The Basic Structure Of The Paper Machine According To The Needs Of The Papermaking Process, The Paper Machine Has A Variety Of Structural Forms, Generally Consisting Of Parts Such As Flow, Forming, Pressing, Drying, Finishing, Coiling And Driving, And Auxiliary Equipment Such As Auxiliary Systems.

Forming Part

It Is Composed Of Headbox, Breast Roll, Forming Net, Suction Tank, Couch Roll, Etc. The Headbox Distributor Uniformly Sprays The Slurry From The Flow System To The Forming Wire, And The Slurry Speed Should Match The Wire Speed. The Main Factor To Select Headbox Type Is To Control The Jet Speed And Wire Speed. The Fully Closed Hydraulic Headbox Adjusts The Pulp Speed By Adjusting The Pulp Feeding Pressure Of The Pulp Flushing Pump, Which Is Suitable For High-speed Paper Machines; The Air Cushion Headbox Regulates The Speed By Adjusting The Air Cushion Pressure, While The Open High Headbox Regulates The Speed By Adjusting The Pulp Level In The Box, Which Is Suitable For Medium Speed Paper Machines; Open Compartment Headbox Is Suitable For Low-speed Paper Machine. The Forming Net Is A Endless Ring Net. A Horizontal Or Slightly Inclined Flat Net Surface Is Formed Between The Breast Roll And The Couch Roll. As The Working Section Of Pulp Dewatering, It Is Used To Call It The Net Table, So It Is Called The Long Net. If The Endless Forming Mesh Is Placed On The Round Mesh Cage To Become An Arc Shaped Working Section For Dewatering And Forming, It Is Called The Round Mesh. If The Steel Mesh Drum With Holes Is Used To Pump Vacuum From The Shaft End To Accelerate The Dewatering Of Pulp On The Surface Of The Forming Mesh, It Is Called Vacuum Round Mesh Or Vacuum Forming Mesh. If The Pulp Is Clamped By Two Long Nets, And The Two Nets Are Dewatered And Formed At The Same Time, It Is Called The Net Clamping Former (fig. 2). These Shapers Use Different Types Of Dewatering Elements To Accelerate The Dewatering Of Pulp On The Web. Elements Can Be Divided Into Three Categories: Static, Rotating And Both. Static Elements Such As Dewatering Plate, Curved Vacuum Box, Etc., Rotating Elements Such As Table Roller, Vacuum Forming Roller, Etc. In Addition To Using A Single Formator To Assemble A Long Screen Paper Machine, A Round Screen Paper Machine, And A Screen Clamping Paper Machine, There Are Also Forming Parts For The Combination Of A Long Screen, A Multi Circle Screen, A Multi Clip Screen, And A Variety Of Long Circle Screen Hybrid Formators.

Press Section

The Formed Wet Paper Is Further Dehydrated By Pressurizing. It Consists Of Two Rolls With Hard And Soft Roll Surfaces, Such As Stone Roll And Rubber Roll. The Pressing Section Is Composed Of Pressing Groups Of The Same Or Different Forms, In Which Vacuum Suction Device Is Customarily Included. When Pressing, The Paper Sheet Is Supported By Wool Cloth Of Appropriate Specification, Which Can Evenly Distribute The Pressure And Take Away Part Of The Water Squeezed Out By Pressing, And Can Enhance The Pressure And Improve The Dewatering Capacity Of Pressing. Low Speed Paper Machines Usually Use A Line Pressure Of 20~60kn/m, While High Speed Paper Machines Use A Line Pressure Of Up To 210kn/m. When High Impact Pressing Is Used, For Example, The Line Pressure Of A Wet Sheet Machine Can Be Up To 350kn/m; The Rubber Covered Roll Is Made Into Vacuum Press Roll, Groove Press Roll, Lining Press Roll, Blind Hole Press Roll, Etc., So As To Effectively Take The Press Water Away From The Press Zone. These Are New Technologies Adopted Since The 1950s To Improve The Press Dewatering Efficiency. After That, A Double Press Structure Is Used To Form A Closed Paper Feed. It Is Composed Of Two Or Three Groups Of Pressing And Merging. The Wet Paper Is Stripped From The Forming Net By The Vacuum Suction Roller And Sent To The Composite Press With The Support Of The Wool Cloth. After That, The Paper Is Transferred Between The Press Rollers, Thus Eliminating The Phenomenon Of The End Breakage Caused By The Drag Of The Weight And Other Factors Between The Press In The Past. Since The 1980s, There Has Been A Wide Press Zone Pressing Technology. The Strong And Tough Rubber Belt Or Rubber Roller Deforms Under Strong Pressure, So It Has A Line Pressure Of Up To 750kn/m And A Wider Contact Surface. It Has Significantly Extended The Dewatering Time, Greatly Improving The Press Dewatering Capacity, And Has A More Prominent Effect On High-speed Paper Machines. The Paper Dryness Of The Press Can Be Increased From 30~37% To 43~45%, And Some Even Reach 50%. The Number Of Times The Paper Touches The Smooth Hard Roll Surface, Or The Number Of Times The Rough Glue Surface, And The Amount Of Water Loss On Each Surface Will Affect The Surface Quality Of The Paper. Reasonable Treatment Can Significantly Reduce The Difference Between The Smoothness Of Both Sides Of The Paper, And Vice Versa.

Drying Section

A Group Of Drying Cylinders Driven By Gears Or By Woolen Cloth Forms A Drying Section. The Linear Speed Of