FOAM-FILLED

These methods rely on temperature changes, alternation of channel dimensions and flow rates, to produce foamed articles of a required structure, which is important for manufacturing foamed and foam-filled articles made of plastics, as well as for equipment design in this sphere. 

ALL FILLING MATERIALS EXCEPT PU SHEETS OR BLOCKS. These are tested against ignition source 2 which is a butane flame, approximately 120 mm high and applied to the FR polyester fabric covered filling for 40 seconds(Table VII) to BS 5852 part 2. This applies to all loose foam and non-foam filling when tested singly. 

When the non-foam fillings are used as composite fillings ror upholstered seating or for mattresses and bed bases the multiple layer composite is treated as a single material and tested in its final form to BS 5852 part 2 or BS 6807 respectively. 

Regulations for the PU foam filling of manufactured items generally come into force on 1st November, 1988 for the sale of such items after 1st March 1989. Regulations for furniture intended for use in the open air and for furniture fixed into caravans is applied on 1st March 1990 and is applied to second hand furniture on 1st March 1993. Furniture made before 1950 or materials for the reupholstery of such furniture are exempt from the regulations. 

In the 1970s, several research groups came up with foam-filled columns for GC and HPLC [14-17]. These open pore polyurethane foam stationary phases, which were prepared via in situ polymerization, were shown to possess comparatively good column performance and separation efficiency. They could, however, not achieve general acceptance and broader application due to insufficient mechanical stability and strong swelling behavior. 

Costs for constructing flotation devices are determined on a dollar per pound basis. Topper Industries claims a one-half to three-fourth cost savings by using scrap tire floats over wood, wood-fill, or other alternatives. The tire floats cost approximately 0.06 to 0.08 per pound, whereas the economically closest alternative, foam-filled plastic, costs 0.10 to 0.14 per pound of flotation (14). 

The secondary collimator ensures that only constant angle scatter reaches the detector. As indicated in Fig. 21, it consists of a series of thin lamella that are conical surfaces of resolution around the Z axis. Each of these has a surface area of 0.25 m2 and requires stabilization using a low-density foam filling and/or radial ribs positioned at regular intervals in the sense. The scatter detector and collimator shown in Fig. 21 can be replicated on both sides of the XY plane for increased signal and reduced attenuation artefacts. 

FIGURE 25.6 Heat release rate for PU foams filled with ATH, APP, kaolin, Mg(OH)2, and ZB. 

The liquid saturations in foam flow are typically close to irreducible liquid saturation. As a result, the liquid saturation in a foam filled medium is generally not a good measure of the quality of the in situ foam, but rather the fraction of pore segments completely filled with liquid. More permeable media, such as unconsolidated media, generally have smaller residual liquid saturations (32,33) and thus tend to have higher gas saturations when foam is flowing. 

Foam generation mode Boundary conditions Persistent flow state Typical AP/L at 1 m/day 5W in foam-filled medium Porous-medium length Cone, for strong foam Gas displaces surfactant AP fixed Gas or nothing flows 0.1-1 bar/m < wc Long (>0.5-1 m) Typically >0.5% Coinjection Gas and liquid rates fixed Foam flows Often >10 bar/m >Swc Any (often short) 0.01 to >1%... 

Data on a variety of materials ranging from foams filled with various gases to evacuated multilayer insulations have been reported elsewhere P ] in this paper typical test results are presented to illustrate the versatility of the apparatus. 

Gas-Filled Porous Insulations. Table I shows some of the results of tests on porous or vesicular materials. One test sample was 1-in. thick sintered perlite, evacuated to 4 X 10 torr. The other was a foam-filled honeycomb, f in. thick, in a helium atmosphere tested between room and liquid-hydrogen temperatures. The heat flux for this sample reached 600 Btu/hr-ft-, which approached the design limit of the apparatus. In another test the foam-filled honeycomb sample was filled with nitrogen and allowed to cryopump. 

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