PKG-322 Lecture #6: Paper and Paperboard Grades

What determines the suitability of paper for a specific packaging application?

Its mechanical and barrier properties.

What property allows lightweight paper bags to stand freely and cartons to have sharp creases?

Stiffness.

Which paper property measures resistance to rupture under pressure?

Bursting strength.

Which property allows paper to withstand constant tension during high-speed printing and lamination?

Tensile strength.

What property prevents ripping during heavy handling?

Tear resistance.

What is the primary requirement for stackable boxes?

Compression strength.

What do barrier properties protect paper from?

Water, grease, oxygen, and solvents.

What machine produces most paper and paperboard?

The Fourdrinier machine.

What are the six main paper grading criteria?

Grammage, color, usage, raw material, finish, and surface.

What is the grammage range for tissue paper?

Less than 40 g/m².

What is the grammage range for paper?

40–120 g/m².

What is the grammage range for paperboard?

120–200 g/m².

What is the grammage range for board?

Greater than 200 g/m².

What is newsprint and what is it used for?

A low-quality paper made of ~95% mechanical pulp used for wrapping fragile items or void fill.

What is glassine paper used for?

Packaging oily products due to its resistance to grease, air, and moisture.

What is pouch paper and where is it used?

Virgin kraft paper treated with plasticizers for flexibility; used in food and medical packaging.

What makes parchment paper unique?

It is chemically treated, non-stick, and resistant to grease, water, and heat up to 420°F.

What is butcher paper used for?

FDA-approved kraft paper used for wrapping meat.

How does waxed paper create a barrier?

It is treated with paraffin or beeswax to resist moisture.

What is natural kraft paper used for?

High-strength applications like grocery and industrial multiwall bags.

Why is paperboard popular for rigid packaging?

It has flat stiffness and is easy to cut, fold, and glue.

What is chipboard made from and what are its limitations?

100% recycled fiber with poor printing and folding quality.

What is newsboard commonly used for?

Mailers made from recycled newspapers.

What does CCNB stand for and why is it used?

Clay Coated News Back; provides a smooth surface for printing.

What is Solid Bleached Board (SBB/SBS)?

A premium white-through paperboard made from bleached virgin pulp.

Where is Solid Bleached Board commonly used?

Medical packaging, milk cartons, and cosmetics.

What is Solid Unbleached Board (SUB/CUK/CNK)?

A tough paperboard made from unbleached virgin kraft fiber.

What is Solid Unbleached Board commonly used for?

Beverage carriers such as beer and soft drink cartons.

What is Folding Boxboard (FBB)?

A multi-ply board with mechanical pulp for added stiffness.

What is Single White-Lined (SWL) chipboard?

Chipboard with a white front and gray back.

What is Double White-Lined (DWL) chipboard?

Chipboard with white layers on both the front and back.