Washing the Pretreatment Process of Wool Products
- Created on Tuesday, 29 January 2019 22:13
- Last Update: Tuesday, 01 February 2022 21:50
- Published on Tuesday, 29 January 2019 22:13.
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The following pre-treatment processes are applied to woolen products:
Washing Process and Purpose
Washing is the most important process in the pre-treatment of woolen products, both in the form of fleece and fabric.
Foreign materials on wool can be classified in various ways:
Animal sweat, oil, urine, etc.
Garbage, thorn, grass, hook, etc.
Paint, dust, oil from machines, etc.
Washing process is carried out in order to remove these listed dirt from the woolen product before the finishing processes.
The most important points to be considered while washing woolen products are as follows:
1-woolen productsIt shows felting feature in the face of excessive movement and mechanical effects.
2-woolen productsIt is sensitive to basic processes, especially to alkaline processes at high temperatures.
During the finishing processes of woolen products, working with strong basic solutions (pH above 10), basic processes at high temperatures (above 55 °C), excessive movement and mechanical stresses should be avoided.
Otherwise, the scale layer on the surface of the wool fiber will be damaged.
Thus, the quality of the wool decreases. In addition, due to excessive movement and temperature, the fibers get into each other and an undesirable complex structure called felting occurs.
Felting causes a large amount of fiber to be broken and damaged during yarn production.
In the form of fabric, it prevents the production of delicate and flowing fabrics of the desired quality.
Washing Wool in Wet Environment
It is the most widely used method in our country in terms of cleaning wool fiber.
If attention is paid to the basic environment in the washing bath, a very good cleaning can be achieved without damaging the wool fiber.
Wool fiber washed in this way is less affected by reducing agents in further processing.
Soda, which is used as an alkali during the washing of the wool fiber, both provides the basic environment and increases the degree of cleanliness by saponifying the oils in the fiber.
Wool, dust etc. It is washed to remove the dirt and to clean it enough to keep the wool oil at a rate of 0,5-0,15 %.
If this cleaning process in the wool is done while the wool is in the form of wool, cleaner and smoother yarns are obtained during the yarn production.
During the washing of the wool, depending on the amount of oil and pollution in the wool, 1-3 g/ Ɩ soda 1- 5 g / Ɩ soap is used.
Washing temperature is 45- 55 °C. The pH of the washing bath should not exceed 10.
Since wool oil is removed in wool washing, there is no need to add soda while washing the fabric, only washing with soap is sufficient.
If soda-soap washing is required due to the blending oil used during yarn making, soda is used.
Soda Detergent Wash
Although it is a method similar to the soda soap method, it has not found as much application as the soda soap method.
Although the cleaning degree of wool washed by this method is higher and it provides more comfortable working during yarn making, it is not preferred in our country due to its high cost.
In addition to the detergent used during washing, the washing effect rises to higher levels when the soaps produced with the oils in the bath are added.
However, due to this intense effect on the fibers, elasticity decreases and fragility increases.
This is one of the downsides of the method.
Neutral Detergent Wash
Since it performs a milder washing with detergent in neutral environment without adding alkali, negativities such as felting during washing and yarn making are minimized. In addition, yellowing caused by alkali residues is not seen in this method.
Since the desired cleaning cannot be achieved and it does not make a noticeable difference during yarn production, soda is less preferred than soap washing.
There is almost no application area in our country.
Washing at Iso-Electrical Point (Acidic Environment)
In a weak acidic environment (pH 5-6), the danger of damaging the wool fibers and felting is low.
However, difficulties are encountered during yarn making as the wool fibers washed in this way harden and their flexibility decreases.
At the same time, this washing method could not find application in our country, since washing in an acidic environment causes corrosion (abrasion) in the machines.
Washing in Wool Sweat
Potassium salts of organic acids contained in water-soluble wool sweat have a good washing effect.
At the same time, it is not possible to damage the wool.
Duhamel method In this washing, which is also called, special closed-circuit washing machines are needed.
At the same time, since a good cleaning cannot be achieved, a mild soap or detergent wash should be done afterward.
For this reason, it has not found an application area in our country.
Washing Process According to the Condition of the Material
Fiber Washing (Follow Washing)
With the impurity it contains, wool fiber makes it difficult to work comfortably during yarn making and weaving.
Washing can be done in various product forms.
In order to facilitate yarn and weaving processes, fiber washing should be preferred.
The common name of the machines that wash the wool as fibersLeviathanis ”.
These machines, which consist of many boats, are named according to the systems that provide the movement of the wool inside the machine. These:
1-Rake or fork wool washing machines
2-Perforated drum wool washing machines
Apart from these, there are also types that are not widely used.
They are the most used rake or fork wool washing machines in our country.
In these machines, the fiber placed in the first boat is transferred from the boat to the boat by moving with the help of forks and harrows.
There are baths in the boats with the chemical substances that make up the washing steps.
Wool washed in Leviatan machines gives less wastage during yarn making, and a smoother yarn is obtained.
Before washing, the wool is opened in openers and sent to dust sieves.
In this way, foreign materials on the wool are removed.
Considering the dirt and oil content on the wool, the softening process is done by giving steam at 40–45 °C in the sweating rooms and left for 1 day.
The kept wool is washed in the leviathane. The process flow in the 5-tub leviatan is as follows:
The wool, which is opened again in the opening machine, comes to the 1st pool thanks to the conveyor belts.
Average temperature is 35–40 °C.
The wool, which is immersed in the water by the rakes, comes to the squeezing rollers after being purified from the dirt left on it during the transition.
Here he gets bored and goes to the 2nd pool.
Average temperature is 40–45 °C, pH is 8–9.
