Fabric Inspection Standards and Equipment Essential for the Textile Industry
China is a textile powerhouse and the textile industry stands as one of the fundamental pillars of China's economy. Over the past two decades, the business climate index of the textile industry has shown fluctuating changes, reaching its cyclical peak during the periods of 2003, 2007, 2011, 2013, and 2017, while hitting its phase-specific nadir during 2002, 2004, 2009, 2012, and 2016. In 2013 and 2014, the overall business climate index of the textile industry remained within the growth range, yet the pace of growth has been slowing down in comparison to prior years. In recent years, the business climate index of the textile industry has remained stable and roughly on par with previous years.
In 2018, China's textile enterprises with a certain scale achieved a cumulative main business scale of 5.37 trillion yuan, a year-on-year increase of 2.90%. However, in 2019, the growth momentum of textile enterprise investment was weak, and the profitability level declined. The main economic indicators showed a slowing trend. The textile and clothing enterprises with a certain scale achieved operating income of 4.94 trillion yuan, a decrease of 1.47% compared with the same period of the previous year. In 2020, due to the impact of the pandemic, the textile industry was relatively sluggish in the first half of the year, but the surge in orders in the second half of the year almost made up for the losses in the first half. Overall, the textile industry is still relatively prosperous.
Over the past decade, the value added of the textile industry in the scale-above industry has continued to increase, albeit with a slowdown in recent years. Specifically, the situation is as follows:
In 2017, the textile industry in China's scale-above industry grew by 4.0%. In 2018, the retail sales of clothing, shoes, hats, knitted and textile products above the national quota increased by 8% year-on-year, with a growth rate that was 0.20% higher than the previous year and 2.30% higher than the growth rate of commodity retail sales above the quota during the same period. However, in 2019, the growth rate of the domestic market for textile and clothing products in China slowed down. The retail sales of clothing, shoes, hats, knitted and textile products above the national quota increased by 2.90% year-on-year, which was 5.10% slower than the growth rate in 2018.
Overall, the textile industry is susceptible to unfavorable factors such as fluctuations in international economic growth, rising raw material and labor costs, exchange rate fluctuations, and intensified industry competition. Although the growth rate has slowed down, the textile industry still maintains a stable and growing trend. In the past decade, China's textile yarn, fabric, and product exports have shown a trend of increasing year by year.
Although the growth rate of the textile industry has slowed down significantly, the overall market is still huge and exports continue to grow year by year, indicating great potential. Currently, in addition to external environmental factors, obstacles to the growth of the textile industry include its own industry structure, production processes, and technological issues. In order to meet the development needs of the textile industry, it is necessary to improve production efficiency and the quality of textiles, and textile machinery is developing towards intelligentization.
In the textile production process, the key link to improve production efficiency and fabric qualification rate is fabric inspection. In recent years, fabric inspection machines have undergone continuous technological innovation. In order to improve the inspection speed, automatic fabric inspection technology has emerged. However, due to the difficulty of automatic fabric inspection and its high cost, it has not been widely promoted and used.
Many companies, including SUNTECH, are researching automatic fabric inspection technology, and it is believed that it will replace traditional manual inspection in the future. However, for now, most fabric inspection is still carried out using a combination of fabric inspection machines and manual inspection.
So, how can we improve the speed and accuracy of fabric inspection during the fabric checking process? In addition to using intelligent equipment, inspectors should also be familiar with defects and proficient in fabric inspection standards.
Fabric Defects & Handle Methods
Fabric defects are extremely complex, including spinning defects, weaving defects, printing and dyeing defects, and so on. The fabric defects caused by spinning include uneven drying, thick warp, wrong weft, double yarn, warp break, weak twist, strong twist, foreign fibers, yellow-white yarn, colored warp, colored weft, oil stains, coal ash yarn, knotting, skirt wrinkles, and so on. Due to the widespread use of new electronic clearing devices in spinning machines, which can remove most yarn defects such as long and thick segments, short and thick segments, fine segments, double yarn, knotting, foreign fibers, colored yarns, and so on, the overall clearance efficiency can only reach 70% to 80%, and some defects are still missed. Once a long segment of thick warp is missed, it can cause continuous multiple or even dozens of defect fabrics, which puts higher requirements on fabric inspection.
