What is the principle problem when forming a bottle using ...

[jasdeep_brar]

What is the principle problem when forming a bottle using injection molding?
 
  What will be an ideal response?

Question 2

What key processing considerations must be met in order to use PET to make soft-drink bottles?
 
  What will be an ideal response?

[Alyson.hiatt@yahoo.com]

Answer to Question 1

If the diameter of the mouth of the bottle is smaller than the diameter of the body, some method must be provided to remove the core pin. The core pin will have the diameter of the body and, therefore, must collapse or be reduced in diameter by some other method. This is a difficult mechanical problem that is eliminated when blow molding is the method for forming the bottle.

Answer to Question 2

The parison must be formed as an amorphous material. Therefore, it is formed from hot resin and quenched quickly. Then, the material is heated to about 30C above the Tg and stretch blow molded. This stretching gives biaxial orientation and induced crystallization which increases many desirable properties of the bottle.

[jasdeep_brar]

Thanks for the timely response, appreciate it

[amit]

Excellent