阅读说明：本技术 一种浸胶帘子布全幅宽经线密度的测量方法及经线密度均匀性的改善方法 (Method for measuring full-width warp density of gum-dipped cord fabric and method for improving warp density uniformity ) 是由 仵晓 李新 路晓冬 刘晓光 谷慧平 赵金辉 吴晓明 翟松涛 蔡海军 王晓川 曹子 于 2020-04-25 设计创作，主要内容包括：本发明提供了一种浸胶帘子布全幅宽经线密度的测量方法及经线密度均匀性的改善方法。沿着纬线方向将整幅宽的浸胶帘子布进行拓印于纸张上；将得到的拓印纸进行单向折叠,折线与纬线垂直,折纸顶端与纬线平行方向放置直尺,直尺置于折纸下面进行扫描,得到多个折叠后纸面的扫描图；将扫描图置于处理软件中进行处理,测得浸胶帘子布经密；该方法能够在短时间内完成全幅宽浸胶帘子布经密的测量,停机时间非常短,且测量结果精度明显提高。浸胶帘子布经密测量精准度的提高为浸胶帘子布经线密度的改善提供了更好的改善基础,为生产经密均匀的浸胶帘子布提供了基础,能够得到经密均匀性明显提高的浸胶帘子布。(The invention provides a method for measuring the full-width warp density of gum-dipped cord fabric and a method for improving the uniformity of the warp density. Rubbing the whole width of the gum dipping cord fabric on paper along the weft direction; the obtained rubbing paper is folded in a single direction, the folding line is perpendicular to the weft, a straight ruler is placed at the top end of the folding paper in the direction parallel to the weft, and the straight ruler is placed under the folding paper for scanning to obtain a plurality of scanned images of the folded paper surface; placing the scanned image in processing software for processing, and measuring the warp density of the gum dipping cord fabric; the method can complete the measurement of the warp density of the full-width gum dipping cord fabric in a short time, the stop time is very short, and the precision of the measurement result is obviously improved. The improvement of the warp density measurement accuracy of the dipped cord fabric provides a better improvement foundation for the improvement of the warp density of the dipped cord fabric, provides a foundation for producing the dipped cord fabric with uniform warp density, and can obtain the dipped cord fabric with obviously improved warp density uniformity.)

1. A method for measuring the density of full-width warp threads of gum-dipped cord fabric is characterized by comprising the following steps:

s1: rubbing the whole width of the gum dipping cord fabric on paper along the weft direction;

s2: folding the rubbing paper obtained in the step (1) in a single direction, wherein the folding line is vertical to the weft, a straight ruler is placed at the top end of the folding paper and parallel to the weft, and the straight ruler is placed under the folding paper for scanning to obtain a plurality of scanned images of the folded paper;

s3: placing the scanned image in processing software for processing, and measuring the warp density of the gum dipping cord fabric; the method comprises the following specific steps:

a: selecting a first scale and a second scale with the distance of a on the picture ruler, and measuring the distance between the first scale and the second scale as b by adopting picture processing software;

b: selecting n warps on the picture, and measuring the total distance of the n warps in the weft direction as c by adopting picture processing software;

c: calculating the warp density N of the N warp ranges as follows:

in the formula, N represents the density of the warps, a represents the actual distance between the first scale and the second scale of the straight steel ruler, b represents the distance measured by a on the software, N represents the number of warps in each measuring range, and c represents the width occupied by N warps measured by the software.

2. The method according to claim 1, wherein the paper used in step S1 is computer stylus printer paper.

3. Measuring method according to claim 1 or 2, characterized in that the length of the rubbing in the warp direction is not less than 2mm, preferably not less than 5mm when rubbing the dipped cord with the paper of step S1.

4. The measurement method according to claim 1, wherein n is preferably 5.

5. A method for improving the warp density uniformity of a dipped cord fabric by using the measuring method of claim 1, which is characterized by comprising the following steps:

(a) determining the relationship between the warp density of the dipped cord fabric and the warp density of the white blank cord fabric

K＝d×ln(e+f)-g (2)

In the formula, K represents the relation coefficient of the warp density of the dipped cord fabric and the warp density of the white blank cord fabric, d, e and g are empirical constants, and f is any distance between the edge part and the center in the weft direction of the dipped cord fabric;

in the formula, N₁The warp density value, w, of the white blank cord fabric obtained after the correction of the formula (2)₁Is a target width value, T, of white cord fabric₁Is the target warp density value, s, of the dipped cord fabric₁The target width value of the dipped cord fabric is obtained;

(b) and (c) preparing the white blank cord fabric meeting the requirement according to the warp density value of the white blank cord fabric corrected by the formula (2) obtained in the step (a), and then performing gum dipping to obtain the gum dipping cord fabric with improved uniformity of the warp density.

