JP7444515B1 - leather products - Google Patents

Abstract

[Problem] To provide a leather fabric in which sewing machine stitches using relatively thick multifilament thread are continuously formed on the surface with good appearance.
[Solution] A leather product in which sewing machine stitches are sewn onto a leather fabric is such that a first thread constituting the sewing machine stitch is formed on a first surface of the front side of the leather fabric, and a second thread that constitutes the sewing machine stitch is sewn on a second surface of the back side of the leather fabric. and a second thread constituting the sewing machine stitch. The thickness of the leather fabric is between 2 and 12 millimeters. The first thread and the second thread are multifilament threads. The thickness of the first thread is 1,600 to 4,000 decitex, which is 600 decitex or more thicker than the second thread. The thickness of the second thread is 1000-1800 decitex. The knot between the first thread and the second thread is located closer to the second surface in the thickness direction of the leather fabric.
[Selection diagram] Figure 2

Description

This specification discloses technology related to leather products and methods for manufacturing the same.

Leather products made by sewing machine lock stitches onto leather fabrics (including natural leather, synthetic leather, and artificial leather) are used for various objects that are visible to the human eye, such as automobile interior parts, furniture, and bags. Patent Document 1 describes an automobile interior part in which lock-stitch sewing machine stitches are sewn onto leather fabric.

Japanese Patent Application Publication No. 2016-198943

When using a relatively thick multifilament thread of about 1,600 to 4,000 dtex (product count: 5 to 0) to sew lockstitch stitches on leather fabric, looseness between the upper and lower threads may occur. There is a problem in that stitches occur in places and it is difficult to obtain continuous stitches that look good.

The technology disclosed in this specification can be realized as the following form.

A method for manufacturing a leather product in one embodiment disclosed in this specification is a method for manufacturing a leather product in which lock stitches are sewn onto a leather fabric. This manufacturing method includes a thread preparation step of preparing an upper thread and a lower thread in a sewing machine, a mounting step of placing the leather material on the throat plate of the sewing machine with the back side of the leather material facing upward; a sewing step of forming the sewing machine stitches on the leather fabric by sewing the leather fabric placed on the throat plate with a lock stitch using the sewing machine with the upper thread and the lower thread prepared; Be prepared. The thickness of the leather fabric is 2 to 12 mm. The upper thread and the lower thread are multifilament threads. The thickness of the needle thread is 1000 to 1800 decitex. The thickness of the lower thread is 1,600 to 4,000 decitex, which is 600 decitex or more thicker than the upper thread. In the thread preparation step, the tension of the upper thread is adjusted to 15 to 21 Newtons, and the tension of the lower thread is adjusted to 1 to 2 Newtons. According to this method of manufacturing leather products, it is possible to continuously form a good-looking sewing machine stitch on the surface of a leather fabric using a relatively thick multifilament thread of 1,600 to 4,000 decitex by lock stitching.

A leather product in one embodiment disclosed in this specification is a leather product in which lock-stitch sewing machine stitches are sewn onto a leather fabric. This leather product includes a first thread forming the sewing machine stitch on a first surface on the front side of the leather fabric, and a second thread forming the sewing machine stitch on a second surface on the back side of the leather fabric. Equipped with. The thickness of the leather fabric is 2 to 12 mm. The first thread and the second thread are multifilament threads. The thickness of the first thread is 1,600 to 4,000 decitex, which is 600 decitex or more thicker than the second thread. The thickness of the second thread is 1000 to 1800 decitex. The knot between the first thread and the second thread is located closer to the second surface in the thickness direction of the leather fabric. The leather fabric is a leather with urethane foam pasted on the back side, and the sewing machine stitches are sewn to the leather and the urethane foam. According to this type of leather product, it is possible to improve the quality of sewing machine stitching by lock stitching using a relatively thick multifilament thread of 1,600 to 4,000 decitex.

The technology disclosed in this specification can be realized in various forms different from leather products and methods for manufacturing the same. The technology disclosed in this specification can be realized, for example, in the form of automobile interior parts, furniture, bags, etc. using leather products.

It is a top view showing the leather product of this embodiment. It is a sectional view showing a leather product of this embodiment. It is a process diagram showing a method for manufacturing a leather product.

FIG. 1 is a plan view showing a leather product 10 of this embodiment. FIG. 2 is a sectional view showing the leather product 10 of this embodiment. The cross-sectional view in FIG. 2 shows the cross-section F2-F2 in FIG.

