CN114645483A

CN114645483A - Composite papermaking felt and preparation method thereof

Info

Publication number: CN114645483A
Application number: CN202210157810.2A
Authority: CN
Inventors: 陆剑峰; 陈平; 姜华; 陆进锋
Original assignee: Jiangsu Jinni Engineered Fabric Co ltd
Current assignee: Jiangsu Jinni Engineered Fabric Co ltd
Priority date: 2022-02-21
Filing date: 2022-02-21
Publication date: 2022-06-21

Abstract

The application discloses a composite papermaking felt and a preparation method thereof, wherein the composite papermaking felt comprises a first composite fiber layer and a second composite fiber layer, and the second composite fiber layer is laid on the first composite fiber layer; the second composite fiber layer is provided with a plurality of wool layers, needle tracks are formed on the wool layers, and the depth of the needle tracks is gradually reduced along with the increase of the number of the wool layers. The method ensures that the manufactured composite papermaking felt is not easy to fall off through a special flocking needling method, ensures the smooth and fine effect of the felt, and is particularly suitable for manufacturing paper products with high requirements on flatness, such as decorative paper, cultural paper, tissue paper and the like.

Description

Composite papermaking felt and preparation method thereof

Technical Field

The application relates to the technical field of papermaking industry, in particular to a composite papermaking felt and a preparation method thereof.

Background

Papermaker's felts, which are an essential material in the paper industry, are a dewatering device in the press section of a paper machine and function primarily to dewater the press nip of the press section, support the wet paper sheet, and direct the wet paper sheet through the nip.

The paper-making felt commonly used on the paper machine at present is a bottom net needling flocked flannelette blanket which generally consists of a base fabric layer and a fiber layer, but the produced felt has great performance difference due to different used raw materials, base fabric structures and treatment processes. In addition, the paper machine has different pressing forms, different paper making types and different performance requirements on the paper making felt. For example, a papermaking felt of a papermaking type has a relatively low requirement for surface flatness, while a papermaking felt for making specialty papers such as cultural paper and tissue paper has a high requirement for surface flatness. Some paper mills adopt the mode of increasing the fiber content to improve the flatness of the blanket surface, but the mode is poor in pressure resistance, the blanket is easy to harden in the later period of use, the water permeability is reduced, the frequency of shutdown cleaning and the line pressure reduction through speed reduction need to be increased, otherwise, the phenomenon of crushing easily occurs to the paper. Therefore, a papermaking felt with certain pressure resistance and water containing space is needed, and meanwhile, the effects of being not easy to fall off and keeping the surface of the felt smooth and fine are achieved, so that the papermaking felt can be used for manufacturing paper machines such as high-grade decorative paper, cultural paper, tissue paper and the like which require high surface flatness.

Disclosure of Invention

The technical problem mainly solved by the application is to provide the composite papermaking felt and the preparation method thereof, and the problem that the surface of the papermaking felt is not smooth and fine in the prior art can be solved.

In order to solve the technical problem, the application adopts a technical scheme that: providing a composite papermaking felt, comprising a first composite fiber layer and a second composite fiber layer, wherein the second composite fiber layer is laid on the first composite fiber layer; the second composite fiber layer is provided with a plurality of wool layers, needle tracks are formed on the wool layers, and the depth of the needle tracks is gradually reduced along with the increase of the number of the wool layers.

And the intervals of the needle-punched marks are gradually reduced along with the increase of the layer number of the wool layer.

Wherein the depth and the interval of the needle-punched traces are gradually reduced in a proportion of 5%.

Wherein the second composite fiber layer comprises a front surface inner fiber layer and a surface layer fiber layer which are stacked.

Wherein the surface fiber layer comprises first fibers and second fibers, and the melting points of the first fibers and the second fibers are different.

Wherein the melting point of the first fiber is 110-180 ℃, and the melting point of the second fiber is 250-260 ℃.

The surface fiber layer further comprises third fibers, and the fineness of the third fibers is 3D-15D. The first fibers and the second fibers account for 10% -30% of the content of the surface fiber layer.

