Soft Calender Of Paper Calendering Machine
Paper calender machine can be divide into soft calender, hard calender and supercalendering, but what’s the soft calender advantages compared with hard calender and supercalendering?
Soft Calender Advantages
Comapared with hard calender:
1. The tightness is consistent of pressed paper: The soft calender is soft than hard calender, the tightness of pressed paper is more consistent.
2. Improve opacity, eliminate stains: As the soft roller can be rebound, so the roller surface can be adapted to the paper uniformity and quantitative changes. The paper thinner contact with the hot roller, while for the thick ares, the thickness will not be a greater reduction, this can increase its fine smoothness, eliminate the stain.
3. Printing ink is well absorbed: Due to the paper tightness is consistent, and the thickness reduction is not great, so the printing ink absorbtion is good and uniform.
4. Soft calender stability and line pressure adjustment with large range, can be adapted to different requirements of the calendering paper.
Compared with supercalendering:
1. Supercalendering maximum allowable temperature can not exceed 85 degrees, while the soft calendering temperature can up to 160~200 degrees.
2. Soft calender can be the same speed as the machine or coating machine, don’t need to slow down at the time of licking paper.
3. Supercalendering is difficult to control paper thickness.
4. Supercalendering covers large area, high cost and high investment.
Soft Calender Disadvantages
The biggest disadvantage of soft calendering is that once its working width is determined, it can not be changed at will. Because the soft roller surface outside the sheet is directly in contact with the hard (hot) roll, the soft roller is liable to be damaged, and the roller surface is contact with the hot roller, causing the local temperature to be large. If the temperature difference exceeds the soft roller material bearing (generally controlled within 5 degrees), it is easy to deformation. Therefore, ensure the paper width of the pressure area in making production.