Method for producing a body made from a granular mixture
AssigneeHuttenes Albertus France
InventorsStéphane Sarrazin, Manuel Vargas
Life of this patent
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Abstract
The invention relates to a method for producing a body including: preparing a granular mixture including a) at least 90 wt % of mineral oxide grains; b) 0.3 to 3 wt % of resin polycondensed with formaldehyde and/or the derivatives thereof, the percentage being calculated in terms of dry resin extract; c) 0.001 to 1 wt % of a hardening agent, the percentage being calculated in terms of dry hardener extract; d) 0.005 to 0.35 wt % of a formaldehyde scavenger compound; and e) 0.2 to 3 wt % of water; contacting said granular mixture with a surface of a forming tool; and insufflating a gas flow at 50 to 380 degrees into the granular mixture for 1 to 300 seconds in order to at least partially cure said mixture, the formaldehyde scavenger being carbohydrazide.
Claims15
A method for producing a body, said method comprising at least the following successive steps:
- preparing a granular mixture, comprising:
- a—at least 90% by weight of particles, said particles being mainly composed of at least one mineral oxide, and at least 80% of said grains having a size of 10 to 3000 μm,
- b—0.3 to 3% by weight of at least one resin polycondensed with formaldehyde and/or its derivatives, the percentage being calculated in dry resin solids, wherein the at least one resin is a composition of at least one resin having undergone a chemical reaction between a first element chosen from urea and its derivatives, melamine, benzoguanamine, glycoluril and a second element selected from the group consisting of formaldehyde and its derivatives,
- c—0.001 to 1% by weight of at least one curing agent, the percentage being calculated in dry curing agent solids,
- d—0.005 to 0.35% by weight of at least one formaldehyde scavenger compound, and
- e—0.2 to 3% by weight of water;
- placing said granular mixture in contact with at least one surface of a forming tool, and
- blowing at least one gas stream into the granular mixture, the at least one gas stream having a temperature of 50 to 380 degrees Celsius, for a duration of 1 to 300 seconds, to ensure at least partial curing of said mixture,
- the method being such that the formaldehyde scavenger compound is carbohydrazide, and
- wherein, during the step of at least partial curing of said mixture, the formaldehyde reacts as a priority with the curing agent.
Dependencies are inferred from the claim text.