The front surface inner fiber layer comprises nylon fibers, and the fineness of the front surface inner fiber layer is 30D-60D.

Wherein the first composite fiber layer comprises a bottom fiber layer and a base fabric layer which are stacked, and the first composite fiber layer is laid on the base fabric layer.

Wherein the scrim layer comprises a first scrim layer and a second scrim layer. The weave structure of the first base fabric layer includes 1/3 broken twill weave, and the first base fabric layer includes first warp threads and first weft threads interwoven with each other. The first warp is monofilament, and the material of the first warp comprises nylon. The first weft is a plied yarn, and the material of the first weft comprises nylon.

Wherein the diameter of the first warp thread is 0.34mm-0.4mm, and the density of the first warp thread is 175-300 threads/10 cm. The diameter of the first weft is 0.18mm-0.2mm, and the density of the first weft is 180-260/10 cm.

Wherein the weave structure of the second base fabric layer comprises 1/3 broken twill weave, and the second base fabric layer comprises second warp yarns and second weft yarns interwoven with each other. The second warp is monofilament, and the second warp is made of nylon. The second weft is a plied yarn, and the second weft is made of nylon and space-variant yarns.

Wherein the diameter of the second warp is 0.25mm-0.38 mm. In the second weft, the diameter of the chinlon is 0.18-0.2 mm, and the air textured yarn comprises terylene.

The bottom fiber layer comprises nylon fibers, and the fiber fineness of the bottom fiber layer is 40D-60D.

In order to solve the above technical problem, another technical solution adopted by the present application is: provided is a method for manufacturing a composite papermaking felt, comprising: providing a first composite fiber layer, and sequentially laying a plurality of wool layers on the first composite fiber layer;

and respectively carrying out needling treatment on the plurality of wool layers, wherein the plurality of wool layers subjected to needling treatment form a second composite fiber layer, and the needling depth is gradually reduced along with the increase of the number of layers of the wool layers.

Wherein, in the step of respectively carrying out needling treatment on the plurality of wool tops, the needling interval is gradually reduced along with the increase of the number of layers of the wool tops.

Wherein, the depth and the interval of the needling are gradually reduced by 5 percent.

Wherein, in the step of laying a plurality of batt layers on the first composite fiber layer, the plurality of batt layers forming a second composite fiber layer, the second composite fiber layer includes a surface fiber layer and a front surface inner fiber layer, the surface fiber layer includes first fibers and second fibers; wherein the melting points of the first fibers and the second fibers are different.

The beneficial effect of this application is: when laying second composite fiber layer, pile up a plurality of wool tops and lay, every wool top of laying carries out a acupuncture, and along with the increase acupuncture's of laying the wool top number of piles degree reduces gradually, make the degree of depth of the acupuncture trace on upper strata wool top surface diminish, the sunken degree on wool top surface has effectively been alleviateed, finally in having guaranteed in the second composite fiber layer between each wool top and under the condition that has sufficient cohesive force between second composite fiber layer and the first composite fiber layer, make the surperficial fine and smooth exquisiteness of composite papermaking wooller, satisfy the demand that the high paper class product of requirement blanket face roughness such as manufacturing high-grade decorative paper, culture paper, tissue paper.

Drawings

FIG. 1 is a schematic cross-sectional view of a composite papermaking felt according to an embodiment of the present disclosure.

FIG. 2 is a schematic structural view of a second composite fiber layer in a composite papermaking felt according to an embodiment of the present application.

Fig. 3 is a schematic perspective view of a composite papermaking felt according to an embodiment of the present application.

Fig. 4 is a schematic view of a knitting structure of a first base fabric layer provided in an embodiment of the present application.

Fig. 5 is a schematic view of a knitting structure of the second base fabric layer provided in the embodiment of the present application.

Fig. 6 is a schematic flow chart of a method for manufacturing a composite papermaking felt according to an embodiment of the present application.

FIG. 7 is a schematic flow chart of a method of making a composite papermaking felt according to another embodiment of the present disclosure.

