Online detection method for fabric cross-direction basis weight deviation

Abstract

The present invention relates to the technical field of textile printing and dyeing processes, and in particular to an online detection method for a fabric cross-direction basis weight deviation, comprising: obtaining the weight and fabric quantity of a full-width preset-length fabric; when the fabric quantity is the total number of warps of the full-width preset-length fabric, on the basis of the number of warps of the fabric within a preset width in a fabric cross-direction, the total number of warps of the full-width preset-length fabric and the weight of the full-width preset-length fabric, calculating the weight of the fabric within the preset width in the fabric cross-direction; or when the fabric quantity is the total number of loops in the full-width preset-length fabric, on the basis of the number of loops in the fabric within a preset width in the fabric cross-direction, the total number of loops of the full-width preset-length fabric and the weight of the full-width preset-length fabric, calculating the weight of the fabric within the preset width in the fabric cross-direction; and on the basis of the weight of each woven fabric or knitted fabric within the preset width, obtaining the weight distribution thereof in the fabric cross-direction. The present invention solves the problem in the prior art of the inability to detect a fabric cross-direction weight deviation.

Description

An online detection method for fabric widthwise weight deviation Technical Field

[0001] The invention relates to a weight measurement method, in particular to an online detection method for widthwise weight deviation of a fabric, and belongs to the technical field of textile printing and dyeing technology. Background Art

[0002] As one of the main indicators for assessing the quality of fabrics, especially knitted fabrics, gram weight is highly comprehensive. It not only affects the physical and mechanical properties and wearing comfort of knitted fabrics, but is also an important basis for economic accounting and cost control in the production process.

[0003] Knitted fabrics are prone to deformation during finishing, and unqualified weight products often appear during production. In fact, after dyeing and finishing, the detection of excessive or insufficient weight and weight deviation of finished fabrics is actually a manual inspection. The process involves cutting a small piece of fabric per unit area, weighing it on a scale, converting the weight of the fabric, and verifying whether the weight at this time is within the process target threshold. The sample is cut from the left, middle, and right sides of the fabric, which causes significant fabric loss. The work is also intensive, with poor real-time performance, and is easily affected by human subjective factors, resulting in large errors. As a result, the weight difference between the left, middle, and right sides of the knitted fabric is also very difficult to detect. The test results cannot effectively standardize the weight deviation of knitted fabrics, and the test data cannot guide the optimization of related process parameters. Therefore, manual inspection is completely unsuitable for the needs of weight deviation detection for all types of fabrics. Summary of the Invention

[0004] Aiming at the shortcomings of the existing methods, the present invention solves the problem in the prior art that the lateral weight deviation of the fabric cannot be detected.

[0005] The technical solution adopted by the present invention is: an online detection method for fabric width weight deviation includes the following steps:

[0006] Obtain the weight and quantity of a full-width, preset-length fabric;

[0007] The fabric is a woven fabric, the fabric quantity is the total number of warp yarns of the fabric of the preset length in the full width, and the weight value of the preset width in the fabric width direction is calculated based on the number of warp yarns of the fabric of the preset width in the fabric width direction, the total number of warp yarns of the fabric of the preset length in the full width, and the weight of the fabric of the preset length in the full width;

[0008] The fabric cross direction may be, but is not limited to, crossing the fabric warp yarns. Specifically, the fabric cross direction may be perpendicular to the fabric warp yarns. The fabric cross direction may also be considered to be along the fabric width direction.

[0009] Or the fabric is a knitted fabric, the fabric quantity is the total number of turns of the fabric of the preset length in the full width, and the weight value of the preset width in the fabric width direction is calculated based on the number of turns of the fabric of the preset width in the fabric width direction, the total number of turns of the fabric of the preset length in the full width, and the weight of the fabric of the preset length in the full width;

[0010] Obtaining weight distribution in the width direction of the fabric according to weight values ​​of woven or knitted fabrics of various preset widths;

[0011] The formula for the weight value in the web direction of the fabric is:

[0012] or

[0013] Among them, P i is the number of warp yarns of the fabric with a preset width in the i-th fabric width direction or the number of loops of the fabric with a preset width in the fabric width direction, is the total number of warp yarns of the fabric of the full width preset length or the total number of loops of the fabric of the full width preset length, n is the total number of preset widths of the fabric in the crosswise direction, and W is the weight of the fabric of the full width preset length; The ratio of the number of warp yarns with a preset width in the i-th fabric crosswise direction to the total number of warp yarns or the number of loops with a preset width in the crosswise direction to the total number of loops; It is the weight ratio of a single warp yarn or a single loop to the fabric of a preset length of full width, that is, the average weight of a single warp yarn or a single loop in the width direction.

