Coated board paper making line include two parts:paper pulp making line and paper making line.So, a complete paper industry must contain paper pulp machines and paper machine.
Waste papers are conveyed by chain conveyor into the hydrapulper( You can choose D-type hydrapulper or Drum pulper according to your request)for pulping.Due to the Corrugated white cardboard paper is more complicate than Kraft paper and corrugated paper,so ,it need more than one hydapulper to graving kinds of raw materials.
Kinds of stock pulp will enter a series screening equipment（such as pressure screen,vibrating screen etc.) to remove oversized,troublesome and unwanted particles from good paper making fibers.In most instances, it is the size of perforations(usually holes and slots) that determine the minimum size of debris that will be removed.
3.Finally the fine pulp will be screened again by more than one inflow pressure screen to into the kinds of headbox of paper machine .The complete paper pulp making line is finished.
1.Formatting of paper sheet
The paper will be formed from stock pulp on a cylinder machine(one parts of paper machine),the paper will be removed the water as far as possible and carried onto the wire for sheet formation.The kinds of stock pulp will be enter the cylinder mould as order,the bottom layer pulp,the middle layer pulp and then top layer pulp.
As the Coated white cardboard paper sheet enters the press section it is still quite wet.Considerable amounts of water may be removed by the pressing and suction extered by the press part.
The permeability of paper to liquids,such as water,writing inks etc,is very important property.
The sheet,as it passes from the press section,should be as dry as possible so that it can be made mechanically.From this point it is necessary to apply heat in order to reach the desired state of dryness.The most usual method of drying uses steam-heated dryers.
As the sheet undergoes the drying process there is a tendency for the fibers to lift slightly, it is passed through a stack of heavy metal rolls where it is calendered under high pressure.The purpose of calender stack is to compress the sheet and give it a fine smooth finish.
6.Reeling and Winding
Paper making is a continuous process from the headbox to the calender.After the sheet leaves the calender it must be put into a form that can be easily transported and handled.The first step in this process is to wind the sheet on a reel,then the large roll taken from the reel must be slit and trimmed on winder into the size required by converting and customer.
This line includes Chain Conveyor, Drum Pulper, D Type Hydrapulper, Mid Consistency Pressure Screen, Double Disc Refiner, Inflow Pressure Screen, and so on. Paper pulp machine used to make waste paper (such as waste packing box,waste office paper and so on) turn to fine pulp for paper forming on the paper machine.