Study On The Waterproof And Moisture Permeable Coating Technology Assisted By The Micro-pores Forming Mechanism Of Thickener Agent

The waterproof and moisture permeable coating fabrics can prevent the droplets frominfiltrating into the fabric, but the sweat vapor can pass through the fabric and diffuse to outside. Sothe sweat can’t accumulate or condenses under the clothes and the user can’t feel clammy. Theclothes made with such fabric could keep out wind and rain and keep the body warm. So suchclothes are comfortable to dress and widely applied in many fields. But the waterproofness andmoisture permeability of the fabrics are incompatible with each other, and therefore the finishingtechnology is very difficult. It has been the focus of research for technicists among various countriesto develop a kind of simple, environment friendly and low-cost way to produce the waterproof andmoisture permeable fabrics, so this study has very important practical meaning.This paper discussed about processing technology of the waterproof and moisture permeablecoating fabrics which possess unique style and appearance and become very popular among people,and the process was optimized. In addition, a research was made on the improvement of themoisture-penetrability of the coating fabrics.Part one: the discussion of the waterproof processing of the polyester fabric.In order to prevent the water diffuse coating agent from infiltrating into the fabric whenfinishing the fabric and ensure its waterproof properties, the first thing we need to do was the waterrepellent finishing. In this part, we used the fluorine finishing agent TG-410C. By examiningimpacts of the fishing agent mass concentration, amount of the crosslinking agent, bakingtemperature and time on the moisture permeable properties of the fabric, we concluded the optimumprocess for water-repellent finishing: the fishing agent mass concentration was20g/L, amount of thecrosslinking agent was6g/L, baking temperature was160℃and baking time was60s. The fabricafter finishing was investigated by scanning electron microscopy (SEM) and X-Ray Diffraction(XRD), the results showed that a layer of thin film covered the surface of the fabric, which increasedthe smoothness of the fiber surface, and part of the holes on the fiber surface and gaps between fiberswere filled and covered by thin film of finishing agent, so the waterproof property was greatlyimproved, but the permeability declined; It was also found that the crystallinity of the fiber and the mechanical properties didn’t change.Part two: the discussion of the environmental friendly waterproof and moisture permeablecoating technique.At present, the organic solvent coating agent has been mainly used for fabrics, but this kindof agent pollutes the environment and presents potential safety hazards. So the water diffuse coatingagents which are safe and environmental friendly will be the direction of future development.However, the fabrics coated in this agent haven’t the ideal waterproofness and washing fastness, andmoreover, baking process takes a long time, so its application is subject to certain restrictions. Thispart discussed the coating technique of water diffuse polyacrylic acid ester coating agent DS330.First of all, we tried to find out the factors influencing the coating thickness, and then the foctorscoating thickness, baking temperature and time were studied. Finally the optimized techniqueconditions by which water diffuse coating agent DS330applied on the polyester fabric were asfollows: organic silicon surfactants BYK-346dosage for6%of the mass of coating agent, thickenerAT-75dosage for3%of the mass of coating agent, the coating thickness was S5,9, bakingtemperature was160℃, baking time was60s. SEM results of the finished fabrics showed that thecoating film was density and continuous which made the hydrostatic pressure resistance of thecoating fabrics reach730mmHg. However, it’s anticipated that the permeability was poor with itsvalue1130g/m2·24h. The optical microscope and infrared spectroscopy analytic results revealed thatthe combination style between the coating agent and polyester fibers was mainly the physicalinteraction such as holding and adsorption.Part three: Research on the improvement of the water vapor permeable property of the coatingfabrics.It had been mentioned that although we got the ideal coating technique in the part two, thepermeability of the fabrics was still poor, which was far from meeting comfort requirements of theclothes. So in this part, we chose cellulosic polymer as the thicken agent of the polyacrylic acid estercoating agent DS330. By using this kind of agent, we could achieve thicken effect through retainingwater. It rarely absorbed the coating agent latex particles, so it could fill the whole even water phaseafter absorbing water. During the process of becoming film when drying, it dehydrated andflocculated, and thus destroyed the local consistence of the coating film. As a result, manymicropores formed. Besides, the flocculation cellulose particles further dehydrated resulting in the dramatically shrink of their volumes in drying film process, and then the pores left in the coating film.Those micropores’ diameter ranged from zero to150nm by controlling the technique conditionssuitably, which greatly improved the moisture permeability of the polyester coating fabrics andmeanwhile it had good water repellency, and the scope of application in the field of coating fabricshas enlarged. Besides, its production process is simple, environment-friendly and cost-effective.