Exam 1 Flashcards
Papermaking Process
free fibers in water, deposit on grid, remove water
Pulping process machines
wood = digester , recycled = hydrapulper
Paper converted in North America is typically made from . . .
Cellulose Fiber derived from wood
two major classifications of trees
softwoods and hardwoods (common to use a mixture)
______________ is the most important characteristic in papermaking
Fiber Length (longer the fibers, the stronger the paper)
Shorter fibers yield . . .
paper with a smoother surface and uniform density characteristics (have reduced physical strength properties)
Cellulose Fiber separation techniques
Mechanical Abrade (Wood Cutting) & Chemical Processing
The Paper Mill will adjust the _____________ to optimize the papers performance for specific applications
level of refining
Fourdrinier Paper Machine Process
Forming, Pressing, Drying & Finishing
Calendering
Compress-Denser / Smooth out the paper surface
Surface Coatings
Starch, Clay, Calcium carbonate and Titanium dioxide
Paper Mill Variables
-No two paper mills will product an identical paper.
-Paper can have slight tolerance difference levels from run to run
Fiber Orientation
Direction in which the Fibers lie
Formulation
Laydown of the Fibers
Physical Characteristics that are Directional
Stiffness, Tear, Tensile, Stretch, Cutting, Scoring & Folding
Relative Humidity (paper is hydroscopic) decreases
Burst, Tensile, Fold, Stiffness
Paperboard Brightness
a measure of how the paper’s surface reflects light
Recycled Folding Carton Substrates
Single White lined (SWL), Double White Lined (DWL), Coated Recycled Board (CRB) and Clay Coated Newsback(CCNB), Special Bending News (SBN), Kraftback
Non-Recycled Folding Carton Substrates
Solid Bleached Sulfate (SBS), Thermal Mechanical Pulp (TMP), Solid Unbleached Sulfate (SUS)
Paperboard Tests
Caliper, Basis Weight, Apparent Density, Taber Stiffness, Moisture, Brightness, Tensile, Tear, Viscoelasticity, Mullen, Curl, Smoothness, Glue-ability
Folding Carton design categories
tube, tray, multi-pack, specialty
Dimensions are always expressed
L (length) x W (width) x D (depth)
Grain directions of the paperboard is important for:
integrity, compression, & Production Considerations
Four Primary Printing Process:
Lithography, Flexography, Gravure, Digital