Spray Foam To Polyurea
SPRAY FOAM TO POLYUREA
We are often asked if the same spray foam equipment can be used to apply polyurea. It’s a very good question, and we can certainly understand why you would ask such a question. There’s a wide range of spray equipment out there and why would you want to buy more than what you need?
Coating equipment and spray machines are not equal in their capacity to operate with certain materials, as they necessitate varying pressure to apply. Most high-pressure equipment could be interchangeable regardless of whether it is used for spraying polyurea or foam, but lower pressure machines are generally only used for spray foam. The proper pressure for coatings needs to be at or above 1800 – 3500 psi, while foam application is able to be performed by machines in the ranges of 800 to 2000 psi. Lower pressure machines are suited for spray foam only under the condition of not using long hoses, as those require higher pressure to effectively spray the material.
Material Supply Pumps:
With polyurea, the material supply pumps should be capable of delivering 2X the material that the proportioner is distributing. The lowest output for the supply pump should be at about four gallons per min. Most will use a hydraulically driven pump for large scale polyurea jobs because of overall performance and material supply. As the material in the drums cools, production decreases. Therefore, it is important that the materials are appropriately conditioned and stored according to the system supplier, which is usually above 70°F.
As you know, there are many heated metering pumps out there. These can be hydraulic, electric, or pneumatic. Each has its own characteristics and requirements. Most will use a hydraulically driven pump for large scale polyurea projects due to overall material supply and performance. It’s crucial to understand what the maximum fluid flow rate for the unit is, as well as the heating capacity. Contrary to widespread belief, the proportioning pump does NOT make pressure; it provides the flow of material.
The “pressure” comes from how flow is limited. If the material is too cold, it will have a higher viscosity and therefore, will be more difficult to pump, leading to higher pressured results. For polyurea systems, it is necessary to heat and preserve the materials at a higher temperature than with spray foam. Please keep in mind that for polyurea systems, the ISO side is typically more viscous than the resin side unlike spray foam systems, so you may detect more pressure on the ISO than on the resin during the treatment. This is the temperature at which the unit can heat it to at the rates you are using. Polyurea systems are generally heated to a minimum of 140°F to 160°F, NOT for reactivity, but to lower the viscosity of the materials in order to allow for correct mixing and atomization. Therefore, higher wattage heating units are typically required for polyurea systems.
Is A Spray Hose...Right?
It is incorrect to assume a spray hose is a spray hose. Often, little attention is paid to this part of the system. Since material viscosities are much higher than normal spray foam systems for polyurea systems, heating capability, hose selection, and size are incredibly important, the more spray hose you use. It’s all about flow and how it may be restricted, supplying that pressure. So remember, the pressure gauges are at the proportioner, not the spray gun.
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Take the first step towards a low cost polyurea, polyurethane, or spray foam business opportunity and call us at 800.227.2905 or fill out our contact form below. Someone from our company will contact you to answer your questions and provide you more information.