The leather product 10 is a product in which lock stitches 200 are sewn onto a leather fabric 100. The leather product 10 can be used for various objects that come into contact with the human eye, such as automobile interior parts, furniture, and bags.

The leather fabric 100 of the leather product 10 is a sheet-like leather. Leather fabric 100 is in the form of a sheet having a front surface 110 and a back surface 120. The surface 110 is the first surface that becomes the front side that is visible to the human eye when the leather product 10 is used as a final product. The back surface 120 is the surface opposite to the front surface 110. The back surface 120 is a second surface that is not visible to the human eye when the leather product 10 is used as a final product.

In this embodiment, the leather fabric 100 is synthetic leather laminated with urethane foam. In this embodiment, the front surface 110 is formed from synthetic leather and the back surface 120 is formed from urethane foam. In other embodiments, the leather fabric 100 may be artificial leather or natural leather. In other embodiments, the leather fabric 100 may be a leather laminated with a material different from urethane foam (for example, a woven fabric, a non-woven fabric, etc.) or a leather not laminated with any other material. Good too.

From the viewpoint of forming the sewing machine stitches 200 continuously on the surface 110 of the leather fabric 100 with good appearance, the thickness T of the leather fabric 100 is preferably 2 mm (millimeter) or more and 12 mm or less.

The leather fabric 100 has a plurality of needle holes 130 penetrating from the front surface 110 to the back surface 120. The needle hole 130 is formed by a sewing machine needle (not shown) when sewing the sewing machine stitch 200 on the leather fabric 100. The needle hole 130 holds the sewing machine stitch 200.

The machine stitches 200 of the leather product 10 are lockstitch stitches sewn on the leather fabric 100 by a sewing machine (not shown). The sewing machine stitch 200 includes a front thread 210 and a back thread 220. The surface thread 210 is the first thread that constitutes the sewing machine stitch 200 on the surface 110 of the leather fabric 100. The back surface thread 220 is a second thread that constitutes the sewing machine stitch 200 on the back surface 120 of the leather fabric 100.

The sewing machine stitch 200 has a knot 230 between a surface thread 210 and a back surface thread 220 in each of the plurality of needle holes 130 in the leather fabric 100. The knot 230 is located closer to the back surface 120 in the thickness direction of the leather fabric 100.

The sewing pitch P of the sewing machine stitch 200, which is also the distance between two adjacent needle holes 130, is a constant interval. From the viewpoint of forming the sewing machine stitches 200 continuously on the surface 110 of the leather fabric 100 with good appearance, the stitching pitch P is preferably 4.0 mm or more and 6.0 mm or less.

The front thread 210 and back thread 220 of the sewing machine stitch 200 are multifilament threads. In this embodiment, the front thread 210 and the back thread 220 are multifilament threads made of polyester. In other embodiments, the surface yarns 210 and the back surface yarns 220 may be made of nylon or silk, or may be blended or blended yarns. Further, the material of the front thread 210 may be different from that of the back thread 220.

From the viewpoint of forming sewing machine stitches 200 continuously on the surface 110 of the leather fabric 100 with a good appearance, the thickness of the surface thread 210 is 1600 dtex or more and 4000 dtex or less (product number 5 to 0), It is preferable that it is thicker than the back thread 220 by 600 dtex or more. Further, the thickness of the back thread 220 is preferably 1000 dtex or more and 1800 dtex or less (number 8 to 5 in terms of product number).

FIG. 3 is a process diagram showing a method for manufacturing the leather product 10. When manufacturing the leather product 10, the operator first performs a thread preparation step (step P110). In the thread preparation step (step P110), the operator prepares the sewing machine with an upper thread and a lower thread. The operator assembles the multifilament thread, which will become the back thread 220, into the sewing machine as the upper thread. The size of the sewing machine needle is preferably 18 to 24 depending on the thickness of the upper thread. The operator assembles the multifilament thread, which will become the surface thread 210, into the sewing machine as a bobbin thread.

In the thread preparation step (step P110), the operator adjusts the tension of the upper thread to 15 to 21 newtons. When measuring the tension of the needle thread, the operator attaches the needle thread passed through the sewing machine ten pin at the upper limit position to the tension gauge. Thereafter, the operator pulls out the upper thread horizontally by 100 mm from the sewing machine tensioner to the left side of the sewing machine. Thereafter, the operator uses a tension gauge to pull the upper thread in the horizontal direction at a rate of 50 mm/sec, and measures the value on the tension gauge at that time as the tension of the upper thread.