2 g / into this pool Ɩ soda is given. As the wool coming from the 1st pool passes through this pool, the oil layer on the wool swells with the help of soda and heat.
Swelling oils are removed from the wool by squeezing in the squeezing rollers.
Average temperature is 45–55 °C, pH is 9.
1 g / into this pool Ɩ soda, 3 g / Ɩ washing soap is added.
The wool coming from the 2nd pool gets rid of the oil remaining on it with soda and washing soap while passing through this pool, and is sent to the 4th pool by being squeezed again in the squeezing cylinder.
Average temperature is 40–45 °C, pH is 8–9.
1 g / Ɩ washing agent is given.
The wool coming from the 3rd pool passes from here with the help of the mechanism and gets rid of the oil and dirt completely.
He gets bored and goes to the 5th pool.
5. Pool: Average temperature is 35–40 °C.
Here, the wool washed in other pools is rinsed and wrung out and sent to the machines to be dried or taken out to the sun.
The wool coming to the dryer is dried here and passed through dust sieves again and left to rest.
Washing recipes vary according to each wool.
Even wool from the same region differs from year to year. For this, geographical conditions are very important.
Washing in Fabric
Wool, which is generally washed as fibers, has been cleaned from the dirt that comes from nature and is in its structure.
Wool, which is turned into fabric, is dirty because it contains the dirt taken from the machine and the environment during yarn making and weaving, and the blending oil given for convenience during yarn making.
These dirt, which is taken later during the washing in the form of fabric, are cleaned.
The common washing process is done in the form of rope in dink washing machines, which are also used as dink machines.
Most of the time, after washing, the resting process is continued without removing the fabric from the machine.
In addition, open-width washing machines are also used for delicate and difficult to work fabrics.
Fabrics that are at risk of crushing and breaking are washed in open-width washing machines.
There is a widespread use for rope washing.
During the washing process, it not only cleans the fabric, but also contributes to its physical properties.
A fuller, softer fabric can be obtained.
Rope washing is the most applied method for fabrics other than delicate worsted fabrics.
It may be necessary to fix before washing on fabrics with broken and wrinkle marks.
Cracking is usually applied for fixation.
In rope washing, soda-soap washing can be done, as well as neutral soap or detergent washing.
Commonly applied is soapy washing in alkaline medium.
The method to be washed is decided by looking at the characteristics of the blending oil in the fabric, the dirt of the fabric and, if the fabric is dyed, the dyestuff on it.
The important points to be considered in order to obtain a good washing effect and to ensure that the fabric is washed without any damage during rope fabric washing are as follows:
The fabric, which has become an endless rope, must undergo a change in shape as it rotates in the machine and passes between the squeezing rollers.
Breaks and dents are inevitable in the fabric that passes in the same way many times.
When the fabric edges are sewn together, the fabric looks like a long pipe.
Therefore, the air trapped inside the fabric causes the fabric to inflate like a balloon before it enters the cylinder.
Due to this structure, the fabric is folded from a different point each time it passes through the cylinder.
This helps to prevent cracks and wrinkles in the fabric.
It is the point where the washing process is most effective.
The fabric that absorbs the liquor throws the liquor inside as it passes through the squeezing rollers.
Along with the flotte, oil and dirt penetrating into the fabric are also removed. If the squeezing pressure of the cylinders is low, the washing effect is reduced and its duration is extended.
In case of excess, fractures and roller marks occur on the fabric.
The roller pressure is determined by the thickness of the fabric and the weave structure.
For a good wash, the cylinder pressure must be adjusted correctly.
Wide wash (Open Width Wash)
Open-width washing machines are preferred for thin fabrics and synthetic blended wool fabrics with a high risk of breaking marks.
In this machine, the fabric rotates in the form of an endless band, as in a rope washing machine.
Unlike the rope washing machine, it is worked in the open width.
Although the washing effect obtained in wide washing machines is good, it does not contribute to fullness and softness as in rope washing machines.
For this reason, it is not the type of machine preferred by wool producers.
In this machine, while the fabric washing process is in progress, the rope passes between the rollers as in the washing machine.
The roller pressure is adjusted according to the fabric thickness.
Openers function to prevent wrinkling and folding of the fabric that is running open transversely, and scale rollers to prevent the fabric from sliding left and right.
In addition, a perforated tube that sprays the liquor onto the fabric sprays across the width of the fabric.
A small trough located just below the squeezing rollers prevents the pressed water from returning to the bath and transfers it to a separate place.
While open-width washing machines used to wash fabrics sewn in endless bands in the past, they are used as continuous washing machines today. In these machines, the washing process is done by passing the fabric through 5-8 boats.
During these washings, soap and wool preservatives are generally used.
The washing process in the boats is applied with the following recipe:
1.Boat: 1–3 g/Ɩ The washing of the fabric is started by adding soap. The temperature is 50 °C.
2. Boat: Overflow washing is done with water at 50 °C.
3. Boat: Overflow washing is done with water at 50 °C.
4. Boat: Overflow washing is done with water at 50 °C.
5. Boat: It is passed through water with added wool preservative at 50 °C.
6. Boat: Overflow washing is done. This wash is done with water at room temperature.
The points to be considered while washing in an open-width washing machine are as follows:
1-The sprinklers that spray water in the machine must be constantly clean and have open holes.
Otherwise, local soiling will remain in the direction of the fabric warp and cause an error during washing.
2-A good cleaning should be done before washing in the machine.
Dirt remaining on the rollers will adhere to the fabric and cause an error.
3- The fabric should be given to the machine in an open state, without any broken or crease.
This should also be taken into account during operation.
Wrinkles become fixed due to the pressure of 4-5 bar in the squeezing rollers during washing and cause an error.
It is very difficult to fix these fractures later.