Part 14
Let's learn the secrets of stationery!
if a small child put it in their mouth by mistake?
Which glue is relatively safe
if it gets in your mouth?
Oh dear, that's not right.
Hold on! Don't put that in your mouth!
The main ingredient of glue sticks is a chemically produced synthetic resin called PVP (polyvinylpyrrolidone). Although this is a safe substance also used as an additive in food and medicine, glue sticks contain gelling agents and alcohol as well, so you should avoid putting them in your mouth.
HintGlue made from grains should be safer to put in your mouth.
Correct!
The round grains in the electron microscope image below are starch.
Starch is derived from grains such as corn, so it's relatively safe if it gets in your mouth by mistake. However, it contains other ingredients such as preservatives as well,
so don't eat it as food! (Make sure to keep it out of the reach of children.)
Oh dear, that's not right.
Hold on! Don't put that in your mouth!
The main component of liquid glue is a chemically produced synthetic resin called PVA (polyvinyl alcohol). Although this is a safe substance also used as an additive in food and medicine,
liquid glue contains preservatives as well, so you should avoid putting it in your mouth.
HintGlue made from grains should be safer to put in your mouth.
so I want a glue that dries quickly.
But I don't want the paper to get all wrinkly.
Which glue dries fast and doesn't wrinkle the paper?
Oh dear, that's not right.
Ugh, it's not drying at all! And the paper is covered in wrinkles!
Starch glue contains a lot of moisture and soaks into the paper. Because of this, it takes a long time to dry and can make the paper soggy and wrinkled if too much is applied.
HintA stick-shaped glue with less water content would avoid soaking into the paper. That might be just the ticket!
Correct!
Glue sticks contain less moisture than starch or liquid glue.
This makes them quicker to dry and less likely to cause wrinkles in the paper.
Oh dear, that's not right.
Ugh, it's not drying at all! And the paper is covered in wrinkles!
Liquid glue contains a lot of moisture and soaks into the paper. Because of this, it takes a long time to dry and can make the paper soggy and wrinkled if too much is applied.
HintA stick-shaped glue with less water content would avoid soaking into the paper. That might be just the ticket!
