Textile Industry
The textile industry encompasses a wide range of processes and machinery. Thermal spray technology has found several useful applications in this industry, mainly for enhancing the performance and durability of textile equipment.
thermal spray technologies that can be applied in the textile industry
Flame Spray
Working Principle:
It utilizes the high-temperature flame generated by the combustion of fuel gas (such as acetylene, propane, etc.) mixed with oxygen to heat the spraying materials to a molten or semi-molten state. Then, the materials are atomized by compressed air and sprayed onto the surface of the workpiece to form a coating.
Application Advantages in the Textile Industry:
Simple Equipment and Low Cost: For textile enterprises, the equipment investment and operation costs of this technology are relatively acceptable. Flame spray equipment is relatively compact and easy to operate. It is suitable for processing some components in textile machinery that are not overly complex in shape and do not have extremely high requirements for coating precision, such as some ordinary rollers and small support shafts.
Wide Material Adaptability:
It can be used to spray a variety of materials, such as metals (zinc, aluminum, etc. for corrosion prevention), alloys (nickel-chromium alloys for corrosion resistance and a certain degree of wear resistance), and some polymer materials (such as polytetrafluoroethylene for anti-sticking). For example, spraying an aluminum coating on the surface of some components of textile machinery can provide basic corrosion protection and resist the erosion of moisture and chemical substances in the textile environment.
On-site Repair Capability:
If local coating damage or wear occurs on textile equipment in the workshop, the flame spray equipment can be easily moved to the site for quick repair, reducing equipment downtime. For instance, when the anti-sticking coating on the surface of a printing roller is partially peeled off, it can be promptly repaired by flame spraying.
Arc Spray
Working Principle:
Two continuously fed metal wires are used as consumable electrodes. An electric arc is generated at their ends as a heat source to melt the metal wires. Then, the molten metal is atomized by high-speed airflow and sprayed onto the surface of the workpiece to form a coating.
Application Advantages in the Textile Industry:
High Efficiency and Thick Coatings:
For textile machinery components that require large-area protection or thick coatings, arc spray is a good choice. For example, for the outer surface protection of large textile machines or the surface of heat exchangers in large drying equipment, a relatively thick protective coating can be quickly formed. When an arc spray copper-based coating is applied on the surface of a heat exchanger to improve heat transfer efficiency, the required coating thickness can be achieved in a relatively short time.
Good Bonding Force and Wear Resistance:
The bonding between the coating and the substrate is mainly mechanical bonding and metallurgical bonding, with relatively strong bonding force. On the surfaces of some textile components that bear a certain amount of friction, such as rollers and some transmission components, the metal coatings (such as zinc, aluminum, or alloy coatings) formed by arc spray can provide good wear resistance and extend the service life of the components.
Diverse Material Selection:
Various metal wire materials can be used as spraying materials, making it convenient to select appropriate materials according to the specific requirements of textile equipment. For example, for the components of dyeing machines that are prone to corrosion, nickel-chromium alloy wire materials can be used for arc spraying to enhance the corrosion resistance of the components.
Plasma Spray
Working Principle:
It uses a plasma arc as a heat source to heat the powdered spraying materials to a molten or semi-molten state and then sprays them onto the surface of the workpiece to form a coating. The temperature of the plasma arc can reach tens of thousands of degrees Celsius and can melt almost all spraying materials.
Application Advantages in the Textile Industry:
High-Quality Coatings:
It can prepare high-quality coatings and performs excellently on textile components that require high precision and high density. For some key rollers of high-precision printing equipment or molds with complex shapes (used for textile product molding, etc.), plasma spray can provide uniform and dense coatings to ensure the precision and performance of the components. For example, when a ceramic coating is sprayed on the surface of a roller that requires precise printing, a smooth, uniform coating with good bonding to the substrate can be obtained through plasma spray, which is beneficial for the accurate transfer of dyes and improves the printing quality.
