A shoe press felt for papermaking process reconstituted tobacco and its preparation method and application

Abstract

The application provides a shoe press felt for papermaking process reconstituted tobacco and a preparation method and application thereof, which comprises an upper surface layer, a middle fiber layer and a lower surface layer; the upper surface layer and the lower surface layer independently comprise a mixture of acrylonitrile-butadiene-styrene copolymer (ABS) and polylactic acid (PLA) with a volume ratio of (5:1) to (3:1); and the middle fiber layer is prepared from conifer fiber fluff pulp. The felt surface layer prepared from the mixture of ABS and PLA can block the direct contact between the pollutants of the papermaking process reconstituted tobacco and the water-absorbing fiber layer (the middle fiber layer), avoid the blockage of the felt caused by the direct contact between the pollutants and the fiber layer, and further improve the dehydration efficiency of the felt; the fiber layer prepared from the conifer fiber fluff pulp has good water absorption, and can greatly improve the dehydration efficiency of the felt.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of shoe press felt, and particularly relates to a shoe press felt for paper-making reconstituted tobacco and a preparation method and application thereof. BACKGROUND

[0002] The key core technology battle and new technology upgrading initiative battle of paper-making reconstituted tobacco require promoting the transformation of paper-making reconstituted tobacco from good to excellent and creating new advantages for the development of reconstituted tobacco. The main function of paper-making felt is to help paper dewatering. It is usually placed in the press roll where paper has been placed to remove water on the wet paper web in a water absorption manner without damaging the paper.

[0003] The shoe press technology is advanced. Compared with the traditional low-efficiency vacuum press, the shoe press has high pressure, large press area, long dewatering time, low pressing ratio, and greatly reduces steam energy consumption. Through the research on the influencing factors such as selection and cleaning of shoe press felt and selection of vacuum dewatering tank, the dewatering efficiency of shoe press is further improved, and the base sheet dryness is improved. However, there is no preparation research on the shoe press felt for paper-making reconstituted tobacco at present. SUMMARY

[0004] Therefore, the present application aims to provide a shoe press felt for paper-making reconstituted tobacco and a preparation method and application thereof. The shoe press felt has high dewatering efficiency.

[0005] The present application provides a shoe press felt for paper-making reconstituted tobacco, which comprises an upper surface layer, a middle fiber layer and a lower surface layer.

[0006] The upper surface layer and the lower surface layer independently comprise a mixture of acrylonitrile-butadiene-styrene copolymer and polylactic acid in a volume ratio of (5:1) to (3:1).

[0007] The middle fiber layer is made of needle-leaf wood fiber fluff pulp.

[0008] Preferably, the thickness ratio of the upper surface layer, the middle fiber layer and the lower surface layer is (0.5-1):(1-2):(0.5-1).

[0009] Preferably, the grammage of the middle fiber layer is 500-600 g / m 2 .

[0010] Preferably, holes are arranged on the upper surface layer and the lower surface layer, respectively.

[0011] The holes are uniformly distributed on the upper surface layer and the lower surface layer in an array form, and the number of holes per square centimeter is 14-30.

[0012] The shape of the holes is square, and the side length of the holes is 0.6-1.4 mm.

[0013] Preferably, the PLA has a molecular weight of 60000-100000.

[0014] The application provides a preparation method of the boot-type pressing felt for paper-process reconstituted tobacco leaves.

[0015] The mixture of acrylonitrile-butadiene-styrene copolymer and polylactic acid with a volume ratio of (5:1)-(3:1) is printed in a 3D printing mode according to a preset model to obtain the upper surface layer and the lower surface layer.

[0016] The needle wood fiber fluff pulp is air-formed to obtain a fiber layer, and then extruded to obtain the middle fiber layer.

[0017] The upper surface layer, the middle fiber layer and the lower surface layer are combined to obtain the boot-type pressing felt for paper-process reconstituted tobacco leaves.

[0018] Preferably, the printing temperature is 180-230 DEG C, and the printing speed is 300-500 mm / s.

