Preform concentricity measurement system.
Enhance laboratory testing efficiency and productivity.
Greater precision versus handheld hall-effect methods.
Data output compatible with most commercial SPC software packages.
“Light-weighting” in the plastic packaging industry is now commonplace as manufacturers adapt to eco-friendly initiatives that also reduce material costs. While reducing the amount of resin in a preform is both an environmentally and financially commendable strategy, the quality and production controls required to maintain consistent production of high-quality preforms must be equally robust.
Common mold maintenance practices such as mold “flashing” often result in injection ‘pin’ deflection. Mold shift results in preforms that appear to be of good quality -- and may even pass basic metrology tests -- but will cause major bottle performance problems downstream.
AVID is pleased to introduce P-TES, a preform concentricity analysis system designed to detect preform quality issues caused by core pin shift/deflection. P-TES replaces AVID’s previous preform thickness measurement system, the ‘THIKCHEK.’
Several measurement technologies exist for determining preform concentricity, each with drawbacks that make them imperfect for detecting thickness issues. Mechanical and hall-effect gauges (“Magnamikes”) are difficult to use on curved surfaces because they require precise gauge placement and stable part orientation during rotation for repeatable measurement. Laser gauges eliminate the measurement variations caused by operators, but are subject to effects caused by wall surface variations (scratches and surface defects) as well as part movement. Ultrasonic tools are impacted by changes in material temperature, moisture, and density that alter the sound velocity through the product material.
AVID has addressed these measurement handicaps and delivers a proper optical measurement solution for preform concentricity measurement. P-TES makes fast concentricity measurements and incorporates a design that automatically corrects for optical effects that can cause measurement errors in most available optical devices. Magnification variations -- due to part movement -- are mathematically corrected eliminating the need for precise part positioning.
The user selects a part from the part library that contains the parameters for all customer parts. The user positions the height of the centering tool to the indicated position via a slide indicator. The preform is then placed onto the centering tool.
Varying height preforms can generally be accommodated with only 1 or 2 change-out pieces. The operator then presses the start button on the touchscreen. Concentricity measurement is available to the operator following measurement (individual thicknesses or max/min/avg thickness measurements are not provided by the system).
The basic P-TES is available as a manually loaded standalone tool that plugs into an existing customer PC. The system is also available in the P-TES-A configuration featuring an autoloading system that can accommodate up to 196 preforms. The system is also available as an optional integrated module for the AVBIS 3000P automated precision preform measurement system. Contact AVID for more information.