JP2020002490A - Apron band for spinning - Google Patents

Abstract

To provide an apron band for spinning that is excellent in durability.SOLUTION: An apron band for spinning includes a rubber layer and a resin layer that is attached to the rubber layer, and the rubber layer contains nitrile rubber and styrene butadiene rubber, and the resin layer contains a polyolefin-based resin. In the rubber layer, a mass ratio of the nitrile rubber to the styrene butadiene rubber is greater than 25:75. The mass ratio of the nitrile rubber to the styrene butadiene rubber is preferably less than 75:25.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a spinning apron band used for drawing a fiber or a fiber bundle in various spinning processes.

  In spinning applications, draft devices for drawing fibers and fiber bundles are used. FIG. 4 is a side view schematically showing the draft device. The draft device includes a pair of central first rollers 47 and 48 to which an apron band is attached, a pair of second rollers 41 and 42 and a pair of first rollers 47 and 48 disposed so as to sandwich the pair of first rollers 47 and 48. 3 rollers 45 and 46 are provided. Apron bands 43 and 44 are attached so as to contact a part of the respective peripheral surfaces of the first rollers 47 and 48, respectively. Ten servers 49, 50 are arranged such that predetermined regions on the outer peripheral surfaces of the apron bands 43, 44 are in contact with the fiber bundle F, respectively. The apron band 43 is bridged between the first roller 47 and the ten server 49. Similarly, the apron band 44 is also bridged between the first roller 48 and the ten server 50. The fiber bundle F is sent from the second rollers 41 and 42 to the third rollers 45 and 46, and is stretched while passing through these rollers.

  The apron band is required to have a certain degree of flexibility to be brought into contact with the fiber bundle or the fiber. Therefore, conventionally, a rubber apron band has been used (Patent Document 1). Since the inside of the apron band is required to have slidability with respect to the ten server, the surface of the rubber apron band is generally treated with an acid. Further, it has been proposed to bond a lubricating coating layer having a low coefficient of friction to the inside of an apron band with an adhesive (Patent Document 2).

JP-A-10-102328 Japanese Utility Model Publication No. 61-11243

  However, the apron bands of Patent Document 1 and Patent Document 2 have low durability.

One aspect of the present invention includes a rubber layer and a resin layer bonded to the rubber layer,
The rubber layer includes a nitrile rubber and a styrene butadiene rubber,
The resin layer contains a polyolefin-based resin,
The present invention relates to a spinning apron band having a mass ratio of the nitrile rubber to the styrene-butadiene rubber of more than 25:75.

  ADVANTAGE OF THE INVENTION According to this invention, the apron band for spinning excellent in durability can be provided.

It is a cross section in the thickness direction of the apron band concerning one embodiment of the present invention. It is a cross section in the thickness direction of the apron band concerning other embodiments of the present invention. It is a cross section in the thickness direction of the apron band concerning another embodiment of the present invention. It is a side view which shows typically the general draft device provided with an apron band.

[Apron band for spinning]
The spinning apron band according to one aspect of the present invention includes a rubber layer and a resin layer bonded to the rubber layer. The rubber layer contains a nitrile rubber and a styrene-butadiene rubber (hereinafter, also referred to as SBR). The resin layer contains a polyolefin-based resin. The mass ratio of nitrile rubber to SBR is greater than 25:75. The fact that the rubber layer and the resin layer are joined means that the apron band has an adhesive interface between the rubber layer and the resin layer.

  When the rubber layer contains nitrile rubber, high flexibility and fiber retention can be secured. In addition, by combining SBR contained in the rubber layer and a resin layer containing a polyolefin-based resin, high affinity between the rubber layer and the resin layer can be ensured. Therefore, the rubber layer and the resin layer can be joined without using an adhesive, and high joining properties can be secured. When the mass ratio of the nitrile rubber to SBR is greater than 25:75, high wear resistance is obtained, and the resin layer is superior in strength and chemical resistance as compared with rubber. Therefore, the durability of the apron band can be improved. Further, since the rubber layer and the resin layer are joined, high dimensional stability can be obtained. Further, even when the thickness of the apron band is reduced, the strength of the apron band can be easily secured. When the resin layer is arranged inside the apron band, high slidability with respect to the ten server is easily obtained, so that conventional acid treatment or the like is not required. Since the number of steps of applying the adhesive and the acid treatment step can be reduced, it is advantageous in terms of cost.

