TH30174A - Methods for the production of multi-layer foam components. - Google Patents

Abstract

DC60 (06/03/41) revealed a process for preparing multi-layered foam components, such as automotive seats. The mold is positioned with the bottom surface flat or at an angle of up to 40 degrees to the horizontal plane. The first liquid foam mixture, designed to produce soft foam, is poured into the mold from the mixing outlet, in streaks across the mold's seating lines, along lines parallel to but close to the outer walls of the seating lines. A second liquid foam mixture, designed to produce rigid foam, is then poured into the mold from the same or a different mixing outlet, in streaks across the mold's seating lines, along lines parallel to but close to the outer walls of the seating lines, more than the first mixture. The second liquid foam mixture is then allowed to spread on top of the first. The mold is then closed, and the foam is allowed to expand and cure in the mold. This process reveals a method for producing components with excellent layered foam seating areas. Alternatively, at an angle of up to 40 degrees to the horizontal plane, pour the first liquid foam mixture designed to produce soft foam into the mold from the mixing nozzle outlet, in streaks, across the mold's seating line, along a line parallel to but close to the outer wall of the mold's seating line. Then, pour the second liquid foam mixture designed to produce hard foam into the mold from the same or a different mixing nozzle outlet, in streaks, across the mold's seating line, along a line parallel to but close to the outer wall of the mold's seating line, more than the first liquid foam mixture was poured. Allow the second liquid foam mixture to spread on top of the first liquid foam mixture. Close the mold and allow the foam to swell and cure in the mold. This process produces objects with an excellent layered foam seating area.

Claims (12)

1. A process for preparing multi-layered foam material in a mold arranged with the bottom surface of the mold flat or at an angle up to 40 degrees to the horizontal plane, by foaming and curing a first liquid foam mixture designed to produce a softer foam and a second liquid foam mixture designed to produce a harder foam, which is characterized by the following steps: (a) pouring the first liquid foam mixture into the mold in streaks across the mold lines from the mixing outlet; and (b) pouring the second liquid foam mixture into the mold in streaks across the mold lines from the same or different mixing outlet, parallel to the pouring of the first liquid foam mixture but spaced apart, so that the second liquid foam mixture touches the mold where the mold is not wetted by the first liquid foam mixture, and allows the second foam mixture to spread on top of the first liquid foam mixture. 2. The process described in claim 1 is characterized by the simultaneous pouring of a liquid foam formulation designed to produce foams of varying hardnesses from at least two mixing head outlets, strip by strip, into the aforementioned lines of the mold along the different lines as the mixing head moves over and across the aforementioned lines of the mold. 3. The process specified in claim 1 is characterized by the sequential pouring of a liquid foam formulation designed to produce foams of varying hardnesses from a single mixing head outlet, strip by strip, into the aforementioned lines of the mold along lines that differ from the aforementioned lines of the mold. 4. The process described in claims 1 through 3 is characterized by the pouring of the first liquid foam formulation designed to produce soft foam, strand by strand, into the mold, and after a hazard period of 0.05 to 10 seconds, the second liquid foam formulation designed to produce rigid foam, strand by strand, into the mold. 5. The process described in claims 1 through 4 is characterized by the pouring of the first liquid foam mixture in streaks in the first direction, and then the pouring of the second liquid foam mixture in streaks in the opposite direction to the pouring of the first liquid foam mixture. 6. The process described in claims 1 through 5 is characterized by the mold moving relative to one or more mixing outlet channels during the pouring of the liquid foam formulation. 7. The process described in claims 1 through 6, which is characterized by the mixing head outlet being maintained relative to the horizontal plane while the liquid foam formulation is being poured into the mold. 8. The process described in claims 1 through 6 is characterized by the mixing nozzle outlet being angled relative to the vertical plane while the liquid foam formulation is being poured into the mold. 9. The process described in claims 1 through 8 is characterized by the formulation of a liquid foam that is a flexible polyurethane foam. 10. The process described in claims 1 through 9, which is specific to the manufacture of a product consisting of layered foam seating areas. 11. The procedure under claims 1 through 10 is carried out by pouring the first and second mixtures along each line near the outer wall of the mold. 12. The procedure under claim 11, whereby the aforementioned line is parallel to the aforementioned wall (12 claims, - Figure).