What is the difference between low-pressure and high-pressure polyurethane foam systems?
High-Pressure Polyurethane Foam Systems
High-pressure polyurethane foam systems are used to insulate large surface areas and include significant equipment costs. High-pressure polyurethane foams are dispensed through impingement mixing, meaning the chemicals are delivered through heated hoses from supply tanks into a gun chamber where the two components react and are spray-applied at elevated temperatures and pressures. With the higher pressure of the polyurethane foam being dispensed, the opportunity for emission of chemicals is greater, so the re-entry time for a home or building is 24+ hours.
- Typically dispensed at pressures exceeding 1,000 psi
- Output at full trigger is up to 30 lbs. per minute
- Product temperature of 120–150°F (49–65°C)
- One hour startup & shutdown
- 80+ serviceable parts to gun components
- High output, high emissions, greater re-entry time (24–48 hour re-occupancy)
- 55-gallon drums to transport and dispose
- Approximate startup costs range from $15,000–$120,000
Low-Pressure Polyurethane Foam Systems
Low-pressure polyurethane foam systems are used to air seal and insulate small to mid-size areas with low equipment costs. Low-pressure polyurethane foam chemicals are combined in the nozzle chamber and sprayed at room temperatures and at a significantly lower pressure. The output of 5-7 lbs. per minute decreases the chemical emissions, allowing for a faster home and building re-entry time.
- Dispensed at pressures less than 250 psi
- Output at full trigger is 5–7 lbs. per minute
- Product temperature of 70–85°F (21–29°C)
- Quick startup & shutdown
- Minimal maintenance and associated costs
- Lower output, low emissions, quicker re-entry time (One hour re-occupancy)
- Refillable tanks
- Approximate startup costs range from $3,000–$8,000
Under the low-pressure polyurethane foam category there are three subcategories of foam based on application method; spray polyurethane foam (SPF), pour-in-place polyurethane foam (PIP) and one-component polyurethane foam sealants and adhesives (OCF).
- Low-pressure spray polyurethane foam is a chemically cured, two-component system designed to fill and insulate large voids and surfaces. This delivers excellent adhesion properties and creates a continuous air barrier completing the building envelope, which results in improved indoor air quality and lower heating and cooling costs.
- Low-pressure pour-in-place polyurethane foam is a chemically cured, two-component system specifically designed for filling cavities, molds, fixtures or holes where a slower curing and expanding polyurethane foam is required. Within this pour-in-place polyurethane foam category, a new technology emerged called High Flow Technology®, which uses a unique blowing agent that allows the foam to flow even further before expansion. This advanced technology has the ability to completely fill voids and cavities of all shapes and sizes with minimal fill points while allowing the foam to flow greater distances, making it ideal for a wide variety of applications.
- Low-pressure one-component polyurethane foam sealants and adhesives are pre-reacted in the can and undergo further reaction with ambient moisture at the time of application. One-component polyurethane foam sealants and adhesives are generally used for smaller bead applications.