WO2022095340A1

WO2022095340A1 - Method for preventing moiré stripes during transfer dyeing of twill

Info

Publication number: WO2022095340A1
Application number: PCT/CN2021/087619
Authority: WO
Inventors: 钟博文
Original assignee: 长胜纺织科技发展(上海)有限公司
Priority date: 2020-11-09
Filing date: 2021-04-16
Publication date: 2022-05-12
Also published as: CN112373212A; CN112373212B

Abstract

A method for preventing Moiré stripes during transfer dyeing of a twill, comprising: scanning, by means of a scanning device, a design original to be used during transfer dyeing to obtain an original pattern, the obtained original pattern corresponding to a predetermined position or angle at which the design original should be located in a plate-making page; performing color separation processing on the obtained original pattern by means of image processing software to obtain one or more color separation layers which allow the original pattern to be printed, each color separation layer comprising one color and each color separation layer being formed of corresponding dots, and rotating the dots of the color separation layers by different predetermined angles according to the number of color separation layers to obtain a color separation pattern used for plate-making; performing plate-making by using the obtained color separation pattern used for plate-making as a stencil; and performing transfer dyeing on the twill. By means of the method, the pitch of moiré stripes can be reduced to such a level that moiré stripes cannot be perceived by the human eyes, thereby increasing the yield of products.

Description

Method for preventing moire fringes during transfer dyeing of twill

technical field

The present disclosure generally relates to printing and dyeing techniques for the textile industry. More particularly, the present disclosure relates to a method for preventing moire fringes during the transfer dyeing process of twill fabrics, which can avoid moire fringes during the transfer dyeing process of twill fabrics, thereby significantly improving product yield.

Background technique

Moiré fringes are an optical phenomenon first discovered by French researcher Moir in the 18th century. Technically speaking, Moiré fringes are the visual result of interference between two lines or objects at a constant angle and frequency. When the human eye cannot distinguish these two lines or two objects, it can only see the pattern of interference. The interference pattern in this optical phenomenon is the Moiré fringe. From the point of view of the generation mechanism of Moiré fringes, when two linear gratings are superimposed at an angle θ, diffraction fringes with alternating light and dark can appear.

In printing production, in order to make the ink color of large-area color blocks in the printed product more uniform and thick, and to better control the consistency of ink color, printing companies often use spot color printing for some large-area color blocks. Under normal circumstances, large-area color blocks have no major conflict with the normal printed four-color, but in some special designs, especially for some gradients, when the four-color and spot colors are mixed with each other in both directions, the printing screen cannot be staggered. Angle, often leads to random moire fringes on the printed product, which is commonly known as the same angle collision phenomenon in the industry, thus affecting the quality of the printed product.

In screen printing, the moire phenomenon is more serious than other printing methods due to the existence of the warp and weft of the screen. Screen printing, like other printing methods, uses screen screening to reproduce the color gradation of the original. The dots of various colors overlap and interfere with each other, and various dot interference patterns appear, and the patterns change with the angle of the dots of various colors. At certain dot angles, the dots are piled up and scattered according to specific rules, the patterns are thick, and the color depth is uneven, which destroys the performance of the dots to reproduce the color tone. These abnormal patterns are moire fringes. From a mechanism point of view, when two screens are superimposed at a certain angle, the distribution of the dots of the two screens will show three situations of juxtaposition, partial overlap, and complete overlap. When observed by the human eye: the density of the overlapping area is small, and the density of the juxtaposed area is high, thus forming light and dark stripes.

In the production process of transfer dyeing of denim, since the denim is usually twill, when the denim fabric is transferred and dyed with a pattern with a twill effect, if the twill of the pattern is between the twill texture of the denim fabric If the angle is not appropriate, Moiré fringes will appear, which will bring challenges to the quality of the product.

SUMMARY OF THE INVENTION

One of the objectives of the present disclosure is to provide a method for preventing moire during transfer dyeing of twill fabrics, which can overcome one or more of the problems existing in the prior art.

