In the application of fabric coatings, waterborne polyurethane not only plays the role of an adhesive but also carries specific functional characteristics. The full play of its performance depends on whether the coating can closely adhere to the substrate. So, where exactly does the adhesion force between the waterborne polyurethane coating and the substrate come from? What methods are there to enhance this adhesive force and make the fabric substrate bond more firmly? From the perspective of academic theory, the early bonding theory tended to be the mechanical action theory, suggesting that the adhesive force mainly relied on the micro-pore anchoring effect and the physical interlocking caused by surface roughness. Accordingly, the surface characteristics of the adhesive and the substrate have become the key factors determining the adhesion strength. Subsequently, the adsorption theory further deepened our understanding of the bonding mechanism, regarding it as a special interface phenomenon. Various polar groups in the polyurethane molecular chain, such as carbamate bonds, hydroxyl groups, ether-oxygen bonds, etc., constitute the core elements of the cohesive force of the adhesive by forming dispersion forces. In addition, the diffusion theory emphasizes the mutual permeability between the adhesive and the adherend. It vividly depicts the viscous characteristics of polymers with a "crawler" model, indicating that highly branched polymers exhibit more significant advantages in bonding performance compared to linear polymers. Comprehensive classical theory above, we can extract the following key strategies: improve coating adhesion and fabric of the fabric surface appropriately pretreatment, to increase its wettability; Adjust the polarity of waterborne polyurethane molecules to promote stronger intermolecular interactions; And increase the branching degree of molecules, taking advantage of the spatial structure of polymer chains to further enhance the adhesion effect. These measures together constitute an effective way to optimize the bonding strength between the coating and the fabric.

In the field of textile coatings, waterborne polyurethane dispersions can endow textiles with better wear resistance, flexibility, cleaning resistance and other properties. Water based polyurethane dispersion (PUD) refers to polyurethane dispersion without emulsifiers, also known as polyurethane dispersion. It features high flexibility and excellent coating and adhesion on high-performance substrates such as wood, cement, metal, plastic, paper, textiles and rubber, and can be widely used in automotive base paint and touchdown paint. The coating fields include primers and colored coatings, wood and furniture coatings, durable floor coatings, etc., as well as textile coatings, shoemaking, papermaking, adhesives, etc. In recent years, with the rapid development of water-based coatings as substitutes for solvent-based coatings, the market size of water-based coatings has also been continuously expanding. The expansion of the water-based coatings market will drive the growth in the application demand for water-based polyurethane dispersions in the coatings field. Coatings based on waterborne polyurethane dispersions will become the preferred choice in fields such as wood, leather, automobiles, construction, metals, furniture, plastics, and decorative glass. Sinograce Chemical is developing a variety of superior and more sustainable water-based product systems to replace solvent-based products and meet the diverse needs of more users. From this perspective, Sinograce Chemical will create new growth opportunities for itself by developing customizable PUD products and increasing the output of waterborne polyurethane dispersions. In addition to the fields of coatings and adhesives, waterborne polyurethane dispersions can also be used in the coating of textiles and the production process of fiber-reinforced plastics. In the field of textile coatings, waterborne polyurethane dispersions can endow textiles with better wear resistance, flexibility, cleaning resistance and other properties. In the future, as the production scale of coated fabrics further expands, the application volume of them in textile coatings will increase significantly, which will also indirectly drive the demand scale for polyurethane dispersions. Waterborne polyurethane dispersions are important auxiliary materials in fields such as coatings and adhesives. With the continuous improvement of global environmental protection requirements and standards, waterborne polyurethane dispersions that do not contain VOC or have extremely low VOC content will meet the requirements of more and more countries and regions for the environmental protection and greenness of industries. Waterborne polyurethane dispersions will also enjoy a broader development space.

What is waterborne polyurethane primer? What characteristics does it have? In which scenarios is it applicable Waterborne polyurethane primer is a type of coating with waterborne polyurethane resin as the base material and water as the dispersion medium. It has the advantages of low production cost, non-flammability, non-toxicity, no environmental pollution and saving organic solvents. In addition, it retains some excellent properties of traditional solvent-based polyurethane coatings and has good adhesion to wood, fiberboard, metal, concrete, etc. Compared with solvent-based polyurethane resins, water-based ones have less toxicity and excellent color retention. Product Features: 1. It is non-toxic, odorless, pollution-free and poses no harm to human health, truly achieving green environmental protection 2. Non-flammable and non-explosive, and convenient for transportation 3. It can be diluted with tap water. Construction tools, equipment and containers should also be washed with tap water 4. The drying time is fast, which improves work efficiency and reduces labor costs 5. The adhesion between the coating and the substrate is good Product application: 1. It is applicable to industries such as automobiles, ships, grid structures, mechanical manufacturing, containers, railways, Bridges, boilers, and steel structures 2. It is applicable to metal anti-rust coating in industries such as industrial equipment, mechanical manufacturing, hardware and electrical appliances, and household appliances Matching solution:Waterborne polyurethane primer + waterborne polyurethane intermediate coat + waterborne polyurethane topcoat

The following types of resins are commonly used in water-based glass resin, each with its own characteristics. They can be selected according to specific needs: Acrylic resin • Advantages: It has excellent weather resistance, light and color retention, relatively high hardness, and a relatively fast drying speed. It can form a hard and glossy coating film on the surface of glass paint, with good adhesion to glass. Moreover, water-based acrylic resin uses water as the solvent and has superior environmental protection performance, meeting current environmental protection requirements. For instance, it is widely used in some glass handicrafts and decorative glass products, which can maintain bright colors and a shiny appearance for a long time. • Disadvantages: Its solvent resistance and wear resistance are slightly inferior to those of some resins. In some application scenarios that require frequent contact with organic solvents or excessive friction, the coating film may be damaged. Polyurethane resin • Advantages: It has excellent comprehensive performance, good flexibility of the coating film, excellent wear resistance, and the hardness can be adjusted to an appropriate level through formula adjustment. At the same time, it performs outstandingly in terms of chemical corrosion resistance, water resistance, etc. It has a good adhesion to glass and can adapt to various different usage environments. It can be applied to the coating of frequently wiped and cleaned glass furniture, glass doors and Windows, etc., and can maintain the integrity of the coating film and stable performance for a long time. • Disadvantages: The cost is relatively high, the preparation process may be more complex, and the storage stability of some polyurethane resin products needs to be strictly controlled, with certain requirements for storage conditions such as temperature and humidity. Epoxy resin • Advantages: It has extremely strong adhesion to various substrates such as glass, good chemical stability, and excellent corrosion resistance. The water-based glass paint made from it can be used for protective coating of some glass products with high chemical protection requirements, such as laboratory glassware and glass pipes involved in chemical production, effectively blocking the contact of external corrosive media with the glass surface. • Disadvantages: Its weather resistance is relatively weak. When exposed to outdoor environments for a long time, it is prone to discoloration and powdering. Moreover, the texture of epoxy resin after curing is relatively brittle, and its flexibility needs to be improved by adding appropriate additives and other means. Sinograce Chemical produces waterborne polyurethane resin for waterborne glass baking varnish ink.