[0019] Preferably, the extrusion pressure is 10-15 MPa.

[0020] The application provides a paper-process reconstituted tobacco leaf base sheet dehydration method, which comprises a dehydration step of using the boot-type pressing felt for paper-process reconstituted tobacco leaves.

[0021] The application provides a boot-type pressing felt for paper-process reconstituted tobacco leaves, which comprises an upper surface layer, a middle fiber layer and a lower surface layer; the upper surface layer and the lower surface layer independently comprise a mixture of acrylonitrile-butadiene-styrene copolymer (ABS) and polylactic acid (PLA) with a volume ratio of (5:1)-(3:1); and the middle fiber layer is prepared from needle wood fiber fluff pulp. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 The application provides a structure diagram of the boot-type pressing felt for paper-process reconstituted tobacco leaves.

[0023] Figure 2 The application provides a model for 3D printing. DETAILED DESCRIPTION

[0024] The application provides a boot-type pressing felt for paper-process reconstituted tobacco, which comprises an upper layer, a middle fiber layer and a lower layer.

[0025] The upper layer and the lower layer independently comprise a mixture of acrylonitrile-butadiene-styrene copolymer (ABS) and polylactic acid (PLA) with a volume ratio of (5:1) to (3:1).

[0026] The middle fiber layer is made of coniferous fiber fluff pulp.

[0027] Referring to Figure 1 wherein 1 is the upper layer, 2 is the middle fiber layer, and 3 is the lower layer.

[0028] The felt is prepared by using the mixture of ABS and PLA to form the upper and lower layers, so that the pollutants of the paper-process reconstituted tobacco cannot directly contact with the water-absorbing fiber layer (the middle fiber layer), the pollutants cannot directly contact with the fiber layer to block the felt, and the dehydration efficiency of the felt is improved; the fiber layer prepared by using the coniferous fiber fluff pulp has good water absorption, and the dehydration efficiency of the felt is greatly improved.

[0029] The boot-type pressing felt for paper-process reconstituted tobacco comprises an upper layer, and the upper layer comprises a mixture of acrylonitrile-butadiene-styrene copolymer (ABS) and polylactic acid (PLA) with a volume ratio of (5:1) to (3:1).

[0030] The boot-type pressing felt for paper-process reconstituted tobacco comprises a lower layer, and the lower layer comprises a mixture of acrylonitrile-butadiene-styrene copolymer (ABS) and polylactic acid (PLA) with a volume ratio of (5:1) to (3:1). The PLA has a molecular weight of 60,000 to 100,000. In specific embodiments, the PLA has a molecular weight of 100,000, 80,000 or 60,000.

[0031] The upper layer and the lower layer are respectively provided with holes.

[0032] The holes are uniformly distributed on the upper layer and the lower layer in an array form, and the number of holes per square centimeter is 14 to 30; the shape of the holes is square, and the side length of the holes is 0.6 mm to 1.4 mm. In specific embodiments, the side length of the holes is 0.6 mm, 0.85 mm or 1.4 mm.

[0033] The holes penetrate the upper layer and the lower layer.

[0034] The present application does not require the volume ratio of ABS and PLA in the upper and lower surface layers, and the volume ratio of ABS and PLA in the two layers can be the same or different. In specific embodiments of the present application, the volume ratio of ABS and PLA in the upper surface layer is 5:1, 4:1 or 3:1. The volume ratio of ABS and PLA in the lower surface layer is 5:1, 4:1 or 3:1.

[0035] The present application provides a boot-type pressing felt for papermaking process reconstituted tobacco, which comprises a middle fiber layer; the middle fiber layer is prepared from needle-leaf wood fiber fluff pulp. The grammage of the middle fiber layer is 500-600 g / m 2 . In specific embodiments, the grammage of the middle fiber layer is 500 g / m 2 , 550 g / m 2 , or 600 g / m 2 .

