Sizing Solution for Paper ( internal Sizing) [18 Feb. 2011, 8:20:05]

Basoplast 2016 is very effective for sizing paper in the neutral to slightly alkaline pH range. It is particularly effective for sizing paper filled with chalk. The best results are obtained if Basoplast 2016 is added in advance of the fillers.

Unbleached grades of paper and paper made from deinked waste paper can be sized very effectively with Basoplast 2016 if the pH of the stock is in the neutral to slightly alkaline range ( ca. 7.5) . This prevents any alum left over in the waste paper from having any detrimental effect on sizing. Basoplast 2016 can be used to size paper of this type in the neutral to slightly acid pH range, but the size consumption is higher.
It can also be used to size paper in somewhat more acidic media provided a cationic fixing agent such as Catiofast® PL ( 0.05 – 0.15% , concentration as supplied) or cationic starch ( ca. 0.5% , expressed as a proportion of the stock) is added in advance. Basoplast 2016 needs to be added at rates of 1 – 2% in order for hard-sized paper to be obtained.

Paper sized with Basoplast 2016 usually has to be left to cure on the reel for 1 - 2 days before the full sizing effect can develop. The time required for the size to cure depends on the type of paper in question, and less time is required if the paper is dried intensively after it has been sized or if the stock is slightly alkaline. It is often the case that paper made from unbleached pulp in slightly alkaline media is cured to a very large extent when it is wound off the paper machine. An assessment of the results that can ultimately be obtained can be made by drying a freshly sized sheet of paper for 5 min at 120° C in an oven.