlace process to obtain a composite fiber layer;

[0148] E, the composite fiber layer is vacuum dried, the vacuum drying temperature is controlled at 87°C, and the temperature rising speed is controlled at 9.5°C / min;

[0149] F, the composite fiber layer is subjected to heating and bonding treatment by a hot calender to bond and reinforce the two layers of wood pulp fiber layers and one layer of the intermediate reinforcing layer of the composite fiber layer, thereby obtaining the low longitudinal-transverse strength ratio wood pulp composite material.

[0150] Example 7

[0151] The embodiment provides a low length-width strength ratio wood pulp composite material forming process, and comprises the following steps.

[0152] A, preparing a wood pulp fiber layer:

[0153] (1) cooking and refining of wood pulp fibers: steam the wood pulp fibers at 123 DEG C. for 1.2 min, and then place the wood pulp fibers at 90 DEG C. for 1.2 min;

[0154] (2) refining: mix the wood pulp fibers and regenerated polyester fibers, and place the mixture in a refiner for refining treatment, and the refining concentration is 5.4 w / w %;

[0155] the mass ratio of the wood pulp fibers to the regenerated polyester fibers is 11:5; and the regenerated polyester fibers are obtained by crushing waste polyester fabric;

[0156] (3) forming the wood pulp fiber layer by using a water jet forming process;

[0157] B, preparing an intermediate reinforcing layer:

[0158] (1) mixing graphene, mica and sodium carbonate, and performing calcination and activation treatment at 380 DEG C. for 1.6 h; and grinding into a mixed powder;

[0159] the mass ratio of the graphene, mica and sodium carbonate is 9.2:13:4; the graphene and mica are nanoscale; and the mixed powder is nanoscale;

[0160] (2) mixing the mixed powder, polypropylene fibers with a melt index of 32 g / 10 min and 3,6,9-trimethyl-1,4,7-triperoxonane, and extruding and granulating, and the extrusion temperature is controlled at 239 DEG C.;

[0161] wherein the mass ratio of the polypropylene fibers to the 3,6,9-trimethyl-1,4,7-triperoxonane is 92:2.7;

[0162] (3) heating and melting the extruded particles, and spinning to obtain the intermediate reinforcing layer;

[0163] C, laying one intermediate reinforcing layer on one wood pulp fiber layer by using a carding machine, and then laying one wood pulp fiber layer on the intermediate reinforcing layer;

[0164] the thickness of the intermediate reinforcing layer is 0.76 times the thickness of the wood pulp fiber layer; and the number of the intermediate reinforcing layers is also designed to be multiple layers according to needs, and the multiple layers are all clamped between two wood pulp fiber layers;

[0165] D, reinforcing the two wood pulp fiber layers and the one intermediate reinforcing layer by using a water jet process, to obtain a composite fiber layer;

[0166] E. Vacuum drying the composite fiber layer, the vacuum drying temperature is controlled at 89℃, and the temperature rising speed is controlled at 12℃ / min;

[0167] F. Heating and bonding treatment of the composite fiber layer through a hot calender to bond and reinforce the two wood pulp fiber layers and the one intermediate reinforcing layer, thus obtaining the low longitudinal-transverse strength ratio wood pulp composite material.

[0168] Comparative Example 1

[0169] The embodiment provides a low longitudinal-transverse strength ratio wood pulp composite material forming process, including the following steps:

[0170] A. Preparing a wood pulp fiber layer:

[0171] (1) Cooking and refining of the wood pulp fiber: steam the wood pulp fiber at 122℃ for 3min, and then place the wood pulp fiber at 80℃ for 2min;

[0172] (2) Refining: mix the wood pulp fiber and the regenerated polyester fiber, and put them into a refining machine for refining treatment, the refining concentration is 5.3w / w%;

[0173] wherein the mass ratio of the wood pulp fiber to the regenerated polyester fiber is 10:5; the regenerated polyester fiber is obtained by crushing waste polyester fabric;

[0174] (3) Forming the wood pulp fiber layer by using a water jet forming process;

[0175] B. Preparing an intermediate reinforcing layer:

[0176] (1) Mixing graphene, mica and sodium carbonate, and calcining and activating the mixture at 200℃ for 4h; grinding into a mixed powder;

[0177] wherein the mass ratio of the graphene, the mica and the sodium carbonate is 8:22:3; the graphene and the mica are nanoscale; and the mixed powder is nanoscale;

[0178] (2) Mixing the mixed powder and polypropylene fiber with a melt index of 30g / 10min, and extruding and granulating, the extrusion temperature is controlled at 245℃;

[0179] (3) Heating and melting the extruded particles, and spinning to obtain the intermediate reinforcing layer;

[0180] C. Laying one intermediate reinforcing layer on one wood pulp fiber layer by using a carding machine, and then laying one wood pulp fiber layer on the intermediate reinforcing layer;

