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Archive for November, 2014

Bio-Based Powder Coating in the Near Future

Posted on: November 17th, 2014 by byersbushblog

One thing that is always certain is change. Even the powder coating industry is subject to change and it is coming. It is coming in the form of bio-based powder coating formula. While they are not yet available for use in shops or for sale on the commercial market, researchers are close to making them ready for the public.

Are Corn and Soybeans in the Future of Powder Coating

Powder coating formulas have been looking for ways to access the monomers in bio-based materials like corn and soybeans so they can formulate powder coating resins. Researchers have also been using sugar cane, flax from linseed oil, and palm trees to create the monomers. In order to make the monomers useful polyester resins, they need to have at least two reactive sites and they need to be able to function as carboxyl or hydroxyl.

Reasons Shifting to Bio-Based Powder Coating

There are several reasons why bio-based powder coatings will be helpful for several reasons. The most obvious reason is that powder coating products made from bio-materials will reduce the powder coating industry’s reliance on petroleum-based products which are now used throughout the powder coating process. Another useful reason that bio-based powder coatings would be useful is the price of petroleum. With the political unrest in the oil-producing nations, the prices of petroleum show their instability. If the industry were able to rely on products that can be farm-grown, then prices of powder coating materials would become stable.

Price and Production Challenges

At this point, it is rather expensive to produce bio-based powder coatings. This problems is what is prohibiting the industry from embracing the bio-based materials. In order to convert the raw material into a monomer and then to a polymer is too difficult a process and too expensive. Even though petroleum is pricy, it is less expensive to use than bio-based materials are at this time.

Infrastructure Needs Development

Eventually, bio-based materials will take over the industry, but the entire infrastructure of growing, reaping, and converting needs to be developed. Many feel that the process will harm the environment more than sticking with the petroleum status quo. This same problem is occurring in the ethanol industry as the cost of turning corn into ethanol outweighs the benefits. In order to bring the price of bio-based materials down, the industry needs to develop ways to make it cost efficient, which could involve soy instead of other plants.

Considering Other Industries

Before the powder coating industry can move to a plant-based material, the food industry has to be taken into account. Right now, corn is being used for several industries, including the food industry as well as the livestock industry for corn-fed beef. If corn is going to be used to create monomers for powder coating, then another industry will lose out, so the justification of using corn for powder coating is difficult to establish.

Attempts in History

In past years, there have been several attempts to develop plant-based monomers. In many cases, the monomers were successfully developed from materials like citric acid, isosorbide, and succinic acid. Whether the resins were made from one of these materials or from a combination of several, the resins did not last as long as the ones made from petroleum-based materials. The plant-based materials yellowed, had a low melting point, and they did not do well in extreme weather showing their deficiencies in resisting impact and in cheical resistance.

Even with the historic short comings, the powder coating industry will eventually turn to plant-based materials. Researchers are keyed in on finding a bio-based source that is affordable and will withstand the elements like the current petroleum-based materials do.

Byers Bush has been providing powder coating services to our customers in the South-Central Ontario region for four decades. If you have questions about the impact of powder coating on the environment, please contact us at 905-625-4334.

Efficient Powder Coating Transfer

Posted on: November 10th, 2014 by byersbushblog

Electrostatic charges are what make powder coating work. The gun creates a charge on the powder particles, so when the charge is higher, the transfer becomes more efficient. There are important factors that affect the strength of the electrostatic field. Those factors include the voltage of the applicator and the target distance between the applicator and the part that is being powder-coated.

Charging the Powder Particle

When the powder particle is charged, the time the particle is in the field will affect the the charge. The first pass transfer efficiency is affected by the time in the field and the strength of the field, too. You can easily adjust the speed of the gun, so you slow the velocity of the powder to improve the efficiency of the coating.

Improving Transfer Efficiency One Setting at a Time

There are other ways to improve the transfer efficiency of the first pass with a few techniques that can be used on manual and automatic applications.

Adjust the Voltage

Adjusting the voltage of your powder coating gun is the best way to improve the first pass transfer efficiency. The recommended voltage setting is the maximum setting. There are some rejection issues that can occur when working with thicker films, so you might have to lower the setting to make sure the powder releases from the gun efficiently.

Set the Gun for Fewer Faraday Cage Issues

The setting of the gun is important, but so is the part ground. This setting needs to be set at a resistance that is equal to or less than one megohm. With this setting, you will be following the NFPA guidelines and you will also have fewer problems with Faraday Cage issues as well as rejection at the electrostatic level. With this setting, the maximum voltage can also be set.

Create the Ideal Distance from Gun to Part

The distance of the gun from the part is another way to improve the transfer efficiency. Ideally, the gun should be 6 to 12 inches away from the part. If you move the gun less than 6 inches from the part, then you run the risk of disrupting the attraction between the forces. The aerodynamics shift when you move the gun too close to the part and it can cause unwanted effects.

