Preparation Of Starch-coated Calcium Carbonate Filler And Its Application In Manufacture Of Copy Paper

It is advantageous to using mineral filler in papermaking industry. However, the more filler in the paper, the more decrease of the paper strength properties. As a kind of filler, calcium carbonate has its unique advantages. Calcium carbonate is one of the most used filler in China. But calcium carbonate filler used in the papermaking process also has negative effects. In recent years, many research have been done on the improvement of calcium carbonate performance in papermaking industry. But the practical application of thisresearch is very limited. Starch has good film-forming properties and low price. Itcan improve the paper strength. In addition, starch can be easied obtained through variety resources. Starch is a good coating material. Therefore, this paper attempts to use calcium carbonate as filler and apply starch to coat calcium carbonate. The modified calcium carbonate was also used as filler in copy paper production This paper also analyzed the coating methods and their effects on the properties of paper..Adding calcium carbonate fillers to the papermaking furnish can reduce the use of plant fibers and improve some of final paper properties. But this practice couldsacrifice paper strength properties such as tensile, burst, tear, and stiffness. In order to improve the bondability between filler and lignocellulosic fiber, the calcium carbonate fillers were coated by starch to prepare the starch-coated calcium carbonate fillers. The effect of starch coating on the retention, resistance against shear force of calcium carbonate filler and the subsequent paper strength properties was investigated. The experimental results indicated that the retention of calcium carbonate fillers was improved, and better resistance against shear force was obtained after modified by starch coating. The paper strength with starch modified calcium carbonate fillers were improved and their downward trends significantly slowed down when compared with unmodified calcium carbonate fillers.In this paper, starch-coated calcium carbonate filler was preparation and was added into production line in Fujian xiyuan paper Co., Ltd.. The results showed that the starch coated calcium carbonate filler had no adverse effect on the papermaking. After adding starch coated calcium carbonate paper filler, the performance of the paper can meet or exceed the requirements of the national quality standard. Compared with the ordinary calcium carbonate fillers, the tensile strength of the copy paper was significantly improved after adding starch coated calcium carbonate fillers. The application ofstarch coated calcium carbonate filler can guarantee paper performance.In the meanwhile the increase of calcium carbonate filler dosage d (from 18.6% to 24.2%), could greatly save the amount of plant fiber reduces the production cost andenhance the market competitiveness. Starch coated calcium carbonate filler has the advantages of simple production process, low cost, high stability, and good applicability in the production process.In this paper, a method of rapid determination of calcium carbonate in paper by headspace gas chromatography was established. Using a high-speed blender and sodium hydroxide dilute solution to preparethe samples,. Using sulfuric acid TO acidify the samples to produce carbon dioxide. The carbon dioxide levels were determined by headspace gas chromatography (GC) and the content of calcium carbonate in the paper on the basis of the content of carbon dioxide. This method has the characteristics of fast, accurate, heavy dominant and easy operation. The content of calcium carbonate in the paper test method can be applied to the papermaking process. This method can effectively monitor the paper filler content, which allows to ensure the normal operation of the paper machine and the quality of the final product stability.In this paper, a new method for the rapid determination of the amount of starch in starch modified calcium carbonate filler by headspace gas chromatography was established. Firstly, Take a certain amount of starch modified calcium carbonate filler samples, secondlygrinding with mortar and sulfuric acid grinding after the change of calcium carbonate filler specimen produces carbon dioxide; thirdly using headspace gas chromatography to determine of the content of gas phase carbon dioxide. The content of calcium carbonate in the filler was calculated according to the content of carbon dioxide.t. The quality of the starch could be got by the total mass of the modified calcium carbonate filler minus calcium carbonate. This method has the characteristics of fast, accurate, heavy dominance, easy operation. This method can be used in filler preparation process, can effectively monitor the change of starch in calcium carbonate filler and the modified effect of starch calcium carbonate filler on the quality of the final product.