6. The improvement method according to claim 5, wherein d is in the range of 0.04 to 0.08, e is in the range of 10 to 300, and g is in the range of 0.25 to 0.45.

Technical Field

The invention relates to the technical field of cord fabrics, in particular to a method for measuring full-width warp density of a dipped cord fabric and a method for improving warp density uniformity.

Background

The gum dipping cord fabric is mainly used as a carcass framework material of bias tires and a carcass framework material of car and light truck radial tires. The dipped cord fabric is a weft fabric with sparse wefts, the wefts are only convenient to produce and use, and the number of warps contained in unit length of the dipped cord fabric is the density of the warps under the conditions that the wefts are not creased and tensioned. The warp density (warp density for short) is a main performance for embodying the impregnated cord fabric. If the warp density is not uniformly distributed, the thickness uniformity of the rubber cord fabric, the mutual infiltration of rubber during the calendering process and the stress consistency of the tire are seriously influenced. Therefore, the measurement and improvement of the warp density of the cord fabric is also an urgent problem to be solved in the field.

At present, the measurement of the warp density comprises methods such as a fabric decomposition method, a fabric analysis mirror method, a movable fabric density mirror method and the like, wherein the fabric decomposition method is to cut a sample slightly larger than the minimum measured length at a proper position of a humidity-adjusted sample; part of the weft yarn was removed at the edge of the sample and measured with a straight steel ruler to bring the sample to a minimum measured length of 2 cm. The prepared sample is detached point by point from the edge, and the number of the warps in a certain length can be obtained by arranging the warps into a group of 10 for counting. The fabric analysis mirror method is used for measuring the number of warp threads seen in a fabric analysis mirror window and converting the number of warp threads contained in the fabric analysis mirror window to a length of 10cm, and comprises the following specific steps: the fabric is flattened, a fabric analysis mirror is placed on the fabric analysis mirror, one warp is selected and is parallel to one side of a window of the analysis mirror, and therefore the number of warps in the window is counted one by one. The movable fabric density mirror method is characterized in that the number of warp threads in a certain length is measured by using a movable fabric density mirror, and the number of warp threads contained in the length of 10cm is converted, and the method comprises the following specific steps: the fabric is flattened, a fabric densitometer is placed on the fabric densitometer, a graduated scale of the densitometer is perpendicular to the warp direction, and the number of warps is counted within a specified measuring distance by rotating a screw. Other methods include a parallel line grating density mirror method, a diagonal line grating density mirror method, a photoelectric scanning densitometer method, a fabric density analysis method based on mathematical morphology and the like, can quickly and roughly estimate the warp density, but have low measurement precision and limitation. The existing measuring methods have the problems of small measuring range, large measuring error, inconvenient measurement and the like, so that the warp density of the dipped cord fabric cannot be effectively improved. Moreover, the measurement of the warp density of the dipped cord fabric needs to be stopped, the number of warp threads of the dipped cord fabric is large (generally 800-3000), the full-width warp density of the dipped cord fabric is measured according to the existing method, long stopping time is needed, and the measurement cost is huge, so that the warp density of the whole dipped cord fabric is predicted by measuring a part of warp density, the error is large, and the full-width warp density of the dipped cord fabric cannot be well improved.

Disclosure of Invention

Aiming at the problems, the invention provides a method for measuring the full-width warp density of the dipped cord fabric and a method for improving the uniformity of the warp density. The method can complete the measurement of the warp density of the full-width gum dipping cord fabric in a short time, the stop time is very short, and the precision of the measurement result is obviously improved. The warp density obtained by the measuring method can be used for better improving the warp density of the dipped cord fabric.

