Points for attention in the detection of textile fiber content

Fiber content testing is very important in various textile testing. Almost every batch of samples needs to be tested for component content. The testing data is not only related to the cost of manufacturers and distributors, but also to the health of consumers. According to the requirements of GB/T 29862-2013 "Labeling of Fiber Content of Textiles": "Each product should be attached with a fiber content label", especially in random inspections at all levels, this item is a mandatory inspection item. However, there are errors in any inspection, especially for inspection items with strong manual dependence. Therefore, it is particularly important to improve the accuracy of detection data. Based on the inspection experience, this paper summarizes the common missed detections in the current textile fiber content detection, in order to improve the accuracy of the inspection data.

Misjudgment and missed inspection caused by different types of fabrics

01 Denim fabric

Through the research and analysis of the testing data of nearly 100 batches of denim fabrics, it is found that the samples containing 1% to 2% (or even lower) of regenerated cellulose fibers are prone to be missed at present. After excluding the influence of personnel experience and physical condition of personnel, the reasons for the missed inspection were analyzed because the denim fabric itself was deeply dyed and the microscope observation was not clear. But through empirical analysis, the main reason is the abnormal morphology of regenerated cellulose fibers. The longitudinal section of the regenerated cellulose fibers in these denim fabrics is often streamer-like, transparent and shiny, rather than the ordinary viscose fiber shape. And in some cases, not every fiber is in this form, and often only one of 3~4 or more fibers has this condition, which requires the inspector to be careful enough.

02 Pure mercerized cotton fabric

At present, the composition of pure mercerized cotton fabrics on the market is more complex, but there is little difference in the overall appearance, vision and feel. In recent years, lyocell fiber, flax fiber and mulberry silk fiber have been detected in similar fabrics, and in most cases, the content of flax fiber and mulberry silk fiber is very low. It is easy to cause misjudgment and missed detection.

03 Fabrics with no difference in appearance pattern

In order to increase strength and comfort, some garments are made of fabrics with different fibers in different positions. If these fabrics are located in the parts with obvious differences such as sleeves, body, cuffs and necklines, it will not affect the inspectors; if they exist in the same part and there is no obvious difference in appearance, it is easy to miss the inspection. For example, the upper and lower fiber components of the front piece of a knitted sweater are different; two samples with the same jacquard pattern have different fabric components, etc. This requires inspectors to have a systematic understanding of the entire fabric before conducting inspection, and multi-point sampling is required for fabrics with no difference in appearance.

04 Lower foot fiber fabric

For garments made of fibrous fabrics, special attention should be paid to low-content fibers and trace fibers. It is recommended to use the dyeing method to characterize the fabrics, not only to have an accurate characterization of the fiber components, but also to have a general understanding of their content. Quantitative dissolution and other tests provide reference.

05 Yarn-dyed jacquard fabric

For the samples of yarn-dyed fabrics with irregular jacquard patterns, the yarns of different colors should be inspected separately, and the inspection data should be issued separately. Experience has shown that if the composition of each color yarn is very different, the data obtained from the inspection of different parts will vary greatly, which will seriously affect the inspection results.