Manipulate the Gun Setting for More Time in the Field

The speed of the powder particles can also affect the transfer efficiency of the first pass. When the particles travel quickly through the electrostatic field the first pass transfer efficiency drops. When you reduce the velocity of the powder output and use gentle patterns devices on your gun, you will reduce the speed of the powder particles. With a slow gun motion, the transfer efficiency improves because the powder particles spend more time in the electrostatic field.

Set the Part to Face the Gun

The position of the surfaces that are being coated is also important key to success. The surfaces need to be positioned facing the sprayers and guns so the results meet your expectations. With proper positioning, transfer efficiency is at its best and wasted effort is reduced. The positioning of the part helps improve the other suggested principles.

Improving Efficiency and Reducing Waste One Job at a Time

When you pay attention to the details of powder coating and gun use, you will improve the efficiency of the first pass. This removes the amount of overspray and less to reclaim. With the right settings, you create less waste and you will be able to save money in the long and short run.

Thermoplastic Powders

Posted on: November 3rd, 2014 by byersbushblog

In the world of powder coating, there are different types of resins that can be used to cover a part. The two categories of resins are thermoplastic and thermoset. Thermoplastic is commonly used because to powder melts when heat is applied so it can flow onto the part. Thermoplastics also maintain the same chemical makeup in powder and solid form. Thermoset powder does the same thing when applied to parts but the powders create a film that creates a different chemical makeup than the original powder form has.

Thermoplastic or Thermoset

Thermoplastic coatings to provide a smoother finish that thermoset coatings, but in hot temperatures, thermoplastic coatings can become molten again. Thermosetting coatings with their new chemical makeup stay solid in high heat. They adhere better to metal parts and they show more resistance to chemicals than thermoplastic resins. The benefits of the thermoplastic technology is the fact that less energy is needed to heat the resin. Because of the lower rates of adhesion, many parts are either primed or pretreated in another way to improve the adhesion.

Different Types of Resins

Thermoplastic powders come from different types of resins. They include nylon, polyester, polyolefins, and polyvinyl chloride. Each type of resin works differently than the others. The thermosetting resins include epoxy, urethane polyester, and acrylic.

Nylon

Nylon powders come from type 11 or nylon 6/10. These types of coatings create a smooth finish that is impact resistant, durable, and tough abrasion resistance. Most shops will use a primer with a nylon-based coating because it adds to the adherence of the powder coating. This type of coating is best used with items that require low friction, like shelving units, food prep products, light fixtures, and seats. Nylon powder coatings are also used in the marine industry, especially on hardware pieces like fittings and bolts.

Polyester

Polyester is one thermoplastic powder that does not require the use of primers or pretreatments. This powder coating resin is durable in the weather and has strong UV resistance, too. Polyester coatings work well on pieces that will be outdoors because of the durability, but they are more difficult to apply than other thermostatic coatings.

Polyolefin

Polyolefin powder coatings are readily identifiable by their waxy films. This type of coating is lower in cost than other thermostatic technology and it is also much easier to apply. They are resistant to chemicals and they do not absorb water, which makes them good choices for equipment that is used in laboratory and in automotive parts. Even though they are good with chemicals, polyolefin coatings break down with certain solvents.

Polyvinyl Chloride

Polyvinyl chloride is more commonly known as PVC and this type of powder coating gives a glossy and flexible coating that is resistant to salt water spray and challenging weather conditions. With the water resistance, PVC coatings are often used with chain link fencing as well as in appliances like dishwasher baskets and freezer shelves. PVC coatings do require primers.

Epoxy

Epoxy coatings are used to provide insulated coatings for electrical parts. They also provide protection in locations with a wide variety of temperatures. Epoxy coatings are usually quite thick and they can often withstand temperatures over 150͒C. This type of coating can get chalky with excessive UV exposure, so it is usually applied to parts that are not used outside. Epoxy coatings can be made to look decorative and they come in many different colors.

Urethane Polyesters

Urethane polyesters are preferred when a thin, but tough film is needed. This type of coating is commonly used on car wheels and trim as well as other items that need a durable, but decorative finish. The film is often compared to the urethane paint that is used on planes, trucks, and buses.

Acrylics

Acrylic powder coatings are also durable with a thin finish. They are resistant to chemicals, but they have trouble with impacts and flexibility. In many instances, they are used over metals like chrome and brass, and sometimes they are applied with epoxy for better binding. Acrylic powder coats are generally attractive when finished and they are often used on products that need a high quality finish. Acrylic powders are being tested as an option for clear coats over automotive body paint.

At Byers Bush are proud to use thermoplastic powder coating product. For more information, please give us a call at 905-625-4334.