Confirmation of textile color samples and solutions to common problems

Self evaluation of 1 color plate sample

Color with gray card. Grade 4.5 is required between the original sample and the sample. When using the matching instrument to check the color, it is generally △ e < 1. Considering the system error, the internal control standard △ e < 0.6 should strive for one accurate sample. In case of high requirements, hue △ h and chromaticity △ C should also be taken into account.

To fully understand the thermal sensitivity and photosensitivity of dyes. For example, Cibacron yellow CR-01 should not be used, especially c-2r. Most dyes are more or less heat sensitive, and the performance of Shilin dyes is more prominent. Cold, hot, dry and wet have an impact on the color shade. When proofing and color matching of such dyes, the trend of stable color shade of dyes should be taken into account, and it is intended to deviate a little in reverse direction. If the color light of most dyes is stable, the red light is slightly darker, and when the proofing is slightly cold, the green light should be slightly brighter, so that when the color light is stable, it is just equal to the original color. As the main color proofing of photosensitive and heat sensitive dyes, it may cause stack color printing of large-scale color cloth, and even irreversible in serious cases, such as olive green R, yellow c-2r and other dyes. Therefore, such dyes cannot be used.

Whether the sample is in line with the requirements of customers, we should know well about the proofing of regular customers, and it is easy to get accurate samples in combination with customers' habits. Different regions have different preferences for colors. For example, orders in Europe should avoid red, and they can be slightly green. Different consumer groups of fabrics have different color light bias, such as children's wear generally like gorgeous; men's wear should try to be neutral, with low color saturation and a little gray; women's clothing should be bright.

Generally, customers require at least 3 samples, i.e. a, B and C samples, and sometimes 12 samples are required. In order to improve the accuracy of primary sample, we should consider the depth, light and shade, brilliant light and color equality.

2. Approval of sample

When the customer's opinion is different from the actual situation, the possible light source problem should be considered and communicated with the customer.

When the customer thinks that most of the samples in a color plate are too deep, it should be considered that the customer may be double-layer proofing, especially for the thin and transparent fabric, and the layered sample will become deeper. Some large companies require 4 layers of color matching for thin and transparent fabrics and knitted fabrics. The conventional color matching is a single layer.

When the "light jump" is serious, consider changing the dye to improve the "jump light". In order to understand the "metamerism" property of dyes, we should make full use of colorimeter to screen dyes. When the applicable dyes in our factory can not meet the customer's "lamp jumping" requirements or the "lamp jumping" is less than 0.5, we should communicate with customers. Once the sample of our factory has been confirmed and the confirmed sample is taken as the reference sample, there will be no "lamp jumping" problem. Do not choose unstable dyeing formula for mass production to meet the requirements of customers.

In the direct production of small sample color, should try to color under various light sources, such as D65 natural light, fluorescent lamp, there is no serious "jump lamp", if serious, please confirm the customer before production.

Production confirmation of 3 large samples (head cylinder samples)

The color and luster requirements of large sample production should be strictly in accordance with the customer's approval opinions, and the deviation should be based on the original sample to the confirmed sample, and it is better to persuade the customer to bias to the original sample based on the confirmed sample. Because the fabric specification of the confirmed sample is consistent with that of the bulk sample, it is easy to see the sample, the dyes used are consistent, and there is no "lamp jumping" phenomenon. Generally, the color light is between the two, and the gray card reaches grade 4 or above, △ e < 1 (internal control standard is generally △ e < 0.8), which will be recognized by customers.

The batch difference should be controlled above grade 4 of gray card, the color difference of left, middle and right should be controlled above 4-5, and the batch difference △ e < 1 (within 0.8 of internal control). When choosing the dye, try to use the same dye as the sample prescription. Adjusting the color light, the newly added dyes may cause the phenomenon of "lamp jumping". When the large sample and the confirmed sample have obvious "jumping light", there will be the risk of rejection of large goods, which will bring economic loss and reputation reduction to the enterprise. For example, dyes with reverse spectrum, such as turquoise blue, Shilin RB yuan, B green, t green, R red, etc. should be treated carefully when adding dyes. If there is serious "lamp jumping" under each light source, it can not be added.

