At present, some laundry factories have problems of one kind or another in water washing, such as poor stain removal effect and unclean linen washing. There are more and more opinions from customers, which ultimately leads to a decline in business volume. Everyone is also trying to find the reasons: improvements have been made in the washing equipment, washing liquid, water quality, etc. Of course, these are also the reasons for the poor washing effect, but everyone has overlooked an important reason, that is, the water temperature. Today, I will explain to you the influence of the water temperature on the washing effect.
White table cloth, mouth cloth, wardrobe, and single washing process
Pre-wash for 3 minutes, middle-off for 1-3 minutes, main wash (80-85°C) for 20-30 minutes, middle-off for 1-2 minutes, bleaching (70-75°C) for 10-15 minutes, middle-off for 3 minutes, over Water for 3 minutes twice, and neutralize for 5 minutes. Spin dry for 6 minutes and remove clothes.
Main wash: strong powder, synthetic alkali, emulsifier
Bleaching addition: Chlorine bleaching powder
Neutralizing addition: neutralizing powder, softener
Towel, bath towel, bathrobe washing process
Let the water pass twice for 3 minutes and neutralize for 5 minutes. Spin dry and remove clothes.
Main washing add: general powder (washing powder), emulsifier, color bleaching
Neutralizing addition: neutralizing powder, softener
Towel deashing and washing process
Pre-washing for 3 minutes, middle-off for 1-3 minutes, main washing (50°C) for 5-10 minutes, middle-off for 1-2 minutes, bleaching (60°C) for 10-15 minutes, middle-off for 3 minutes, and overwater for 3 minutes Second, neutralize for 5 minutes. Spin dry for 6 minutes and remove clothes.
Main washing add: general powder (washing powder), emulsifier, strong powder
Bleaching addition: chlorine bleaching powder or deliming and whitening powder
Neutralizing addition: neutralizing powder, softener
Color table cloth, mouth cloth washing process
Main washing add: general powder (washing powder), emulsifier, color bleaching, strong washing powder.
Neutralizing addition: neutralizing powder, slurry powder
Washing process of bed linen and duvet cover
Pre-washing for 3 minutes, middle dewatering for 1-3 minutes, main washing (65-75°C) for 15-20 minutes, middle dewatering for 1-2 minutes, watering for 3 minutes twice, and neutralization for 5 minutes. Spin dry for 6 minutes and remove clothes.
Main wash: strong powder, emulsifier, color bleaching
Neutralizing addition: Neutralizing powder
1. Cold soaking and pre-washing
Sort the pre-treated clothes according to their colors, and perform the cold soaking and pre-washing before the main wash. Put these clothes in cold water for 2 to 3 minutes of pre-washing. The purpose is to make the dirt on the clothes and the fabrics After the bonding force between the fibers is destroyed, it creates conditions for the next washing. This not only saves detergent, but also facilitates rinsing. However, it should be noted that the cold soaking and pre-washing time should not be too long to prevent color and color crossover.
2. Main wash
Put the cold-soaked and pre-washed clothes into the mechanical drum, turn on the inlet water and put in an appropriate amount of water, and then add detergent dissolved in water from the machine's feeding port {most clothes use neutral liquid detergents} Turn on the heating and washing switch, and when the washing temperature is reached, wash for 10 to 15 minutes to complete the main washing process. In the main washing process, the following requirements should be mastered: the laundry tub is loaded with 70% of the washing capacity as the standard, 2 particularly light and thin clothes should be packed in laundry net bags, and placed in the tub to prevent damage, 3 colored shades of clothing Should be washed separately, 4 high temperature resistant and non-high temperature resistant clothing should be washed separately. When washing, the water in the clothes tube should not be too much, and the water level should be kept low.
