Flexible integral skin foams

Use is made of integral skin foams. They are flexible urethane foams with a high density skin. They are used in applications such as steering wheels, arm rests, and protective covers that must combine a tough surface and a soft feel. 

Preparation of Integral-Skin Flexible Foams. The major polyisocyanates for use in making integral-skin flexible urethane foams are liquid MDl and TDl prepolymers. In order to make light-stable integral-skin foams, aliphatic diisocyanates, e.g., HDl (hexamethylene diisocyanate) and IPDl (isophorone diisocyanate) in modified forms are used. 

Properties of Integral-Skin Flexible Urethane Foams. The foam densities of integral-skin foams of commercial products are in the range of about 300 to 950 kg/m and their Shore A hardnesses are in the range of about 90. Shore D hardnesses are about 40 to 90. Figure 13 shows an example of density distribution of integral-skin foams. 

The alkoxylation process is easy to apply to PU foams having a low concentration of urethane and urea groups such as flexible and semiflexible foams, integral skin foams, PU elastomers and so on. Urea groups react in a similar way with urethane groups, with the formation of oxazolidones and amines by an intramolecular alcoholysis of urea groups (reaction 20.15). 

Flat parts with sufficient draft angle on the side do not require additional demolding aids. Flexible and semirigid integral skin foam parts can be ejected using compressed air. Rigid PUR integral skin foam products are ejected with mechanically or... 

Molds for flexible, PUR integral skin foams are required in the production of motor cycle seats, sun visors, and simple seat upholstery. These large molds usually consist of two parts. For suitable venting, molds for annular headrests require auxiliary parting planes that can be mounted with hinges on one of the mold halves. 

Integral-skin semi-flexible foams (ISSF)... 

The isocyanate used is of the less toxic type and may be Table 6. Typical properties of integral skin semi-flexible foam. 

The most interesting development in rigid polyurethane foams recently has been the advent of integral-skin rigid foams. These foams are formed in a similar way to integral-skin semi-flexible foams (discussed earlier) and are finding application in decorative mouldings, furniture pieces, domestic appliance cabinets and the like. In future they may even find application in the automotive industry. 

Rigid, flexible/slabstock foam, microcellular plastomers,and integral skin foam Rigid, flexible, integral skin, flexible molded,microcellular foam, coatings, and elastomers... 

Unlike other polymers, we have no universally accepted chemical nomenclature for polyurethanes. Instead, we typically refer to polyurethanes in terms of their general characteristics. Thus we refer to flexible polyurethane foams , polyurethane elastomers , integral skin polyurethane foams , and others. 

The European Parliament has adopted phase-out dates for the use of HCFCs in rigid foam applications which are basically in line with those in the USA and Japan. From 1 January 2000, the use of HCFCs for integral skin PU and PE foams is prohibited. From 1 January 2002, the use of HCFCs in expanded PS foams is prohibited. From 1 January 2003, the use of HCFCs in flexible-faced PU foam laminates, appliances and sandwich panels is prohibited. EUROPEAN PARLIAMENT... 

Semi-flexible foams (or semi-rigid foams) are sometimes classified as subdivisions of flexible foam because the foams have higher load-bearing properties and good compression recovery. Microcellular flexible foams and integral-skin flexible foams may also be classified in this category. In some classifications, however, microcellular foams are classified as elastomers. 

Integral-skin urethane foams are classified into two types, flexible and rigid. The former foams will be described here, and the latter will be described in the rigid-foam section. 

Figure 13. Density profile of integral-skin flexible polyurethane foam. Flame Retardant Flexible Foams...

Applications cold moulded high resilience flexible PU foams, semiflexible and integral skin PU foams, microcellular elastomers (shoe soles) ... 

Two-pack flexible coating for integral skin polyurethane foam... 

The glass transition temperature lies considerably above the temperature of use with rigid foams and considerably below the temperature of use with flexible foams. The cellular structure may be open, closed, or mixed. All cells are open to each other with open cellular structures. In contrast, each cell is sealed off or encapsulated from the other cells by a plastic wall in closed-cell structures. Structural foams are foams with a dense outer skin and an interior of lower density they are also called integral foams or self-skinning foams. In contrast to normal foams syntactic foams do not directly enclose the gas but contain small hollow bodies of glass, ceramics, or plastics which are under vacuum or are filled with a gas. 

In flexible slabstock and molded polyurethane foam production, methylene chloride, CO2 (liquid or gas injection), and water are used as ABAs. In rigid insulation foams CFCs have been replaced with HFC-134a (sometimes blended with HFC 152a) or liquid CO2. In integral skin polyurethane products, CO2, water, and hydrocarbons are used for the purpose. 

Oldoflex Integral skin, flexible foams Buesting Fasch Co. 

Elastocast, Castable polyurethane elastomer systems, BASF Corp., Urethanes Specialties Elastoflex, Flexible polyurethane systems, BASF Corp., Urethanes Specialties EUastoflex R, Semi-flexible polyurethane systems, BASF Corp., Urethanes Specialties EUastoflex TF, Thermoformable polyurethane foams, BASF Corp., Urethanes Specialties Elastoflex W, Hexible polyurethane foam systems, BASF Corp., Urethanes Specialties Elastofoam I, Rexible integral skin polyurethane systems, BASF Cap., Urethanes Specialties Elastofoam WB, Water-blow flexible integral skin PU systems, BASF Corp., Urethanes Specialties... 

The fire properties of flexible foams continue to receive considerable attention details of suitable fire tests have been collated by the International Isocyanates Institute.One growing trend in the flexible foam area is to use MDI-based products, which have advantages over the more conventional toluene diisocyanate systems of shorter demould times and excellent foam structure. Another area which has attracted some attention is that of light-stable integral skin flexible foams. These can be made by utilizing aliphatic isocyanates, u.v. stabilizers, or barrier coatings. ... 

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