[0036] In the present application, the thickness ratio of the upper surface layer, the middle fiber layer and the lower surface layer is (0.5-1):(1-2):(0.5-1). In specific embodiments, the thickness ratio of the upper surface layer, the middle fiber layer and the lower surface layer is 0.5:1:0.5; or 1:1:1; or 1:2:1.

[0037] The present application provides a preparation method of the boot-type pressing felt for papermaking process reconstituted tobacco described in the above technical solution, which comprises the following steps:

[0038] A mixture of acrylonitrile-butadiene-styrene copolymer and polylactic acid with a volume ratio of (5:1)-(3:1) is printed in a 3D printing manner according to a preset model to obtain the upper surface layer and the lower surface layer;

[0039] The needle-leaf wood fiber fluff pulp is air-formed to obtain a fiber layer, which is then extruded to obtain a middle fiber layer;

[0040] The upper surface layer, the middle fiber layer and the lower surface layer are compounded to obtain the boot-type pressing felt for papermaking process reconstituted tobacco.

[0041] In the present application, the temperature for 3D printing is 180-230 DEG C, and the speed for 3D printing is 300-500 mm / s. In specific embodiments, the printing temperature is 180 DEG C, 200 DEG C or 220 DEG C, and the printing speed is 300 mm / s, 400 mm / s or 500 mm / s.

[0042] In the present application, the fiber layer is prepared by air-forming; and the extrusion pressure is 10-15 MPa. In specific embodiments, the extrusion pressure is 10 MPa, 13 MPa or 15 MPa.

[0043] The surface layer of the blanket prepared by 3D printing after ABS and PLA are compounded in the application is wear-resistant and can prevent the pollutants of the paper-making reconstituted tobacco from directly contacting the water-absorbing fiber layer; the middle layer of the application adopts fluff pulp, has good water absorption, greatly improves the dehydration efficiency of the paper-making reconstituted tobacco, and reduces the energy consumption of subsequent drying.

[0044] The application provides a paper-making reconstituted tobacco substrate dehydration method, which comprises the dehydration step of using the shoe press blanket for paper-making reconstituted tobacco.

[0045] In order to further illustrate the application, the shoe press blanket for paper-making reconstituted tobacco and the preparation method thereof provided by the application are described in detail below in combination with examples, but they cannot be understood as limiting the protection scope of the application.

[0046] Example 1

[0047] A shoe press blanket for paper-making reconstituted tobacco comprises an upper surface layer, a middle fiber layer and a lower surface layer.

[0048] A mixture of acrylonitrile-butadiene-styrene copolymer and polylactic acid with a volume ratio of 5:1 is printed in a 3D printing manner according to a preset model, the molecular weight of the PLA is 60000, the temperature of 3D printing is 180 DEG C, the printing speed is 300 mm / s, and the upper surface layer and the lower surface layer are obtained; the upper surface layer and the lower surface layer are respectively provided with array distributed holes. The holes are uniformly distributed on the upper surface layer and the lower surface layer, the mesh is 14 meshes; the shape of the hole is square, the side length is 1.4 mm; the hole penetrates the upper surface layer and the lower surface layer.

[0049] The middle fiber layer is prepared from needle wood fiber fluff pulp. The needle wood fiber fluff pulp is air-formed to obtain a fiber layer, and the fiber layer is extruded under a pressure of 10 MPa to obtain the middle fiber layer, and the grammage of the middle fiber layer is 500 g / m 2 .

[0050] The upper surface layer, the middle fiber layer and the lower surface layer are compounded to obtain the shoe press blanket for paper-making reconstituted tobacco. The thicknesses of the upper surface layer, the middle fiber layer and the lower surface layer are 0.5 cm, 1 cm and 0.5 cm respectively.

[0051] Example 2

[0052] A shoe press blanket for paper-making reconstituted tobacco comprises an upper surface layer, a middle fiber layer and a lower surface layer.