3. Rinse
After finishing the main wash water, enter the rinsing. Use clean water to remove detergent and dirt from the fabric through the mechanical force and temperature in the liquid cylinder. The following arrangements should be followed when rinsing: 1 The rinse water level should be slightly higher than the main wash water level, 2 General clothing needs to be rinsed 3 to 4 times. 3 Rinsing also requires temperature and the water temperature for each rinse should be lowered. For example, the water temperature of the main wash is 50 degrees. The rinsing water temperature should be 40 degrees for the first time, 30 degrees for the second time, and 20 degrees for the third time.
4. Dehydration
After rinsing, the fabric can enter the dehydration stage. Generally, the time required for dehydration can be properly controlled according to the requirements of the laundry. The dehydration time should not be too long. The moisture content of the fabric after dehydration should be greater than 20%. , In order to facilitate the drying of the fabric.
5. Dry or dry
After rinsing, the clothes need to be dried. There are two drying methods, air-drying or dryer drying. For clothes marked on the label that cannot be heated or air-dried, they need to be laid or hung according to the fiber characteristics of the fabric. For clothes that are marked to be dried on the label, the drying process must be completed in the dryer for a certain period of time according to the drying temperature of the clothes.
Treatment after washing
After the fabric passes through the main washing and bleaching, the washing comes to an end. However, in order to make the clean fabric need to be chemically treated according to different uses to meet the people's best use of the fabric, it needs to be treated after washing. . , The post-washing treatment includes six processes: watering, softening, neutralizing, whitening, simmering, and dehydrating.
1. Over water
Whether it is household laundry or industrial laundry, the overall washing quality must be ensured. In addition to the control of the main wash and the supplement of bleach, the over-water link should not be neglected.
Generally, in the washing process, in order to maintain a sufficiently large concentration gradient between the water and the washing residue contained in the fabric to be washed, and to improve the water passing efficiency, a high water level is usually used. The number of times of water passing is closely related to the performance of the fabric and the performance of the detergent used. Pure cotton fiber has excellent water absorption performance. During the washing process, it absorbs many times more lotion than others. The same cotton fiber fabric has different water absorption properties due to different structures. The green towel fabric is better than the plain weave structure. Cotton fiber fabric has excellent water absorption performance. For fabrics washed with detergents containing a large proportion of alkalis, because the rinsing performance of alkalis is very poor, relatively large number of water passes are required. Experimental data shows that a 50 kg washing machine After the towel is washed with high water level, the towel contains 16.7% of the residual lotion after the first wash, 3.23% after the second wash, and 0.108% after the third wash , After the fourth pass, it was 0.0117%. Therefore, 3 to 4 passes are generally applicable to most fabrics.
After the main wash, the fabric needs a certain amount of heat to pass the water, but there is a principle to choose the temperature, and the water temperature should be reduced in proportion to each time, and it should not be suddenly changed. For example: the main wash temperature is 80%, then the first water temperature is 70%, the second water temperature is 55%, and the third water temperature is 35%
When using high water level, the time should be 1.5-3 minutes, the time of washing machine under 50 kg class can be 1.5-2 minutes, and the time above 50 kg class can be 2-3 minutes.
2. Soft
After finishing the main washing and bleaching, for some comfortable, soft and fluffy fabrics, it is necessary to go through the softening process after the washing to achieve the purpose.
Softness: After finishing the main washing and bleaching of the fabric, although it has achieved good cleanliness, it is not very soft. The softening process is to use a softener, which is dispersed in water and has a proper affinity for the fabric to make the fabric fiber And the process of internal smoothness to a good state, softness, fluffy and antistatic effect,
Softening process: When the fabric is passed through the water for the last time, add softener from the feeding port when the water temperature reaches 20 degrees at room temperature, and keep the water level soft and wash for about 5 minutes.
Softness requirements: when softening, it should be used strictly according to the amount specified in the softener product description. Excessive use will cause fabric dyes to change color. At present, softeners are all cationic softeners and must not be used at the same time as fluorescent whitening agents. The time must be alternated.