The invention is realized by the following technical scheme

A method for measuring the density of full-width warp threads of gum-dipped cord fabric comprises the following steps:

s1: rubbing the whole width of the gum dipping cord fabric on paper along the weft direction;

s2: folding the rubbing paper obtained in the step S1 in a single direction, wherein the folding lines are perpendicular to the weft lines, a straight ruler is arranged at the top end of the folding paper and parallel to the weft lines, and the straight ruler is arranged below the folding paper for scanning to obtain a plurality of scanned images of the folded paper;

s3: placing the scanned image in processing software for processing, and measuring the warp density of the gum dipping cord fabric; the method comprises the following specific steps:

a: selecting a first scale and a second scale with the distance of a on the picture ruler, and measuring the distance between the first scale and the second scale as b by adopting picture processing software;

b: selecting n warps on the picture, and measuring the total distance of the n warps in the weft direction as c by adopting picture processing software;

c: calculating the warp density N of the N warp ranges as follows:

in the formula (1), N represents the density of the warps, a represents the actual distance between the first scale and the second scale of the straight steel ruler, b represents the distance measured by a on the software, N represents the number of warps in each measuring range, and c represents the width occupied by N warps measured by the software.

Further, the paper used in step S1 may be computer stylus continuous printing paper.

Further, when rubbing the dipped cord fabric with the paper in step S1, the rubbing length along the warp direction is not less than 2mm, preferably not less than 5 mm. The length of the rubbing can be determined according to actual needs, such as 2mm, 3mm, 4mm, 5mm, 6mm, 8mm, 10mm, 12mm, 14mm, 16mm, 17mm, 18mm, 19mm, 20mm and the like.

Further, the value of n is preferably 5.

A method for improving the warp density uniformity of the dipped cord fabric by using the measuring method comprises the following steps:

(a) determining the relation between the warp density of the dipped cord fabric at the measuring section and the warp density of the white blank cord fabric at the measuring section

K＝d×ln(e+f)-g (2)

In the formula (2), K represents the relation coefficient between the warp density of the dipped cord fabric and the warp density of the white blank cord fabric, d, e and g are empirical constants, and f is any distance from the edge to the center in the weft direction of the dipped cord fabric; f represents any distance from the end part to the central line in the width direction (the weft direction) of the dipped cord fabric, f takes any value between 0 and q, and q is the vertical distance from the width edge of the dipped cord fabric to the central line;

in the formula (3), N₁The warp density, w, of the white blank cord fabric obtained after the correction of the formula (2)₁For a target width value (i.e. the designed theoretical width value), T, of the white shade fabric₁For a target warp density value (i.e. the designed theoretical warp density value), s, of the dipped cord fabric₁The target width value (namely the theoretical width value) of the gum dipping cord fabric;

(b) and (c) preparing the white blank cord fabric meeting the requirement according to the warp density value of the white blank cord fabric corrected by the formula (2) obtained in the step (a), and then performing gum dipping to obtain the gum dipping cord fabric with improved uniformity of the warp density.

Furthermore, the value range of d is 0.04-0.08, the value range of e is 10-300, and the value range of g is 0.25-0.45.

The warp density of the dipped cord fabric in the field is the number of warp contained in the dipped cord fabric within the width of 10 cm.

Compared with the prior art, the invention has the following positive beneficial effects

Drawings

Figure 1 shows a schematic view of a rubbing paper,

FIG. 2 shows a scanned pictorial view of a rubbing sheet and a ruler (a view of one side after folding, one complete rubbing sheet folded to give one of a plurality of folded paper sides),

FIG. 3 shows one of the schematic diagrams when processing a picture (in the figure, the number of warp threads in each group is 5 in the number of warp threads 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, … … in the group of warp threads),

figure 4 shows a second schematic diagram when processing pictures,

figure 5 shows a partial enlargement of figure 4,

FIG. 6 is a graph showing the results of detecting the warp density of the cord fabric in example 1.

Detailed Description

The present invention will be described in more detail with reference to the following embodiments for understanding the technical solutions of the present invention, but the present invention is not limited to the scope of the present invention.

