Coating Factory
Powder coating is a finishing process in which dry, free-flowing thermoplastic or thermoset materials are applied to surfaces and melted into an even coat. This coating technology is a cost-effective alternative to liquid coating methods for producing functional and decorative surface finishes.
Manufacturing companies can complete powder coating operations in-house with standard equipment or by using a finishing service contractor. The latter provides custom systems that are tailored for specific industrial coating applications.
Preparation
Powder coating is a process of applying dry powdered paint onto the surface of a metal part to form a strong and long-lasting protective layer. This coating can be either decorative or functional. It is a high-tech and eco-friendly alternative to liquid coating because it does not use solvents or chemicals to create the coat.
This method of coating has become extremely popular in the metal industry, especially among companies that require a durable and attractive appearance for their products. Its benefits include resistance to corrosion, heat and other environmental factors. Powder coating is also an economical solution because it is extremely versatile and highly customizable. It can be applied to any type of metal object. It can be used for machinery, furniture, vehicles, and other items.
Before a piece of metal can be coated, the surface must undergo extensive preparation. This includes cleaning, rinsing, and etching to remove contaminants. It is important to remove any dirt or other residues, as they can affect the adhesion of the new coating. The etching process can be used to smooth out rough surfaces and create a better profile for the new coating.
Depending on the type of coating, the surface may need to be baked in an oven before it can be finished. This is particularly important for metals that have a higher tendency to absorb oils during manufacturing. A pre-baking step will help eliminate any unwanted oil stains or moisture that can cause the new powder to chip or flake off.
A wide range of equipment can be used for the preparation process, including wash stations, blast rooms, and dry-off ovens. It is important to follow the correct procedures for each of these stages, as they will determine how well the finished product adheres to the substrate.
The etching and baking steps are usually done by hand, but some companies offer automated solutions. This allows the coating to be done more quickly, and it also reduces the chance of errors. It is also possible to apply a clear or metallic finish to the surface of a piece of metal, which adds visual appeal and protects the surface against corrosion.
Coating
A coating is a protective and/or decorative layer applied to an object, referred to as the substrate. A coating may be made from liquids, gases or solids. Industrial coatings may be decorative, functional or both. They can include a wide range of characteristics and benefits including abrasion resistance, dry film lubrication, anti-static, and corrosion resistance.
Coating equipment is typically configured based on the production requirements of the product. A wide variety of fully continuous and semi-continuous systems are available, ranging from single-pan to multi-pan designs. A fully continuous system is a complete assembly that is capable of applying the desired coating in-line with a high-speed tableting process. A typical system utilizes several coating pans arranged in a line (either horizontal or vertical) with the substrate being fed into the coater from one end and packaged finished products emerging from the other.
A semi-continuous system is similar in design to a fully continuous system, but operates with a lower processing time. This allows the operator to vary the dwell time in each individual coating segment to meet a specific application requirement. For example, short dwell times can be used for cosmetic coatings with low weight gains, while longer dwell times may be required for coated tablets requiring higher target weight gains.
Powder coating is a finishing method in which dry, free-flowing thermoplastic or thermoset powder material is applied to a surface and then melted and hardened into an even coating. It is an environmentally friendly alternative to liquid coating, as it produces fewer volatile organic compounds (VOCs) which contaminate indoor air. Powder coatings are also available in a wide variety of colors, finishes, textures and thicknesses that are not easily achievable with liquid coating processes.
Specialty coating lines are often utilized to produce release liner paper and films, as well as a broad variety of pressure sensitive adhesive tapes and laminates. These lines are typically based on a roll design and consist of a metering system for applying the coating material to the carrier substrate, followed by a drying tunnel before the coated web is rewound.
Curing
A key component of any coating system is the curing process. It is responsible for shaping the final properties of a coating, influencing how well it adheres to the substrate, and how long it will last before degrading. The curing process involves raising the temperature of the workpiece to a specified level for a period of time. This allows solvents to evaporate and the resins in the coating to crosslink, forming an inert and tough film.
This is one of the most critical stages in the process, and getting it wrong can significantly undermine the performance of an industrial coating. A failure to cure a powder coat can cause it to underperform in many different ways, including failing to provide the desired corrosion resistance and other surface-related benefits.
Curing is a multifaceted process and requires a great deal of time, precision and monitoring. While most people are familiar with the drying stage of liquid paints, they may not understand that powder coating also has a curing stage. The curing stage of powder coating is important because it allows the synthetic polymer chains in the power coating to bond together, forming an inert and hard-wearing finish.
The powder curing stage can be more complicated than the drying process of liquid paint because it requires a precise combination of temperature, humidity and exposure time. The curing oven needs to be carefully maintained and calibrated in order to produce the correct curing conditions for a particular coating material. If these factors are not carefully monitored, the coating will fail to meet its performance specifications and can even be a source of product defects.
Powder coating can also be more cost-effective than liquid coatings in the long term because it results in a faster turnaround and lowers the need for costly storage space. However, the upfront costs of buying powder coating equipment can be prohibitive for some companies. In addition, touching up items with powder coating is difficult and requires more labor than liquid coating, so it is often necessary to use a finishing service provider.
The key is to find the right balance between these conflicting requirements. The best way to achieve this is to have a good understanding of the process and how it works, so that you can make informed decisions about the technology type that will be most appropriate for your specific application. This can help you match up your coating selection with performance, application and regulatory requirements.
Maintenance
Coating maintenance is a key to maximizing the life of a corrosion protection system. Too often, facility managers are not thinking about a maintenance plan from the outset of a project. As a result, they may find themselves with an aging bridge or tank that is structurally deficient years down the road.
In many cases, rapid coating breakdown indicates that a chemical to which the coating is not resistant has been introduced. In this case, the coating must be removed, cleaned and re-coated to restore its integrity. This process can be time consuming, especially when an entire facility or structure must be evacuated to perform the work.
To prevent expensive repair costs, engineers can prepare cost-effective maintenance schedules during the initial installation stage. This approach enables the customer to evaluate the life-cycle cost of each option, compared against a Present Value Analysis (PVA). Depending on the circumstances, the PVA may also assist in making decisions about capitalizing or not capitalizing the cost of a protective coating system. A prescriptive maintenance program can be much more cost-effective than hiring a consulting firm to inspect a facility or structure, write up a recommended plan and then charge upwards of tens of thousands of dollars for their services.