Detailed Description

In order to make the purpose, technical solutions and advantages of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings and the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

It should be noted that if the description of "first", "second", etc. is provided in the implementation of the present application, the description of "first", "second", etc. is used for descriptive purposes only and is not to be construed as indicating or implying any relative importance or implicit indication of the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, technical solutions between various embodiments can be combined with each other, but must be realized by a person skilled in the art as a basis, and when the technical solutions are contradictory or cannot be realized, such a combination of technical solutions should be considered to be absent and not be within the protection scope of the present application.

Referring to fig. 1, fig. 1 is a schematic sectional view of a composite papermaking felt according to the present invention. The present application provides a composite papermaking felt 100, and the composite papermaking felt 100 may be a wet felt or a dry felt, and may be specifically configured according to an actual scenario, which is not specifically limited herein. It should be noted that the present application will describe the technical solution of the present application with the composite papermaking felt 100 as a wet felt, but is not limited thereto.

With continued reference to FIG. 1, the composite papermaking felt 100 includes a first composite fiber layer 12 and a second composite fiber layer 16. In one embodiment, the first composite fiber layer 12 may include a bottom fiber layer 22 and a scrim layer 24 stacked together, wherein the scrim layer 24 may include a first scrim layer 40 and a second scrim layer 42. The second composite fiber layer 16 includes a face side inner fiber layer 60 and a face side fiber layer 62.

The first base fabric layer 40 and the second base fabric layer 42 serve as a skeleton structure of the composite papermaking felt 100 to support and provide the composite papermaking felt 100 with a certain strength; fiber layer 60 and bottom fibrous layer 22 can absorb the moisture of paper in top layer fibrous layer 62, the front, and laid the two-layer fibrous layer of fiber layer 60 and top layer fibrous layer 62 in the front above second base cloth layer 42, and have certain space in the front between fiber layer 60 and the top layer fibrous layer 62 for composite papermaking felt 100's the water space of holding is bigger, has improved drainage performance.

Referring to FIG. 2, FIG. 2 is a schematic structural view of a second composite fiber layer in a composite papermaking felt according to the present application. In one embodiment, the second composite fiber layer 16 includes a face fiber layer 62 and a face-side fiber layer 60. The front inner fabric layer 60 includes a first batt layer 601, a second batt layer 602, and a third batt layer 603, and the needle-punched

traces

31, 32, 33 of the

first batt layer

601, 602, 603, and 34 of the top fabric layer 62 are formed. In fig. 2, the front inner fiber layer 60 formed by three batt layers is taken as an example, and the batt layers may be more than three or less than three, and are not limited herein.

In one embodiment, second composite fiber layer 16 has a plurality of batt layers with needle tracks formed thereon, such as needle tracks 31, 32, 33, 34 in FIG. 2. The depth of the needle-punching mark gradually decreases as the number of batt layers increases, and as shown in fig. 2, the second composite fiber layer 16 has a first batt layer 601, a second batt layer 602, a third batt layer 603, and a surface fiber layer 62 stacked in this order. The depth of the needle traces 31 on the first batt 601 is larger, the depth of the needle traces 32 on the second batt 602 is second, the depth of the needle traces 33 on the third batt 603 is shallower than the needle traces 32 on the second batt 602, the depth of the needle traces 34 on the surface fiber layer 62 is shallowest, and the positions of the needle holes formed by the needle traces 31, 32, 33, 34 are kept different as much as possible. In some embodiments, the depth of the needle mark is gradually reduced in a proportion of 5%.

Flocking needling can produce cohesive force between the laid wool layers to tightly connect the layers. When laying the top layer fibrous layer, pile up a plurality of wool layers and lay, whenever lay a wool layer and carry out acupuncture once, the degree of depth of acupuncture becomes shallow gradually along with the number of piles of wool layer, has reduced the sunken degree of relative upper strata wool layer surface acupuncture point, makes the surface of top layer fibrous layer 62 also level and smooth relatively after the acupuncture, and then the surface of the compound papermaking felt 100 of preparation is also level and smooth fine and smooth.

