1. There is rust on the dining linen. After oxalic acid treatment, wash in the washing machine. After cleaning, it was found that the rust had not been removed. Acidification is the latter step in the laundry process. The quality of acid agents is crucial in laundry products. It can make up for the defects and deficiencies in previous processes, making the washing material perfect and reaching the ideal state. Oxalic acid is usually used in some laundry rooms, which is not enough. Calcium oxalate precipitation will form in unsoftened water and adsorb on the fabric, causing it to become gray, hard, and brittle.

用草酸除锈是不干净的、暂时的。这种反应是可逆的，即Fe++（棕色）Fe++（浅绿色）。干燥后，织物上残留的铁被空气氧化很长时间，然后变成铁++。只有在草酸中加入其他酸性络合剂，或使用其他除锈化合物形成稳定的络合物或螯合物，才能将其去除。

Removing rust with oxalic acid is unclean and temporary. This reaction is reversible, i.e. Fe++(brown) Fe++(light green). After drying, the remaining iron on the fabric is oxidized by air for a long time and then turns into iron++. Only by adding other acidic complexing agents to oxalic acid or using other rust removal compounds to form stable complexes or chelates can it be removed.

2.在餐饮布草洗涤小方巾时，使用了洗衣专用美白粉、氯漂白粉和次氯酸钠，但效果不佳。产生严重灰烬的原因如下：

2. When washing small square towels with catering linen, special laundry whitening powder, chlorine bleaching powder, and sodium hypochlorite were used, but the effect was not satisfactory. The causes of severe ash formation are as follows:

① 洗涤前，先了解洗涤方巾区域的水质特性，无论是软水还是硬水。如果是硬水，就意味着钙、镁离子和金属离子的含量很高。然后，清洗时必须添加软水剂，后处理时必须使用中和剂。

① Before washing, first understand the water quality characteristics of the washing area, whether it is soft or hard water. If it is hard water, it means that the content of calcium, magnesium ions, and metal ions is high. Then, a softener must be added during cleaning, and a neutralizer must be used during post-processing.

② 洗涤毛巾时，应该同时使用氧气漂白粉和洗衣粉。不要使用氯漂白粉，因为氯漂白粉具有高度氧化性，容易损坏毛巾。

② When washing towels, both oxygen bleach and laundry detergent should be used. Do not use chlorine bleach as it has high oxidation resistance and can easily damage towels.

③ 硬水可以产生钙和镁离子，形成钙和镁皂。钙镁皂本身就是一种污垢，俗称皂垢或碱花。钙镁皂的残余垢很难去除。如果长时间积累，会破坏纤维和色素，使衣服和棉织物变得稍硬，失去光泽，并改变色光。它对纤维非常有害，如脆性、断裂、牢度降低等。铁以离子或离子化合物的形式存在于水中。如果它沉积在织物上或变成棕色斑点，它会使白色织物整体变黄，使有色织物的颜色变暗，并对漂白有一定的催化作用。在严重情况下，还会导致织物损坏。。

③ Hard water can produce calcium and magnesium ions, forming calcium and magnesium soaps. Calcium magnesium soap itself is a type of dirt, commonly known as soap scale or alkaline flower. The residual scale of calcium magnesium soap is difficult to remove. If accumulated for a long time, it will damage fibers and pigments, making clothes and cotton fabrics slightly hard, losing luster, and changing the color and luster. It is very harmful to fibers, such as brittleness, breakage, and reduced fastness. Iron exists in water in the form of ions or ionic compounds. If it deposits on the fabric or turns into brown spots, it will cause the white fabric to turn yellow as a whole, darken the color of the colored fabric, and have a certain catalytic effect on bleaching. In severe cases, it can also cause fabric damage..

1） 从身体上寻找原因

1) Find the cause physically

① 洗衣服的时间太长了。餐饮布草毛巾在洗衣机中洗涤时，大部分时间都会不断上下滚动，从而产生揉搓和摩擦运动。这种摩擦和摩擦运动是清洁毛巾的一个重要因素，因为脏毛巾不能仅通过浸泡在洗涤液中来清洁。这种摩擦不仅起到清洁毛巾的作用，还会磨损纤维，降低毛巾的牢固度。因此，控制合理的洗涤时间可以减少不必要的磨损，从而保证毛巾的正常洗涤寿命。

① The washing time is too long. When dining linen towels are washed in the washing machine, they will continuously roll up and down most of the time, resulting in rubbing and friction movements. This friction and frictional movement is an important factor in cleaning towels, as dirty towels cannot be cleaned solely by soaking them in detergent. This type of friction not only cleans the towel, but also abrades the fibers, reducing the firmness of the towel. Therefore, controlling a reasonable washing time can reduce unnecessary wear and ensure the normal washing life of towels.

② 脱水时多次高压汽提速度过快，离心力过大会使毛巾棉纤维马拉松，就像我们用手拧毛巾时用力过大，会使编织结构松动，导致毛巾中部或整个松散损坏，而正常损坏一般从边缘开始。

② During dehydration, the high pressure steam extraction speed is too fast multiple times, and excessive centrifugal force can cause the cotton fibers of the towel to marathon. Just like when we use excessive force to twist the towel by hand, it can loosen the weaving structure and cause loose damage to the middle or entire part of the towel, while normal damage usually starts from the edge.