“Which Cushion Is Best For Me?”
This is the most commonly asked question by our customers. The answer depends on many individual factors such as the users body weight, level of support required and application.
SunMate cushions are available in eight different degrees of support: Extra-Soft, Soft, Medium-Soft, Medium, Medium-Firm, Firm, Extra-Firm and Hard. This provides a wide support range for any weight or weight-distribution need. The SunMate formulation can also be customized to meet special requirements.
Soft SunMate gives easily and is gentle on mild deformations or pressure-sensitive areas. It provides comfort and enough support for a small, lightweight person. A sheet of Soft SunMate provides a cushy layer of comfort when used as a mattress topper. A Soft SunMate cushion can be placed on a firmer seating surface like an office chair or car seat to provide more comfort as well.
Medium SunMate provides more support under pressure than a Soft cushion. It is well-suited for a wide range of body weights. A 2-inch-thick cushion supports a person weighing between 80-120 lb, a 3-inch-thick cushion accommodates weights up to 200 lb, and a 4-inch-thick cushion supports weights up to 300 lb.
SunMate has a thermoplastic quality, which means it will soften slightly when it's hot, and firm slightly when it's cold. Firm cushions are often used in hot, humid climates where they provide support comparable to a Medium cushion in a more moderate climate.
Calculating Seating Pressure
Except for the lower leg weight, which is supported by foot rests or the floor, a seated person is supported by the body contact area of the seat cushion. This contact area is outlined in Figure I.
FIGURE I. The average support pressure is found by dividing the weight of the person by the area of the seating imprint (shown at left) in square inches. A support pressure in the range of 0.9 to 1.0 PSI is typical for an average-weight person.
This is where the unique properties of SunMate come into play. SunMate cushions can be formulated to comfortably and uniformly support any weight. The proper cushion will allow the body to sink to a suffcient depth to maximize the contact area and reduce seating pressure without bottoming-out.
A support pressure reading (in PSI) correlates to the softness of a SunMate cushion. Figure II shows which type of cushion is typically used for a given application.
FIGURE II. Different cushion support pressures perform optimally for different functions.
Choosing the Correct Cushion
Figure III can be used as an aid in the selection of SunMate and Laminar cushions. For example, a body weight of 180 lb is represented on the chart by a horizontal dotted line. A vertical dotted line is extended from the desired cushion thickness, 2.5 inches.
FIGURE III. Use this chart to calculate which support pressure will likely be most beneficial for you. Remember:
□ Cushions less than 1" thick generally do not provide maximum support, and are only recommended when used in conjunction with another cushion.
□ Cushions more than 4" thick are usually in excess of body support requirements.
The point at which the lines meet is between the diagonal envelope boundaries for Medium and Firm cushions. Therefore, a 2.5-inch thick Medium-Firm SunMate cushion would be recommended. The shaded areas of the chart represent cushion specifications that are usually not required.
SunMate is designed to absorb tremendous amounts of impact shock and vibration energy, as shown in Figure IV. That is why SunMate is used for many engineering applications.
FIGURE IV. Firmer SunMate cushions are more energy-absorbent. Energy absorption is temperature-dependent:
Normal use temperature range: 0–120°F
Functional temperature range: -20–150°F
Slow degradation starts: 300°F
Density: 5 lb/ft3
In cold temperatures, SunMate cushions become slightly firmer while retaining flexibility. In hot temperatures, SunMate cushions soften slightly but still retain good resilience and strength.