At Gantrade, we provide the components essential to the manufacture of polyurethane foam, a material with a broad universe of industry applications.
Polyurethane Foam Applications
There are two major types of foams in use in a variety of applications: flexible polyurethane foams and rigid polyurethane foams. Flexible foams hold the greatest market share currently, due to their wider variety of uses. Let’s take a detailed look at the major polyurethane foams and their applications.
Flexible Polyurethane Foams
Flexible polyurethane foam is widely used as a cushioning material in the production of mattresses, seating, and specialty items. It’s produced by reacting a polyol blend (containing catalysts, surfactants, blowing agent, cell opener, etc.), with a TDI or MDI Isocyanate. Formulators regulate flexible polyurethane foam properties through raw material choices and formulation processes. Flexible foam can be very firm or very soft, or even visco-elastic.
In North America, flexible foam properties are designated by ASTM 3574. Indentation load (force) deflection or ILD (IFD) is the test method for urethane foam to determine firmness, stiffness, or load-bearing capacity. Foams are also tested for compression sets, density, tensile strength, tear, and elongation. Some foams, based on use case demands, may require the addition of flame retardants or anti-microbials.
Flexible slabstock foam is produced in a continuous application, where the mixed materials are laid down on a moving substrate and allowed to rise unrestricted. Typical substrates are foil and kraft paper. This foam is then cut and fabricated to the end-use size and shape. This foam is usually low density.(1.5-2.5 pcf).
Flexible molded foam is produced using molds that form the foam shape during cure. Typical applications are seating used in office furniture, transportation, recreational vehicles, and medical positioning. This foam is usually medium density. (3.0 – 5.0 pcf).
Integral skin foam is produced in much the same way as FMF, but it forms its own tough outer skin during cure. Typical applications for integral skin foam include armrests, steering wheels, shoe soles, and recreational padding. This foam utilizes a blowing agent and is much denser than the other foam types. Hardness is tested using a Shore “A” gauge.
Rigid Polyurethane Foams
Rigid polyurethane foams are used predominantly in the insulating of doors, buildings, and appliances. In recent years, the industry has been under new legislative guidelines to use more eco-friendly alternatives to “blow” or expand the foam (SNAP)..Blowing agents can be water, hydrocarbons or hydrofluorocarbons.
It’s important to note the K-factor and R-value of these foams, and recent moves have been made by industry and regulatory bodies to include U-factor as a composite value of performance.
Described in their most basic terms, R-value is a measure of heat resistance, while U-factor (also known as U-value) is a measure of heat transfer (heat gain or loss). The lesser-known K-factor is simply the reciprocal of the R-value of the insulation divided by the thickness.
Installers use rigid polyurethane foam to insulate entry doors and garage doors, and the process can be continuous or discontinuous. For panels used in walk-in refrigerators and SIPS, installers use rigid polyurethane form, and the substrates can be metal, wood, or PVC. And for appliances, we see rigid polyurethane foam installed to insulate hot water heaters, ice machines, and drink machines, among other applications.
Structural rigid polyurethane foams are another well-defined application area. These foams can be used for floatation, architectural trim, signage, and chair backs. They often mimic the characteristics of wood, but without the inherent issues that make wood unacceptable for certain applications. Structural foam does not rot, harbor insects, or become water-logged.
Spray foam sector has emerged as one of the more popular applications of rigid polyurethane foam.This foam can be sprayed on rooftops or in between wall studs to create a sealed building envelope, making it a preferred choice for energy efficiency construction and retrofits. We also see spray foam used in the field for ditch breaks, and even packaging foam is considered a “spray foam” due to its low density.
Construction uses for rigid polyurethane foams include house sheathing, concrete lifting, pole setting, and the aforementioned ditch breaks. The foam is either sprayed or injected via a low-pressure gun delivery system.
Another rigid polyurethane foam that’s found wide market acceptance is known as an energy-absorbing (EA) foam. In automotive applications, for example, parts are typically molded and then installed in the knee area, bolsters, or bumpers. NVH (noise, vibration, and harshness) foams are used for acoustical and vibration damping in doors, dashboards, and ceilings.
Polyurethane Foam Processes
Now, let’s take a look at processes for developing polyurethane foams. These foams are mixed and dispensed in a variety of ways:
- High-pressure processing, also commonly referred to as impingement mix, has two components (A&B). These two components are mixed in a machine head by direct impingement, where the two metered streams are sprayed together before dispensing from the machine. The equipment is usually more expensive than that used for low-pressure processing
- Low-pressure processing involves two streams entering a mixing chamber, where a high speed “propeller” mixes the two components before dispensing. Low-pressure processing is quite common in shoe sole applications.
Polyurethane Foam Delivery Options
Gantrade can deliver polyurethane foam components in a variety of container sizes to meet your unique demands. We can ship polyurethane foam components in several ways:
- Totes
- Drums
- Pressure-cylinders
- Bulk
- Rail cars
Further Considerations
When processing polyurethane foam, you must be diligent in monitoring process conditions for a variety of factors, including the following
- Component temperatures
- Substrate temperatures
- Ratio of A/B components
- Pack density
- Mix efficiency
- Formulation parameters
When you take all of these considerations on board, you will develop optimized polyurethane foam products that find market success for their versatility and durability.
Final Thoughts
Polyurethane Foams can fill a vast array of applications in the marketplace, thanks to the existence of several varieties of flexible and rigid foams There are a myriad of possibilities via formulation manipulation and component choice. Gantrade offers a full line of polyurethane foam components for your successful utilization.
For more information, contact Gantrade today. Our team of technical specialists will help you with a just-right solution for your product demands.
