The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 06, 1990
Filed:
Apr. 12, 1988
Michael M Blackstone, Savannah, GA (US);
Cheng-I Chen, Jacksonville, FL (US);
Thomas W Woodward, Jacksonville, FL (US);
Betz PaperChem, Inc., Jacksonville, FL (US);
Abstract
The present invention is directed to the use of certain ethoxylated compounds to increase the yield of chemical pulping processes, the compound have the following structures: ##STR1## These ethoxylated compounds have molecular weights of from about 500 to about 30,000 the (CH.sub.2 CH.sub.2 O) comprising from about 20 to 80 percent of the compound; and a, b, and c are each at least 1. The compounds are surface active agents which are added to the cooking liquor. The wood chips are cooked from about one-half and ten hours at a temperature of from about 200 and 500 degrees Fahrenhelt in a liquor including sodium hydroxide, sodium sulfide, and the surface active agent. The wood plug would have a reject level of at least 5% when the chips are cooked in the absence of the surface active agent. The process provides a simultaneous reduction in the level of rejects and an increased yield of pulp.