Abstract: Paper that is uniquely suitable for use in the aseptic packaging of foods, beverages, and the like is produced via a two step sizing process comprising an internal size step and a surface size step. The internal size includes approximately 1.0% anionic rosin and about 1.3 to 2.6% alum (based on the dry pulp weight) blended to a 4.0 to 4.5 pH controlled papermachine headbox stock furnish. Following web formation and drying, the surface size is applied with a composition including about 0.025 to 0.050% alkyl ketene dimer (based on the dry pulp weight) blended with a traditional starch formulation and sufficient sodium bicarbonate to both neutralize any unreacted alum present near the surface of the internally sized web and to produce a paper having a water extractable pH level of from about 4.0 to below 6.0. Secondary web drying follows the surface size application.

Abstract: The flammability of non-condensible blow gases from a wood pulping digester is continuously monitored by venting a low volume sample flow stream of such gases through a small combustion chamber where the stream is subjected to an intermittent ignition source. Unusually high pressures in the combustion chamber resulting from ignition of a flammable mixture are detected by pressure measuring means providing the operative result of automatically venting a dangerous flow increment of the gas.