When turning over and replenishing orders, the head cylinder confirmation sample is generally used as the reference to shift to the original sample and the confirmed sample, so as to keep the color and luster of the whole batch consistent. However, when the customer insists on taking the original sample or confirmed sample as the reference, the color light direction of the bulk sample must be considered.

After finishing has an effect on the color, and the color of different colors is different. Therefore, it is necessary to adjust the shade before dyeing to meet the requirements of customers.

Common problems and Countermeasures

Color fastness to light

For the color plate with light color fastness requirements when making small samples in laboratory, dyes with good light fastness shall be selected before making small samples, including auxiliary colors, which shall also meet the customer's color fastness requirements. If there is a dye with poor sun fastness in a formula, the sun fastness of this color number will be decreased. In addition, the compatibility of dyes should also be considered. For example, the light fastness of Ciba red c-2bl and yellow CR-01 decreases when used together, but the light fastness is good when used separately. Although the light fastness of the mixture of green FFB and yellow GCN did not decrease, the cellulose fiber was still brittle. The light dye is a kind of Shilin dyestuff, but it can't be dyed with reactive dye.

The light fastness on dye color card refers to ISO standard, and the test result is 8 grade system; American Standard AATCC standard is 5 grade system, which is quite different. The light fastness series on the dye color card refers to the level when the standard concentration is I: 1. Therefore, when dyeing light colors with reactive dyes, we should see the corresponding concentration series on the dye color card, such as 1 / 6, 1 / 12, 1 / 25, etc.

2. Metamerism

Skipping is one of the most common problems in proofing. In the actual operation, the phenomenon of light color conversion and metamerism will be encountered.

Use the lamp box to check the "lamp jumping" situation, and initially select the dyeing prescription proofing of synchronous "jumping lamp" from the accumulated experience prescription. When the close dye formula cannot be selected from the accumulated color block samples, the original sample and monochromatic sample are used to search for similar "jump lamp" dye color template under the light source.

With the help of colorimeter and color measuring software, the data between the standard sample and the single chromatogram is calculated, and the combination of dyes is preliminarily selected, which requires color measurement technology and prediction experience.

With the help of colorimeter and color matching software, we can quickly find out the dye formula that meets the requirements of light source and close to customers, and intuitively and accurately knows whether it meets the requirements of customers for multiple light sources. There are many brands of colorimeters, and the data measured by them are also different. GretagMacbeth 7000A software is better, it can be compatible with the world's major brands of color meters, the most characteristic is the netprofiler software, it is based on the Internet between the color meter data exchange, its online correction and detection function makes the error between each online colorimeter and the standard colorimeter of the United States reduced to the allowable range. It can choose the color matching of three light sources at the same time, so it can obtain the optimal formula in a few minutes. If it meets the customer's requirements, it can immediately sample and test color, and send the data to the customer for confirmation. If the problem of "light jumping" cannot be solved, the "light jumping" situation of color matching can be transmitted to the customer first, and then proofing after consulting the customer's opinions, which greatly shortens the proofing confirmation One process. When Wal Mart Company of the United States orders from 2005, it will adopt the way of data transmission. The color quality control procedure of textiles is based on the data of colorimeter. Therefore, colors in the future can be described by numbers.

Online ordering and online bidding have become a common thing in today's social trend. Purchasers ask more than one textile management company to bid for one order, while marketers often place orders to multiple manufacturers to print color plates at the same time. Therefore, for enterprises, fast, accurate, good color pattern is the first step to win orders. Do a good job in product quality and quality, do accurate, do stable color light is the test of enterprise strength and endurance, is the foundation of enterprise sustainable development.