[0014] Calculate the weight value of the preset width in the fabric banner direction respectively, when W1=W2=…W n When W1 to W n The value can intuitively reflect the weight distribution in the fabric banner direction; the weight value of the preset width in the fabric banner direction is divided by the area of ​​the preset width in the fabric banner direction to obtain the gram weight distribution of the preset width.

[0015] As a preferred embodiment of the present invention, the number of threads of the fabric also includes: the number of weft yarns or the number of warp and weft yarns.

[0016] You can choose different calculation methods for different fabrics according to their characteristics.

[0017] As a preferred embodiment of the present invention, the preset width in the width direction of the fabric is 1 / 3 of the fabric width.

[0018] Usually, to analyze whether the fabric process meets the requirements, it is only necessary to analyze whether the fabric weight distribution in the left, middle and right areas in the width direction of the fabric banner is uniform. 1 / 3 means dividing the fabric into the left, middle and right areas.

[0019] As a preferred embodiment of the present invention, the number of warp yarns and the number of loops of the fabric are collected by a camera or a density meter.

[0020] The number of warp yarns or loops can be collected through a variety of devices. For example, a camera can be used to capture the fabric image, and the warp and weft yarns in the image can be extracted to obtain the number of warp or weft yarns. Alternatively, a traditional density meter can be used to project light onto the fabric to extract the warp and weft yarns. Alternatively, the number can be counted manually with the naked eye.

[0021] As a preferred embodiment of the present invention, the number of warp yarns and the number of loops of the fabric are collected using an online fabric weight measurement system. The online fabric weight measurement system includes a central processing unit and a first lower fabric guide roller, an upper fabric guide roller and a second lower fabric guide roller arranged in sequence along the fabric running path. Several cameras or density meters are arranged in the fabric cross-sectional direction between the upper fabric guide roller and the second lower fabric guide roller; or several cameras or density meters are arranged in the fabric cross-sectional direction between the upper fabric guide roller and the first lower fabric guide roller.

[0022] Since the weight between the upper and lower cloth guide rollers can be easily measured, it is more convenient to synchronously capture the image of the fabric between the two cloth guide rollers and calculate the number of roots or turns of the fabric; capturing between other rollers of the textile equipment is also within the scope of protection of the method of the present invention and will not be repeated here.

[0023] As a preferred embodiment of the present invention, the weight distribution in the fabric width direction further includes: calculating the weight deviation value of a preset width in the fabric width direction, the formula is:

[0024] Among them, P i is the number of warp yarns of the fabric with a preset width in the i-th fabric width direction or the number of loops of the fabric with a preset width in the fabric width direction, is the total number of warp yarns of the fabric of full width preset length or the total number of loops of the fabric of full width preset length, n is the total number of preset widths of the fabric in the banner direction, λ is the correlation coefficient, and W is the weight of the fabric of full width preset length.

[0025] As a preferred embodiment of the present invention, λ=1.

[0026] That is, there is no need to correct by correlation coefficient.

[0027] The degree of balance of the fabric's mass distribution can be analyzed by the weight deviation value of the preset width in the fabric's width direction.

[0028] As a preferred embodiment of the present invention, the weight distribution in the fabric width direction further includes: calculating the weight deviation value of a preset width in the width direction of two adjacent fabrics, the formula is:

[0029] Among them, P i P is the number of warp yarns of the fabric with a preset width in the i-th fabric width direction or the number of loops of the fabric with a preset width in the fabric width direction; j is the number of warp yarns of the j-th fabric with a preset width in the fabric width direction or the number of loops of the fabric with a preset width in the fabric width direction, j=i+1.

[0030] By calculating the weight deviation values ​​of two adjacent fabrics with a preset width in the width direction, the deviation degree of the weight of the adjacent fabrics can be obtained.

