JP2589551B2 - Manufacturing method of alkali-resistant roll - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for producing an alkali-resistant roll such as a squeezing roll, a pinch roll and a ringer roll used in the fields of iron making, paper making and the like.

[Problems to be solved by conventional technology and invention]

Conventionally, as a method of manufacturing an alkali-resistant roll, a spunbonded nonwoven fabric made of polyethylene, polypropylene, or the like is punched into a circle, and a plurality of the circular pieces are assembled into a shaft to form a roll. Because it is paper-like with high density, when punching and forming to a predetermined hardness during lamination molding,
There is a problem in that the layers are peeled off, uniform drawing performance cannot be obtained, and wear resistance is quickly consumed and abnormal wear is easily caused. In addition, the one molded under a high-pressure load in order to eliminate the peeling between the laminations, although the above problem is solved, becomes a very hard roll of resin tone, and it is difficult to adjust a predetermined drawing ratio. However, there is a disadvantage that the roll becomes difficult to use.

Furthermore, in order to solve the above problem, after the polyethylene-polypropylene composite fiber is temporarily fixed by needle punch, it has been developed to use a highly elastic dry nonwoven fabric in which the fibers are bonded and fixed with an alkali-resistant synthetic resin as a roll base material. However, the adhesion between the hydrophobic and non-polar polyethylene-polypropylene fiber and the synthetic resin cannot be sufficiently obtained, and the initial performance is excellent. Is caused, and there is a problem that stable drawing performance cannot be obtained for a long period of time.

[Means for solving the problem]

As a result of intensive studies in view of the above problems, the present invention has focused on the fact that air is most effective as a cushioning material, and that polyethylene and polypropylene fibers have poor compatibility with other resin binders. Is a non-woven sheet formed from a composite short fiber composed of a polyester component and a polyolefin component such as a polyethylene or a polypropylene component as a sheath. A roll formed by integrally heating and adhering and fixing adjacent base materials to each other by performing a heat treatment after winding and forming is insoluble in the sheath component of the roll base material composite short fiber, and only the polyester component of the core portion is formed. Extraction and removal of only the polyester component with a solvent that dissolves Grant in fins, impact resilience as rolls liquid holding together confer an air layer of the hollow portion, by applying a liquid-absorbent, is obtained to give alkali resistance roll to solve the above problems. Incidentally, the fiber diameter of the conjugate short fiber used in the present invention is not particularly limited as long as it is a short fiber, and may be selected as needed according to the performance as a roll.

That is, it is preferable to use a thick denier as a roll emphasizing rebound resilience, and to use a fine denier for applications requiring precise drawing. The cut length of the fiber is preferably short in consideration of extraction and removal with a polyester-soluble solvent, and is preferably about 28 to 51 mm in terms of the production method as a dry nonwoven fabric. The formation of the web using the core-sheath type composite fiber is most preferably a land web by a non-directional air flow, but the parallel and cross webs of the card system can sufficiently satisfy the performance as a roll. The fixing between the fibers of the web is preferably performed by a mechanical needle punching method. Particularly, as a roll base material requiring bulkiness and softness, fusion fixing by hot air is also effective. Next, the composition ratio of the composite fiber composed of the polyester component in the core portion and the polyolefin component such as polyethylene or polypropylene in the sheath portion should be arbitrarily selected depending on the performance as a roll.
Rolls requiring hardness contain 10 to 20 polyester components
It is preferable to select a composite fiber in the range of weight%, and use a composite fiber of 20 to 60 weight% as the high repulsion roll having low hardness. The roll is formed by punching a non-woven sheet into a circular shape, laminating and compressing the sheet, and then forming the sheet by thermoforming. It can also be obtained by heat treatment at the above temperature, bonding and integrating the layers, finishing the outer diameter, and then extracting and removing with a polyester component soluble solvent. For low-hardness rolls, the punch lamination method is preferred.

〔Example〕

 Hereinafter, the present invention will be described in more detail with reference to the drawings.

Example 1 As shown in FIGS. 1 and 2, 100% of a composite fiber (3) 2d × 51 mm (6080 manufactured by Unitika) having a core (1) composed of a polyester component and a sheath (2) composed of a polyethylene component. It is spun by a card machine to form a cross web with a basis weight of 200 g / m ² . Next, using a needle punching machine, a needle ring (4) was performed under the conditions of a number of shots of 400 P / cm ² and a depth of 14 mm, and the fibers were entangled alternately up and down. Then, the melting point of the polyethylene component was 130 ° C. Hot air treatment, crossover between fibers,
30Kg / 5c fresh breaking strength by forming a fused part (5) at the contact part
m, width 40Kg / 5cm, breaking elongation 50%, width 70% 2
A nonwoven fabric sheet having a thickness of 00 g / m ² and a thickness of 25 mm is obtained. Next, as shown in FIG. 3, a roll base material (6) punched into a disk shape having a keyway having an outer diameter of 152.4 mm and an inner diameter of 76.2 mm is inserted and laminated on a shaft (7), and the roll density is 1.0 g. / cm ^3, and the laminated layers are adhered and fixed together by a hot air treatment machine at 110 ° C. to form a roll body. Then roll the roll with 40% KO
H solution, immersed at 80 ° C. for 1 hour to extract and remove the polyester of the core component to form hollow fibers (8) shown in FIG. 4, wash and dry, and finish the outer peripheral surface of the roll by polishing roll finish to a predetermined value. Outside diameter (127mm) and roll density 0.7g / cm
^{3. An} alkali-resistant roll with excellent elasticity, shore rubber hardness of 60 and excellent liquid absorption and liquid retention performance was obtained.

