Knowledge

The functions and characteristics of the inner cavity coating of molds and various coatings are as follows:

I. Functions of the Inner Cavity Coating of Molds

1. Enhance Wear Resistance: By applying a high-hardness coating material, such as titanium carbide (TiC) or titanium nitride (TiN), on the inner surface of the mold, it can effectively resist wear and impact during the mold's operation. This coating forms a strong protective barrier when the mold comes into contact with materials, significantly extending the mold's service life. Especially in high-intensity and high-frequency production environments, the application of wear-resistant coatings is particularly important. It not only reduces the frequency of mold replacement but also lowers maintenance costs and improves overall production efficiency.

 

2. Improve Corrosion Resistance: Coating the mold surface with a material that has excellent corrosion resistance, such as chromium (Cr) or nickel (Ni) alloys, can effectively prevent corrosion when the mold comes into contact with corrosive media (such as acids, alkalis, and salts). This coating not only maintains the mold's surface smoothness and precision but also prevents mold deformation and failure caused by corrosion, ensuring the stability and consistency of product quality. In industries with severe corrosive environments, such as chemical and metallurgical industries, the role of anti-corrosion coatings is irreplaceable.

 

3. Increase Production Efficiency: Lubricating coatings form a low-friction coefficient film on the mold surface, significantly reducing the friction between the mold and the material, minimizing energy loss and heat generation. This not only helps improve production efficiency but also effectively prevents mold deformation or damage due to overheating. Moreover, good wear resistance and corrosion resistance also help reduce the frequency of mold maintenance and replacement, further lowering production costs and enhancing the economic benefits of the enterprise.

 

II. Characteristics of Various Coatings

1. PVD Coating: For cold working molds, physical vapor deposition (PVD) technology, especially the reactive ion beam evaporation method, can form a coating on the mold surface that is highly adherent, extremely hard, and has excellent corrosion resistance. This coating not only significantly improves the mold's wear resistance and service life but also effectively resists the erosion of various corrosive media. However, for hot working molds, due to the relatively thin and brittle nature of PVD coatings, TiC and other coatings tend to decompose at high temperatures and have poor heat resistance, making them less suitable.

 

2. PA Coating (Polyacrylate Fabric Coating): This is the most common and ordinary type of coating, widely used in the surface treatment of various fabrics. After application, the fabric not only feels fuller but also effectively resists wind and increases drape. PA coatings are often used for anti-down, enhancing hand feel, color fixation, and sand fixation, among other purposes. Its advantages include good light and weather fastness, excellent transparency and compatibility, strong wash resistance, and firm adhesion, with relatively low cost. However, it has poor elasticity, is prone to wrinkling, has poor surface smoothness, and is difficult to adjust the hand feel.

 

3. PU Coating (Polyurethane Coating): After application, the fabric feels fuller and more elastic, with a film-like surface. PU coatings have many advantages, such as soft and elastic coating, high coating strength, suitable for extremely thin coating treatment, good porosity, moisture permeability and breathability, wear resistance, moisture resistance, and dry cleaning resistance. However, it has relatively high cost, poor weather resistance, and is prone to hydrolysis when exposed to water, heat, and alkali.

 

4. Anti-Down Coating: This coating is specifically designed to prevent down-like fillers from escaping from the fabric and is widely used in the production of down jacket fabrics. Its unique coating structure effectively seals the fabric's pores, ensuring the stability and warmth of the down.

 

5. Silver Gel Coating: Applying a silver-white gel on the fabric surface endows it with excellent light-blocking and radiation-proof functions.

 

6. Pearlescent Coating: Through a special process, a layer of coating with a pearl-like luster is formed on the fabric surface, available in both silver and color series. After application, the fabric presents a unique lustrous effect and is widely used in the production of high-end clothing and decorative materials, making the products more beautiful and fashionable.

 

7. Flame Retardant Coating: By impregnating or coating the fabric, it is endowed with excellent flame retardant properties. This coating not only forms a flame retardant protective layer on the fabric surface but can also be applied in different colors or silver as required. It is widely used in curtains, tents, and flame retardant clothing, effectively enhancing the safety performance of the products.

 

8. Teflon Coating: This coating endows the fabric with outstanding water-repellent, oil-repellent, and stain-resistant properties. The unique chemical properties of Teflon (PTFE) material enable it to effectively repel water and oil substances, and it is widely used in outdoor clothing, protective clothing, and special workwear.

 

9. UV-resistant Coating: Through special UV-resistant treatment of the fabric, it is endowed with excellent UV resistance, that is, the ability to prevent UV penetration. This coating is more difficult to achieve on light-colored fabrics but relatively easier to meet standards on dark-colored fabrics. It is widely used in the fabric coating of sun umbrellas, sun-protective clothing, and other products, effectively protecting the human body from UV damage.

 

Please note that different types of molds and working environments may require different types of coatings. When choosing, a comprehensive consideration should be made based on specific needs and conditions. Each coating has its unique advantages and limitations. Only by fully understanding its performance characteristics can the most suitable choice be made to ensure the quality and performance of molds and products.

 

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