[0031] As a preferred embodiment of the present invention, the corresponding mechanical wave diagram is output according to the weight of the preset width in the fabric banner direction, the weight deviation value of the preset width in the fabric banner direction, and the weight deviation value of the preset width in the two adjacent fabric banner directions.

[0032] The mechanical wave diagram of the fabric can intuitively show the fabric's processing status on the time axis.

[0033] As a preferred embodiment of the present invention, the central processing unit is a digital controller or an embedded control system or an industrial computer with a human-machine interface.

[0034] Beneficial effects of the present invention:

[0035] 1. The present invention can promptly warn of uneven weight in short sections of dyed and finished fabrics, and promptly detect whether the weight deviations in the left, center, and right directions of the fabric width exceed the allowable threshold. This allows the process to be guided according to the deviation amount and relative position indicated by the system. This allows adjustments to be made to the hot air outlet guidance of the setting machine, the overfeed amount on both sides of the fabric, the fabric tension, the left, center, and right liquid pick-up rates, and the tail-end wetting condition to be checked. This fundamentally ensures the quality and classification grade of the finished product, avoids economic losses for the enterprise, and effectively solves a major problem that has long plagued the printing and dyeing industry.

[0036] 2. The present invention also provides guiding improvement measures in the production and processing of fabrics at the textile stage. Based on the mechanical waves of gram weight and uneven deviation, it is helpful to find out whether there is a deviation from the nominal fineness of the textile yarn, the count of the blended yarn, and the number calculation problem. It helps to analyze and indicate the key technical measures for the post-printing and dyeing finishing of air-spun staple yarn fabrics, optimize the production process, reduce costs and increase efficiency in the textile, printing and dyeing finishing processes, and improve processing quality.

[0037] 3. This invention provides inspiration for the configuration and improvement of dyeing and finishing equipment. Based on the uneven weight and deviation prompts of the system and the quality requirements of the fabric, it can suggest whether to install a weft straightening machine or add a loose pre-shrinking device, thereby significantly improving the style and wearability of the fabric.

[0038] 4. The present invention obtains the weight distribution of the fabric in the banner direction through a variety of calculation methods, thereby improving the detection accuracy and efficiency of the fabric production process. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] FIG1 is a schematic diagram of an embodiment of a method for online detection of fabric widthwise weight deviation according to the present invention;

[0040] FIG2 is a schematic diagram showing the positions of the camera disposed on the first lower cloth guide roller and the upper cloth guide roller;

[0041] FIG3 is a schematic diagram showing the positions of the camera disposed on the second lower cloth guide roller and the upper cloth guide roller;

[0042] FIG4 is a schematic diagram of measuring the number of threads and turns of a fabric using three cameras;

[0043] FIG5 is a schematic diagram of the total number of warp yarns of a fabric of a preset length for a full width;

[0044] FIG6 is a schematic diagram of the total number of turns of a fabric of a full width and preset length;

[0045] Among them, 1. first lower cloth guide roller; 2. upper cloth guide roller; 3. second lower cloth guide roller; 4. camera; 5. fabric; 41. first camera; 42. second camera; 43. third camera. DETAILED DESCRIPTION

[0046] The present invention will be further described below in conjunction with the accompanying drawings and embodiments. This figure is a simplified schematic diagram, which only illustrates the basic structure of the present invention in a schematic manner, and therefore only shows the components related to the present invention.

[0047] As shown in FIG1 , a method for online detection of fabric widthwise weight deviation includes the following steps:

[0048] Obtain the weight and quantity of a full-width, preset-length fabric;

[0049] The fabric is a woven fabric, the fabric quantity is the total number of warp yarns of the fabric of the preset length in the full width, and the weight of the fabric of the preset width in the width direction is calculated based on the number of warp yarns of the fabric of the preset width in the width direction, the total number of warp yarns of the fabric of the preset length in the full width, and the weight of the fabric of the preset length in the full width;

[0050] or the fabric is a knitted fabric, the fabric quantity is the total number of turns of the fabric of the preset length in the full width, and the weight of the fabric of the preset width in the width direction is calculated based on the number of turns of the fabric of the preset width in the width direction of the fabric, the total number of turns of the fabric of the preset length in the full width, and the weight of the fabric of the preset length in the full width;

[0051] According to the weight of woven or knitted fabrics of each preset width, the weight distribution in the widthwise direction of the fabric is obtained.

