The cashmere is a noble subject and as all the precious objects, we owe of the good maintain it.
Here is some advice so that your pullover lasts longer
The pilling is created by the friction of the fibers of cashmere between them and on outside commeles elements braces of bag.
It can happen when your pullover is new.
Nevertheles, the pilling should stop after some washes.
To remove the pills do it by hand or with razors specially conceived for this usage.
You will wear and love it for long....