Tuesday, September 28, 2021

Cashing In On The Polyurea Coatings Market

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In the rapidly growing sprayed polyurea coatings market there is a margin for error much shorter than conventional coatings. While there are numerous opportunities for companies to jump onto the polyurea trend, the growing number of applications and superior properties of sprayed polyurea require that particular attention be paid to the equipment used for dispensing.

The following explanation can quickly help any contractor/applicator to understand the polyurea application process, the interplay between the various pieces of equipment, and the important design considerations of the pump, hoses, and spray gun.

 This information will create an entirely new market for companies in coatings who wish to expand their business.


The New Frontier in Coatings

Polyurea is becoming increasingly sought-after in a variety of applications previously that were dominated by acrylic, epoxy, and polyurethane. Particularly, it's the aliphatic (an open-chain organic chemical) polyurea compounds that increasingly are the coating preferred due to their outstanding physical properties (up to 30000 psi tensile strength and 250-500-psi burst strength) and low-temperature flexibility (even at temperatures as low as 40 C) and the UV stability (color durability is superior to polyurethanes) and lower volatility (due to the fact that it is 100 percent solids creation).

The ability to adhere easily to the substrates such as brick, cement as well as fiberglass, the polyureas are employed in a variety of construction projects, such as creating asbestos ceilings by encapsulating them and coating floors. In contrast to polyurethanes, polyureas can are able to cure in conditions that have high humidity and moisture so long as the right surface preparation is done.

In the manufacturing and process industries, polyureas have found usage in everything from a coating of storage tanks, to covering floors of shops and walls of plants. Polyureas significantly outperform paint which is typically unable to stand up to the rigorous cleaning processes employed in food and pharmaceutical processing facilities, for example. The extremely quick reaction speed (three or 10 seconds) that is characteristic of polyurea systems is attractive to facility managers since it allows for quick installation and very little disruption to the process activities.



These benefits to performance explain, partially, why the growing market for polyurea systems will continue to grow in the near future. "From what we've learned through an association, as well as the interactions I have had with application experts within the field, as well as companies that make the systems as well as the basic materials used in the process, I can see between 15 and 20 percent increase per year in this field," says Garry Froese who was President of ArmorThane of Springfield MO. Primarily the innovator of sprayed polyurea systems, Froese is well-positioned to offer advice and guidance to companies who are interested in joining the market.

A little background information can go an Extensive Way

Polyurea systems arise from mixing two elements that are isocyanate and amine resin. The combination of these two components creates a urea linkage that is extremely flexible, as opposed to the crystal characteristics that is typical of polyurethane systems. The first formulations were developed in 1986 after someone told Froese that polyureas were not able to be sprayed. Froese took the request.

Garry Froese would say: "I didn't know any better. So I set out on myself to find out what could be possible. I first needed the equipment to determine formulas, if any, could be made and I contacted the first manufacturer of equipment I could find that was Gusmer. I wanted the largest two-part delivery/spray machine they built." In 1961, Gusmer was founded. Lakewood is a New Jersey-based company. Gusmer Corp. has long been a major manufacturer of multi-component proportioning equipment to spray coatings made of elastomeric.

"Once our equipment was delivered, it was operational the first time, because it delivered both B and A parts in a consistent and constant way," continues Froese. Once the equipment was functioning properly, "It gave us the opportunity to further improve the formulation of resin."

The first commercially sprayed polyurea coating was applied to roofing systems in 1989. Since then, the development of coatings is forever altered. Polyureas offer the greatest performance only when properly mixed in accordance with Froese, selecting the appropriate equipment to accomplish this is crucial.

The challenge of getting the Perfect Mix

There is no chemical catalyst is required, however because of the extremely rapid cure and reactivity, multiple types of equipment is required. High pressure is required for elements to blend. It is also necessary to heat the components to reduce the viscosity in order to boost the mix and improve the atomization process. The heating takes place in the pump as well as the hoses, and mixing happens within the gun, in the area where the two components come together with high velocity. Mechanical mixing is crucial for uniform concentration (hence better adhesion on the substrate). The importance of having equipment specifically created to spray polyureas can't be stressed enough.

"The quality and tolerances used in the manufacture of the equipment used for spraying make an enormous difference on the final output of your product," Froese says. "Good equipment is more expensive but it's not the best time to sacrifice quality when you're looking to spray polyurea. The most important factor to process is in the proportioning pump as well as that of the spray gun. This is the "life support system to ensure correct installation and application."

The Fun Starts at the Pump

If you are spraying using polyureas it is important to consider the choice of a high output pump. The higher pressure provides greater kinetic power to the mixing area. Pumps can be hydraulically or pneumatically operated. Both need an air compressor as the air is the force driving the drum pumps which deliver the substance. The pumps are split into horizontal or vertical arrangements.

Vertical pumps are the preferred choice for paint contractors. But, when it comes to high-solids coating systems such as polyureas, vertical pumps are not able to fill components with different viscosities simultaneously and at the same speed. An imbalance in pressure is always evident between the down and upstroke. This can result in an erratic flow material into the spray gun, which can affect the spray pattern, as well as its coating consistency.

Polyureas are mixed using even and solid heads of pressure. If the pressure is different either on one side or the other it can affect the performance of the blended substance and the uniformity that the spray pattern on the gun may be adversely affected. Without sufficient volume and a poor mix, it can result in poor atomization and the final results.

Hoses

The hoses that connect elements to the gun should also be heated, otherwise, all the gains gained by breaking down the viscosity of the pump will be wasted. Normal hoses, which are made specifically for polyurethanes, are not able to cope with the greater pressure and temperature required to spray polyureas. The initial heating is done inside the pump, the hoses have to maintain the temperature for the entire length, even as long as the length of a football field. These requirements require specially designed hoses.