[0052] The number of threads of a fabric also includes: the number of weft yarns or the number of warp and weft yarns; for example, knitted fabrics usually collect the number of warp yarns of the fabric.

[0053] In this embodiment, as shown in Figure 5, the fabric width is 1, assuming that the preset width in the fabric banner direction is 1 / 3 of the fabric width, that is, when n=3, the preset width is 1 / 3, and the fabric banner direction is divided into three equal areas on the left, middle, and right. The number of roots of the woven fabric or the number of loops of the knitted fabric in the left area is P1 (i=1), the middle area is P2 (i=2), and the right area is P3 (i=3); the weights of the preset widths in the fabric banner direction of the three areas are W1=W*(P1 / (P1+P2+P3)), W2=W*(P2 / (P1+P2+P3)), and W3=W*(P3 / (P1+P2+P3)), where subscript 1 is the left area of ​​the fabric, subscript 2 is the middle area of ​​the fabric, and subscript 3 is the right area of ​​the fabric.

[0054] The weight of fabrics of several preset widths can also be calculated based on the weight of the preset width, that is, the sum of the weights of the fabrics of several preset widths is divided by the area of ​​the preset widths. The area of ​​several preset widths = several preset widths * preset lengths. For example: the fabric width is 1 meter, the fabric length is 1 meter, and the preset width is 0.1 meter. The weights of 3, 5, and 2 preset widths are calculated respectively, that is, the area of ​​the preset widths is calculated to be 0.3 meters respectively. 2 , 0.5 meters 2 , 0.2 meters 2 , the weight distribution of fabric at different preset widths can be obtained.

[0055] It should be noted that the preset width can be customized; for example, the fabric width of 1 meter can be divided into 5 equal parts along the fabric banner direction according to the preset width of 0.2 meters; the number of warp yarns in each 0.2-meter width is the number of warp yarns in the fabric of the preset width in the fabric banner direction; similarly, the number of turns in each 0.2-meter width is the number of turns of the fabric of the preset width in the fabric banner direction.

[0056] Since the number of roots or loops of fabric is linearly related to the weight of fabric, if P1=P2=P3, then: the weight of the fabric in the left, middle and right areas is The weight of the three areas in the fabric banner direction is uniform; otherwise, the weight in the fabric banner direction is uneven and there is a deviation; in this embodiment, only three areas are set, and the actual area can be an integer multiple of the preset width in the fabric banner direction.

[0057] The weight W of a fabric of full-width preset length can be obtained by adopting the technical solution in patent CN202111579979. For example, in Figures 5 and 6, the width of the fabric in the horizontal direction of the fabric is 1 meter, and the length of the fabric in the longitudinal direction of the fabric is 1 meter, that is, the preset length is 1 meter, wherein the preset length can be customized; the weight W of the fabric of full-width preset length is 200 grams; the weight W of the fabric of full-width preset length can also be obtained by manual weighing, for example, the weight W of the fabric of full-width preset length is obtained by weighing the cut fabric; the fabric in Figure 5 is a woven fabric, and the total number of warp yarns of the fabric of full-width preset length is the total number of warp yarns in the horizontal direction of the fabric. The total number of warp yarns of the fabric of full-width preset length in the figure is 9; the fabrics in Figures 6(a) and 6(b) are knitted fabrics, which are knitted weft knitting and knitted warp knitting, respectively. The total number of turns of the fabric of full-width preset length is the total number of turns in the horizontal direction of the fabric. The total number of turns of the fabric of full-width preset length shown in Figure 6(a) is 5 turns as shown in the dotted box.

[0058] The total number of warp yarns or the total number of loops of the fabric of the full-width preset length can be obtained from the input working parameters of the system before fabric processing, or can be collected by a camera or a density meter, or obtained by manual counting by visual inspection.

[0059] The number of warp yarns and the number of loops of the fabric are collected by a camera or a density meter.

[0060] Both cameras and density meters are existing equipment that can directly measure the number of roots or turns of different types of fabrics. Density meter models include HV-PC02D. Ordinary cameras capture fabric images, pre-process the images, and then calculate the number of warp yarns or turns of the fabric.

