A4 copy paper machine which in fact is a paper making line is also consists of different sections;
1‐ Approach flow section which adjust the flow for ready pulp mixture to make paper with given basis weight. Basis weight of a paper is the weight of one square meter in grams. The flow of pulp slurry which is diluted will be cleaned, screened in slotted screens and sent to head box.
2‐ Head box spread the flow of the pulp slurry very uniformly across the width of the paper machine wire. The performance of the head box is determined in the development of the quality of final product.
3‐ Wire Section; Pulp slurry is uniformly discharged on the moving wire and which the wire is moving toward the end of the wire section, almost 99% of the water is drained and a wet web with the dryness of about 20-21% is transferred to press section for further dewatering.
4‐ Press Section; The press section dewaters the web further to reach the dryness of 44-45%. The dewatering process in mechanical without using any thermal energy. The press section usually employs 2-3 nips depending on press technology and configuration.
5‐ Dryer Section: Dryer section of the writing, printing and copy paper machine is designed in two sections, per-dryer and after-dryer each using a number of dryer cylinders using saturated steam as heating medium.In pre-dryer section, the wet web is dried to 92% dryness and this dry web will be surface sizing 2-3 grams/square meter/side of paper starch which has prepared in glue kitchen. The paper web after sizing will contain about 30-35% water. This wet web will be further dried in after-dryer to 93% dryness suitable for end use.
6‐ Calendaring: The paper out of after-dryer is not suitable for printing, writing and copying because the paper surface is not sufficiently smooth.Calendaring will reduce the surface roughness of the paper and improves its runnability in printing and copying machines.
7‐ Reeling; At the end of the paper machine, the dried web of paper is wounded around a heavy iron roll up to 2.8 meter in diameter. The paper on this roll will amount to 20 tons. This jumbo paper roll winding machine is called pope reeler.
8‐ Rewinder; The width of the paper on master paper roll is almost the width of the paper machine wire. This master paper roll need to be cut lengthwise and widthwise as ordered by end uses. This is the function of the rewinder to split the jumbo roll in narrower rolls.
Post time: Sep-23-2022