According to an embodiment of the present disclosure, the method includes: Step 1: Using a scanning device to scan a design manuscript to be used in the transfer dyeing process to obtain a manuscript pattern, the manuscript pattern corresponding to the design manuscript should be used in the plate making page Step 2: Use image processing software to perform color separation processing on the obtained manuscript pattern to obtain one or more color separation layers capable of printing the manuscript pattern, each color separation map The layer includes a color and each color separation layer is composed of corresponding dots, and the dots of each color separation layer are respectively rotated by different predetermined angles according to the number of the color separation layers to obtain a color separation pattern for plate making; Step 3: using the obtained color separation pattern for plate making as a base draft for plate making; and Step 4: performing transfer dyeing on the twill fabric.

According to an embodiment of the present disclosure, the step 1 includes: determining the angle at which the design manuscript is placed on the platform of the scanning device according to a predetermined position or angle of the manuscript pattern in the plate-making page.

According to an embodiment of the present disclosure, the step 1 includes: using a protractor to accurately measure the angle at which the design manuscript is placed on the platform of the scanning device.

According to an embodiment of the present disclosure, the step 1 includes: firstly using a scanning device to scan the design manuscript at any angle to obtain a preliminary pattern, and then using the image processing software to rotate the preliminary pattern until the design manuscript is The position or angle that should be in the plate-making page to obtain the original pattern.

According to an embodiment of the present disclosure, in the step 2, when the one or more color separation layers are a single color separation layer, the dot angle of the single color separation layer is rotated by 45 degrees.

According to an embodiment of the present disclosure, in the step 2, when the one or more color separation layers are two color separation layers, the dot angle of the color separation layer including the main color is rotated by 45 degrees , and rotates the dot angle of the separation layer containing the secondary color by 75 degrees.

According to an embodiment of the present disclosure, in the step 2, when the one or more color separation layers are three color separation layers, the dot angle of the color separation layer including the main color is rotated by 45 degrees , rotate the dot angle of the color separation layer containing the first color by 15 degrees, and rotate the dot angle of the color separation layer containing the second color by 75 degrees.

According to an embodiment of the present disclosure, in the step 2, when the one or more color separation layers are four color separation layers, the dot angle of the color separation layer including the main color is rotated by 45 degrees , rotate the dot angle of the color separation layer containing the first strong color by 15 degrees, rotate the dot angle of the color separation layer containing the second strong color by 75 degrees, and rotate the dot angle of the color separation layer containing the weak color Rotate 0 degrees.

According to an embodiment of the present disclosure, in the step 3, an appropriate mesh is selected in the plate making process, so that the mesh ratio between the mesh and the twill thread density of the twill fabric is between 3.5 and 10.

According to an embodiment of the present disclosure, in the step 3, both the integer digit and the first decimal digit of the mesh number and the mesh ratio of the twill thread density of the twill cloth are odd numbers.

According to an embodiment of the present disclosure, the twill fabric is a cotton woven fine-grained fabric, and the mesh ratio is 5.3.

According to an embodiment of the present disclosure, in the step 3, any one of screen plate making, gravure plate making, or creating an input document of an inkjet printing machine is performed.

According to an embodiment of the present disclosure, in the step 4, any one of the following operations is performed: transfer dyeing is performed on the twill fabric with the screen mesh made, and transfer is performed on the twill fabric with a gravure roll Dyeing, transfer dyeing was performed on the twill with an inkjet printer based on the created input document of the inkjet printer.

According to one embodiment of the present disclosure, the twill is denim.

According to one embodiment of the present disclosure, the scanning device is a flat scanner.

It is to be noted that aspects of the present disclosure described with respect to one embodiment may be incorporated into other different embodiments, even if not specifically described with respect to such other different embodiments. In other words, all embodiments may be combined and/or features of any embodiment may be combined in any manner and/or combination as long as they do not contradict each other.

Description of drawings

Aspects of the present disclosure will be better understood after reading the following detailed description in conjunction with the accompanying drawings.

Fig. 1 is the schematic diagram of the generation mechanism of moire fringes in the dyeing process of twill, the reference numerals in the figure represent respectively:

1- Stripe lines in a striped pattern; 2- Twill lines in twill; 3- Moire;

d - the spacing between adjacent stripe lines in the stripe pattern;

The spacing between adjacent twill lines in k-twill;

m - the spacing between adjacent moire fringes;

Theta - the angle between the stripe line in the stripe pattern and the twill line in the twill.