Example 2 100% of a composite fiber 2d × 51 mm (6080 made by Unitika) 100% of a composite fiber composed of a core polyester component and a sheath polyethylene component is spun by a carding machine to form a cross web having a basis weight of 200 g / m ² . Next, the fibers are entangled alternately with the needle punching machine under the conditions of the number of injections of 400 P / cm ² and the injection depth of 14 mm, and then hot air treatment is performed at a temperature (130 ° C.) higher than the melting point of the polyethylene component. , Breaking strength, vertical 30Kg / 5cm, horizontal 40
Kg / 5cm, breaking elongation 50%, width 70%, basis weight 200g / m ² ,
A 25 mm thick nonwoven fabric was obtained.

Then the outer diameter of 101.6 mm, coiling tighten laminated to a predetermined outer diameter 152.4mm steel core having a key groove of an inner diameter of 76.2 mm, after the density of 1.5 g / cm ^3, placed in a 110 ° C. hot air processor Then, they are integrally fixed by the mutual adhesion between the laminated layers to form a roll body. Next, the above-mentioned roll is placed in a 40% aqueous solution of KOH at 80 ° C.
The core part of the conjugate fiber is extracted and removed from the polyester component, washed and dried. The roll surface is further polished to give an outer diameter of 127 mm, a density of 1.0 g / cm ^{3 and} a resilience of a Shore rubber hardness of 90. A hard alkali-resistant roll having excellent liquid absorption and liquid retention properties was obtained.

Comparative Example A cross-web having a basis weight of 200 g / m ² was formed using a composite fiber of polyethylene with a core polyester sheath in the same manner as in Example 1, and needle punching was performed under the same conditions as in Example.
A non-woven fabric having a thickness of 2.5 mm was formed. Next, impregnation processing (DPU = 40%) is performed with an alkali-resistant synthetic resin, and after drying, punched out in the same shape as in Example 1 and compression-laminated so as to have a density of 0.7 g / cm ^3. Obtained.

Next, the three types of rolls obtained in the above Examples and Comparative Examples were subjected to performance tests such as alkali resistance and draw ratio.

 The results obtained are shown in the table below.

As shown in the table, as a result of the test, all of the alkali-resistant rolls according to the present invention were excellent in characteristics.

〔The invention's effect〕

According to the present invention, the bonding strength between the fibers is very strong, the wear resistance is excellent, and the air in the hollow fibers exhibits a cushioning effect, is very rich in repulsion, and the stable drawing ratio is high. This has the effect of easily producing an alkali-resistant roll having characteristics such as excellent liquid absorption and liquid retention properties.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of the configuration of a nonwoven fabric sheet used in the present invention, FIG. 2 is an enlarged perspective view of a conjugate fiber constituting the nonwoven fabric sheet, and FIG. 3 is a perspective view of an alkali-resistant roll according to one embodiment of the present invention. FIG. 4 is a perspective view of the hollow fiber constituting the alkali-resistant roll. (1) ... core, (2) ... sheath (3) ... composite fiber, (4) ... needling (5) ... fused part, (6) ... roll base material (7) …… Shaft, (8) …… Hollow fiber

Claims (2)

(57) [Claims] 1. A method for producing a nonwoven fabric roll in which a plurality of roll base materials obtained by punching a sheet-like nonwoven fabric into a predetermined shape are assembled into a shaft, laminated and compressed, and fixed integrally. A nonwoven fabric sheet is formed by entanglement and heat treatment of a composite fiber web having a core portion made of a polyester component and a sheath portion made of a polyolefin component. An alkali-resistant roll characterized by being heat-treated and integrally fused and fixed, and then extracting and removing the polyester component of the core portion of the composite fiber with a soluble solvent that dissolves only the core portion to form a hollow fiber. Production method. 2. A method for producing a nonwoven fabric roll, wherein a sheet-like nonwoven fabric is wound and fixed on a core so as to have a predetermined thickness and density, wherein the nonwoven fabric sheet constituting the roll is made of a polyester component. The sheath portion is formed by entanglement of a composite fiber web made of a polyolefin component, by heat treatment, and heat-treated between the nonwoven sheets wound on the core at a temperature equal to or higher than the melting point of the sheath component and integrally fused and fixed. A method for producing an alkali-resistant roll, comprising extracting and removing a polyester component of a core portion of a conjugate fiber with a soluble solvent that dissolves only the core portion to obtain a hollow fiber.