QUESTIONS 1. What is the principal problem when forming a bottle using injection molding? 2. Why is continuous extrusion blow molding not recommended for large blow molded parts? 3. List three advantages of the moveable mold system versus the rotary system for contin- uous extrusion blow molding. 4. In a blow molded part, where are the thinnest sections likely to occur? 5. Why can blow molding molds be made out of aluinum, whereas injection molding molds are usually made out of tool steel? 6. What is the advantage of a progranmable parison device 7. What method is used in injection blow molding to achieve the type of part wali thick- ness control that can be obtained in programmable parisons? S. Describe sliding/compression blow moding and indicate its advantage 9. What factors are likely to determine the maximum size part that can be blow molded? 10. What key processing considerations must be met in order to use PET to make soft 11. When making botties by blow molding, you find that about every tenth bottle has a 12. Milk bottles are sometimes annealed after blow molding. Why is this done? drink bottles? small hole in the wall. Indicate four possibie causes for this defect, and explain what you would do to correct each possible problem. 13. A resin supplier has suggested that a blow molder of polystyrene parts add 20% polyethylene to improve properties. What property differences would you expect? What processing differences would you expect