How sunshade fabric is manufactured

Abstract

To provide a method for manufacturing a sunshade fabric that can be easily pleated and has complicated light shielding intensity.SOLUTION: A method for manufacturing a sunshade fabric consists of following four steps: a first step to manufacture a fiber web by randomly accumulating polyethylene terephthalate fibers; a second step to manufacture a fiber fleece that is formed of first convex parts 1 corresponding to warp and second convex parts 2 corresponding to weft and has a plain weave mesh fabric pattern on which parts other than the first convex parts 1 and the second convex parts 2 are concave parts 3 by making the fiber web pass through between a heating uneven roll and a heating smooth roll; a third step to obtain a nonwoven fabric by applying a resin binder over the entire fiber fleece in thickness direction; and a fourth step to give a stripe pattern consisting of a plurality of belt-like concave parts 4 and belt-like parts 5 existing between adjacent belt-like concave parts by making the nonwoven fabric pass through between the heating uneven roll and a non-heating smooth roll.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a sunshade fabric used for sunshades, and more particularly to a method for manufacturing a sunshade fabric used when making sunshade parts such as blinds and curtains that are installed on windows of buildings. [Background technology]

[0002] It has been known for some time that nonwoven fabrics are used as the fabric for the sunshades (slats) of blinds. Slats come in a variety of forms, including foldable structures made by pleating nonwoven fabrics and structures made by connecting slats formed into rectangular columns such as hexagonal columns in the vertical or horizontal direction. Various patterns have also been applied to the surface of slats. For example, Patent Document 1 proposes that a striped pattern consisting of a plurality of band-shaped recesses and band-shaped protrusions formed between the band-shaped recesses can be applied to the surface of a nonwoven fabric to achieve varying degrees of light blocking.

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-196955 DISCLOSURE OF THE INVENTION [Problem to be solved by the invention]

[0004] The present invention is an improvement over the invention described in Patent Document 1, and aims to provide a sunshade fabric that is easier to pleat and has more complex light blocking strengths and weaknesses. [Means for solving the problem]

[0005] The present invention solves the above-mentioned problems by providing a sunshade fabric with a combination of a specific plain weave mesh fabric pattern and a specific striped pattern. Specifically, the present invention relates to a method for producing a sunshade fabric, comprising: a first step of producing a fiber web by randomly collecting polyethylene terephthalate fibers; a second step of passing the fiber web between a heated uneven roll and a heated smooth roll to partially press the polyethylene terephthalate fibers constituting the fiber web together to produce a fiber fleece having a plain weave mesh fabric pattern consisting of first convex portions corresponding to warp threads and second convex portions corresponding to weft threads, with concave portions located outside the first convex portions and the second convex portions; a third step of applying a resin binder to the fiber fleece throughout its thickness to bond the polyethylene terephthalate fibers together to produce a nonwoven fabric; and a fourth step of passing the nonwoven fabric between a heated uneven roll and an unheated smooth roll to partially press the polyethylene terephthalate fibers constituting the nonwoven fabric together to provide a striped pattern consisting of a plurality of concave bands and convex bands located between adjacent concave bands.

[0006] The first step is to produce a fiber web by randomly collecting polyethylene terephthalate fibers. Polyethylene terephthalate fibers are used because they have excellent weather resistance and are advantageous for producing sunshade fabrics. The polyethylene terephthalate fibers may be either long or short fibers, but long fibers are preferred. This is because an aggregate of long fibers provides higher strength when used as a sunshade fabric. The fineness of polyethylene terephthalate fibers is approximately 2.2 to 5.5 decitex. If the fineness is less than 2.2 decitex, the strength of the resulting sunshade fabric tends to decrease. If the fineness exceeds 5.5 decitex, the fiber is less likely to soften simply by contacting a heated roll, making it difficult to press the fibers together. The basis weight of the fiber web is optional, but is generally 25 to 70 g / m 2As a method for randomly collecting polyethylene terephthalate fibers, in the case of long fibers, the fibers may be opened by a known method after melt spinning and then collected on a moving carrier. In the case of short fibers, the fibers may be opened by a card or the like and then collected on a moving carrier.