Defects caused by weaving are obviously the focus of fabric inspection, mainly including crossbars, sparse and dense routes, double yarn, warp break, sparse weft, skipped stitches (skipped yarn, skipped stitches, star skipped), warp shrinkage, weft shrinkage, hundred feet (referring to twill fabric), edge defects, edge sagging defects, broken warp, holes, foreign objects woven in, oil stains, dragged yarns, foreign fibers, cotton balls, fabric blooming, bamboo nodes, and so on. Generally, seven defects such as dragged yarns, cotton balls, fabric blooming, weft shrinkage, wool edge, sporadic bamboo nodes, foreign object weaving are listed as small defects and can be removed during manual inspection. The main defects should be marked for subsequent repair or opening and cutting.
In weaving defects, special attention should be paid to controlling defects such as weft bars, missing picks, double picks, skip marks, broken warp, and holes. Once these defects occur, they should be classified, recorded, marked, and evaluated. If they occur continuously or repeatedly, the machine must be stopped promptly for processing.
Fabric Inspecting Standard-Score
The scoring of the appearance defects of fabric is generally based on the length of defects in the warp or weft direction. If a point has both warp and weft problems, such as a hole, it is generally considered a major defect.
The basic test items for fabrics include color difference (batch difference, piece difference, edge and end), weight, width and bias, handle, organization, color, appearance, size, odor, shrinkage (ironing shrinkage, water shrinkage), water fastness, and rubbing fastness.
Fabric inspectors should be familiar with the domestic and foreign standards for scoring fabric defects in order to accurately judge defects and score fabrics. Currently, the commonly used standard for fabric defect scoring is the American "Four-Point System." The scoring method is as follows:
- Defects up to 3 inches (7.5 cm) - score 1 point;
- Defects over 3 inches and up to 6 inches (7.5-15 cm) - score 2 points;
- Defects over 6 inches and up to 9 inches (15-23 cm) - score 3 points;
- Defects over 9 inches (23 cm or more) - score 4 points.
Of course, there is some error between centimeters and inches, and there is some flexibility in using the four-point system to inspect fabric. It is not rigidly set that 7.4 centimeters must be scored one point and 7.6 centimeters must be scored two points. It depends on the type of defect and the customer's requirements.
Whether using the American four-point system or the European fabric inspection standard, the ultimate goal is to meet the customer's standards. The American four-point system or European standards are only reference points. Strictly speaking, the American four-point system is just an inspection standard, not a strict standard. As for what standard or score the American four-point system should reach, it depends on the country of export, the customer's grade, and the fabric.
If the customer's grade is not particularly high, the following standards can be used as reference:
For shirt fabric or synthetic cotton fabric, the score should be below 18 points per 100 square meters; for knitted sweat fabric or pure cotton twill fabric, the score should be below 24 points per 100 square meters; for ammonia fiber, silk, or jacquard fabric, the score should be below 30 points, and for linen, it should be below 48 points. The European standard is similar, but uses defect size instead of points deduction.
There are significant differences in the understanding of rating standards between Europe and America and China: for example, China requires mandatory standards such as GB18401 or some certifications, such as CMA certification for testing institutions. However, SGS and ITS did not undergo CMA certification before entering China, but this did not affect their international influence. China values certification and standards, while Europe and America place more emphasis on the recognition of historical customers.
Thus, customer satisfaction is the best standard for fabric inspection. Similarly, the quality of fabric inspection machines and other equipment is based on customer feedback.
Currently, SUNTECH fabric inspection machine perfectly integrates the two major aspects of fabric inspection and packaging, and can significantly improve production efficiency. SUNTECH fabric inspection machine and fabric inspection packaging line have more than 4,500 customers and 10,000 machine installation cases worldwide, using well-known brand components and 4mm A3 steel material, and have a high reputation. Please feel free to inquire for more information.
评论
发表评论