Detailed ways

The present disclosure will be described below with reference to the accompanying drawings, which illustrate several embodiments of the disclosure. It should be understood, however, that this disclosure may be presented in many different ways and is not limited to the embodiments described below; indeed, the embodiments described below are intended to be thorough in this disclosure and to provide further Those skilled in the art fully explain the protection scope of the present disclosure. It should also be understood that the embodiments disclosed herein can be combined in various ways to provide still further embodiments.

It should be understood that the phraseology in the specification is used to describe particular embodiments only and is not intended to limit the present disclosure. All terms (including technical and scientific terms) used in the specification have the meanings commonly understood by those skilled in the art unless otherwise defined. Well-known functions or constructions may not be described in detail for brevity and/or clarity.

As used in this specification, the singular forms "a", "the" and "the" include the plural forms unless clearly indicated otherwise. The terms "comprising", "including" and "containing" are used in the specification to indicate the presence of a claimed feature, but not to exclude the presence of one or more other features. As used in this specification, the term "and/or" includes any and all combinations of one or more of the associated listed items.

The terms "between X and Y" and "between about X and Y" used in the specification should be construed to include both X and Y. As used in this specification, the phrase "between about X and Y" means "between about X and about Y," and as used in this specification, the phrase "from about X to Y" means "from about X to Y" to about Y".

In the specification, the terms "first", "second", or "third" are used only for convenience of description and are not intended to be limiting. Any technical features represented by "first", "second", or "third" are interchangeable.

In order to prevent moire fringes during the transfer dyeing of twill fabrics (eg, denim, etc.), the present disclosure proposes a method for preventing moire fringes during transfer dyeing of twill fabrics, which is mainly based on the large-area color patches of the transfer dyeing. The characteristics of the pattern are proposed, but it is also applicable to the transfer dyeing of other different types of patterns.

As shown in FIG. 1, the applicant has found in practice that if the large-area color patch pattern for transfer dyeing has a striped pattern and the large-area color patch pattern uses a spot color in the transfer dyeing, then when the adjacent stripes of the striped pattern are The spacing between the lines 1 is d, the spacing between the adjacent twill lines 2 of the twill fabric is k, and the angle between the stripe lines 1 of the striped pattern and the twill lines 2 of the twill fabric is θ. The spacing between the moiré fringes 3 is m=dk/(d ² +k ² -2dkcosθ) ^1/2 . When the distance m is large enough, it can be detected by the human eye. Therefore, in order to avoid moire fringes on twill fabrics, it is necessary to destroy the above-mentioned factors that cause moire fringes.

In order to solve the technical problem of generating moire fringes during the transfer dyeing process of twill, the method of the present disclosure may include: step 1: scanning a design manuscript to obtain manuscript patterns; step 2: performing color separation processing on the obtained manuscript patterns to obtain manuscript patterns One or more color separation patterns for plate making; step 3: each obtained color separation pattern for plate making is used as a manuscript for plate making; and step 4: transfer dyeing the twill fabric. Each step will be described in detail below.

In step 1, the original pattern may be obtained by scanning the design original to be used in the transfer dyeing process using a scanning device. In order to obtain a high-quality original pattern, during the scanning process, the angle at which the design original is placed on the platform of the scanning device may be determined according to the predetermined position or angle of the design original on the plate-making page. In one embodiment according to the present disclosure, a protractor may be used to accurately measure the angle at which the design manuscript is placed on the platform of the scanning device, so as to improve the accuracy of placement of the design manuscript. In one embodiment according to the present disclosure, the scanning device may be a flatbed scanner. Of course, the present disclosure is not limited thereto, and the scanning device may be any other type of scanning device.

In another embodiment according to the present disclosure, a design manuscript may be scanned at any angle by a scanning device to obtain a preliminary pattern, and then the obtained preliminary pattern may be input into image processing software (such as photoshop, etc.) An original pattern to be used that is rotated to a predetermined position or angle where the design original should be in the plate making page.

In step 2, use image processing software (such as photoshop, etc.) to perform color separation processing on the obtained original pattern. In this step, it is determined that several colors can be used for printing by observing and analyzing the composition of several colors in the original pattern, and the relationship between the shades of various colors is arranged according to the intensity of the colors or the primary and secondary colors. The principle of color separation is to print the pattern closest to the original design with the fewest colors possible. After several colors to be adopted are determined, a separate layer is established for each color, so as to obtain one or more color separation layers, each color separation layer is composed of corresponding dots, and the dots can form cable.