[0007] The second step is a step of producing a fiber fleece by passing the fiber web obtained in the first step between a heated uneven roll and a heated smooth roll to partially press-bond the polyethylene terephthalate fibers constituting the fiber web. The surface temperature of the uneven roll and the smooth roll and the linear pressure between the rolls are preferably such that the polyethylene terephthalate fibers are softened; specifically, the surface temperature is about 210 to 220°C and the linear pressure is about 40 to 60 kg / cm. The fiber fleece obtained in the second step is imparted with a plain weave mesh fabric pattern by the uneven roll. The plain weave mesh fabric pattern is, for example, as shown in Figure 1. That is, the pattern is composed of first convex portions 1 corresponding to warp yarns and second convex portions 2 corresponding to weft yarns, with concave portions 3 formed in areas other than the first convex portions 1 and second convex portions 2. The widths of the first convex portions 1 and second convex portions 2 are arbitrary, but are generally about 0.3 to 1.0 mm. The shapes of the first convex portions 1 and the second convex portions 2 are not limited to the rectangular shape shown in FIG. 1 , and may have rounded corners. The shape of the first convex portions 1 may be an ellipse elongated in the warp direction, and the shape of the second convex portions 2 may be an ellipse elongated in the weft direction. The area ratio of the first convex portions 1 and the second convex portions 2 to the entire surface is preferably about 40 to 70%. When such a plain weave mesh fabric pattern is provided, the fabric is easily bent in the vertical direction along the first convex portions 1, which correspond to the warp threads, or in the horizontal direction along the second convex portions 2, which correspond to the weft threads.

[0008] The third step is a step of applying a resin binder throughout the thickness of the fiber fleece obtained in the second step, particularly by bonding the polyethylene terephthalate fibers present in the first convex portion 1 and the second convex portion 2 with the resin binder to produce a nonwoven fabric. Known resin binders, such as acrylic binders, urethane binders, NBR binders, and SBR binders, are used as the resin binder. Among these binders, acrylic binders are preferred because they are soft and highly elastic, reducing noise, such as friction and vibration, generated by the resulting sunshade fabric. A common method for applying the resin binder throughout the thickness of the fiber fleece is to immerse the fiber fleece in a dispersion liquid in which the resin binder is dispersed. Alternatively, the resin binder can be applied throughout the thickness of the fiber fleece by spraying the dispersion liquid onto the surface of the fiber fleece and suctioning it from the backside. Furthermore, the dispersion liquid can be retained between a pair of rolls, and the fiber fleece can be passed between these rolls to impart the resin binder to the entire thickness of the fiber fleece. The amount of resin binder to be applied is optional, but is generally 3 to 10 g / m 2 In this way, the fiber fleece is impregnated with the dispersion, and then dried and / or cured to obtain a nonwoven fabric in which the polyethylene terephthalate fibers are bonded together with the resin binder. The nonwoven fabric obtained by this method has a good feel without losing its flexibility.

[0009] The fourth step is to produce a sunshade fabric by passing the nonwoven fabric obtained in the third step between a heated uneven roll and an unheated smooth roll to partially press the polyethylene terephthalate fibers constituting the nonwoven fabric together, thereby forming a striped pattern. The heated uneven roll is generally made of metal, while the unheated smooth roll is generally made of rubber, fiber, or resin. The surface temperature of the heated uneven roll and the linear pressure between the rolls may be such that the polyethylene terephthalate fibers are softened. The striped pattern is preferably coarser than the plain weave mesh fabric pattern. Therefore, the surface temperature is preferably higher than the surface temperature when forming the plain weave mesh fabric pattern, and the linear pressure is preferably lower than the linear pressure when forming the plain weave mesh fabric pattern. Specifically, the surface temperature is approximately 220 to 250°C, and the linear pressure is approximately 5 to 20 kg / cm. Here, the striped pattern may be, for example, one as shown in FIG. 2. That is, the pattern is composed of a plurality of band-shaped recesses 4, 4, 4 and band-shaped protrusions 5 located between adjacent band-shaped recesses 4, 4. While the band-shaped recesses 4 run at a 45° angle in FIG. 2, the running direction is arbitrary; for example, the band-shaped recesses 4 may run vertically or horizontally. The widths of the band-shaped recesses 4 and the band-shaped protrusions 5 are arbitrary, but it is preferable that the width of the band-shaped recesses 4 is narrower than the width of the band-shaped protrusions 5. The sunshade fabric obtained by the preferred method of the present invention has a pattern that combines a plain weave mesh fabric pattern and a striped pattern, as shown in FIG. 3. Therefore, even if the band-shaped protrusions 5, which have low light-blocking properties, are wide, the light-blocking properties are improved by the recesses 3 of the plain weave mesh fabric pattern. Furthermore, as can be seen from FIG. 3, the light-blocking strength is not simple but complex, making it possible to achieve a tasteful light-blocking effect.