3. Neutralization
Due to the alkalis, chlorine and calcium substances contained in the washing liquid during the main washing and bleaching, it is attached to the fabric when it is heated and subjected to water treatment. Due to the influence of washing machine and other factors, it cannot be absolutely guaranteed that these substances will not remain in the fabric, which will cause the white fabric to turn gray or yellow, affect the color vividness of the colored fabric, and make the fabric feel hard. In order to eliminate these remaining substances, it is necessary to carry out the washing treatment process of neutralization. The neutralizing acid agent is used to reduce the alkali substances, so that the pH value of the fabric surface is maintained between 5.8-6.5, and a feeling of comfort is produced. Neutralization removes calcium oxide and calcium chloride substances while whitening the fabric to a soft hand. At the same time, adding neutralizing acid when passing water will reduce the number of times of water passing and save energy.
Neutralization process: for the second or third time, when the water temperature is 30 to 40 degrees, add an appropriate amount of neutralizing acid from the feeding port and wash for 3 to 5 minutes.
Requirements: The amount of neutralizing acid is generally controlled at 0.2 to 0.3%. In actual operation, it is necessary to test the pH value of the lotion after washing with neutralizing acid to ensure the exact amount of acid in it, so as to avoid heating and cooling of the fabric to corrode the equipment and adhesion of the fabric after drying.
4. Sizing
This step is mainly for tablecloths, napkins, some uniforms and other cotton fabrics or mixed fiber fabrics in the catering industry. The sizing treatment can make the surface of the sizing fabric stiff, prevent the fiber from fluffing, and have a good look and feel. At the same time, it also provides a protective layer on the surface of the sizing fabric, which prevents the penetration of dirt to a certain extent. The bonding effect of the sizing agent can strengthen the fiber to a certain extent, and it can play a certain role in prolonging the service life of the fabric.
When the fabric is sizing, due to the wetting and penetration of the slurry, the relative slippage of the fiber is prevented when external The bonding ability between the fibers will form a firm layer on the surface of the fabric when subjected to a certain amount of heat.
There are many types of sizing agents. In view of the characteristics of fabric fibers, the frequently used sizing agents should have the following characteristics:
1. The cohesive force is large, and it has a certain degree of adhesion, which can form a layer on the surface of the fiber.
2. Have a certain ability to enhance fiber strength
3. It is easy to wash off and there should be no peculiar smell
4. After sizing, the surface color of the fiber fabric will not be affected.
Commonly used slurries are divided into two categories: natural and chemical slurries. Commonly used in the washing industry are fixed-powder slurries that belong to natural slurries and polyethylene Xichun slurries that belong to chemical slurries. Here is an introduction:
(1) Starch
Starch is a natural polymer, a polysaccharide substance, which is widely present in some plant fruits, tubers, roots or seeds
Starch has good adhesion and adhesion to hydrophilic natural fibers, and has a certain texture ability. High-quality starch is amorphous white or slightly yellow, shiny and fine powder, and it is hard but brittle. It is a resource of starch. More abundant, low price, widely used in washing enterprises, generally more commonly used tapioca starch
(2) Polyethylene glycol
Polyglycol is a synthetic slurry, which is made from polyglycol ester monomer polyglycol after alcoholysis. The external light of polyethylene glycol is white powder. Part of the alcoholysis product of polyethylene glycol is suitable for synthetic fibers, and the complete alcoholysis product is suitable for cellulose fibers, and the mixture of the two is suitable for the blending of cellulose fibers and synthetic fibers. According to the technical needs of sizing, different specifications of polyethylene glycol can be selected. Generally, the layer formed by partial alcoholysis is soft, elastic and slightly hygroscopic, while the layer formed by complete alcoholysis is firmer and plump. .
Polyglycol has good sizing properties for synthetic fibers and cellulose. It is mostly used for sizing small batches of fabrics. It is generally not used for sizing treatment with tablecloths and napkins.