The invention provides a method for measuring the density of full-width warp threads of gum-dipped cord fabric, which comprises the following steps:

s1: rubbing the whole width of the gum dipping cord fabric on paper along the weft direction;

after the gumming machine or the rewinding machine is stopped, the gumming cord fabric is flatly covered on the cloth surface of the gumming cord fabric supported by a roller by paper (preferably computer needle type continuous beating printing paper) with the length being larger than the breadth of the gumming cord fabric under the conditions that the warp of the gumming cord fabric is tensioned (more than or equal to 30Kg), the weft direction is unfolded and the cloth surface is flat, and the rubbing of the gumming cord fabric on the paper is finished by stably rubbing the paper from one end of the weft direction to the other end of the weft direction by an oil painting stick. And simultaneously measuring the width of the dipped cord fabric. As shown in fig. 1.

The length of the rubbing on the paper along the warp direction is not less than 2mm, preferably not less than 5mm for subsequent measurement.

S2: folding the rubbing paper obtained in the step (1) in a single direction, wherein the folding lines are perpendicular to the weft (parallel to the warp), a straight ruler is arranged at the top end of each folded paper in the direction parallel to the weft, and the straight ruler is arranged below the folded paper for scanning to obtain a plurality of scanning images of the folded paper;

after the rubbing paper is folded, a plurality of folded paper surfaces are obtained, each paper surface is scanned, and when each folded paper surface is scanned, a ruler is placed along the weft direction at the edge of the top end of each paper surface to be scanned together with the rubbing paper, as shown in fig. 2. And scanning a plurality of folded paper surfaces until the whole paper is scanned.

S3: placing the scanned image in processing software for processing, and measuring the warp density of the gum dipping cord fabric; the method comprises the following specific steps:

a: selecting a first scale and a second scale with the distance of a on a straight scale of the picture, and measuring the distance between the first scale and the second scale as b by adopting picture processing software;

b: selecting n warps on the picture, and measuring the total distance of the n warps in the weft direction as c by adopting picture processing software;

c: calculating the warp density N of the N warp ranges as follows:

in the formula, N represents the density of the warps, a represents the actual distance between the first scale and the second scale of the straight steel ruler, b represents the distance measured by a on the software, N represents the number of warps in each measuring range, and c represents the total space width occupied by N warps measured by the software. The value of n is preferably 5, that is, 5 cord warps are selected, and the width value of the cord warps is measured.

The image processing software can be any version of AutoCAD software, Photoshop software, Excel table and the like.

If the scanned picture is processed by using AutoCAD software, the method specifically comprises the following steps:

firstly, importing a picture to be processed into CAD software, making a horizontal auxiliary line, and moving the picture to enable the length direction of a straight ruler on the picture to be parallel to the horizontal auxiliary line; then selecting a first scale and a second scale with a distance of a on a straight scale of the picture, drawing a first perpendicular line and a second perpendicular line perpendicular to the horizontal auxiliary line along the first scale and the second scale, and measuring the distance between the first perpendicular line and the second perpendicular line as b through CAD software; as shown in fig. 3, 4, 5;

selecting n warps on the picture, and measuring the total space width of the n warps by CAD software to be c; it can be obtained that the interval readings of n warps on the ruler are:

thirdly, the warp density of the dipped cord fabric is the number of warps in the length of 10cm, so that the density N of the N warps is as follows:

the warp density of the gum dipping cord fabric can be obtained.

The detection method has the advantages of short time, high efficiency, small introduced error and high accuracy, and can be better used for improving the warp density of the dipped cord fabric.

Example 1 is provided below

The method is adopted to detect the warp density of the cord fabric of 1400 dtex/2.

Flatly paving computer needle type continuous printing paper on the cord fabric, and rubbing by using an oil painting stick (the length of rubbing is 1.45m, namely the width of the cord fabric in the weft direction is 1.45 m); the length of the rubbing along the warp direction is 17 mm;

folding the paper after rubbing in one direction, wherein the folding line is vertical to the weft, and the paper is folded once every 28cm (namely the width of the paper after folding is 28 cm;

then, a rigid ruler (the ruler is placed in parallel with the weft, namely transversely) with the length of 15cm is placed at the edge of the top end of each folding paper surface, the ruler is placed below the paper and placed on a scanner to scan, and each page of folding paper is scanned by adopting the same operation until the whole piece of rubbing paper is scanned;

and (3) placing a plurality of scanned images obtained by scanning in AutoCAD software for processing, measuring according to the method, taking every 5 warps for detection (namely taking 5 as the n value), and obtaining the warp density value of the full width of the gum dipping cord fabric through a plurality of measurements, wherein the warp density value is shown in FIG. 6.

