Low Pressure Applied Polyurea
Tuesday, May 8, 2018
Since the discovery of fast set polyurea spray during the mid-1980’s by Mr. Dudley Primeaux of Texaco Chemical Company®, it has been necessary to apply this newly discovered technology through the use of a plural element high-pressure pump system which could consistently manage processing temperatures ranging from 130°F to 170°F. It was also imperative that the material remains heated until it is 22through an impingement gun where the polyurea was permanently mixed. However, for proper mixing, it was necessary that the polymer maintains these heats throughout a lengthy set of rubber hoses (up to 325 feet). The primary purpose of heating the material was to reduce viscosities of both components (Iso and Resin) to increase mixing in the high-pressure straightforward impingement gun. This heated material and high pressures resulted in excellent atomization of the polyurea. Invented and developed by Elastomer Specialties, Inc, the technology now exists to process specific aromatic and aliphatic polyurea systems using a low-pressure pump with no external heat applied to the cylinders or hose. In low-pressure polyurea applications, the use of direct impingement mixing is limited, and a static mixing wand is utilized following in a form that requires considerably less equipment maintenance and monitoring With the identification of the “Condor” low-pressure polyurea application machine, it is conceivable to spray pure polyureas at some multiple Low-Pressure Polyurea Being Utilized on Concrete as a Koi Pond liner size ratios thereby allowing a wide variety of formulation capacities. Contemporary Polyurea Application Problems, One of the primary difficulties associated with the application of polyurea coatings and standard high-pressure plural element application material, is the continued maintenance required to maintain an excellent operational Condition. This maintenance can include: Breaking down and cleaning of the direct impingement spray guns Monitoring of drum transfer pumps and replacing internal packing and seals• Constant monitoring of high-pressure pumping equipment, heat series, and pressure to ensure proper quantity ratios. Another standard issue associated with polyurea applications is the large amount of over spray caused by spraying highly pressurized and heated polyurea systems.
When applying chemical using an elastomeric coating system, it is usually desirable to have as limited air entrapment as possible. In other words, it is superior to have a smooth, continuous membrane. When spraying polyurea by high-pressure methods, it is common to see a phenomenon known as “Pin-Holing”. Pin-Holing is small holes in the polyurea coating most commonly correlated with spraying on solid substrates. Research has shown this phenomenon is presented by highly cooked and pressurized material getting in contact with ambient temperature concrete. The air/moisture present at the surface of the concrete will try to leave the coating system by transferring to the area of least friction. The polyurea system usually gels before the escape of the air/moisture resulting in “pin-hole”. There are some primers available on the business that reduces this phenomenon; however, we are not aware of a primer that eliminates this phenomenon effectively. Polyurea implemented by low-pressure techniques can substantially eliminate “pin-holing” Because of the lack of heated material and high pressures. The applied material temperature is usually near the same temperature as the substrate thereby eliminating the migration of air and moisture to the path of least friction.