[0010] After the fourth step, any additional steps can be added as desired. For example, a dyeing, textile printing, or printing step, a lamination step in which other layers such as paper or film are laminated, or a coating step in which a resin is applied to the front or back surface to form a resin layer can be added. The resulting sunshade fabric can be cut to a predetermined size and used as blind slats. The sunshade fabric can also be pleated and used as folding blind slats. Furthermore, the sunshade fabric can be folded to form a rectangular pillar such as a hexagonal pillar, which can be joined vertically or horizontally to form a slat. The sunshade fabric obtained by the method of the present invention can be used not only as blind slats, but also for desired applications such as curtains and car sunshades. [Effects of the Invention]

[0011] The sunshade fabric obtained by the method of the present invention has a specific plain weave mesh fabric pattern, so it is easy to fold along the first convex portion and / or the second convex portion of the plain weave mesh fabric pattern, and there is little return to its original shape after folding, which makes it easy to pleat and form into a rectangular column.In addition, since the pattern is a combination of a specific plain weave mesh fabric pattern and a specific stripe pattern, it has the effect of providing complex light blocking and realizing light blocking that is full of taste. [Example]

[0012] Example 1 Polyethylene terephthalate with a melting point of 256°C was melt-spun to obtain long fibers with a fineness of 3.0 dtex (fiber diameter 18 μm), and the long fibers were randomly accumulated on a conveyor to produce a fiber weight of 39 g / m. 2 A fiber web having the above structure was obtained. This fiber web was passed between an uneven roll and a smooth roll heated to a surface temperature of 215°C under a linear pressure of 50 kg / cm, and the unevenness of a plain weave mesh fabric pattern was imparted to obtain a fiber fleece. The widths of the first and second convex portions corresponding to the warp and weft yarns of the plain weave mesh fabric pattern were 0.6 mm, and the area ratios of the first and second convex portions were 60%. This fiber fleece was immersed in an acrylic emulsion (manufactured by DIC Corporation, trade name "Boncoat", glass transition temperature 2°C), squeezed with a mangle roll, dried at about 100°C, and then heat-treated at about 150°C to promote the cross-linking reaction of the acrylic binder, resulting in a fabric weight of 45 g / m 2 A nonwoven fabric of 1000 g was obtained. This nonwoven fabric was passed between a heated steel embossed roll heated to a surface temperature of 230°C and an unheated resin roll to obtain a sunshade fabric. The convex portions of the heated embossed roll were arranged in a spiral, and the fabric was processed at a speed of 14 m / s and a pressure of 10 kg / cm. As a result, a striped pattern of approximately 1 mm wide recessed bands and approximately 4 mm wide protruding bands running at a 45° angle was obtained. The resulting sunshade fabric was as shown in Figure 4.

[0013] Example 2 A sunshade fabric was obtained in the same manner as in Example 1, except that instead of a heated uneven roll with spirally arranged convex portions, a heated uneven roll with multiple linear convex portions arranged parallel to the axial direction on the roll surface was used.

[0014] The sunshade fabrics obtained by the methods according to Examples 1 and 2 were easy to pleat and could provide a stylish shade. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a schematic diagram showing an example of a plain weave mesh knit pattern used in the present invention. [Figure 2] FIG. 2 is a schematic diagram showing an example of a stripe pattern used in the present invention. [Figure 3] FIG. 1 is a schematic diagram showing an example of a combination of a plain weave mesh knit pattern and a stripe pattern used in the present invention. [Figure 4] 1 is a photograph of the surface of the sunshade fabric obtained by the method according to Example 1. [Explanation of symbols]

[0016] 1. First convex part of plain weave mesh fabric pattern 2. Second convex part of plain weave mesh fabric pattern 3. Concave portions existing outside the first convex portion and the second convex portion 4 Striped recess 5 Striped convex band

Claims

1. A first step of randomly collecting polyethylene terephthalate fibers to produce a fiber web; a second step of passing the fiber web between a heated uneven roll and a heated smooth roll to partially press-bond the polyethylene terephthalate fibers constituting the fiber web together, thereby producing a fiber fleece having a plain weave mesh fabric pattern consisting of first convex portions corresponding to warp yarns and second convex portions corresponding to weft yarns, with concave portions formed in areas other than the first convex portions and the second convex portions; a third step of applying a resin binder to the fiber fleece throughout the thickness direction to bond the polyethylene terephthalate fibers together to produce a nonwoven fabric; and A method for manufacturing a sunshade fabric, characterized by comprising a fourth step of passing the nonwoven fabric between a heated uneven roll and an unheated smooth roll to partially press the polyethylene terephthalate fibers that make up the nonwoven fabric together, thereby imparting a striped pattern consisting of a plurality of band-shaped recesses and band-shaped protrusions located between adjacent band-shaped recesses.

2. 2. The method for manufacturing a sunshade fabric according to claim 1, wherein the width of each of the recessed bands in the stripe pattern is narrower than the width of each of the raised bands.

3. 3. The method for manufacturing a sunshade fabric according to claim 1, wherein the plain weave mesh fabric pattern has recesses in the area of ​​each of the belt-like protrusions of the stripe pattern.

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