Patents
US 9416490 B2: Cross-linked glycerol based polymers as digestion aids for improving wood pulping processes
- Granted
- 2016-08-16
- Filed
- 2013-02-04 application 13758299
- Type
- Utility · 19 claims
- Elsewhere
- Google Patents ↗ · USPTO patent document ↗ · USPTO Patent Center record ↗
Abstract
The invention provides a method of improving the digestion of wood chips into pulp. The method involves: adding a cross-linked glycerol-based polymer additive to a solution used in the digestion process. This additive is unexpectedly effective at facilitating digestion. The branched and ether structure of the additive allows it to withstand the harsh nature of a high stress environment. In addition, it is more soluble in the harsh condition than other surfactants. The structure, resistance, and particular balance between hydrophobic and hydrophilic regions, causes the additive to increases the interaction between the wood chips and the digestion chemicals. This in turn reduces the costs, the amount of additive needed, and the amount of reject wood chunks that result from the digestion process.
Source: PVGPATDIS, file of 2026-04-10 (ipg160816.xml).
Assignees
| Assignee | Type | Place | Also on furp.org | Source |
|---|---|---|---|---|
| Nalco Company LLC 271 patents | US company or organization | Naperville, IL | PVGPATDIS, file of 2026-04-10 |
Inventors
| Inventor | Place | Patents | Person page | Source |
|---|---|---|---|---|
| Prasad Y. Duggirala | Naperville, IL | 22 | PVGPATDIS, file of 2026-04-10 | |
| Xiaojin Harry Li | Palatine, IL | 38 | PVGPATDIS, file of 2026-04-10 |
CPC categories
| Subclass | Category | First group | Source |
|---|---|---|---|
| D21C | Production of cellulose by removing non-cellulose substances from cellulose-containing materials; regeneration of pulping liquors; apparatus therefor | D21C3/22 | PVGPATDIS, file of 2026-04-10 |
Cooperative Patent Classification, as currently assigned (one row per subclass).
Assignments and security interests
| Recorded | What | From | To | Reel/frame | Source |
|---|---|---|---|---|---|
| 2017-07-28 | Assignment Assignment of assignor's interest | NALCO COMPANY LLC signed 2017-02-27 | ECOLAB USA INC. ST. PAUL, MN | 43133/904 | ECORSEXC, file of 2026-09-25 |
| 2017-06-21 | Name change Change of name | NALCO COMPANY signed 2015-12-21 | NALCO COMPANY LLC WILMINGTON, DE | 42939/866 | ECORSEXC, file of 2026-09-25 |
| 2013-03-21 | Assignment Assignment of assignor's interest | DUGGIRALA, PRASAD Y signed 2013-03-11 LI, XIAOJIN HARRY signed 2013-03-11 | NALCO COMPANY NAPERVILLE, IL | 30058/319 | ECORSEXC, file of 2026-09-25 |
Documents recorded with the USPTO Assignment Recordation Branch that list this patent. A security interest is a lender’s claim on the patent as collateral; a release ends it.
USPTO bulk data: PatentsView granted patents, disambiguated (PVGPATDIS) for patents, assignees, inventors, places and CPC categories; the USPTO Patent Assignment Dataset (ECORSEXC) for assignments and security interests. Patents filed in the last 20 years. No claims or full text. Links to other records are by name (and state): EXACT means the identical full name and state; FUZZY means a looser name match, with the confidence shown.