Since the introduction of PET bottles, light weighting has been an important tactic in reducing costs. As producers continue to reduce the material content in PET bottles, they are closing in on the light weighting limits. Producers are realizing that the closer you get to the limits, it becomes all the more difficult to process these bottles. Minor changes in the process can have major effects on the material distribution and the performance of an ultra-light bottle. The more material that is removed, the smaller the overall processing window becomes. At this point, tight control over the process is imperative. Therefore the need to control the location and the thickness of the remaining material is critical.
Agr’s Process Pilot® blowmolder management system offers manufacturers a means to take the variability out of light weighting and provides the additional process feedback that makes it possible to take light weighting to the limits with full confidence. Where material is limited and safety margins are very tight, the Process Pilot system can provide the detailed, in-process feedback to manage and maintain bottle material distribution to a very high level of precision, resulting in the production of consistent, quality bottles, even at the fastest production speeds.
How Process Pilot facilitates light weighting
Agr’s Process Pilot system works in conjunction with the reheat stretch blowmolder to proactively manage and maintain container material distribution at a specified thickness to within ~0.01mm. This is accomplished by continuously monitoring every bottle for material distribution, analyzing minute changes and adjusting the blowmolder controls to maintain pre-defined distribution levels. Unlike operator adjustments, the Process Pilot system can adjust one or all of the blowmolder controls simultaneously to achieve the best possible material distribution.
By monitoring the material distribution of the blown container, the Process Pilot is able to account for subtle changes in the process that would normally go undetected by the operator. This prevents the process from drifting out of control before the operator’s next quality sample and averts the loss of precious little processing margin.
In the course of bottle production, an untold amount of variables in the production cycle can affect the processing and quality of light weight bottles. The Process Pilot system can accommodate many types of environmental changes as well as preform preparation and storage conditions that can occur. Compensation can be made for temperature, moisture content, and minor Intrinsic Viscosity (IV) changes of the preform to maintain a consistent process, within the smallest process window.
The Process Pilot system operates very similar to the auto-pilot in an aircraft. The process engineer sets up the optimized process for a given bottle. A one-time control characterization is performed (learn mode) to finalize the recipe and establish a baseline. Once set to the defined recipe, Process Pilot manages the blowmolder as if on auto-pilot, continually adjusting control parameters to maintain precise thickness distribution as the process changes. Since the Process Pilot system can oversee blowmolder operation on a 24/7 basis, it provides a continuity in bottle production that is not possible with other methods.
Some of the benefits this product offers in addition to improved light weighting capabilities include the elimination of the need for section weights, reduced scrap, improved overall bottle performance and quality, and lower incidences of downtime in the blowing operation and the filling line.
A recent expansion of the Process Pilot system included the addition of the Pilot Vision™ integrated vision inspection component. The Pilot Vision can be configured with up to 6 cameras for comprehensive inspection of performs and blown bottles for all commonly occurring bottle defects. With the Pilot Vision component, concern over random defects, especially those associated with increased PCR content, can also be eliminated.
Details on the Process Pilot products can be found on the Agr website by using the following link: http://bit.ly/YXMw41
Photo Agr International, Inc.:
Agr Process Pilot® automated blowmolder control system makes it possible to produce consistent, high-quality, light-weight PET bottles on a 24/7 basis regardless of preform, environmental and other common variations that affect bottle production.