[0061] At least one camera is set in the banner direction of the fabric. As shown in Figure 4, a first camera 41, a second camera 42 and a third camera 43 are respectively set in the banner direction of the fabric 5. The number of cameras 4 can be customized according to the fabric banner, the longitudinal viewing distance of the camera and the environment of the production workshop.

[0062] The number of warp yarns and the number of loops of the fabric are collected by using an online fabric weight measurement system. The online fabric weight measurement system comprises a central processing unit and a first lower fabric guide roller (1), an upper fabric guide roller (2) and a second lower fabric guide roller (3) which are sequentially arranged in an upper and lower manner along a fabric running path. A plurality of cameras (4) or a plurality of density meters are arranged in the fabric width direction between the upper fabric guide roller (2) and the second lower fabric guide roller (3); or a plurality of cameras or density meters are arranged in the fabric width direction between the upper fabric guide roller (2) and the first lower fabric guide roller (1).

[0063] The distance between the camera and the fabric must meet certain conditions: for example, the longitudinal fabric from point a to point b in Figure 2 is within the camera's field of view, or the longitudinal fabric from point c to point d in Figure 3 is within the camera's field of view.

[0064] The weight distribution in the fabric banner direction also includes: calculating the weight deviation value of the preset width in the fabric banner direction, the formula is:

[0065] Among them, P i is the number of warp yarns of the fabric with a preset width in the i-th fabric width direction or the number of loops of the fabric with a preset width in the fabric width direction, is the total number of warp yarns of the fabric of full width preset length or the total number of loops of the fabric of full width preset length, n is the total number of preset widths of the fabric in the banner direction, λ is the correlation coefficient, and W is the weight of the fabric of full width preset length.

[0066] The value of λ can be obtained through test fitting or on-site calibration. λ is mainly related to the yarn count or number of turns, and is also affected by the yarn material, weaving method, etc. When λ = 1, no correction is considered.

[0067] By calculating the weight deviation value of the preset width in the fabric banner direction, if the absolute value is negative, it means that the weight of the fabric of the current preset width is lighter than the total weight, otherwise it is heavier. In this embodiment, the left, middle and right three areas are taken as examples to calculate If the number in the absolute value of δ1 is negative, the left area is lighter than the standard weight; if the number in the absolute value of δ2 is negative, the middle area is lighter than the standard weight; if the numbers in the absolute values ​​of δ1 and δ2 are both negative, the left and middle areas are lighter than the standard weight, and so on. When the value in any one or two areas is negative, the corresponding area is lighter than the standard weight.

[0068] The weight distribution in the fabric banner direction also includes: calculating the weight deviation value of the preset width in the two adjacent fabric banner directions, the formula is:

[0069] Among them, Pi P is the number of warp yarns of the fabric with a preset width in the i-th fabric width direction or the number of loops of the fabric with a preset width in the fabric width direction; j is the number of warp yarns of the j-th fabric with a preset width in the fabric width direction or the number of loops of the fabric with a preset width in the fabric width direction, j=i+1.

[0070] Taking the three adjacent areas of left, middle and right as an example, the percentage of weight deviation of the left relative to the middle is δ 12 : If the absolute value is negative, it means the left side of the cloth is lighter; similarly, the percentage of the weight deviation of the right side relative to the middle is δ 32 : The percentage of weight deviation of the right side relative to the left side is δ 31 :

[0071] The corresponding mechanical wave pattern is output according to the weight of the preset width in the fabric banner direction, the weight deviation value of the preset width in the fabric banner direction, and the weight deviation value of the preset widths in the two adjacent fabric banner directions.

[0072] By analyzing the warp and weft density of fabrics in different areas or with different preset widths, a mechanical wave diagram of weight unevenness at each moment can be obtained. The trend of the mechanical wave diagram on the time axis can be used to find out whether there is a deviation in the nominal fineness of the textile yarn, the count of the blended yarn, or the calculation of the number. It helps to analyze and indicate the key technical measures for the finishing of air-spun short fiber yarn fabrics after printing and dyeing, optimize the production process, reduce costs and increase efficiency in the fabric weaving, printing and dyeing finishing processes, and improve processing quality; or, based on the uneven weight, it can prompt whether to install a weft straightening machine or add loose pre-shrinkage equipment to significantly improve the style and wearing performance of the fabric.

