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US 5,665,287 AGranted
Froth process for continous manufacture of polyurethane foam slab-stocks
AssigneeFoaming Technologies Cardio BV
InventorsCarlo Fiorentini, Anthony C. Murray Griffiths
Life of this patent
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Abstract
A process and a system for the continuous manufacture of polymeric foams. Reactive chemical components and additives comprising a low boiling blowing agent are mixed under pressure; the mixture is then frothed before chemical reaction takes place by feeding the mixture through a pressure equalizing and frothing device comprising a pressure-drop zone opening into a frothing cavity having an output aperture to discharge the froth onto a moving substrate.
Claims45
A process for the continuous production of polyurethane slab-stock foam including the steps of:
- forming a mixture of reactive chemical components;
- mixing the reactive chemicals with a non-reactive low boiling liquid blowing agent under sufficient pressure conditions to maintain the mixture in a liquid state;
- distributing the mixture under pressure controlled conditions by passing the resulting mixture along an elongated pressure equalizing chamber and through an enlarged pressure-drop slot dimensioned to maintain back pressure on the upstream mixture so as to maintain the mixture containing the blowing agent in a liquid state yet permit frothing of the mixture to be initiated under pressure controlled conditions to avoid, upon discharge of the mixture from the pressure-drop slot, turbulent evaporation of the blowing agent;
- thereafter forming the discharged mixture into a progressively non-reactive expanding frothing material by progressively releasing gaseous blowing agent from the liquid mixture into the frothing material as the frothing material flows along a frothing cavity and through an outlet aperture;
- and
- discharging the expanding frothing material onto a substrate and permitting the reactive chemicals to react and rise freely into slab stock where the volume of the discharged froth is less than about 50% of a final foam volume.
3 more elements
A process for the continuous production of polymeric foams including the steps of:
- preparing a reaction mixture of liquid chemical components together with a liquid low boiling blowing agent while subjecting the resulting mixture to a pressure sufficient to maintain the resulting mixture in a liquid state;
- frothing the resulting mixture under pressure controlled conditions including the additional steps of equalizing the pressure on the resulting mixture in an elongated pressure equalizing chamber, passing the resulting mixture through an elongated pressure-drop slot to initiate expansion of a frothing material so as to avoid turbulent evaporation of the blowing agent, flowing the expanding frothing material along a frothing cavity wherein the blowing agent is gradually released as a gas into the frothing material prior to the initiation of chemical expansion of the reactive mixture of chemical components to freely rise into foam.
A process for the continuous production of polyurethane slab stock foam including the steps of:
- forming a mixture of reactive chemical components;
- mixing the reactive chemicals with a low boiling blowing agent under sufficient pressure conditions to maintain the mixture in a liquid state;
- frothing the mixture under pressure controlled conditions by passing the resulting mixture along a pressure equalizing chamber to equalize pressure along an enlarged pressure-drop zone, and through the pressure-drop zone to initiate frothing;
- and
- flowing the frothing and expanding mixture along a frothing cavity and through an outlet aperture thereby discharging the still frothing mixture into an expansion enclosure where the mixture freely rises by reaction between the reactive chemicals into slab stock.
2 more elements
A process for the continuous production of polymeric foams including the steps of:
- preparing a reaction mixture of chemical components together with a low boiling blowing agent while subjecting the mixture to a pressure sufficient to maintain the mixture in a liquid state,
- frothing the mixture under pressure controlled conditions including the additional steps of equalizing the pressure on the mixture in an elongated pressure chamber, passing the mixture out of the pressure chamber through an elongated pressure drop zone, and flowing the mixture along a frothing cavity wherein the blowing agent is gradually released as a gas into the frothing mixture prior to the initiation of chemical expansion of the reactive mixture of chemical components into foam where the volume of froth is less than about 50% of the volume of foam.
A process for continuous production of polyurethane slab-stock foam including the steps of:
- forming a mixture of reactive chemical components;
- mixing the reactive chemicals with CO.sub.2 under sufficient pressure conditions to maintain the mixture in a liquid state,
- distributing the mixture by passing the resulting mixture along an elongated pressure equalizing chamber and discharging it through a pressure-drop zone having cross-sectional dimensions and being axially extending in the direction of the flow to provide sufficient back pressure to keep the mixture containing CO.sub.2 in a liquid state upstream of the pressure-drop zone and to initiate frothing under pressure controlled conditions to avoid turbulent evaporation of the CO.sub.2 ;
- and then flowing the frothing material along a frothing cavity and through an outlet aperture, and discharging an expanding frothing material onto a substrate where the reactive chemical components react and rise freely into slab stock.
1 more element
A process for continuous production of polyurethane slab-stock foam including the steps of:
- forming a mixture of reactive chemical components;
- mixing the reactive chemicals with CO.sub.2 under sufficient pressure conditions to maintain the mixture in a liquid state,
- distributing the mixture by passing the resulting mixture within a pressure equalizing chamber and flowing the mixture through a pressure-drop zone having cross-sectional dimensions and extending in the direction of flow therethrough to provide sufficient back pressure to keep the mixture containing CO.sub.2 in a liquid state upstream of the pressure-drop zone and to initiate development of an expanding froth material under pressure controlled conditions to avoid turbulent evaporation of the CO.sub.2 ;
- and then discharging a still expanding frothing material onto a substrate where the reactive chemical components react and rise freely into slab stock by reason of a chemical reaction by the components.
1 more element
Dependencies are inferred from the claim text.