The invention also provides a method for improving the warp density uniformity of the dipped cord fabric by using the measuring method, which comprises the following steps:

(a) determining the relationship between the warp density of the dipped cord fabric and the warp density of the white blank cord fabric

The dipped cord fabric is obtained by dipping the prepared white blank cord fabric, and the warp density of the white blank cord fabric is changed after dipping; the relationship between the warp density of the dipped cord fabric and the warp density of the white blank cord fabric is as follows:

K＝d×ln(e+f)-g (2)

in the formula, K represents the relation coefficient of the warp density of the dipped cord fabric and the warp density of the white blank cord fabric, d, e and g are empirical constants, and f is the distance (unit is mm) from the edge to the center in the weft direction of the dipped cord fabric; wherein the value range of d is preferably 0.04-0.08, the value range of e is preferably 10-300, and the value range of g is preferably 0.25-0.45.

And then calculating the warp density value of the white blank cord fabric corrected by the formula (2) according to the value of K, wherein the warp density value is as follows:

in the formula, N₁The warp density value, w, of the white blank cord fabric obtained after the correction of the formula (2)₁Is a target width value, T, of white cord fabric₁Is the target warp density value (i.e. the designed theoretical warp density value), s, of the dipped cord fabric₁The target width value (namely the theoretical width value) of the gum dipping cord fabric;

(b) and (c) preparing the white blank cord fabric meeting the requirement according to the warp density value of the white blank cord fabric corrected by the formula (2) obtained in the step (a), and then performing gum dipping to obtain the gum dipping cord fabric with improved uniformity of the warp density.

The white blank cord fabric meeting the requirements is prepared according to the calculated warp density value of the white blank cord fabric corrected by the formula (2), and the uniformity of the warp density of the dipped cord fabric obtained after the obtained white blank cord fabric is dipped can be better improved.

The reason for improving the warp density uniformity is that the warp density measurement results of the white blank cord fabric and the dipped cord fabric in the early stage are high in accuracy, the relation between the warp density value of the white blank cord fabric and the warp density value of the dipped cord fabric can be well determined according to the warp density measurement result with high accuracy, and then the warp density value of the white blank cord fabric required by the dipped cord fabric with high uniformity warp density value is determined, so that the warp density uniformity of the dipped cord fabric obtained after the white blank cord fabric is dipped is obviously improved.

The method comprises the following specific steps: first, a plurality of white-blank fabrics and a plurality of dipped fabrics are measured, and a plurality of K values are obtained by the following formula (4). And then optimizing according to a plurality of K values to obtain a formula (2), wherein the formula can well improve the uniformity of the warp density of the dipped cord fabric.

Wherein K represents the relation coefficient of the warp density of the dipped cord fabric and the warp density of the white blank cord fabric, N₂Measuring warp density values, w, for white shade fabrics₂For measuring width value, T, of white-shade fabrics₂Measuring warp density values, s, for dipped cord fabrics₂The measured width value of the dipped cord fabric;

experiments show that under the conditions that the ideal width of the dipped cord fabric is 1480mm and the warp density is 96.7 pieces/10 cm, the white blank cord fabric (the width is 1580mm) which is knitted by a gradual change reed before is improved, and the relative standard deviation of the full width and the warp density of the dipped cord fabric is 8.6%. By adopting the improvement method, after the design of the reed is improved, the relative standard deviation of the full-width warp density of the dipped cord fabric is 3.9 percent, and the improvement effect is obvious. The relative standard deviation is specifically: after scanning rubbing paper rubbing the dipped cord fabric, measuring one warp density value N per N warp yarns in software, wherein the relative standard deviation is the relative standard deviation of a plurality of warp density values N. Namely, the improved warp density uniformity of the gum dipping cord fabric is obviously improved.

The following examples 2-5 are the relative standard deviation values of the improved impregnated cord fabric full width warp density by the improvement method of the present invention. The embodiment results also show that the warp density of the cord fabric is detected by a high-accuracy and high-precision detection method, and the obtained improvement method can obviously improve the warp density uniformity of the dipped cord fabric.