Method and apparatus for providing an internal surface temperature profile of a thermoplastic preform during a stretch blow moulding process

A method of assessing an internal surface temperature longitudinal profile of a plurality of preforms in a stretch blow moulding production process, the method comprising:

• (a) heating a plurality of in-line cold preforms in a production process to provide a plurality of in-line heated preforms;
• (b) diverting at least one of the plurality of in-line heated preforms to provide at least one off-line heated preform;
• (c) providing the remaining in-line heated preforms to one or more stretch blow moulds for forming the heated preforms into blow moulded products;
• (d) locating one or more temperature sensors inside the at least one off-line heated preform to measure the internal surface temperature longitudinal profile of said at least one off-line heated preform;
• and
• (e) measuring an internal surface temperature longitudinal profile of at least one of the remaining in-line heated preforms;
• (f) controlling the heating of the plurality of in-line cold preforms based on at least the internal surface temperature longitudinal profile;
• wherein the heating is provided by at least one of a heater and a cooler;
• and
• wherein the heating comprises controlling at least one of a location and an intensity of at least one of the heater and the cooler based on at least the internal surface temperature longitudinal profile.

A stretch blow moulding production process comprising:

• (a) heating a plurality of in-line cold preforms in a production process to provide a plurality of in-line heated preforms;
• (b) diverting at least one of the plurality of in-line heated preforms to provide at least one off-line heated preform;
• (c) providing the remaining in-line heated preforms to one or more stretch blow moulds for forming the heated preforms into blow moulded products;
• (d) locating one or more temperature sensors inside the at least one off-line heated preform to measure an internal surface temperature longitudinal profile of said at least one off-line heated preform;
• and
• (e) providing a quality control of the production process utilizing the internal surface temperature longitudinal profile measurement;
• (f) the heating of the plurality of in-line cold preforms based on at least the internal surface temperature longitudinal profile;
• wherein the heating is provided by at least one of a heater and a cooler;
• and
• wherein the heating comprises controlling at least one of a location and an intensity of at least one of the heater and the cooler based on at least the internal surface temperature longitudinal profile.

An apparatus for a stretch blow moulding production process comprising:

• a heating station to heat a plurality of in-line cold preforms to provide a plurality of in-line heated preforms;
• diverting means to divert at least one of the plurality of in-line heated preforms to provide at least one off-line heated preform;
• one or more stretch blow moulds for receiving the remaining in-line heated preforms of the plurality of in-line heated preforms and forming the in-line heated preforms into blow moulded products;
• and
• one or more temperature sensors located inside the at least one off-line heated preform to provide an internal surface temperature longitudinal profile measurement of said at least one off-line heated preform;
• wherein heating of the plurality of in-line cold preforms is based on at least the internal surface temperature longitudinal profile;
• wherein the heating is provided by at least one of a heater and a cooler;
• and
• wherein the heating comprises controlling at least one of a location and an intensity of at least one of the heater and the cooler based on at least the internal surface temperature longitudinal profile.