Page 46 - Glass Machinery Plants & Accessories no. 1-2020

MEASUREMENT SYSTEMS
Measurement systems

The SPT2-Volume system
offers hands-free operation
and can “dynamically” adjust decrease in the volume of the height, the liquid volume will vary
for bottle height and finish container. Neither of these two as the volume of the container
size for multi-line operation situations usually cause prob- changes. This variation is usually
lems, as normal fluctuations in insignificant but can be impor-
these parameters are expected tant if the total liquid volume is
age of the moulds or the weight and taken into consideration in different compared to the volume
of the glass gob. As moulds age the dimensional tolerances on the listed on a label.
during use, the inside surface bottle design blueprints. If a bottle is filled to a speci-
erodes by contact with the hot fied volume, the liquid volume
glass and the total volume of the FILLING THE BOTTLES is assured but the head-space of
mould increases. The result of However, it is imperative to the container (difference between
this erosion is that the outside routinely monitor the volume of the overflow volume of the con-
dimensions of the bottle increase, containers because of the man- tainer and the liquid volume) will
with a corresponding increase in ner in which bottles are filled. vary. If the head-space dimin-
the volume of the container. If Two different filling methods are ishes significantly, then the bot-
the gob weight increases, more typically employed by fillers. One tle performance can potentially
glass is used to form the contain- method fills a bottle to a pre-set be compromised during storage
er within the metal mould. The vertical height while the second under elevated temperature con-
result is that glass thicknesses method fills a bottle to a specific ditions. It is well known that both
throughout the entire container liquid volume. the bottle and the liquid product
increase, with a corresponding If a bottle is filled to a pre-set will expand if a filled bottle is

44 glass machinery plants & accessories 1/2020