Froese stated that, based on their length, the hoses need to have an "step-down" in diameter inside (ID) to limit pressure drop around the spray gun. Also, the ID at the point of pumping should be bigger than the hose section close to the gun.

The Spray Gun

Guns are generally classified into two types: air and mechanical, based on the method by which the substance is removed from the chamber once triggers occur. Solvent purge guns are often used for difficult-to-mix and off ratio spray applications.

The most appropriate spray gun to make use to the polyurea technique is the purge mechanical spray gun. With a mechanical gun it is possible to return the valving rod upon the moment of detriggering closes and cleans out the chamber's mixing area. The snug fit of the rod valve, together with the high-pressure kinetic force that drives its motion, clears every stray material.

"The Mechanical purge gun provides the highest mix and properties in part due to the mix's dynamics inside the chamber," Froese says. "You also receive a complete removal from the chamber that eliminates the risk of holding up the product in this chamber. Hold-up can be a problem due to the fact that it impacts the incoming material as well as the mix that follows."

Air purge guns are air-powered, and an air blast actually blasts the material away after deactivation between sprays. The valve rod is moved forward and backward to let air get into the mixing chamber in contrast to only material.

The issue with air purge devices is that since the air used is to purge, the pressure has to be maintained at a high level to fully cleanse the chamber. If not the tip becomes stuck. A different issue can occur when air gets in the chamber for mixing. The presence of contaminants such as oil and water can be injected through the air compressor onto the substrate. This can lead to blistering and the delamination of the polyurea coating.

Additional Gun-related Considerations

Other factors to consider when selecting the right gun include gun geometry and construction. Speed of operation and maintenance are also important when choosing a polyurea spray system. The ergonomics of the operator should be considered too. In addition, those who are new to the polyurea spraying business should look for a manufacturer of equipment with a solid support system and has a commitment to keep an supply in spare components.

Make sure you do it right the first time

In the end, contractors reap from knowing what equipment is needed to enter the realm of sprayed polyureas. However, knowing the wrong thing could force a contractor in a position to be shut out.

"When you're in the trenches using these applicators, as I am and you'll see the effects of poor equipment in the first place there's it!" explains Froese. "I know of a situation in which a person completed a task for a client, however, two issues occurred. The contractor did not perform the proper surface preparation and the equipment wasn't adequate for the process of applying the polyurea. If the coating failed, the client demanded compensation from the contractor, which was more than the amount the job was worth in terms of the revenue loss."


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HOW WE ARE PRESERVING AND REPAIRING AGING INFRASTRUCTURE WITH GEOPOLYMERS

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Completed underpass
Completed underpass.

The infrastructure that is aging across the U.S. is experiencing increased maintenance and repair expenses. Certain types of structures that require major attention to maintenance include bridges that accommodate trains, cars and pipes racks for pedestrians, and many more.

Bridges require more maintenance because they are enduring greater loads, more frequent traffic, exceeding lifespan, and are confronted with extreme environmental conditions and shifting weather conditions, along with winds and seismic activity. These factors are speeding up the aging process of bridges.

Innovative technologies are being utilized to reduce the cost of maintenance as well as improve the strength and strength and durability of structures and/or extend their lifespan. Newer and more advanced technology is a geopolymer that can be combined with the geosynthetic grid or textile. These types of repair materials are able to be used without needing modification of the structure or requiring significant construction efforts or time. They also help to reduce the spread of traffic during the repair.

Below are some typical aging structures that can be repaired while increasing the strength of the structure and increasing the functional longevity of the structure using a geopolymer/geosynthetic system.

(From left): Load deterioration, stress deterioration, and weather deterioration.
Bridge deterioration
(From left): Load deterioration, stress deterioration, and weather deterioration.


Montana Rail Link (MRL) is a Class II regional railroad company that manages more than 902 route miles of track across Montana as well as Idaho. The goods transported through Montana Rail Link include coal industrial products grains, intermodal transport, and even vehicles. In Montana, state Montana is characterized by major changes in soils and climate conditions and environmental factors that could be harmful to concrete and steel structures that pose a risk for MRL. The inspection department of MRL constantly examines their infrastructure and determines needed structures and rail repairs.

The inspection team discovered the bridge located in Laurel, Montana that needed repairs due to the concrete showing signs of wear and tear due to environmental and climate conditions. The images below highlight the state of the concrete structure prior to the repair.


Existing bridge
(From left): Existing girder conditions, existing bridge underpass, existing column condition(From left): 

MRL was referred to as Shotcrete Montana, based in Billings in Billings, Montana, to smooth the walls of the foundation with Geogrid and geopolymer. The concrete was stopped from deteriorating further. Shotcrete Montana purchased their geopolymer and geogrid from Full Moon Enterprises. Full Moon Enterprises is a supplier of a distinctive geopolymer called GeoSpray by GeoTree Solutions.

GeoSpray is generally regarded as a mortar made of cement by engineers but it has the chemical properties of a polymer that behaves as an engineered stone and offers a variety of unique characteristics like bonding strength and permeability, as well as flexural strength that is higher than all cement mortars that are available. GeoSpray is applied using a trowel or sprayed.

The repair involved cleaning the surface using a thorough cleaning, then applying an extremely thin coating of GeoSpray before applying the geogrid, then spraying it with GeoSpray on top of the geogrid, and then hand trowelling to create the surface smooth and beautiful.

The total area that was repaired was less than 5,000 sq feet which were done within five days with no closing the road during the daytime. The bridge's walkway was reopened after each day of work.

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