  In the apron band according to the present invention, the strength and dimensional stability can be ensured by providing the rubber layer and the resin layer having a predetermined thickness, so that the other layer configuration is not particularly limited. The apron band may have a two-layer structure of a rubber layer and a resin layer, or may have a multilayer structure of more than that.

  Since the rubber layer has excellent fiber holding properties, it is preferable that the rubber layer is disposed on the side that comes into contact with the fibers. FIG. 1 is a schematic cross-sectional view in the thickness direction showing an example of an apron band having a two-layer structure. More specifically, the apron band 1 includes a first surface A on the side in contact with the fiber and a second surface B on the opposite side to the first surface A, and the first surface A is a rubber layer. 2 and the second surface B is the surface of the resin layer 3. In such an apron band, fibers are easily held by the rubber layer on the first surface side, and high slidability with respect to the tenserver is obtained by the resin layer on the second surface side.

  However, the apron band is not limited to the example of FIG. 1. For example, a resin layer may be disposed on the first surface side A and a rubber layer may be disposed on the second surface side B. In the apron band, a resin layer bonded to both rubber layers may be arranged between two rubber layers, and the resin layer and the rubber layer are alternately laminated to form a multilayer structure of four or more layers. It may be. FIG. 2 is a schematic cross-sectional view in the thickness direction showing an example of an apron band having a three-layer structure. The apron band 11 includes two rubber layers 2 and a resin layer 3 interposed between them and joined to both rubber layers 2. The first surface A and the second surface B are the surfaces of the rubber layer 2, respectively. In such an apron band, at least the second surface may be subjected to an acid treatment to impart a slidability to the tenserver to the rubber layer.

  The type and composition of the resin constituting the resin layer may be selected in consideration of the compatibility with nitrile rubber and SBR. In a preferred embodiment, the resin layer includes polyethylene. In this case, it is easy to secure high affinity between the rubber layer and the resin layer by the combination of the SBR and the resin layer. Therefore, the rubber layer and the resin layer can be joined with high strength, and the strength of the apron band can be further increased.

  Since the apron band includes the resin layer, high strength is obtained. However, from the viewpoint of further increasing the strength, the apron band may further include a core yarn embedded inside. The core yarn may be embedded in either the rubber layer or the resin layer, or may be embedded between the two layers in a state of being in contact with both layers. FIG. 3 is a schematic cross-sectional view in the thickness direction of an apron band, showing an example in which a core yarn is embedded in a rubber layer. In the illustrated example, the apron band 21 includes a rubber layer 22 disposed on the first surface A side, and a resin layer 3 bonded to the rubber layer 22 and disposed on the second surface B side. A plurality of core yarns 24 are embedded in the rubber layer 22.

Hereinafter, the configuration of the apron band will be described more specifically.
(Rubber layer)
The rubber layer contains a nitrile rubber and SBR.
Examples of the nitrile rubber include acrylonitrile-butadiene rubber (NBR), acrylonitrile-butadiene-isoprene rubber (NBIR) in which a part of a butadiene unit is substituted with an isoprene unit, and hydrides thereof (for example, hydrogenated NBR). The nitrile rubber may be modified by introducing a third monomer unit (a monomer unit other than acrylonitrile and butadiene) as necessary. The rubber layer may contain one kind or two or more kinds of these nitrile rubbers.

  The ratio of acrylonitrile (AN) units in the nitrile rubber (the amount of bonded AN) is, for example, 18 to 50% by mass, and preferably 30 to 45% by mass. When the ratio of the AN units is in such a range, high oil resistance and wear resistance can be obtained.

  The proportion of the nitrile rubber in the rubber component contained in the rubber layer is preferably more than 25% by mass, and from the viewpoint of further increasing the abrasion resistance, more preferably 50% by mass or more, and more preferably 60% by mass or more. Is more preferred.

  As the SBR, any of various SBRs synthesized by copolymerizing styrene and 1,3-butadiene by various polymerization methods such as an emulsion polymerization method and a solution polymerization method can be used. As the SBR, there are an oil-extended type in which the flexibility is adjusted by adding extender oil, and a non-oil-extended type in which extender oil is not added, and both of them can be used. One or more of these SBRs can be used.

  In the rubber layer (rubber component in the rubber layer), the mass ratio between nitrile rubber and SBR is greater than 25:75. If the mass ratio of the nitrile rubber to the SBR is 25:75 or less, the abrasion resistance is low, and practically sufficient durability cannot be obtained. From the viewpoint of securing the flexibility of the rubber layer and obtaining high abrasion resistance, the mass ratio of the nitrile rubber to the SBR is preferably 50:50 or more, and more preferably 60:40 or more. More preferred.

