The Application of Fluorochemicals on Greaseproof Paper

• Main Authors: Yu-Chun Chen, 陳毓鈞
• Other Authors: Lan-Sheng Kuo
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/22476589037976146245

碩士 === 國立中興大學 === 森林學系 === 92 === Because of the specific characteristics： cheap, recyclable, and chemical stability of fluorochemicals which become the promising additive in paper products for food package in the future. In terms of greaseproofing, softwood bleached kraft pulps were better than those of hardwood pulps. And the lower freeness , the higher greaseproofing is. Air resistance has close relevance to greaseproofing. A 200 ~ 280 mL CSF pulp freeness is suitable to manufacture of greaseproof paper. A mix ratios of softwood pulps and hardwood pulps by 75/25 and 50/50 showed admirable greasrproofing and water resistance. But more hardwood pulps addition will result in adverse effect on greaseprooging. Different fluorochemicals charges will not affect dry opacity and wet opacity of paper but reduce the water resistance to some extents. The more wet strength resin（Kymene 557H）dosages, the better water resistance of the paper is, and the paper air resistance will be improved to a great extent. The more AKD size addition, paper greaseproofing will be improved gradually, and air resistance will be increased markedly. Cationic starch addition will improve the greaseproofing and water resistance. Adding low molecular weight and highly cationic coagulant has slight positive effects on greaseproofing and water resistance. Adding high molecular weight anionic flocculant will lower the air resistance. The order of wet chemicals’ addition, wet strength resin, low molecular weight and highly cationic coagulant, cationic starch, AKD size, fluorochemicals, and high molecular weight anionic flocculant, had produced good effect on paper greaseproofing. Lag AKD size is applied to stock preparation, the better paper water resistance will be. In general, the optimum conditions for the manufacture of greaseproof paper in this experiment we recommended are：fluorochemical 0.12％、AKD size 0.3％、cationic starch 1.0％、wet strength resin 0.4％、low molecular weight and highly cationic coagulant 0.03％、and high molecular weight anionic flocculant 0.03％. Evaluating the influence of wet end chemicals on the greaseproof paper with factorial design at two levels, apparently, AKD size has the most positive effect on dry opacity. Either AKD size or cationic starch has significant positive effect on wet opacity of paper. Besides fluorochemicals, cationic starch has the most significant positive effect on greaseproofing. Either AKD size or cationic starch has significant positive effect on water resistance, and negative effect on water absorption. High molecular weight anionic flocculant addition has apparent influence on air resistance of paper and profound interaction with cationic starch, which have negative effect on air resistance; however, AKD size has positive effect on this. Transforming the effect factors on greaseproofing into significance, a formula can be deduced as follows: Y（greaseproofing,Kit） = 0.2 X1 + 0.6 X4 + 0.2 X1X4 - 0.2 X3X4 + 7.0495 （This equation applies to AKD（X1）：0.2~0.4％、Nalco 7607（X2）：0.01~0.05％、Nalco 625（X3）：0.01~0.05％、Cationic starch（X4）：0.5~1.0％） Adding filler prior to wet end chemicals addition is more suitable to manufacture greaseproof paper than that lag addition. Adding filler such as sericite, CaCO3 and bentonite at 10％ level raised the opacity of paper by 6.5 ~8.5％. Sericite with its layered structure benefits the greaseproofing and air resistance of paper but its filling should not exceed limit 10％. Except bentonite, fillings will reduce the water absorption of paper. With the addition of modified starch by 1.0％, the greaseproofing and water resistance of paper will increase by 14％ and 15％ respectively. The greaseproofing order is cationic starch > etherified starch > soluble starch > P.V.A., and the water resistance has the reverse order. With 10％ SBR latex addition, the water and air resistance of paper can be raised to 24％ and 79％ respectively, and soft SBR latex helps raising the greaseproofing to 11％; however, hard SBR latex is detrimental to the aforementioned properties. Although batch process is prevalent in molded paper manufacture instead of paper machine. In view of this reason, we take for granted that SBR latex can be used as internal addition in molded paper industry. The decrease in paper brightness might be resulted from the liberation of coloring materials by heat and oxidation of wet end chemicals during aging other than fluorochemicals. On the other hand, the greaseproofing of greaseproof paper with fluorochemicals internal addition will not be affected by accelerated aging at 105℃,R.H.＜2％. First of all, the greaseproofing, water resistance, and tear factor of papers we made in this experiment will be raised to some extents, and then decreased.