In some embodiments, second composite fiber layer 16 has a plurality of batt layers having formed thereon needle tracks, such as needle tracks 31, 32, 33, 34 in FIG. 2. The intervals of the needle-punched traces are gradually reduced along with the increase of the layer number of the wool layer. As shown in fig. 2, the second composite fiber layer 16 has a first batt layer 601, a second batt layer 602, a third batt layer 603, and a surface fiber layer 62 stacked in this order. The intervals of the needle-punched traces 31 on the first batt 601 are larger, the intervals of the needle-punched traces 32 on the second batt 602 are next, the intervals of the needle-punched traces 33 on the third batt 603 are smaller than the intervals of the needle-punched traces 32 on the second batt 602, the needle-punched traces 34 on the surface layer fiber layer 62 are the smallest, and the positions of the needle holes formed by the needle-punched

traces

31, 32, 33, 34 are kept different as much as possible. In some implementations, the pitch of the needle traces gradually decreases in a proportion of 5%.

When laying the second composite fiber layer, pile up a plurality of wool layers and lay, every wool layer of laying carries out a acupuncture, and the interval of acupuncture diminishes along with the number of piles of wool layer gradually, and acupuncture point is more intensive promptly to the wool layer surface of upper strata is whole tends to levelly and smoothly, makes the surface of top layer fiber layer 62 also level and smoothly relatively after the acupuncture, and then the surface of the composite papermaking felt 100 of preparation is also levelly and smoothly fine and smooth.

In one embodiment, the surface fiber layer 62 includes first fibers and second fibers, and the first fibers have a melting point different from the melting point of the second fibers. Optionally, the first fibers have a melting point of 110 ℃ to 180 ℃ and the second fibers have a melting point of 250 ℃ to 260 ℃. For example, the melting point of the first fiber is 110 ℃, the melting point of the second fiber is 250 ℃, the melting point of the first fiber is 130 ℃, the melting point of the second fiber is 255 ℃, the melting point of the first fiber is 150 ℃, the melting point of the second fiber is 250 ℃, or the melting point of the first fiber is 180 ℃, and the melting point of the second fiber is 260 ℃.

In the heating and shaping process of the composite papermaking felt 100, the low-melting-point fibers are firstly changed into a softened state, the cohesive force between the surface fiber layer 62 and the front inner fiber layer 60 is higher, the surface fiber layer 62 is not easy to fall, the surface of the composite papermaking felt 100 is smoother and finer, and the paper sheet treatment effect is better.

In one embodiment, the surface fiber layer 62 further includes third fibers, and the third fibers are nylon fibers with fineness of 3D-15D according to paper requirements, for example, nylon fibers with fineness of 3D, 9D or 15D are used as the third fibers.

The selected fiber with thinner fineness can ensure the smoothness and fineness of the surface of the composite papermaking felt 100, and different fineness can be selected according to different paper surface requirements, so that the requirements of papermaking paper can be met.

In one embodiment, the first fibers and the second fibers comprise 10% to 30% by weight of the top fiber layer 10. For example, the first fibers and the second fibers comprise 10%, 20%, or 30% by weight of the top fiber layer 10.

The weight ratio of the first fibers and the second fibers in the surface fiber layer 62 is obtained through a plurality of test optimizations, and the surface fiber layer 62 within the ratio range can generate enough cohesive force with the front surface inner fiber layer 60 and can not affect the flatness of the surface of the composite papermaking felt 100.

In one embodiment, the front inner fiber layer 60 is made of nylon fiber with fineness of 30D-60D, for example, 30D, 45D or 60D, and as shown in fig. 2, the front inner fiber layer 60 includes a first batt layer 601, a second batt layer 602 and a third batt layer 603. The first wool layer 601 adopts 60D nylon fibers, the second wool layer 602 adopts 50D nylon fibers, and the third wool layer adopts 30D nylon fibers. The number of batt layers in the face side of the fibrous layer 60 can be increased or decreased as desired in the composite papermaker's felt 100.