  The rubber component of the rubber layer may include a rubber (third rubber) other than nitrile rubber (first rubber) and SBR (second rubber). Examples of the third rubber include olefin-based rubbers (such as ethylene propylene rubber) such as EPDM, and fluorine rubber. Examples of the fluorine rubber include vinylidene fluoride rubber (FKM), tetrafluoroethylene-propylene rubber (FEPM), and tetrafluoroethylene-purple fluorovinyl ether rubber (FFKM). The third rubber can be used alone or in combination of two or more. The total ratio of the nitrile rubber and SBR in the rubber component of the rubber layer is preferably 70% by mass or more, more preferably 85% by mass or more.

  The rubber layer may contain additives commonly used in apron bands. Examples of the additive include a filler, a vulcanizing agent, a vulcanization accelerator, a vulcanization accelerator, a processing aid, and a plasticizer. The rubber component constituting the rubber layer is preferably vulcanized using a vulcanizing agent (and, if necessary, a vulcanization accelerator).

(Resin layer)
The resin layer contains a polyolefin-based resin. The resin layer containing the polyolefin-based resin is easily compatible with SBR, and it is easy to ensure the affinity between the rubber layer and the resin layer. Examples of the polyolefin-based resin include polyethylene, polypropylene, and ethylene-propylene copolymer. The polyolefin resins can be used alone or in combination of two or more.

  As the polyolefin resin, ultrahigh molecular weight polyethylene having a molecular weight of 1,000,000 to 12,000,000 is suitable. In the case of ultrahigh molecular weight polyethylene, high slidability is easily obtained, and high durability is obtained.

  The resin layer may include a resin other than the polyolefin-based resin, an additive, and the like. The ratio of the polyolefin-based resin in the resin layer is, for example, 50% by mass or more, and preferably 75% by mass or more.

  The substrate on which the resin layer is formed is preferably a film-shaped or sheet-shaped molded product having a thickness of 10 μm to 250 μm. When the thickness is 10 μm or more, the strength of the apron band can be sufficiently ensured.

  The thickness ratio between the rubber layer and the resin layer can be selected, for example, from the range of 99: 1 to 50:50. When the thickness ratio is in such a range, an apron band having an excellent balance between strength and flexibility is easily obtained.

(Core yarn)
As the core yarn, a core yarn conventionally used in a general apron band is used without any particular limitation. The material of the core yarn and the average fiber diameter are appropriately determined according to the desired properties of the apron band and the like. Examples of the core material include natural fibers such as cotton, hemp, and silk, and synthetic fibers such as polyamide fiber and polyester fiber.

(Other)
The thickness of the apron band is, for example, 0.1 to 8.0 mm, and preferably 0.5 to 3.0 mm.

  The apron band is, for example, a sheet made of a resin layer is wound around the peripheral surface of a cylindrical core material (such as an iron core) to thermally weld the overlapping portion, and the surface of the cylindrical resin layer is covered with a rubber layer. It can be manufactured by crimping the whole under heating. Depending on the layer configuration of the apron band, the peripheral surface of the cylindrical core material may be covered with a rubber layer, a sheet made of a resin layer may be wound, and the whole may be pressed under heating. The heating temperature and the pressure at the time of pressure bonding can be appropriately determined according to the composition of the rubber layer or the resin layer. In this embodiment, an apron band in which the rubber layer and the resin layer are joined can be obtained without forming an adhesive layer between the rubber layer and the resin layer.

  When embedding the core yarn between the rubber layer and the resin layer, the core yarn may be disposed between the rubber layer and the sheet, and the crimping may be performed. When the core yarn is embedded in the rubber layer or the resin layer, the core yarn is embedded when the rubber layer or the resin layer is formed. A known method can be adopted for embedding the core yarn.

  If necessary, the surface of the rubber layer or the resin layer of the formed apron band may be subjected to an acid treatment. The acid treatment can be performed using, for example, hydrochloric acid, hypochlorous acid, or the like.

[Example]
Hereinafter, the present invention will be specifically described based on examples and comparative examples, but the present invention is not limited to the following examples.

