Are Fabrics Waterproof And Moisture Permeable With Such Good Materials? They Have Been Realized Today.

Fabric waterproof and moisture permeability, can really be achieved at the same time? For this problem, it is estimated that many small partners and I think the same.

Is waterproof and moisture permeable? How can we achieve this? In fact, waterproofing finishing is a commonly used process.

In recent years, multi-functional requirements have been put forward for waterproof finishing. Let's take a look at how to explain big coffee!

People longed for fabrics to have both waterproof (and windproof) and moisture permeating functions. This seemingly contradictory requirement seems to have entered the circle of ordinary people in the past 20 years after more than 50 years of continuous development.

Its application range, besides major high-performance sports sportswear and casual wear, has also been greatly expanded in medicine and health care products, as well as special uses (such as protective clothing). It is known as Breathable Fabrics.

There are two main ways of moisture permeation and waterproofing.

1. microporous moisture

During the coating process, numerous pores of 5~10 micron m are formed in the coating film, and the moisture inside the garment can be emitted through the micropores when worn.

2. hygroscopic moisture permeation

The coating film itself has hygroscopicity, for example, some polymers with polarity and even ionic groups are used as coating resins. These polymers have good hygroscopicity and can evaporate water outwards on the side of relatively low humidity.

If the sweat from the body is absorbed by it, the water spreads through the thin film to the outside and evaporates.

If the outer side of the coating is subjected to water repellent finishing, it has the function of water repellent (non wetting) and water resistance (high enough water pressure), and the internal moisture can be discharged.

If the above mentioned coating resin is added to the ceramic particles or metal particles mentioned above, waterproof, moisture permeable and thermal insulation fabrics can be obtained.

Three methods of waterproofing finishing must be understood by technicians.

Waterproof finishing is a widely used finishing process for printing and dyeing enterprises.

It is necessary not only to have practical experience, but also to have a theoretical basis for waterproofing.

Next, let's introduce some methods of waterproof finishing.

(Note: the most widely used is breathable waterproof finishing, also known as water repellent finishing.

So this article mainly introduces several commonly used methods of water repellent finishing.

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One is to apply a layer of water-insoluble continuous film on the surface of the fabric by coating. This product is impervious to water, but also airtight. It is not suitable for general clothing, but is suitable for making rainproof tarpaulins and umbrellas.

In recent years, rubber cloth and polyurethane have been used as coating agents in order to improve the handle, elasticity and durability of tung oil.

Another method of sorting is to change the surface properties of fibers, so that the hydrophilicity of the fiber surface can be changed to hydrophobic, and there are still a large number of pores between the fibers and yarns. Such fabrics can not only keep the air permeability but also be difficult to be wetted by water. Only when the water pressure is quite large, can the phenomenon of pervious phenomenon occur, and it is suitable for making raincoat fabrics.

This kind of breathable waterproof water is also called water repellent finishing.

The main methods of water repellent finishing are as follows:

(1) aluminum soap method

The aluminum acetate, paraffin wax, soap and gelatin were made into the working fluid, and the fabric was rolled at room temperature or 55~70 degrees, then dried.

You can also dip the paraffin and soap mixture first, then dry it and then dip it into the aluminum acetate solution to dry.

The aluminum soap method is simple, easy to operate, low in cost, and is not resistant to washing and dry cleaning. However, when the rainproof tarpaulin is useless, the water repellent property can be recovered again by the above finishing method.

(two) washable and water repellent finishing

With long chain compounds containing fatty acids, such as waterproofing agent PF, which is made of fatty acid amide and formaldehyde, hydrochloric acid, pyridine, etc., it can be reacted with cellulose fiber and fixed on the fabric when it is baked. It has durable water repellency.

Organosilicon, also known as polysiloxane, is often used as an oil soluble liquid or 30% emulsion for textile finishing. The main ingredient of the emulsion is easy to use.

(MHPS) and two methyl polysiloxane (DMPS) are used together to make fabrics obtain water repellency and soft handle.

Zinc, tin and other fatty acid salts should be added as catalysts to reduce baking temperature and shorten reaction time.

After treating the fabric with silicone elastomer (or silicone rubber) made from two methylhydroxyl siloxane at the two ends of the molecule and methyl hydrogen polysiloxane, besides having durable water repellency, it also has a fabric full and elastic style.

(three) breathable waterproof coating finish

The polyurethane was dissolved in two methyl formamide (DMF), coated on fabric, and then immersed in water.

DMF is dissolved in water, and many micropores are formed on the polyurethane membrane. It is a porous membrane. It can not only permeate moisture, permeability and water repellency, but also is an ideal fabric for raincoat.