The research advances about die swell, the reduction of friction between die wall and polymer melt, wall slip and melt fracture in polymer extrusion are described in the paper.

Through pratical measurement and calculation, the influence of die wall temperature, metal released heat, dies wall increased heat by different cooling conditions have been researched.

There was a weird sign on the wall in the bathroom, it struck me as odd, it read something along the lines of: If you don't wash your hands you can die!