Example 1
NBR (Nipol 1042S, manufactured by Zeon Corporation, AN ratio: 33.5% by mass) and SBR (JSR 1502, non-oil-extended, styrene content: 23.5% by mass) were combined with 30. : 70 (mass ratio) and kneaded with a kneader. Vinyl chloride resin (ZEST P-21, manufactured by Shin-Daiichi PVC Co., Ltd.) and silica (ULTRASIL VN3, manufactured by Evonik Japan KK) were used as fillers with respect to 100 parts by mass of the obtained mixture (rubber component). 30 parts by mass and 15 parts by mass, 1.5 parts by mass of fine powder sulfur (manufactured by Tsurumi Chemical Industry Co., Ltd., 200 mesh) as a vulcanizing agent, and N-oxydiethylene-2-benzothiazolyl as a vulcanization accelerator. Rusulfenamide (Ouchi Shinko Chemical Industry Co., Ltd., Noxeller MSA-G) 2 parts by mass, zinc oxide (Sakai Chemical Industry Co., Ltd., zinc oxide type 1) 3 parts by mass as a vulcanization accelerator, plastic 10 parts by mass of dioctyl phthalate (DOP, manufactured by J-Plus Co., Ltd.) as an agent, and 1 part by mass of stearic acid (Lunac S-50V, manufactured by Kao Corporation) as a processing aid, And the mixture was kneaded by the leader. The kneaded product was filled in an extruder to prepare an unvulcanized tube (thickness: 1.5 mm).

  A film (thickness: 50 μm) made of ultra high molecular weight polyethylene (Ultra Polymer (UHMWPE), melting point: 136 ° C., manufactured by Yodogawa Hutec Co., Ltd.) is wound around a vulcanized iron core, and the overlapped portion is thermally fused to form a resin. A layer was formed.

  The unvulcanized tube is inserted into a vulcanized iron core on which a resin layer is formed, and a wrapping film is wound around the core and tightened, and then vulcanized at 160 ° C. for 60 minutes in a steam vulcanizer. Was performed and the tube was vulcanized.

  The rubber layer (vulcanized tube) is obtained by removing the wrapping film, decentering the vulcanized iron core, adjusting the outer circumference of the vulcanized tube to a predetermined thickness with a cylindrical polishing machine, and cutting the vulcanized tube to a predetermined width. A tubular apron band (thickness: 1.0 mm) in which the resin and the resin layer (polyethylene film) were joined was produced.

Examples 2 to 8 and Comparative Examples 1 and 2
An apron band was produced in the same manner as in Example 1 except that NBR and SBR were mixed at a mass ratio shown in Table 1 and masticated to obtain a rubber component.

Comparative Example 3
Without using SBR, only NBR was used as the rubber component. Except for this, two unvulcanized tubes were produced in the same manner as in Example 1.
An unvulcanized tube (for inner layer rubber) was fitted into a vulcanized iron core, and a thread (cotton yarn number 30) immersed in an organic solvent was spirally wound around the unvulcanized tube. . The remaining unvulcanized tube (for outer layer rubber) is further covered on this peripheral surface, and a wrapping film is wound around this peripheral surface and vulcanized at 160 ° C. for 60 minutes in a steam vulcanizer. And vulcanizing both tubes of the inner rubber and the outer rubber.

  The vulcanized tube was obtained by removing the wrapping film and decentering the vulcanized iron core. The vulcanized tube was immersed in an aqueous solution containing hydrochloric acid and hypochlorous acid to perform a surface treatment. After the surface treatment, the outer periphery of the tube was adjusted to a predetermined thickness with a cylindrical polishing machine, and then cut to a predetermined width. Thus, a tubular apron band (thickness: 1.0 mm) in which the core yarn was embedded was produced.

The following tests were performed using the apron bands obtained in Examples and Comparative Examples.
(I) Adhesion Test (Forced Peeling Test) From the apron bands obtained in Examples 1 to 8 and Comparative Examples 1 and 2, a strip-shaped test sample (7 mm in length × 50 mm in width × 1 mm in thickness) was used for each example. Each was produced.
Tensile stress was applied to the test piece, and it was evaluated whether peeling of the resin layer and the rubber layer occurred first or whether the rubber layer was broken first according to the following criteria A to C.
A: In 90% or more of the test samples, the rubber breaks before the film peels.
B: The order of the peeling of the film and the breaking of the rubber varies, and a stable result cannot be obtained as to which one occurs first. (That is, an intermediate result between A and C.)
C: In 90% of test samples, peeling of the film occurs before breaking of the rubber.