Referring to fig. 3, fig. 3 is a schematic perspective view of a composite papermaking felt according to the present application. Wherein the first base fabric layer 40 and the second base fabric layer 42 are woven from warp and weft.

For the sake of distinction, the warp in the first base layer 40 is referred to as a first warp 400, the weft of the first base layer 40 is referred to as a first weft 402, the warp of the second base layer 42 is referred to as a second warp 420, and the weft of the second base layer 42 is referred to as a second weft 422.

In one embodiment, the first warp yarns 400 of the first base fabric layer 40 are monofilament yarns and the first weft yarns 402 are strand yarns. Wherein the strands of the first weft yarns 402 comprise at least one sub-strand, each sub-strand comprising at least three filaments. For example, the strand is formed by twisting 2 strands or 3 strands, and each sub-strand is formed by twisting 3 monofilaments. Optionally, the first warp yarn 400 uses nylon monofilament with a yarn diameter of 0.34mm to 0.4mm, for example, the first warp yarn 400 uses nylon monofilament with a yarn diameter of 0.34mm, 0.38mm, or 0.4 mm. The diameter of the nylon monofilament used for the first weft 402 is 0.18mm to 0.2mm, for example, the diameter of the nylon monofilament used for the first weft 402 is 0.18mm, 0.19mm, or 0.2 mm. Optionally, the density of the first warp threads 400 is 175-300/10 cm, such as 175/10 cm, 225/10 cm, 275/10 cm, or 300/10 cm. The density of the first weft 402 is 180-.

In one embodiment, the second warp yarns 420 of the second base fabric layer 42 are monofilament yarns and the second weft yarns 422 are strand yarns. The strand silk is formed by twisting 2 monofilaments and empty variable yarns. Optionally, the space-variant yarns are high-strength polyester space-variant yarns, and the performance parameters are that the strength is more than or equal to 20 N.m, the elongation is less than or equal to 25%, and the weight is 9g-10g/100 cm. Optionally, the second warp 420 is a nylon monofilament, and the monofilament used for the second weft 422 is a nylon monofilament. The diameter of the nylon monofilament used for the second warp 420 is 0.25mm to 0.38mm, for example, the diameter of the nylon monofilament used for the second warp 420 is 0.25mm, 0.3mm, 0.35mm or 0.38 mm. Optionally, the diameter of the nylon monofilament used for the second weft 422 is 0.18mm to 0.2mm, for example, the diameter of the nylon monofilament used for the second weft 422 is 0.18mm, 0.19mm or 0.2 mm. The warp density is determined according to the principle of meeting the requirement of obtaining a larger tightness of the fabric which is the important sum of the finished product gram, and is not particularly limited herein.

The second warp 420 selects monofilaments to ensure flatness of the surface of the second base fabric layer 42, the second weft 422 is formed by twisting nylon monofilaments and high-strength polyester air-textured yarns, and the air-textured yarns have better softness compared with the nylon monofilaments or plied yarns, so that the second base fabric layer 42 has better flatness, and the composite papermaking felt 100 is not prone to generating felt marks in production and use.

The nylon monofilament has the characteristics of high mechanical strength and strong shape stability, and the nylon monofilament is adopted as the raw material of the base cloth layer, so that the strength of the composite papermaking felt 100 can be improved, and the service life of the composite papermaking felt can be prolonged.

Referring to fig. 4 and 5, fig. 4 is a schematic view of a knitting structure of an embodiment of the first base fabric layer 40, and fig. 5 is a schematic view of a knitting structure of an embodiment of the second base fabric layer 42. In one embodiment, the first scrim layer 40 is formed by weaving the first warp yarns 400 and the first weft yarns 402 using an 1/3 twill weave, and the second scrim layer 42 is woven by weaving the second warp yarns 420 and the second weft yarns 422 using a 1/3 twill weave.