[0053] A mixture of acrylonitrile-butadiene-styrene copolymer and polylactic acid with a volume ratio of 4:1 is printed in a 3D printing manner according to a preset model, the molecular weight of the PLA is 80000, the 3D printing temperature is 200 DEG C, and the printing speed is 400 mm / s, to obtain an upper surface layer and a lower surface layer respectively; an array of holes is arranged on the upper surface layer and the lower surface layer respectively; the holes are uniformly distributed on the upper surface layer and the lower surface layer, the mesh number is 20 meshes; the shape of the hole is square, the side length is 0.85 mm; the hole penetrates the upper surface layer and the lower surface layer.

[0054] The middle fiber layer is made of coniferous fiber fluff pulp. The coniferous fiber fluff pulp is air-formed to obtain a fiber layer, which is extruded under a pressure of 13 MPa to obtain the middle fiber layer, and the grammage of the middle fiber layer is 550 g / m 2 .

[0055] The upper surface layer, the middle fiber layer and the lower surface layer are combined to obtain a shoe press felt for paper process reconstituted tobacco; wherein the thicknesses of the upper surface layer, the middle fiber layer and the lower surface layer are 1 cm, 1 cm and 1 cm respectively.

[0056] Example 3

[0057] A shoe press felt for paper process reconstituted tobacco comprises an upper surface layer, a middle fiber layer and a lower surface layer.

[0058] A mixture of acrylonitrile-butadiene-styrene copolymer and polylactic acid with a volume ratio of 3:1 is printed in a 3D printing manner according to a preset model, the molecular weight of the PLA is 100000, the 3D printing temperature is 220 DEG C, and the printing speed is 500 mm / s, to obtain an upper surface layer and a lower surface layer respectively; an array of holes is arranged on the upper surface layer and the lower surface layer respectively. The holes are uniformly distributed on the upper surface layer and the lower surface layer, the mesh number is 30 meshes; the shape of the hole is square, the side length is 0.60 mm; the hole penetrates the upper surface layer and the lower surface layer.

[0059] The middle fiber layer is made of coniferous fiber fluff pulp. The coniferous fiber fluff pulp is air-formed to obtain a fiber layer, which is extruded under a pressure of 15 MPa to obtain the middle fiber layer, and the grammage of the middle fiber layer is 600 g / m 2 .

[0060] The upper surface layer, the middle fiber layer and the lower surface layer are combined to obtain a shoe press felt for paper process reconstituted tobacco; wherein the thicknesses of the upper surface layer, the middle fiber layer and the lower surface layer are 1 cm, 2 cm and 1 cm respectively.

[0061] Comparative Example

[0062] A shoe press felt for paper process reconstituted tobacco comprises an upper surface layer, a middle fiber layer and a lower surface layer.

[0063] The polylactic acid with a molecular weight of 60000 is printed according to a preset model by using 3D printing, the temperature of 3D printing is 180℃, the printing speed is 300mm / s, and an upper surface layer and a lower surface layer are obtained; the upper surface layer and the lower surface layer are respectively provided with array distributed holes; the holes are uniformly distributed on the upper surface layer and the lower surface layer, and the mesh number is 14 meshes; the shape of the holes is square, and the side length is 1.4mm. The holes penetrate the upper surface layer and the lower surface layer.

[0064] The middle fiber layer is made of coniferous fiber fluff pulp. The coniferous fiber fluff pulp is air-formed to obtain a fiber layer, and the fiber layer is extruded under a pressure of 10MPa to obtain the middle fiber layer, and the grammage of the middle fiber layer is 500g / m 2 .

[0065] The upper surface layer, the middle fiber layer and the lower surface layer are compounded to obtain a shoe press felt for papermaking process reconstituted tobacco; wherein the thicknesses of the upper surface layer, the middle fiber layer and the lower surface layer are 0.5cm, 1cm and 0.5cm respectively.

[0066] The dewatering rate of the shoe press felt is determined by the following method:

[0067] The papermaking process reconstituted tobacco substrate with a basis weight of 100g / m 2 is subjected to a dewatering test under the action of a 3.0MPa pressing force. The specific operation of the experiment is as follows: before dewatering, the mass of the substrate is weighed. After dewatering, the mass of the substrate is weighed again, and then the dewatering rate is calculated by the following formula:

[0068]

[0069] η—dewatering rate, %;

[0070] a1—mass of the substrate before dewatering, g;

[0071] a2—mass of the substrate after dewatering, g.

