CALCIUM SULPHATE-UNIQUE COATING PIGMENT AND ITS IMPACT ON COATING LAYER STRUCTURE AND PRINT QUALITY
The unique calcium sulphate pigments, which have been used in this study, have many advantages such as lower density, higher brightness and less abrasiveness compared with conventional pigments like ground calcium carbonate (GCC) and clay. Furthermore, these pigments can be produced from industrial by-products which is beneficial to environment. Recent development in production technology of calcium sulphate pigment has opened up new possibilities to use calcium sulphate widely as a coating pigment. The tested pigments are either wet ground or precipitated to various crystal shapes. How do these novel pigments impact on coating color properties, paper properties, print quality as well as coating layer structure? The target of our research work is to characterize coating color properties, paper properties, print quality and coating structure of calcium sulphate containing coating color formulations compared with conventional pigments. Testing of novel LWC coating color formulations was carried out in pilot scale at the KCL pilot facility in Espoo, Finland. Papers were printed on a heatset web offset (HSWO)-press at the KCL pilot facility. Printability of the trial points was also tested in laboratory scale. Coating layer structure was studied with mercury porosimetry. Basic properties of unprinted and printed papers were also measured. The experimental data shows that runnability of the novel coating colors containing calcium sulphate is excellent on a high speed blade coater with jet application. Water retention of the novel colors is improved compared with reference while high shear viscosity is at the same level with conventional colors. Similar or improved paper properties, e.g. optics, gloss and surface strength, can be obtained with calcium sulphate containing LWC coating color formulations. The coating layer structural difference provided by conventional and novel pigments is characterized by mercury porosimetry. Calcium sulphate coatings provide generally higher print gloss and delta gloss, while keeping mottling on the same level with conventional clay/carbonate blends.
coating pigment calcium sulphate printability coating structure
Wang Yulong Mari Ojanen Esko Aarni Sami Puttonen Teppo Sahlberg Mikko Oksanen Tarja Sinkko
Changsha University of Science & Technology,Changsha, 410114, China Kemira Oyj, Luoteisrinne 2, Espoo, Finland UPM-Kymmene Corporation, Research Center,Lappeenranta, 53200, Finland
国际会议
广州
英文
1958-1961
2010-11-08（万方平台首次上网日期，不代表论文的发表时间）