(Ii) About abrasion resistance test A test piece was produced using the kneaded materials obtained in Examples 1 to 8 and Comparative Examples 1 and 2, and was subjected to JIS K6264-2: 2005 (vulcanized rubber and thermoplastic rubber- Abrasion resistance was evaluated using an Akron abrasion tester in accordance with the method for determining abrasion resistance-Part 2: Test method). The familiar operation of the test piece was performed at 1000 rotations, then the initial mass (m ₀ ) was measured, and the mass (m ₁ ) of the test piece after 3660 rotations of the test was measured, and the mass change rate (mass%) was obtained by the following equation. Was evaluated, and evaluated using the following four-stage indices of A to D.
Mass change rate (% by mass) = (m ₀ −m ₁ ) / m ₀ × 100
A: The rate of change in mass is less than 2% by mass.
B: The mass change rate is 2% by mass or more and less than 3% by mass.
C: The mass change rate is 3% by mass or more and less than 4% by mass.
D: The rate of mass change is 4% by mass or more.

(Iii) Measurement of Friction Coefficient Test samples of the apron band (100 mm long × 20 mm wide × 1.0 mm thick) obtained in Example 5 and Comparative Example 3 were prepared, and the friction coefficient of the test sample was measured. More specifically, in Example 5, the friction coefficient of the surface on the resin layer side was measured, and in Comparative Example 3, the friction coefficient of the surface on the inner rubber side (that is, the surface on the inner layer side of the apron band) was measured.
The test conditions for the wear coefficient were measured using a surface property measuring device HEIDON Tribo-gear Type 14 manufactured by Shinto Kagaku Co., Ltd. under the conditions of a vertical load of 200 gf (≒ 1.96 N) and a measuring speed of 200 mm / min.

  As shown in Table 1, in the examples, the abrasion resistance was evaluated from A to C, and practically sufficient abrasion resistance was obtained. If the abrasion resistance is evaluated from A to C, it is determined that the abrasion resistance can withstand a load when used as an apron band in a textile machine such as a spinning machine during a desired product life. On the other hand, in Comparative Examples 1 and 2, although the adhesiveness between the resin layer and the rubber layer was high, the abrasion resistance was rated D. In the D evaluation, wear due to abrasion occurs in a period shorter than the product life period, and practically sufficient durability cannot be obtained. From the viewpoint of enhancing the adhesiveness between the resin layer and the rubber layer, the mass ratio between the nitrile rubber and the SBR is preferably smaller than 75:25.

  In Example 5, the coefficient of friction was small. When the value of the coefficient of friction is small, the rotation operation when attached to a textile machine such as a spinning machine becomes smooth, and the fiber can be transported smoothly, so that the effect of improving the quality of the finished yarn can be expected. Further, since the low coefficient of friction of Example 5 is a characteristic brought by the resin layer itself, it is hardly disappeared due to wear during use. On the other hand, the coefficient of friction of Comparative Example 3 is also at the same level as that of Example 5, but this value is obtained by the surface treatment layer obtained by the acid treatment during the manufacturing process, and the friction inherent in rubber is obtained. The coefficient is very high. Therefore, when the textile machine is actually mounted and operated, the friction coefficient increases due to wear, and the operation of the apron band is not smooth, which is a factor of deteriorating the yarn quality.

  The spinning apron band according to the embodiment of the present invention is suitable for use in a draft device for drawing fibers or fiber bundles in various spinning processes such as gil, bobina, drawing, roving, and spinning. I have.

1,11,21: apron band for spinning, 2,22: rubber layer, 3: resin layer, 24: core yarn,
41, 42: second roller, 43, 44: apron band, 45, 46: third roller, 47, 48: first roller, 49, 50: ten server, A: first surface, B: second surface, F: Fiber bundle.

Claims (5)

Including a rubber layer and a resin layer bonded to the rubber layer,
The rubber layer includes a nitrile rubber and a styrene butadiene rubber,
The resin layer contains a polyolefin-based resin,
An apron band for spinning, wherein a mass ratio of the nitrile rubber to the styrene butadiene rubber is greater than 25:75. The spinning apron band includes a first surface that is in contact with the fiber, and a second surface that is opposite to the first surface,
The first surface is a surface of the rubber layer,
The apron band for spinning according to claim 1, wherein the second surface is a surface of the resin layer.   The apron band for spinning according to claim 1 or 2, wherein a mass ratio of the nitrile rubber to the styrene butadiene rubber in the rubber layer is greater than 25:75 and smaller than 75:25.   The apron band for spinning according to any one of claims 1 to 3, wherein the polyolefin-based resin includes polyethylene.   The apron band for spinning according to any one of claims 1 to 4, further comprising a core yarn embedded therein.

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