The color difference of fabrics has always been a headache for the dyeing factory masters. The formula and process are exactly the same. In the end, they will be revised repeatedly due to differences in vats and batches.
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In fact, whether it is vat difference or batch difference, it is a long-standing problem in the dyeing and finishing industry. There are many factors that affect color difference and it is quite complicated. It is difficult to fundamentally overcome it. The problem of batch difference with cylinder difference meter cannot be realized. It can only be carefully analyzed and controlled. It is possible to control the color difference within the minimum range.
We all know that good colors not only score products, but also increase customers’ desire to buy. For the fabric industry, the raw materials of the fabrics we commonly see, such as polyester, acrylic, vinylon, spandex, etc., are all fibers. If you want to reduce the color difference of the fabric to the minimum, you need to start controlling the color difference at the source of the fabric. .
Because the purity of the color of the fabric is inseparable from the fiber.
The main components of natural fiber are cellulose fiber, moisture, and natural impurities (ash). These components will vary depending on the natural growth environment, and some impurities will also be mixed in during the production process. , such as weaving oil, etc. In different raw yarn origins or fabric production companies, these natural impurities and adulterations not only differ in content, but also have different physical and chemical properties. Sometimes even fabrics with the same batch of yarns as raw materials have different effects during dyeing. There are also some differences in performance. If these differences are not handled well, they will directly affect the color of the finished product, resulting in larger color differences.
The effective solution is to strictly control the quality of the weaving process and establish a complete traceability system based on fabric-related data to facilitate timely adjustments to the process formula.
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Dye auxiliaries, The stability of the process will also affect the color of the finished product, and these important links need to be strictly controlled. Another very important point is that the color standards need to be unified. Generally, the operation process of a dyeing factory cannot escape the following key steps:
Customer submission→Laboratory sample→ Send to customer for confirmation → Customer confirms color → Plan cylinder arrangement → Dyeing workshop goes into production
In this process, it is necessary to coordinate the color issues of each link. When producing different batches, when When it is found that the production time interval of the customer’s products of the same color is long, the laboratory should promptly replicate the sample (i.e. re-sample), and correct any large deviations in time.
In the production process, generally customers will specify the △E color difference range. Try to produce the same type of cloth with the same color in the same type of dyeing machine, which can achieve the best results to a large extent. Reduce the occurrence of color difference, of course, this is subject to the actual production conditions of the dyeing factory.
And if the operators can be fixed, the so-called three fixations (fixed personnel, fixed machines, fixed processes), it will be more conducive to the accumulation of experience of the operators. At the same time, human operating errors will naturally be reduced a lot. Most dyeing factories have a consensus on this. Key personnel in key positions have high professional quality requirements and should have business capabilities that combine theory and practice.
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From the source, every It is very necessary to control color difference in a production process, but the prerequisite for us to solve color difference is how to evaluate color difference.
Maybe you think there is color difference, but your colleagues think there is not. What is the standard for color difference? How to test? This also needs to be considered. There are generally two methods for identifying color difference on the market.
1. Use an international standard color light box: look at the color difference between two pieces of cloth under a specific light source. But this method has a small flaw: the same color looks the same under a certain light box, but it looks different when the light source is changed. Of course, if the customer has already requested which light box light source can be matched, then there is no need to worry.
There are generally two types of color matching light boxes. One is domestic color matching light boxes, such as Qiantongcai color matching light boxes; the other is imported color matching light boxes, such as PANTONE color matching light boxes, X-Rite QC light source light box, etc.;
2. Use a spectrophotometer to measure the color of the fabric itself. It does not rely on the light source and can be simulated by itself. Multiple light sources. Spectrophotometers are very suitable for complex color analysis. Of course, they are also relatively expensive. However, if the color difference measured by a spectrophotometer is small, the color difference seen under any light source will be very small. Nowadays, spectrophotometers are also It is gradually replacing the color matching light box and becoming a commonly used color matching tool in the printing and dyeing industry.
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When using a colorimeter, you will generally encounter What are the problems? How to solve it?
1: The colorimeter cannot be turned on when it is powered by a battery. What should I do?
1. If this phenomenon occurs, it means that the battery power is insufficient and the colorimeter needs to be powered;
2. If it still does not work, you can unplug it. Take out the power adapter, plug it in again, and check whether it can be turned on, or try again by unplugging and plugging the power adapter several times;
3. If the above method still does not work, replace the battery and try again. Take a moment;
4. If it still doesn’t work, you can contact the customer service of the supplier where you purchased the colorimeter to solve the problem;
2: What should I do if the measurement results of the colorimeter are abnormal?
1. This situation usually occurs because black and white calibration has not been performed.Caused by inaccurate positive or black and white calibration, black and white plate calibration needs to be performed first.
2. Dirt entering the measuring port will also cause inaccurate measurement. It is best to check before measuring;
3 , check whether the battery consumption is too low;
4. Check whether the instrument and test object are stable during measurement, and whether the measuring port and the measuring surface are in close contact; 5. Check whether the measurement object is too large. Thin light leakage;
6. Check whether the measurement part is mixed color;
3: What should you pay attention to when using a colorimeter?
1. The colorimeter is a precision measuring instrument. Drastic changes in the external environment of the instrument should be avoided during measurement, such as flickering of ambient light during measurement.
2. Generally speaking, colorimeters are not waterproof and must not be used in high humidity environments or water mist.
3. Keep the instrument clean and tidy, avoid water, dust and other liquids, powders or solid foreign matter from entering the measuring aperture and inside the instrument, and avoid collisions with the instrument.
4. If the instrument is not used for a long time, the battery should be removed.
5. After using the colorimeter, it should be returned to the instrument storage box for safekeeping.
6. The instrument should be stored in a dry, cool environment. to avoid damage to the instrument.
In the printing and dyeing process, controlling color difference is a complex process. Simply classifying it as technical or management factors is not objective enough. How to effectively control color difference depends on each printing and dyeing process. Each factory has its own set of experience methods, and the methods are constantly explored. </p
