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Carbamoylethyl Wheat Flour as a Wet‐ and Dry‐Strength Agent for Paper
Author(s) -
Smith H. E.,
Gordon S. H.,
Doane W. M.,
Russell C. R.
Publication year - 1972
Publication title -
starch ‐ stärke
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.62
H-Index - 82
eISSN - 1521-379X
pISSN - 0038-9056
DOI - 10.1002/star.19720240907
Subject(s) - ultimate tensile strength , kraft paper , wet strength , hypochlorite , pulp (tooth) , folding endurance , composite material , kraft process , materials science , aqueous solution , starch , pulp and paper industry , chemistry , food science , organic chemistry , polymer , medicine , pathology , ethyl cellulose , engineering
Unbleached kraft paper exhibiting a ten‐ to fifteenfold increase in wet‐tensile strength accompanied by substantial increases in burst, dry‐tensile strength and folding endurance was obtained from the use of hypochlorite‐treated carbamoylethyl wheat flour as a wet‐end additive. Results with bleached kraft pulps were less spectacular but still good. Such variables as pH of the carbamoylethyl wheat flour (CEWF) paste before hypochlorite treatment, pulp type and freeness, drying and curing temperature of the treated paper and the amount of CEWF influence strength properties of paper. A pH of 2 was optimum for treatment of aqueous CEWF pastes with hypochlorite. Unbleached kraft pulp having a Canadian Standard freeness (CSf) of about 500 ml produced paper exhibiting the best overall strength properties. Maximum wet‐ and dry‐tensile strength was imparted to unbleached kraft handsheets dried at 105°C for 15 min. Strength properties increased as level of addition increased from 0.25 to 5%. Addition of CEWF at a 2% level to unbleached kraft furnishes gave handsheets exhibiting wet‐ and dry‐tensile strength as high as 3340 and 10,510m, respectively, as compared with corresponding values of 240 and 6980 m for the control. Hypochlorite‐treated CEWF was comparable to carbamoylethyl starch in imparting wet‐strength properties to unbleached kraft paper.