In order to avoid moire fringes, according to the number of color separation layers, it is necessary to rotate the dot angle of each color separation layer (which corresponds to the angle of the screen lines formed by the dots) by different predetermined angles respectively to obtain the screen dots for plate making. Separation pattern. specifically:

1) For a single color separation layer (corresponding to a single color), the dot angle of the single color separation layer can be rotated by 45 degrees;

2) For two color separation layers (corresponding to two colors), the dot angle of the color separation layer containing the primary color can be rotated by 45 degrees, and the dot angle of the color separation layer containing the secondary color can be rotated by 75 degrees. ;

3) For the three color separation layers (corresponding to three colors), the dot angle of the color separation layer containing the main color can be rotated by 45 degrees, and the dot angle of the color separation layer containing the first color can be rotated. 15 degrees and rotate the dot angle of the separation layer containing the second color by 75 degrees; and

4) For four color separation layers (corresponding to four colors), the dot angle of the color separation layer containing the main color can be rotated by 45 degrees, and the dot angle of the color separation layer containing the first strong color can be rotated. 15 degrees, rotates the dot angle of the color separation layer containing the second strong color by 75 degrees, and rotates the dot angle of the color separation layer containing the weak color by 0 degrees (ie: no rotation).

In step 3, plate making is performed using each color separation pattern for plate making obtained from step 2 as a draft. Different types of plates can be made according to different dyeing methods, such as screen plate making, gravure plate making, or creating input documents for inkjet printing machines.

In order to prevent moire fringes during the transfer dyeing process of twill, it is necessary to reasonably select the mesh number of the screen, the mesh number of the gravure, and the resolution conversion mesh of the inkjet printing machine.

Specifically, according to different plate-making types, the mesh of the screen, the mesh of the gravure, and the converted mesh of the resolution of the inkjet printing machine are recorded as D (mesh/square centimeter), and the twill line density of the twill fabric (ie : the number of twill lines in each inch) is denoted as L (lpi), and the ratio of mesh and twill thread density is denoted as R=D/L, in order to prevent moire during the transfer dyeing process of twill fabrics stripes, the applicant found that the value of R should be in the range of 3.5-10. Preferably, the integer bits and the first decimal place of R may both be odd numbers.

In step 4, transfer dyeing can be performed on twill with the screen made, or on twill with a gravure roll, or on twill with an inkjet printer based on the created input document of the inkjet printer transfer staining.

In the method according to the present disclosure, by performing scan adjustment, color separation processing, and rotation on the design manuscript, and selecting an appropriate plate-making mesh, the pitch of the moiré can be reduced to a level imperceptible to the human eye. By selecting an appropriate eye-to-line ratio, the transferred-dyed pattern can have a blurred focus effect, which also further weakens the visual effect of moire fringes. Furthermore, in the embodiment according to the present disclosure, both the integer digit and the first decimal place (especially the first decimal place) of the eye line ratio are preferably odd numbers, because the applicant found that if it is an even number, it indicates an ink point There is a greater chance of repetition relative to the twill lines of the twill, and if it is an odd number, it favors the irregularity of the inking spots, which can scatter the configuration of the potential moiré to the extent that the human eye is imperceptible. Therefore, with the aid of the method of the present disclosure, moire fringes visible to human eyes can be prevented from being generated during the transfer dyeing process of twill fabrics, thereby significantly improving the yield of products.

In a specific example, the applicant used the method according to the present disclosure to carry out transfer dye printing on cotton woven twill, the specific details are as follows:

Parameters of cotton woven twill: Specification: 10×10/72×44; Weight: 10 ounces; Width: 58-60”; Composition: 100% cotton;

Dyeing pattern: Denim-like indigo vertical stripes.

In step 1, the original pattern is obtained by scanning the original with a flat scanner;

In step 2, the obtained original pattern is input into Photoshop software for CMYK (cyan, magenta, yellow, black) four-color separation processing, four color separation layers are obtained, and four color separation maps are obtained. The layers were rotated as follows to obtain four color separation patterns for plate making: 45 degrees for the separation layer containing the dominant color; 15 degrees for the separation layer containing the first strong color; Rotate the separation layer of strong colors by 75 degrees; rotate the separation layer containing weak colors by 0 degrees;

In step 3, the color separation pattern for plate making obtained in step 2 is used as a manuscript for plate making. In this embodiment, a gravure roll is selected for plate making, and the mesh ratio R corresponding to the mesh number of the gravure roll is taken as The value is 5.3;

In step 4, the twill fabric is transferred dyed with the gravure roll obtained in step 3.

