Starch Wallboard System and Method
Elevates starch loading and re-engineers the migratory–non-migratory balance to carry the bond through a lightened core.
- Assignee
- United States Gypsum (USG)
- Jurisdiction
- United States
- Filed
- 2005-10-21
- Published
- 2010-07-13
- Status
- Granted
Increases the loading of pregelatinized acid-thinned corn starch in the slurry and pairs it with an STMP-crosslinked retained-in-core fraction, producing a board with simultaneously improved paper bond and core compressive strength at reduced density.
When you lighten a board, the bleed water available to carry migratory starch to the paper line drops. Without the rebalance described here, paper bond fails first and weight reduction stalls. This is the starch half of the lightweight story; the foam patents are the other half.
- Claim 1
Total starch loading range, expressed as % bwoc, divided between migratory and non-migratory fractions.
- Claim 2
Degree of acid-thinning (DE range) required for the migratory fraction to travel with reduced bleed water.
- Claim 3
STMP crosslink density window for the non-migratory fraction to contribute core strength without inhibiting set.
Most plants buy 'a starch.' What you actually want is a starch system: a migratory grade matched to your bleed-water volume and a non-migratory grade matched to your target core strength. Specify both, not one.
- · USPTO Patent Full-Text Database, US 7,754,007 B2
- · ASTM C473 board bond and absorption test methods