There are two ways of sizing: one is raw pulp and the other is cooked pulp. Method of making pulp: When washing the sizing step of the fabric, take an appropriate amount of pulp powder and put it in a small container, stir to dissolve it with a certain room temperature water, and slowly add it to the rotating washing machine, the action time is 2 to 3 minutes, the temperature is 40 To 45 degrees, this method is easy to operate, but the forming effect is not very strong, and it is easy to lose a part of the pulp during drying or ironing, and it requires a higher temperature during ironing. The method of cooked pulp and the sizing process are different from each other. The raw pulp is roughly the same, the difference is that the appropriate amount of pulp powder is dissolved in room temperature water, and then added such as boiling water or heating to make it into a slurry-like liquid, and then slowly added like a rotating water washing machine. The operation of this method is more complicated, but the forming effect is good, and it is not suitable to lose the pulp during drying or ironing. It is only necessary to operate at a moderate temperature during ironing or ironing.
The sizing application is the upper and lower water levels. The dosage of pulp powder is 1 to 100, but the dosage should be determined according to the specific requirements of the unit using the tablecloth and napkin. One disadvantage of using fixed powder as slurry to sizing fabric is that the finished product is more susceptible to erosion by certain insects, so it should be kept properly.
5. Dehydration
The last step of washing is dehydration, which uses the centrifugal force generated when the drum of the washing machine rotates to reduce the water content of the water-containing fabric in the drum as much as possible. , The high-speed dehydration process of the general industrial washing machine with dehydration function can reduce the moisture content of the fabric to 30 to 45 percent. Dewatering efficiency and equipment, fabrics have lower moisture content, and vice versa, but under the same centrifugal force and the same operating time, the moisture content of the surface fabric is higher than that of blended fabrics and chemical fibers, and towels are better than pure cotton sheets. To be higher. The moisture content of the fabric will directly affect its drying and ironing efficiency. For example, a towel with a low moisture content will consume a shorter drying time than a towel with a high moisture content under the same drying conditions, but has a low moisture content. Under the ironing conditions of the same temperature, the ironing speed of the sheets is faster than that of the sheets with a high moisture content.
Different types of washing machines require different dehydration time. For example, the 50 kg-class washing machine has a drum diameter of 100 cm and a drum dehydration speed of 600 revolutions per minute. For standard weight towels, the dehydration time is 10 minutes. 8 minutes, 6 minutes for polyester-cotton sheets, and 1 minute for pure fiber clothing.
For those delicate fabrics, wool fabrics, corduroy, high-end knitwear, clothing with ornaments, etc., high-speed dehydration is not suitable.
1. The washing temperature requirement of white linen
First: When using laundry equipment, as the washing temperature continues to increase, it can not only increase the dissolving ability of the detergent, but also accelerate the dissolution of dirt by the detergent. In addition, high-temperature water can enhance the emulsification of the washing liquid, allowing the dirt to quickly leave the linen surface under the high-concentration washing liquid, ensuring the washing effect.
Second: For washing clothes, washing temperature also plays an important role. As the washing temperature increases, the solubility of the detergent added to the laundry equipment increases, thereby enhancing the decontamination ability.
Third: Increase the washing temperature. The laundry equipment can heat the linen and the dirt at the same time, weaken the adhesion between the two, and accelerate the speed of the dirt leaving the linen. The increase in temperature makes the concentration of the washing liquid higher, which is more conducive to the washing of linen.
2. The main points of dyeing linen water temperature
The washing of the white linen mentioned above requires the higher the water temperature, the better, but for the dyed linen, the washing temperature should be properly controlled. Because dyed linen is easy to fade, the water temperature should be selected from the texture, coloring method and color depth of the linen when washing with the laundry equipment.
3. Water temperature requirements for protein dirt
If the linen is contaminated by protein dirt, high temperature must not be used when washing, because the preheating of protein dirt will expand rapidly, and even penetrate into the inside of the linen fiber, increasing the difficulty of washing. Therefore, when the linen is stained with protein dirt, it should be soaked in cold water first, and then washed with low-temperature water in the laundry equipment.