The Strength Accident: teacher key

How Paper Is Made, grade 9 edition, written for 9th grade. How kraft pulp was found by a mistake, and how paper recycling really works.

Read the book. Print this page for the key.

Questions and answers

How did kraft pulp begin?
- A Dutch beater broke
- A German judge invented it
- A Swedish mill stopped a digester run too early (answer)
Why can't paper be recycled forever?
- Fibers get cut and weakened each time (answer)
- The ink stays
- Machines refuse it
What did Justus Claproth invent in 1774?
- A beater
- A way to remove ink from used paper (answer)
- A kind of tissue
What is black liquor?
- A dye
- A kind of paper
- The used cooking liquid in kraft pulping (answer)
What does deinking mean?
- Removing printing ink from used paper (answer)
- Adding color
- Cutting paper