[0072] The abrasion resistance is determined by GB / T 21196 “Determination of fabric abrasion resistance by the Martindale method”.

[0073] Test results:

[0074] Dehydration rate / % Abrasion resistance rating Example 1 30.05 Class A Example 2 33.16 Class A Example 3 36.62 Class A Comparative Example 29.87 Class B

[0075] From the above embodiment, the present application provides a kind of for papermaking method to reconstruct tobacco boot type pressing felt, including upper surface layer, middle fiber layer and lower surface layer;The upper surface layer and lower surface layer independently include the mixture of (5:1) ~ (3:1) volume ratio acrylonitrile-butadiene-styrene copolymer (ABS) and polylactic acid (PLA);The middle fiber layer is made of coniferous wood fiber fluff pulp.The upper surface layer and lower surface layer of felt are prepared by ABS and PLA mixture, can greatly improve the wear resistance of felt, and with the increase of the middle fiber layer of felt, the dehydration rate of papermaking method to reconstruct tobacco base sheet increases, can effectively reduce the energy consumption of subsequent drying part.The experimental results show that: using the boot type pressing felt of the present application to carry out the dehydration of papermaking method to reconstruct tobacco base sheet, the dehydration rate reaches 30.05-36.62%;The wear resistance grade of boot type pressing felt is A grade.

[0076] The above only describes the preferred embodiments of the present application, and it should be noted that those skilled in the art can make several improvements and refinements without departing from the principles of the present application, and these improvements and refinements should also be considered within the scope of protection of the present application.

Claims

1. An improved shoe press felt for papermaking process reconstituted tobacco, characterized by, The upper surface layer, the middle fiber layer and the lower surface layer are prepared by 3D printing. The upper surface layer and the lower surface layer independently comprise a mixture of acrylonitrile-butadiene-styrene copolymer and polylactic acid in a volume ratio of (5:1) to (3:1). The middle fiber layer is prepared from coniferous fiber fluff pulp. The upper surface layer and the lower surface layer are respectively provided with holes. The holes are uniformly distributed in an array on the upper surface layer and the lower surface layer, with 14 to 30 holes per square centimeter. The shape of the holes is square, and the side length of the holes is 0.6mm to 1.4mm.

2. The shoe press blanket for paper process reconstituted tobacco leaf according to claim 1, characterized in that, The thickness ratio of the upper surface layer, the middle fiber layer and the lower surface layer is (0.5-1):(1-2):(0.5-1).

3. The shoe press blanket for paper process reconstituted tobacco leaf according to claim 1, characterized in that, The intermediate fiber layer has a grammage of 500-600 g / m 2 .

4. The shoe press blanket for paper process reconstituted tobacco leaf according to claim 1, characterized in that, The molecular weight of the PLA is 60000 to 100000.

5. A preparation method of the shoe press felt for papermaking process reconstituted tobacco according to any one of claims 1 to 4, comprising the following steps: The mixture of acrylonitrile-butadiene-styrene copolymer and polylactic acid in a volume ratio of (5:1) to (3:1) is printed according to a preset model by 3D printing to obtain the upper surface layer and the lower surface layer respectively. The coniferous fiber fluff pulp is air-formed to obtain a fiber layer, which is then extruded to obtain the middle fiber layer. The upper surface layer, the middle fiber layer and the lower surface layer are combined to obtain the shoe press felt for papermaking process reconstituted tobacco.

6. The preparation method according to claim 5, characterized in that, The printing temperature is 180 to 230℃, and the printing speed is 300 to 500mm / s.

7. The preparation method according to claim 5, characterized in that, The extrusion pressure is 10 to 15MPa.

8. A papermaking process reconstituted tobacco base sheet dehydration method, comprising a dehydration step using the shoe press felt for papermaking process reconstituted tobacco according to any one of claims 1 to 4.

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