[0073] The central processing unit is a digital controller with a human-machine interface, such as a DDC digital controller or an embedded control system or an industrial computer, etc., not shown in the figure; the central processing unit is used for logical operations of various algorithms and intuitively outputs mechanical wave diagrams.

[0074] With the above-described preferred embodiments of the present invention as a guide, and with reference to the above description, relevant personnel are fully capable of making various changes and modifications without departing from the technical scope of this invention. The technical scope of this invention is not limited to the contents of the specification and must be determined according to the scope of the claims.

Claims

1. An online detection method for fabric width weight deviation, characterized in that: Obtain the weight and amount of fabric of a preset length of full width; The fabric is a woven fabric, the fabric quantity is the total number of warp yarns of the fabric with a preset length in the full width, and the weight value of the preset width in the fabric cross direction is calculated according to the number of warp yarns of the fabric with a preset width in the fabric cross direction, the total number of warp yarns of the fabric with a preset length in the full width, and the weight of the fabric with a preset length in the full width; Or the fabric is a knitted fabric, the fabric amount is the total number of turns of the fabric of the preset length in the full width, and the weight value of the preset width in the fabric banner direction is calculated according to the number of turns of the fabric of the preset width in the fabric banner direction, the total number of turns of the fabric of the preset length in the full width, and the weight of the fabric of the preset length in the full width; According to the weight values ​​of the fabrics of each preset width, the weight distribution in the width direction of the fabrics is obtained.

2. The method for online detection of fabric width weight deviation according to claim 1, characterized in that: The weight distribution in the fabric banner direction also includes: calculating the weight deviation value of the preset width in the fabric banner direction, the formula is: Among them, P i is the number of warp yarns of the fabric with a preset width in the i-th fabric width direction or the number of turns of the fabric with a preset width in the fabric width direction, is the total number of warp yarns of the fabric with a full-width preset length or the total number of turns of the fabric with a full-width preset length, n is the total number of preset widths of the fabric in the cross-web direction, λ is the correlation coefficient, and W is the weight of the fabric with a full-width preset length.

3. The method for online detection of fabric width weight deviation according to claim 1, characterized in that: The weight distribution in the fabric banner direction also includes: calculating the weight deviation value of the preset width in the two adjacent fabric banner directions, the formula is: Among them, P i is the number of warp yarns of the fabric with a preset width in the i-th fabric width direction or the number of turns of the fabric with a preset width in the fabric width direction; P j i is the number of warp yarns of the j-th fabric with a preset width in the fabric width direction or the number of turns of the fabric with a preset width in the fabric width direction, j=i+1.

4. The method for online detection of fabric width weight deviation according to claim 2, characterized in that: λ=1.

5. The method for online detection of fabric width weight deviation according to claim 1, characterized in that: The number of fabric threads also includes: the number of weft yarns or the number of warp and weft yarns.

6. The method for online detection of fabric width weight deviation according to claim 1, characterized in that: The preset width in the fabric banner direction is 1 / 3 of the fabric width.

7. The method for online detection of fabric width weight deviation according to claim 1, characterized in that: The number of warp yarns and the number of loops of the fabric are collected by a camera or a density meter.

8. The method for online detection of fabric width weight deviation according to claim 7, characterized in that: The number of warp yarns and the number of turns of the fabric are collected by using an online fabric weight measurement system. The online fabric weight measurement system comprises a central processing unit and a first lower fabric guide roller (1), an upper fabric guide roller (2) and a second lower fabric guide roller (3) which are arranged in sequence along a fabric running path. A plurality of cameras (4) or a plurality of density meters are arranged in the fabric cross-sectional direction between the upper fabric guide roller (2) and the second lower fabric guide roller (3); or a plurality of cameras or density meters are arranged in the fabric cross-sectional direction between the upper fabric guide roller (2) and the first lower fabric guide roller (1).

9. The method for online detection of fabric width weight deviation according to any one of claims 1 to 3, characterized in that: The corresponding mechanical wave graph is output according to the weight value of the preset width in the fabric banner direction, the weight deviation value of the preset width in the fabric banner direction, and the weight deviation value of the preset width in two adjacent fabric banner directions.

10. The method for online measurement of fabric weight according to claim 8, characterized in that: The central processing unit is a digital controller or an embedded control system or an industrial computer with a human-machine interface.

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