In this specific example, the all-cotton woven twill fabric that has undergone transfer dyeing successfully prevents the occurrence of moiré, resulting in a significantly improved yield.

Exemplary embodiments according to the present disclosure are described above with reference to the accompanying drawings. However, those skilled in the art will understand that various changes and modifications of the exemplary embodiments of the present disclosure can be made without departing from the spirit and scope of the present disclosure. All changes and modifications are included within the scope of protection of the present disclosure as defined by the claims. The present disclosure is defined by the appended claims, with equivalents of the claims to be included.

Claims

A method of preventing moire during transfer dyeing of twill, comprising:

Step 1: scan the design manuscript to be used in the transfer dyeing process with a scanning device to obtain a manuscript pattern, the manuscript pattern corresponding to the predetermined position or angle of the design manuscript in the plate-making page;

Step 2: Use image processing software to perform color separation processing on the obtained original pattern to obtain one or more color separation layers capable of printing the original pattern, each color separation layer includes a color and each Each color separation layer is composed of corresponding dots, and the dots of each color separation layer are rotated by different predetermined angles according to the number of the color separation layers, so as to obtain the color separation pattern for plate making;

Step 3: The obtained color separation pattern for plate making is used as a manuscript for plate making; and

Step 4: Transfer dyeing the twill.
The method according to claim 1, wherein the step 1 comprises: determining the angle at which the design manuscript is placed on the platform of the scanning device according to a predetermined position or angle of the manuscript pattern in the plate-making page.
The method of claim 2, wherein the step 1 comprises: using a protractor to accurately measure the angle at which the design manuscript is placed on the platform of the scanning device.
The method according to claim 1, wherein the step 1 comprises: firstly scanning the design manuscript at any angle with a scanning device to obtain a preliminary pattern, and then using the image processing software to rotate the preliminary pattern to Design the position or angle where the original should be in the plate-making page, so as to obtain the original pattern.
The method according to claim 1, wherein, in the step 2, when the one or more color separation layers are a single color separation layer, the dot angle of the single color separation layer is rotated by 45° Spend.
The method according to claim 1, wherein, in the step 2, when the one or more color separation layers are two color separation layers, the halftone angle of the color separation layer containing the main color is Rotate 45 degrees, and rotate the dot angle of the separation layer containing the secondary color by 75 degrees.
The method according to claim 1, wherein, in the step 2, when the one or more color separation layers are three color separation layers, the dot angles of the color separation layers including the main color are set Rotate 45 degrees, rotate the dot angle of the separation layer containing the first color by 15 degrees, and rotate the dot angle of the separation layer containing the second color by 75 degrees.
The method according to claim 1, wherein, in the step 2, when the one or more color separation layers are four color separation layers, the dot angles of the color separation layers including the main color are determined Rotate 45 degrees, rotate the dot angle of the color separation layer containing the first strong color by 15 degrees, rotate the dot angle of the color separation layer containing the second strong color by 75 degrees, and rotate the color separation layer containing the weak color by 75 degrees The dot angle is rotated by 0 degrees.
The method according to claim 1, wherein, in the step 3, an appropriate mesh is selected in the plate making process, so that the mesh ratio of the mesh and the twill thread density of the twill fabric is in the range of 3.5 to 10 between.
The method according to claim 9, wherein, in the step 3, both the integer digit and the first decimal digit of the mesh number and the mesh ratio of the twill thread density of the twill fabric are odd numbers.
The method according to claim 9, wherein the twill fabric is a cotton woven fine-grained fabric, and the mesh ratio is 5.3.
The method of claim 1, wherein, in the step 3, any one of screen plate making, gravure plate making, or creation of an input document for an inkjet printer is performed.
The method according to claim 12, wherein, in the step 4, any one of the following operations is performed: transfer dyeing is performed on the twill fabric with the screen mesh made, and the twill fabric is dyed with a gravure roll on the twill fabric. Transfer dyeing was performed on the twill using an inkjet printer based on the created input document of the inkjet printer.
The method of any one of claims 1 to 13, wherein the twill is denim.
13. The method of any one of claims 1 to 13, wherein the scanning device is a flatbed scanner.