Strong Material Adaptability:
It can handle various high-melting-point materials, including ceramics, cermets, etc. In the textile industry, for some components that require special properties, such as rollers that need high hardness and high wear resistance or drying equipment components that need to be resistant to high temperature and corrosion, plasma spray can use materials such as tungsten carbide, zirconia, etc. to prepare coatings. In high-temperature drying equipment, the zirconia coating prepared by plasma spray can effectively protect the components and improve their high-temperature and chemical corrosion resistance performance.
Precise Control of Coating Properties:
By precisely controlling the process parameters of plasma spray, such as power, gas flow rate, powder feeding speed, etc., the properties of the coating, such as thickness, porosity, hardness, etc., can be finely adjusted. This is very important for meeting the diverse requirements of different components of textile machinery. For example, the hardness and thickness of the coating can be adjusted according to the usage requirements of different rollers to achieve the best wear resistance and anti-sticking effects.
Applications of Thermal Spray in the Textile Industry
Rollers and Cylinders
Surface Hardening:
Textile rollers such as those used for fabric guiding, calendaring, and printing are subject to wear due to continuous contact with the fabric. Thermal spray can be used to apply hard coatings like tungsten carbide – cobalt (WC – Co) or chromium carbide. These coatings significantly increase the hardness of the roller surface. For example, in a calendaring process, the rollers need to apply pressure to the fabric to achieve a smooth finish. The hard thermal – sprayed coating can withstand the high – pressure contact with the fabric without deforming or wearing out quickly.
Anti – Sticking Properties:
Some textile processes involve the use of rollers that come into contact with sticky substances such as dyes, sizing agents, or adhesives. Thermal spraying a non – stick coating such as polytetrafluoroethylene (PTFE) or ceramic – based coatings can prevent the substances from adhering to the roller surface. This is particularly important in printing rollers where the transfer of accurate dye patterns onto the fabric is crucial. If the dye sticks to the roller, it can lead to uneven printing and affect the quality of the textile product.
Textile Machinery Components
Corrosion Resistance:
Many textile machines operate in environments where they are exposed to moisture, chemicals (from dyes, bleaches, etc.), and various textile – related substances that can cause corrosion. Thermal spray coatings of materials like nickel – chromium alloys or aluminum can provide excellent corrosion resistance. For instance, in a dyeing machine, the parts that come into contact with the dye solution can be protected from corrosion by a thermal – sprayed nickel – chromium coating. This extends the lifespan of the machinery and reduces maintenance costs.
Friction Reduction:
In the moving parts of textile machinery such as bearings, shafts, and gears, friction can lead to energy loss and wear. Thermal spray coatings with materials that have good lubricating properties, like molybdenum disulfide (MoS₂), can reduce friction. This not only improves the efficiency of the machinery but also reduces the wear and tear of the components, resulting in less frequent replacement and maintenance.
Heat – Transfer Components
In Drying and Heat – Setting Equipment:
Thermal spray can enhance the heat – transfer efficiency of components in drying and heat – setting machinery. For example, by applying a coating with high thermal conductivity such as copper – based coatings on the heating elements or heat – exchanger surfaces, the heat can be more effectively transferred to the fabric. This can lead to faster drying or heat – setting processes, improving the overall productivity of the textile production line.
Benefits of Thermal Spray in the Textile Industry
Improved Product Quality:
The use of thermal – sprayed coatings on textile equipment helps in producing high – quality textiles. For example, accurate printing, smooth calendaring, and uniform dyeing are achieved through the use of well – coated rollers and machinery components.
Extended Equipment Lifespan:
The enhanced resistance to wear, corrosion, and other forms of damage significantly extends the lifespan of textile machinery. This reduces the need for frequent replacements, saving costs and reducing production downtime.
Increased Energy Efficiency:
By reducing friction and improving heat – transfer efficiency, thermal spray applications contribute to energy savings in the textile industry. This is in line with the growing demand for sustainable and energy – efficient manufacturing processes.