Читать книгу Encyclopedia of Glass Science, Technology, History, and Culture - Группа авторов - Страница 115

The PB process is used for wide‐mouth containers of all weights, such as jars and baby‐food containers. It differs significantly from the BB process at the blank‐side. After loading the gob (Figure 5), the blank‐mold is closed fully by the baffle and a plunger presses in an upward movement the glass from below into the mold (Figure 5b). The plungers usually are made out of tungsten carbide (WC) or another hard metal to ensure a long lifetime. In contrast to BB‐forming, the process causes the finish to be formed at the end of the blank‐mold process (Figure 5c) and no disturbance such as settle‐wave is introduced into the parison because it is formed by a single (smooth) motion at the blank‐side. As in BB, the baffle is removed after the parison has been formed, the mold opens (Figure 5d), and the parison is transferred to the blow‐side to get its final shape as described above.

Figure 4 (a–d) Forming of the final container at the blow‐side (same for all processes).