Plastic Technologies Inc. (PTI) is introducing an upgraded version of its LeakMonitor device which uses an ultrasonic sensor to continuously monitor the blow molding process for air leaks from machine components and defective bottles. The new capability enables leak detection at production speeds typical for state-of-the-art blowmolding equipment.


Excessive air consumption due to leaks within blowmolding equipment is a costly ongoing concern for blowmolders, which can result in thousands of dollars in wasted compressed air and production downtime, annually.

When pressurized air passes through an orifice, it generates an ultrasonic signal which PTI’s LeakMonitor technology reduces to an electronic waveform. Deviation of the waveform from predetermined parameters can be used to identify defects in the product or in machine components.

During the normal reheat stretch blowing process, the LeakMonitor device listens for leaky bottles, tracks them through the machine and triggers an eject mechanism when they are in the correct position. In addition, routine background noise is monitored and graphed. If the background noise reaches an unacceptable level the ultrasonic sensor can trigger an alarm. Additional features of the upgraded LeakMonitor device include many automated calibration features including a display of the relative severity of air leaks and where they are located on the blow wheel.

The LeakMonitor device is a powerful tool to help ensure that rPET usage does not result in defective bottles leaving the operation. This is accomplished by monitoring the blowing process for leaks in the base or sidewall (usually a result of contamination or high-stretch ratios), for short shots and for other sealing surface defects.
Additionally, PTI’s LeakMonitor is an ideal device to identify and locate leaks from valves, faulty lines, compensation gaskets, stretch rod seals, misaligned tooling, etc.

Plastic Technologies Inc.