Advantages of coating powder and its production process

 一、什么是粉末涂料？

粉末涂料是一种新型的不含溶剂的100%固体粉末状涂料。具有无溶剂、无污染、可回收、节省能源、减轻劳动强度和涂膜机械强度高等特点。粉末涂料包括热塑性粉末涂料和热固性粉末涂料。若以成膜物质的外观，粉末涂料可分为：消光型、高光型、美术型等。

二、粉末涂料与传统涂料相比有何优势？

1、粉末涂料对环境无污染。粉末涂料不使用有机溶剂、水等挥发性溶剂，因此粉末涂料为无机溶剂型涂料，可以说，使用粉末涂料的情况下，溶剂污染指数为零。粉末涂料完全可采用全自动喷涂，是100%的固体份粉末状涂料。过喷的粉末涂料，可经由回收系统全面回收利用。因此粉末涂料涂装能使环境污染的程度降低至最小。

2、粉末涂料节省资源和生产成本。传统液体涂料因为含有有机挥发物，会造成有害物质挥发至大气中。而使用粉末涂料则可以避免此类浪费。此外，粉末涂料涂装的烘烤时间也少于液体涂料涂装，缩短涂装作业线，提高产能，促进整体涂料生产的效率化。

3、粉末涂料经济效益高。因粉末涂料使用静电原理喷涂，涂装设备可达到全自动化，不会形成对人工成本的浪费。即使需要人工辅助，涂装人员也无须经过长期训练，就可喷涂良好的涂膜。

 三、粉末涂料生产工艺　　

 粉末涂料生产技术完全不同于一般的液体涂料。粉末涂料的生产包括以合理的顺序连接不同的工段工作(包括预混合步骤的准备时间、主设备的准备时间和质量控制时间)。

通常生产规模较小的粉末涂料厂家生产过程可以是不连续的；对于具有较高生产能力的粉末涂料厂家来说,通常是将各个单独的工序集合成连续的生产工艺。

1、粉末涂料生产技术之「预混合」。在热熔混合前、将粉末涂料的各种组分进行预混合是决不可忽视的重要过程,对粉末涂料的性能起着决定性的作用。特别是那些用量很少的助剂和着色颜料,如果预混合不充分,是不能够在第二阶段的热熔挤出过程中得到补偿的。

2、粉末涂料生产技术之「熔融挤出」。粉末涂料的混合包括几个步骤,并分别在独立的设备中完成。

In this stage of production, the base material and curing agent (not necessarily present) are melted and mixed at the molecular level, and the pigment clusters are broken into primary particles and dispersed evenly in the molten base/curing agent mixture together with additives . Global Coatings Network understands that at the same time the surface of the pigment particles is wetted by the molten binder. In principle there are 3 types of machines available for hot melt extrusion. The main piece of equipment is the extruder, although things like Z-blade kneaders and heated two-roll mills can also be used.

Mechanical equipment commonly used in the production of powder coatings includes: single-screw extruders, twin-screw extruders, and planetary screw extruders.

3. "Fine crushing" of powder coating production technology. Coating manufacturers should carry out fine grinding after hot melt extrusion. Powder coating manufacturers use different types of pulverizers to make the particle size of the coating meet the desired range, all of which are manufactured using the principle of grinding.

The modern crushing system is provided in a complete set, which includes a particle size classifier and a dust collector.

4. "Powder collection and dust removal" of powder coating production technology. Typically a side filter or more preferably a cyclone with a side filter is used to collect the fines at the air classification outlet. The dust collection device of powder coating depends on the output of the factory and the type and color of powder coating. The tail dust filter can increase the reliability of the crushing and classification operation and improve the control of pollution with almost no maintenance work.

5. "Multi-cyclone powder recovery system" of powder coating production technology. Due to various reasons of electrostatic spraying of powder coatings, there will always be some powders that cannot be fully utilized. To solve this problem, the industry has developed a multi-cyclone powder recovery system. Its function is to collect the powder falling during the spraying process, separate it into usable powder and unusable waste powder, and send them to corresponding devices respectively.

4. CHINA's current powder coating market situation

At present, the market share of powder coatings in CHINA is not large relative to the market share of other types of coatings. But in the relatively mature field of industrial coatings, powder coatings are one of the few products that can maintain a high growth rate.

There are three main markets for powder coatings in the world, namely Europe, the United States and Japan, but due to historical reasons and factors in the utilization of raw materials, these regions have developed their own different product systems.

In the United States and Europe, carboxylate polyester and epoxy resin-based; hybrid powder coatings are popular for interior applications. In North America, lawn and garden equipment products are also an important market, accounting for about 7% of the overall powder coating market share. The general metal surface coating industry is the largest market for powder coatings, accounting for about 50% of the entire market share.

The home appliance industry is an important application field of powder coatings. In the United States, the application of household appliances accounts for 17% of the entire powder coatings market.

In recent years, the application of powder coatings in the automotive industry has also developed rapidly. Other market applications of powder coatings include anti-corrosion powders used in pipelines and reinforced rebars. This type of powder coatings is mainly based on pure epoxy systems (fusion-bonded). This type of powder coating is almost neglected in the European rebar market. No matter in terms of technology or market demand, this market still has a broad space for development.