Guarantee certain intensity when the base cloth layer that twill tissue was woven has certain compliance, 1/3 broken twill is the best of optimizing through the test and weaves the structure, through 1/3 broken twill first base cloth layer 40 and second base cloth layer 42 of weaving, two base cloth layers can not laminate completely together, make the base cloth layer have superior spatial structure, and then improved compound papermaking felt 100 compression resilience performance, be difficult to appear the compaction, phenomenon such as harden, be convenient for continuous use.

In one embodiment, the material of the bottom fibrous layer 22 comprises nylon fibers. During the preparation process, the fiber material is carded into a web by a carding machine, and then is needled into a web by a pre-needling machine, so as to obtain the bottom fiber layer 22.

The polyamide fiber has alkali resistance, and the slurry mainly containing alkali does not corrode or react with the fiber layer, so that the service life of the composite papermaking felt 100 is prolonged.

In one embodiment, the bottom fiber layer 22 is nylon fiber with fineness of 40D-60D, such as 40D, 50D or 60D.

Referring to fig. 6, fig. 6 is a schematic flow chart of a method for manufacturing a composite papermaking felt according to the present application. It should be noted that the present embodiment is not limited to the flow sequence shown in fig. 6 if substantially the same result is obtained. As shown in fig. 6, the present embodiment includes:

s601, providing a first composite fiber layer, and sequentially laying a plurality of wool layers on the first composite fiber layer.

S602: and respectively carrying out needling treatment on the plurality of wool layers, wherein the plurality of wool layers subjected to needling treatment form a second composite fiber layer, and the needling depth is gradually reduced along with the increase of the number of layers of the wool layers.

Every one deck batt of laying just carries out a acupuncture processing on first complex fibre layer, can make the sufficient cohesive force of batt and complex fibre layer and batt like this, and what connect is more firm, has promoted the stability of woollen blanket. The needling depth is gradually reduced along with the increase of the number of the batt layers, so that the sinking degree of the needling points on the surface of the batt layer relative to the upper layer is reduced, the surface of the surface fiber layer 62 is relatively flat after needling, and the surface of the prepared composite papermaking felt 100 is also flat and fine. In some embodiments, the depth of the needle penetration is gradually reduced in a proportion of 5%.

In one embodiment, the needling interval gradually decreases as the number of layers of bristles increases.

The needling interval is reduced along with the increase of the number of the wool layers, namely needling points are more dense, so that the whole surface of the upper wool layer tends to be flat, the surface of the surface fiber layer 62 is relatively flat after needling, and the surface of the prepared composite papermaking felt 100 is more flat and fine. In some embodiments, the intervals of the needling are gradually reduced in a proportion of 5%.

Referring to fig. 7, fig. 7 is a schematic flow chart of a method for manufacturing a composite papermaking felt according to another embodiment of the present disclosure. As shown in fig. 7, the present embodiment includes:

s701: providing a first base fabric layer and a second base fabric layer, stacking the first base fabric layer and the second base fabric layer, and performing heat setting treatment on a setting machine to obtain the base fabric layers.

For specific structural parameters of the first base fabric layer 40 and the second base fabric layer 42, reference is made to the above embodiments, and details are not repeated here.

In one embodiment, the first and second scrim layers 40, 42 are stacked and subjected to a 120-150 ℃ heat setting process, such as 120, 135, or 150 ℃ heat setting process, to provide the scrim layer 24.

The base fabric layer 24 is configured to enhance the strength of the composite papermaking felt 100, and a gap is formed between the first base fabric layer 40 and the second base fabric layer 42, so that the base fabric layer 24 has better resilience and drainage performance, thereby improving the compression resistance of the composite papermaking felt 100. In addition, the internal stress generated in the stretching process is eliminated through heat setting treatment, so that the base cloth layer 24 is stable in shape and structure, the cohesive force is increased, and the change of shape or size in the subsequent use is avoided.

S702: providing a bottom fiber layer, stacking the bottom fiber layer and the base cloth layer, and carrying out needling treatment to obtain a first composite fiber layer.

The specific structural parameters of the bottom fiber layer 22 refer to the above embodiments, and are not described herein again.

