Much interest has also been expressed in new techniques for processing the urethane foams, including spraying, frothing, and molding ( see article, p. 391 for details ).

Most commercial uses of urethane foams require densities between 2 and 30 lb. / cu. ft. for rigid foams, between 1 and 3 lb. / cu. ft. for flexible foams.

In flexible urethane foams, we are referring to the range between the highest and lowest temperatures under which the materials' primary performance remains functionally useful.

The K factor, a term used to denote the rate of heat transmission through a material ( B.t.u./sq. ft. of material/hr./*0F./in. of thickness ) ranges from 0.24 to 0.28 for flexible urethane foams and from 0.12 to 0.16 for rigid urethane foams, depending upon the formulation, density, cell size, and nature of blowing agents used.

The higher-density urethane semi-rigid foams usually have stronger flex fatigue resistance, i.e., the 12 lb. / cu. ft. foam has 8 times the flexural strength of the 3 lb. / cu. ft. density.

( like compression strength of urethane foams, it has a direct relationship to formulation.

Figure 2, above, shows the aging properties of urethane foams as determined by the percent of change in tensile strength during exposure to ultra-violet light.

The closed molding of flexible urethane foams has been a problem ever since the introduction of the material ( molding in open molds was more feasible ).

In 1967, urethane modified polyisocyanurate rigid foams were introduced, offering even better thermal stability and flammability resistance compared to low-density insulation products.

Like other tertiary amines, it catalyzes the formation of urethane foams and epoxy resins.

And in meeting the demands for urethane foam as a garment interlining, new adhesives and new methods of laminating foam to a substrate have been developed.

Simple systems are available that make it possible for urethane foam components to be poured, pumped, etc., into a void where they foam up to fill the void.

These strong hydrogen bonds, for example, result in the high tensile strength and melting point of polymers containing urethane or urea linkages.

Abbat worked for U-Do, Mattel, Kenner, Fisher-Price, and ITT, making toys and telephone parts out of urethane and other plastics.

The installation of the auto glass is done with an automotive grade urethane designed specifically for automobiles.

A mid-year option for the 1976 model year was a sport front end available for the Towne Coupe, which features the 2 + 2's urethane front end and quad headlamps.

That planned ' 70 H / O ended up being introduced as the mid-year Rallye 350, which featured a bright yellow paint scheme for the body along with front and rear bumpers coated with matching yellow urethane.

Currently there are 4 different types of coverstocks for ten-pin bowling balls: polyester, urethane, reactive resin and particle resin.

The options list was updated to include a urethane bumper for impact improvement.

Among them are 4-hole injectors, foamed urethane injected to the A-pillar, centre pillar and B-pillar for noise insulation, immobiliser systems and pedestrian injury reduction body construction.

After the end of the Vietnam War, the U. S. military phased out Saran insoles in favor of Poron ®, a microcellular urethane, for its jungle and combat boots.

In one outstanding example, Whirlpool Corp. found that by switching to urethane foam insulation, they could increase the storage capacity of gas refrigerators to make them competitive with electric models.

Generally, clean inline skate bearings contribute about 2 % of the rolling resistance that the best urethane inline skate wheels produce, so there is very little opportunity in improving speed by spending more money on bearings.

While there are other compounds, such as silicone and urethane that are stronger and last longer, foam rubber is used because it is much easier to work with.

Since the mid 1950s, when urethane foam first made its appearance in the American market, growth has been little short of fantastic.

Wheel optimization has included a trend towards a smaller diameter ( to reduce inertial effects and aerodynamic drag ), the use of custom rubber and urethane compounds on solid tires ( to reduce rolling resistance ), and the use of solvents to swell solid rubber or urethane tires ( also reducing rolling resistance ).

It has a Valmet M76 receiver, which is made from stamped and riveted sheet metal, constructed inside urethane stock.

This coverstock is a similar coverstock to the urethane but also has pores.

Since the late 1960s, when Gordon Clark found the optimum formulation of urethane foam, many of the surfboards in common use have been of the shortboard variety between 6 feet and 7 feet in length, with a pointed nose and a rounded or squarish tail, typically with three skegs ( fins ) but sometimes with two or as many as five.

Although cushioned belts have mostly been deprecated out of use and cushioned replacement belts may be hard to find, many treadmills have rubber or urethane deck elastomers ( cushions ) which are superior in cushioning and last longer than cushioned belts.

Table 1,, p. 394, shows a comparison of K factor ratings of a number of commercial insulating materials in common use, including two different types of rigid urethane foam.

Form Study Prototypes are often hand-carved or machined models from easily sculpted, inexpensive materials ( e. g., urethane foam ), without representing the intended color, finish, or texture.

As with other composite materials, a dental composite typically consists of a resin-based matrix, such as a bisphenol A-glycidyl methacrylate ( BISMA ) resin like urethane dimethacrylate ( UDMA ), and an inorganic filler such as silica.

Modern balls usually consist of several layers of various synthetic materials like surlyn or urethane blends.

A bowling ball is a spherical ball made from plastic, reactive resin, urethane or a combination of these materials which is used in the sport of bowling.

As with other composite materials, a dental composite typically consists of a resin-based oligomer matrix, such as a bisphenol A-glycidyl methacrylate ( BISGMA ) or urethane dimethacrylate ( UDMA ), and an inorganic filler such as silicon dioxide ( silica ).

Future brain implants may make use of more exotic materials such as nanoscale carbon fibers ( nanotubes ), and polycarbonate urethane.

A small cut is made after which a soft silicone or urethane plug is inserted in to each vas tube thereby blocking ( occluding ) sperm.

These are usually latex, polyester, urethane or epoxy compounds which are applied in liquid form to provide a completely seamless floor covering.

Anti-rockers are usually made of Nylon, or a substantially harder urethane than normal wheels, which means if a skater were to catch either of their center wheels on the grinding surface, they are less likely to be slowed or halted by friction between the wheel and rail or ledge.

An air mattress, also known as an airbed is an inflatable mattress, the wide majority of which are usually made of PVC vinyl plastic although recently developed textile-reinforced urethane plastic or rubber versions exist.

Music Man's latest addition was the Bass Player Live Deluxe Classic Collection, which combines the elements of the first Music Man basses-such as a 2-band EQ, a chrome truss rod wheel, vintage skinny fret-wire and nut, a chrome plated, hardened steel bridge plate with " Classic " stainless steel saddles and adjustable mute pads, as well as a 7. 5 " radius urethane finished figured maple neck-with modern features such as a 6-bolt neck fixing and graphite acrylic resin coated body cavity and aluminum control cover.

In order to preserve some of this heritage the Ministry of Transportation created a 1800mm x 1625mm reusable urethane mould of the provincial coat-of-arms from the 5th Line overpass located south of Bradford, which will be used to decorate the replacement structures.

That ball became the AMF Angle and this one coverstock change allowed the ball to get a better grip on the urethane finishes used on natural wood lane surfaces, which changed the nature of the bowling game significantly.