ABSTRACT
Determination of blow ratio You should always know the blow ratio of your product and the normal or average thickness that the project requires. Localized areas can be lower than this nominal value if the parison contacts the wall sooner in different areas of the mold. Different materials or different grades of materials exhibit differing stretch behavior. The blow ratio of a molding is a way of representing the amount of stretch involved for a given combination of parison size and part size. For cylindrical containers, this can be expressed as
Blow ratio = .