The arrangement of the multiple fiber layers can improve the water absorption performance of the composite papermaking felt 100, can fully absorb the moisture of the paper sheets, and can modify the surfaces of the paper sheets to make the surfaces of the paper sheets flat and smooth. The bottom fiber layer 22, the first base fabric layer 40, and the second base fabric layer 43 are needled in a vertically staggered manner to have a certain cohesive force therebetween.

S703: and sequentially paving a plurality of wool layers on the first composite fiber layer, and performing needling treatment on the plurality of wool layers respectively to obtain the primary blanket.

During the needling treatment, the needling depth is gradually reduced along with the increase of the layer number of the wool, and the needling interval is gradually reduced along with the increase of the layer number of the wool. The plurality of batt layers comprise a face side inner fibrous layer 60 and a face side fibrous layer 62, the plurality of batt layers forming the second composite fibrous layer 16.

In one embodiment, the depth and spacing of the needle punches are tapered at a rate of 5%.

When the first composite fiber layer 12 is needled from one side of the second composite fiber layer 16, the coarse fibers in the composite fiber layer 12 are not brought to the front surface, and in addition, the surface fiber layer 10 can be reduced to generate depressions along with the reduction of the needling depth and the interval of the increase of the number of the wool layers, so that the composite papermaking felt 100 is smoother, and the fineness is obviously improved.

In one embodiment, the needling processes in steps S702 and S703 may be performed simultaneously, i.e., from the direction of the bottom fiber layer 22 and from the direction of the front-side back fiber layer 60 in the first composite fiber layer 12, and may be performed in an up-and-down staggered manner.

The vertically staggered manner can increase the cohesive force between the layers of the composite papermaking felt 100, and tightly connect the first composite fiber layer 12 and the second composite fiber layer 16, thereby improving the stability of the composite papermaking felt 100.

S704: and carrying out hollow needling treatment on the primary blanket to obtain a secondary blanket.

The blank needling treatment of the blanket can increase the cohesive force between each layer of the blanket, thereby improving the stability of the blanket and being beneficial to prolonging the service life of the blanket.

S705: and (3) soaking the secondary blanket in a detergent, washing the blanket clean, absorbing water by using a water absorption box, and removing the surface floating hair by a combustion method.

In one embodiment, the blanket is rinsed clean after soaking for 3 hours in 5% alkaline detergent. The cleaned blanket is sucked to be dry by a water suction box and then the surface floating hair is treated by a combustion method. Some fine fluff can exist on the surface of the composite papermaking felt 100 after the needle punching flocking, which affects the smoothness of the felt and also affects the smoothness of the paper surface when in use, and through a combustion method, namely, the fluff can be contracted back to a gap by using flat flame at a certain distance under the uniform speed rotation state of the felt, so that the smoothness of the surface of the composite papermaking felt 100 is improved.

And S706, pressurizing and shaping through a hot oil roller to obtain the composite papermaking felt.

In one embodiment, the composite papermaking felt 100 is pressed and shaped by the oil-heated roller, the shaping temperature is set to the melting point of the first fibers used in the surface fiber layer 62, the surface fiber is partially softened, the cohesive force between the surface fiber layer 62 and the front inner fiber layer 60 is higher, the hair falling is reduced, and the felt surface is smoother. The base fabric layer 24 is heat set twice to further improve the stability of the composite papermaker's felt 100.

To sum up, the application provides a compound papermaking felt and preparation method, when laying second composite fiber layer, pile up a plurality of wool tops and lay, every wool top of laying carries out acupuncture once, and along with the increase acupuncture degree of laying the wool top number of piles reduces gradually, make the degree of depth of the acupuncture trace on upper wool top surface diminish, effectively reduced the sunken degree on wool top surface, finally under the condition that has sufficient cohesive force between each wool top and between top fiber layer and the composite fiber layer in the top fiber layer, make top fiber layer level and smooth and fine, and then make compound papermaking felt's surfacing fine and smooth, satisfy the demand of making high-grade paper, cultural paper, paper tissue paper etc. and requiring paper class product that the face smoothness is high.

