What Items Must be Involved in Appearance Test of Fabric?
Following are the main concentrations of appearance test of fabric: material quality test, fabric quality test, pretreatment procedure test and dyeing quality test.
(1), Test for material quality
Material quality including: uneven pattern material, obvious thick&thin yarn, big-belly yarns, knot and foreign fiber, not good interlaced yarn, too much joints in material, uneven blended yarn, substandard covered Spandex etc. The mostly reason of these problems are because of not put the finished product appearance quality in important position when confirm the roll sample and cylinder sample, and also because some of material color makes the defect not easy to identification and find, so in the process of inspection, patience and carefulness are necessary, at same time the advanced equipment and instrument can help to improve the inspection efficiency and degrees of perfection.
Fabric problem is resulted from many reasons, including the problems of equipment itself, weaving technology, material quality of fabric, organization structure of fabric, temperature and humidity of weave environment, technological level of operator, the mistake and oversight in weave process. Some of the problems and defects of fabric can be repaired, but some not. As for the fabric problems can be repaired, repair them, as for weave problems can not be repaired , adopt wrap and combinedpiece to reduce the influence of weave problem to fabric, as for the serious and obvious defect, cutting fabric is necessary.
(3), Inspection for pretreatment procedure
In the process of pretreatment procedure, different kinds of fabric result in different problems. In some cases, the problems in pretreatment procedure are difficult to find. For example, as for polyester fabric, if water not clean after reduction, the surface of fabric will have yellow spot after dyed color; If not cleaning desizing as for Cotton fabric, some cottonseed hulls will be left. All these problems are difficult to find, if the inspector does not have enough experience, these problems would be considered as dyeing defect or other problems, and not dealt with immediately.
In the process of fabric appearance test, dyeing problems are easy to identified. Color point, stain, color mark are the common dyeing defect, they should be marked obviously in inspection process and deal with it according to the test standard. In the process of dyeing treatment, for some reason, the fabric blocking in vat or decollation, especially blocking in vat would result in obvious trace, spot and defect in the surface of fabric, and these defects are difficult to repair. There are many reasons for this, sometimes it is the special material of fabric, water temperature in the dyeing process, add cold water too fast, or dehydration time too long in the dehydration process. Inspector should pay more attention to this problem, mark and report if found similar problem, summarize the characteristics of this kind of problem and analysis to the courses of reasons in the meantime, repair and process them according to the severity of the defect.
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