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Cut an appropriate size of a sample fabric, and tightly bind each of the four square-ends thereof using a sewing machine twin cotton thread. The appropriate size of the sample fabric to minimize errors is about 10g in weight. Note that when the sample fabric is extremely thin and difficult to collect 10g, 5g of the sample fabric may be collected.
Leave the sample fabric prepared in this way in an incubating room (with a fixed moisture ratio) for one night. On the following day, place the sample fabric in a plastic bag in the incubating room, and place the plastic bag containing the sample fabric in a desiccator to cool it down. Here, the cooling period of at least 30 minutes is required. After the cooling down, weigh the plastic bag containing the sample fabric using an analytical balance. Then, take the sample fabric out of the plastic bag and weigh only the plastic bag. The difference between the weights is regarded as a weight of the sample fabric. Next, perform the complete desizing of the sample fabric. The following describes the desizing method.
Dip Method(Liquor ratio 1:30)
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Treatment method
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PAS-600 5g/L
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90°C×20min.
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Hot rinse and cold rinse
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DESCO AP CONC 5g/L
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90°C×20min.
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Hot rinse and cold rinse
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Desizing is performed by the above method. A judgment as to whether the complete desizing has been achieved or not is based on the criterion that no starch and PVA are detected with the boric iodine solution. In some cases, however, PVA is difficult to remove completely. In such cases, at least 0.3 of the boric iodine coloration should be achieved.
After the complete desizing, dry the fabric at 100°C for one hour in an oven, and then leave the fabric in the incubating room for another one night. After that, weigh the fabric in the same manner as described above. Calculate the weight difference between the previously weighed sample fabric and the completely desized fabric, to obtain the total size amount of the fabric. The calculation method is as follows.
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(weight of sample fabric) -
(weight of completely desized sample fabric)
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(weight of completely desized sample fabric)
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Note:
- The total size amount includes amounts of starch, PVA, acrylic size, wax, and all the other sizes.
- When the sample fabric is not sized with starch, desizing with PAS-600 can be omitted.
- When the sample fabric includes wool, a treatment with DESCO AP CONC should not be performed since the alkalinity of DESCO AP CONC may break down the wool.
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