The above description is only an embodiment of the present application, and not intended to limit the scope of the present application, and all modifications that can be made by using equivalent structures or equivalent processes in the specification and drawings of the present application, or applied to other related technical fields directly or indirectly, are included in the scope of the present application.

Claims

1. A composite papermaking felt, comprising a first composite fiber layer and a second composite fiber layer, wherein the second composite fiber layer is laid on the first composite fiber layer; the second composite fiber layer is provided with a plurality of wool layers, needle tracks are formed on the wool layers, and the depth of the needle tracks is gradually reduced along with the increase of the number of the wool layers.

2. The papermaking felt according to claim 1, wherein the interval of the needle tracks gradually decreases as the number of layers of the batt layer increases.

3. The papermaking felt according to claim 2, wherein the depth and the interval of the needle marks are each gradually decreased at a rate of 5%.

4. The papermaking felt according to claim 1, wherein the second composite fiber layer includes a stacked face-side inner fiber layer and a face-side fiber layer.

5. The papermaking felt according to claim 4, wherein the top fiber layer includes first fibers and second fibers; wherein the first fibers and the second fibers have different melting points.

6. The papermaking felt according to claim 5, wherein the first fibers have a melting point of 110 ℃ to 180 ℃ and the second fibers have a melting point of 250 ℃ to 260 ℃.

7. The papermaking felt according to claim 5, wherein the surface fiber layer further comprises third fibers, wherein the third fibers have a fineness of 3D to 15D; the first fibers and the second fibers account for 10% -30% of the mass of the surface fiber layer.

8. The papermaking felt according to claim 4, wherein the face-side inner fiber layer includes nylon fibers, and the fineness of the face-side inner fiber layer is 30D to 60D.

9. The papermaking felt according to claim 1, wherein the first composite fiber layer includes a bottom fiber layer and a base fabric layer stacked, the first composite fiber layer being laid on the base fabric layer.

10. The papermaking felt according to claim 9, wherein the scrim layer comprises a first scrim layer and a second scrim layer;

wherein the weave structure of the first scrim layer comprises 1/3 broken twill weave;

the first base cloth layer comprises first warps and first wefts, and the first warps and the first wefts are interwoven with each other;

the first warp is a monofilament, and the material of the first warp comprises nylon;

the first weft is a plied yarn, and the material of the first weft comprises nylon.

11. The papermaking felt according to claim 10, wherein the diameter of the first warp threads is 0.34mm to 0.4mm, and the density of the first warp threads is 175-300 threads/10 cm;

the diameter of the first weft is 0.18mm-0.2mm, and the density of the first weft is 180-260/10 cm.

12. The papermaking felt according to claim 10, wherein the weave structure of the second base fabric layer comprises 1/3 broken twill weave;

the second base cloth layer comprises second warps and second wefts which are interwoven with each other;

the second warp is a monofilament, and the material of the second warp comprises nylon;

the second weft is a plied yarn, and the second weft is made of nylon and space-variant yarns.

13. The papermaking felt according to claim 12, wherein the second warp threads have a diameter of 0.25mm to 0.38 mm;

in the second weft, the diameter of the chinlon is 0.18-0.2 mm, and the air textured yarn comprises terylene.

14. The papermaking felt according to claim 9, wherein the bottom fiber layer comprises nylon fibers, and the fineness of the fibers of the bottom fiber layer is 40D to 60D.

15. A method for making a composite papermaking felt, comprising:

providing a first composite fiber layer, and sequentially laying a plurality of wool layers on the first composite fiber layer; and

16. The method of claim 15, wherein in the step of separately needling the plurality of batt layers, the needling interval gradually decreases as the number of batt layers increases.

17. The method of claim 16, wherein the depth and interval of the needling are gradually reduced by 5%.

18. The method of claim 17, wherein in the step of laying a plurality of batt layers on the first composite fiber layer, the plurality of batt layers forming a second composite fiber layer, the second composite fiber layer includes a surface fiber layer and a front surface-side back fiber layer, the surface fiber layer includes first fibers and second fibers; wherein the melting points of the first fibers and the second fibers are different.