[0181] wherein the thickness of the intermediate reinforcing layer is 0.75 times the thickness of the wood pulp fiber layer;

[0182] D, the two layers of wood pulp fiber layer and one layer of intermediate reinforcing layer are reinforced by using a water jet process to obtain a composite fiber layer;

[0183] E, the composite fiber layer is vacuum dried, the vacuum drying temperature is controlled at 85 DEG C, and the heating speed is controlled at 15 DEG C / min;

[0184] F, the composite fiber layer is heated and bonded by a hot calender to bond and reinforce the two layers of wood pulp fiber layer and one layer of intermediate reinforcing layer of the composite fiber layer, thereby obtaining a wood pulp composite material with low longitudinal and transverse strength ratio.

[0185] Tests show that the wood pulp composite material with a grammage of 80 g / m2 has a longitudinal breaking strength of 284.8 N, a transverse breaking strength of 262.3 N, a longitudinal tear strength of 91.4 N, and a transverse tear strength of 80.6 N.

[0186] 1) In the production process of the present application, less toxic and harmful auxiliaries are used, which is conducive to improving the environmental performance of the product production process;

[0187] 2) The longitudinal breaking strength, transverse breaking strength, longitudinal tear strength, and transverse tear strength are high, and the longitudinal and transverse strength ratio is within 1:1.2, which is conducive to expanding the use range of the product.

[0188] The above examples are only used to illustrate the technical solutions of the present application, but not to limit it; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that the technical solutions recorded in the foregoing examples can be modified, or some technical features can be replaced by equivalents; and these modifications or replacements will not change the essence of the corresponding technical solutions out of the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A molding process for wood pulp composite materials with a low longitudinal and transverse strength ratio, characterized in that, Includes the following steps: A. Preparation of wood pulp fiber layer: (1) Cooking and grinding of wood pulp fibers: Place the wood pulp fibers at 122-129℃ for 1-3 minutes, and then place the wood pulp fibers at 80-95℃ for 1-2 minutes. (2) Pulping: Wood pulp fiber and recycled polyester fiber are mixed and put into a pulper for pulping treatment. The pulping concentration is 5.3~5.7w / w%; wherein the mass ratio of wood pulp fiber to recycled polyester fiber is 10~15:

5. (3) The wood pulp fiber layer is formed by hydroentangling molding process; B. Preparation of the intermediate reinforcement layer: (1) Graphene, mica, and sodium carbonate are mixed and calcined at 200–400°C for 1–4 hours for activation treatment; then ground into a mixed powder; the mass ratio of graphene, mica, and sodium carbonate is 8–12:11–22:3–5, and the graphene and mica are nanoscale. (2) Mix the mixed powder, polypropylene fiber with a melt index of 30-35 g / 10 min and 3,6,9-trimethyl-1,4,7-triperoxynonane and extrude granulation. The extrusion temperature is controlled at 225-245℃. The mass ratio of polypropylene fiber to 3,6,9-trimethyl-1,4,7-triperoxynonane is 85-100:1.3-4. (3) The extruded granules are heated, melted, and spun to obtain an intermediate reinforcing layer; C. The carding machine lays an intermediate reinforcement layer on a wood pulp fiber layer, and then lays another wood pulp fiber layer on the intermediate reinforcement layer. The thickness of the intermediate reinforcement layer is 0.75 to 1 times the thickness of the wood pulp fiber layer. D. The two layers of wood pulp fiber and the intermediate reinforcing layer are reinforced by hydroentangling process to obtain a composite fiber layer; E. Vacuum dry the composite fiber layer. The vacuum drying temperature is controlled at 85-102℃ and the heating rate is controlled at 8-15℃ / min. F. The composite fiber layer is heated and bonded through a hot rolling mill, so that the two wood pulp fiber layers and the intermediate reinforcing layer of the composite fiber layer are bonded and reinforced, thus obtaining a wood pulp composite material with a low longitudinal and transverse strength ratio.

2. The molding process for low longitudinal and transverse strength ratio wood pulp composite materials according to claim 1, characterized in that, Recycled polyester fiber is obtained by crushing waste polyester fiber fabric.

3. The molding process for low longitudinal and transverse strength ratio wood pulp composite materials according to claim 1, characterized in that, The mixed powder is nanoscale.

4. The molding process for low longitudinal and transverse strength ratio wood pulp composite materials according to claim 1, characterized in that, The number of intermediate reinforcement layers has been replaced with multiple layers.

5. The molding process for low longitudinal and transverse strength ratio wood pulp composite materials according to claim 1, characterized in that, The wood pulp composite material with a basis weight of 80 g / m² has a longitudinal breaking strength of 318.4 N and a transverse breaking strength of 301.7 N; a longitudinal tear strength of 102 N and a transverse tear strength of 88 N, with a longitudinal to transverse strength ratio within 1:1.2.