In the thread preparation step (step P110), the operator adjusts the tension of the bobbin thread to 1 to 2 newtons. When measuring the tension of the bobbin thread, the operator attaches the bobbin thread pulled out from the bobbin onto the throat plate to a tension gauge. Thereafter, the operator pulls out the bobbin thread 100 mm horizontally from above the throat plate toward the back of the sewing machine. Thereafter, the operator uses a tension gauge to pull the bobbin thread in the horizontal direction at a rate of 50 mm per second, and measures the value on the tension gauge at that time as the tension of the bobbin thread.

After carrying out the thread preparation process (process P110), the operator carries out the mounting process (process P120). In the mounting process (process P120), the operator places the leather fabric 100 on the needle plate of the sewing machine with the back surface 120 of the leather fabric 100 facing upward. In other words, the operator places the leather fabric 100 on the throat plate of the sewing machine with the surface 110 of the leather fabric 100 facing the throat plate.

After performing the mounting process (process P120), the operator performs the sewing process (process P130). In the sewing process (process P130), the operator uses a sewing machine prepared with an upper thread and a lower thread to sew the leather fabric 100 placed on the throat plate with lock stitches, thereby applying machine stitches 200 to the leather fabric. Form to 100. As a result, the leather product 10 is completed.

The applicant conducted an evaluation test in which sewing machine stitches were formed on leather fabric. The conditions for the evaluation test are as follows.
<Leather fabric>
Various leather fabrics with a thickness of 2 mm to 12 mm (including natural leather, synthetic leather, and artificial leather).
<Sewing thread>
Various product numbers of Toyobo Ester Sewing Machine Thread G manufactured by FTC Co., Ltd. <Sewing Machine>
JUKI Co., Ltd. industrial sewing machine LU2-4410-B1T-BF-CS

As a result of this evaluation test, it was found that when the leather product 10 was manufactured under the conditions of the manufacturing method shown in FIG. 2, the sewing machine stitches 200 could be continuously formed on the surface 110 of the leather fabric 100 with a good appearance. In the leather product 10 obtained in this manner, the knot 230 between the surface thread 210 and the back surface thread 220 is located closer to the back surface 120 than the center of the thickness direction of the leather fabric 100 due to the tension relationship between the upper thread and the lower thread during sewing. located on the side.

According to the method for manufacturing the leather product 10 in the embodiment described above, the sewing machine stitches 200 can be continuously formed on the surface 110 of the leather fabric 100 with a good appearance using a relatively thick multifilament thread of 1,600 to 4,000 decitex. . Further, according to the leather product 10 of the present embodiment, the quality of the machine stitch 200 by lock stitching using a relatively thick multifilament thread of 1600 to 4000 decitex can be improved.

The technology disclosed in this specification is not limited to the embodiments, examples, and modifications described above, and can be realized in various configurations without departing from the spirit thereof. For example, among the technical features of the embodiments, examples, and modifications described above, those corresponding to the technical features of each form described in the summary column solve part or all of the above problems. or to achieve some or all of the above-mentioned effects, they can be replaced and combined as appropriate. Furthermore, technical features that are not described as essential in this specification can be deleted as appropriate.

10...Leather product 100...Leather fabric 110...Surface 120...Back side 130...Needle hole 200...Sewing machine stitch 210...Surface thread 220...Back thread 230...Knot

Claims (1)

A leather product sewn with lock-stitch sewing machine stitches on leather fabric,
a first thread forming the sewing machine stitch on a first surface of the leather fabric;
a second thread forming the sewing machine stitch on a second surface of the back side of the leather fabric;
The thickness of the leather fabric is 2 to 12 mm,
The first thread and the second thread are multifilament threads,
The thickness of the first thread is 1600 to 4000 dtex, and is 600 dtex or more thicker than the second thread,
The thickness of the second thread is 1000 to 1800 decitex,
The knot between the first thread and the second thread is located closer to the second surface in the thickness direction of the leather fabric ,
The leather fabric is leather with urethane foam laminated on the back side,
The sewing machine stitch is sewn into the leather and the urethane foam .

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