Where does the ink go when you recycle paper?

My Dear Sexy Readers,

Another request from one of my best SSS fans will be the subject of this post:

Where does the ink go when you recycle paper?
A very seasonal post as well since we are in September and most children have started a new school term!

So to explore this, I will look at what's paper, how it is made, recycled and of course what happens to the ink?

Recycled Paper Recipe

No need to define what's paper, but let's not forget that the name paper is not only used for the stuff we write on but also the thicker material for drawing, packaging, also the paper for magazine, the thinner scrap brown paper, and of course our bank notes, cheques, tickets, toilet paper, etc...

It is basically made from wood by pressing firmly together the cellulose fibers that are extracted from mushy wood. This process has many steps:

Pulping

From Wood: Chemical or Mechanical pulping can occur. During chemical pulping, the lignin can be separated from the cellulose fibers because it can deteriorate with time and make the paper go yellow and brittle. During mechanical pulping, wood logs are fed into a massive grinder and made into fibers still containing the lignin.
From Recycled paper: Pulper chops paper into small pieces and water and chemicals are added.

Screening
The slurry pulp is then passed through screens with different holes of different size in order to eliminate small contaminants such as  bits of plastic or glue.

Cleaning
After a bit of centrifugation, bigger contaminants like staples are eliminated.

Deinking

There are two main protocols to deink paper: washing and floatation!
These were invented by German jurist Justus Claproth in 1774 along with paper producer Johann Engelhard Schmid.
Small particles of ink (or water-based ink) are washed away from the pulp by washing whereas larger particles are treated by floatation.
During floatation, air and chemicals are introduced into the pulp, this makes the ink and other stickies loosen and stick to the bubbles instead. The "inky bubbles" are then easy to remove because they float on top of the main pulp.
When the ink/stickies/plastics recovered are collected, not only its water is removed and reused in the whole process, but this sludge itself can be burnt to create energy for the recycling machines.

Coloring
If the paper was colored, chemical products are added to remove the dyes. If the end product wanted should be white, some bleacher are added such as hydrogen peroxide. Otherwise, it stays brown.
Other additives can be added to improve the characteristics of the paper for writing or printing.

Papermaking
The recycled pulp can be used as such or mixed with new wood fibers (called appropriately virgin fibers) to give extra strength and smoothness. Note: Fibers are degraded with each cycle and can become too weak after 4 to 6 cycles.
Water is removed from the paper and pressed to form sheet where the recycled fibers will bond together. It can also be heated to dry it.

Coating
Depending on the use of the paper, it can be coated to make it smooth and glossy for example by adding calcium carbonate or china clay.

So here you go, my sexy readers, now we know ;)


See you soon,