When making bottles by blow molding, you find that about every ...

[ishan]

When making bottles by blow molding, you find that about every tenth bottle has a small hole in the wall. Indicate four possible causes for this defect and explain what you would do to correct each possible problem.
 
  What will be an ideal response?

Question 2

Describe sliding/compression blow molding and indicate its advantage.
 
  What will be an ideal response?

[apple]

Answer to Question 1

Parison wall not uniform, parison not grasped evenly by the mold halves, resin melt index too high, too much regrind, contaminated resin, parison not at the proper temperature, blow-up air enters too slowly or fast.

Answer to Question 2

Sliding/compression blow molding allows sections to be created on blow molded parts that are undercut or otherwise shaped in some method other than by just blowing outward against the mold cavity. These special sections are created by blowing the parison into a recess in the wall of the mold cavity. The material in this recess is pinched during the molding process, thus compressing the material and giving it form. The pinching is usually done by sliding part of the mold against a fixed part of the mold. The finished part is removed by reversing the sliding and then opening the mold in the normal way for blow molding.

[ishan]

Thank you!

[apple]

Always glad to help...