Paper and Paperboard
In this unit, we will learn about paper and paperboard including the history of paper, the
differences between paper and paperboard, how they are manufactured, their properties, and
how they are used as packaging materials.
Brief History of Paper
Historians do not know precisely when or how paper was invented, but 105 AD is often
listed as the year of invention because that is when Ts'ai Lun, eunuch of the Imperial court of
China, reported the invention of papermaking to the Emperor.
The original raw materials for paper making were rags and cloth, but the tree bark and
other plant materials were also used. Mulberry tree bark was used because it was plentiful in
China and porous and easy to break up.
The early papermaking process started by soaking the rags and bark in limewater and
then beating the mix with a wooden mallet or mortar and pestle to separate the fibers. A single
sheet of paper was formed by pouring the mixture on a screen made from a mat of thin reeds
covered with silk or a horsehair filter. The water passed through the screen, leaving a mat of
fibers behind. The sheets of paper were dried by hanging them out in the air or by pressing
them on a slab of porous or absorbent material. The "dried" sheets were then laid out in the
sun to bleach. This process was kept secret in China for several hundred years.
In the late 700s, a paper plant in Turkestan was captured by Syrian soldiers during a
battle. Several skilled papermakers were taken as prisoners to Samarkand. Using the
knowledge, the Syrians built and operated papermaking facilities. Then, through the
normal process of trade, papermaking soon spread to Baghdad and on to Egypt, Morocco,
England, France, and the rest of the world.
Paper Manufacturing in America
The first plant to make paper in America was located in Philadelphia and opened for
business in 1690. The plant produced a single sheet at a time, using a manufacturing process
that was still very similar to the original batch process invented in China. A similar operation
was established in Jamestown, VA. (This city was quite popular for the development of
packaging processes, eh?).
For centuries, the demand for paper was quite limited; however, that changed around
1500, when Gutenberg invented the printing press. Gutenberg made it possible to
manufacture multiple copies of books and other documents. As a result, the demand for paper
increased rapidly and the rag supply quickly became inadequate. The increased demand forced
a shift to wood as raw material for manufacturing paper because trees ensured a generous and
reliable supply of fibers.
This created a need for continuous processes for faster production. Two processes were