Inspecting the closure on bottled products is becoming more common as companies strive to deliver higher, more consistent quality product to the market.
With improvements in machine vision technology, the cost for this type of inspection system is continually reducing making it a more attractive solution to companies producing bolted products.
There are two aspects to an effective bottle cap inspection system; the selection of the appropriate camera, lights and other hardware and the choice of machine vision software that can provide the required analysis algorithms to provide a robust and reliable solution.
The key to a successful algorithm for bottle cap inspection is to have a system that tolerates a whole range of issues found on Pet bottle caps once the cap has been screwed onto the bottle, but which are difficult to program using conventional toolbox type machine vision software packages.
One particular challenge is water droplets on the bottle.
Azitech has developed a bottle cap inspection system where the analysis algorithms have been customised to handle water droplets and plastic burs on the bottles.
Through the use of two cameras set at 90 degrees to each other and 45 degrees to the conveyor, Azitech is able to offer a significantly better detection system than if only a single camera is used.
With the huge advances in current camera technology and huge reductions in the cost of the technology, Azitech is able to offer a two camera system for less than a single camera system would have cost a couple of years ago.
The Azitech system has been developed to detect the following defects:
- Caps cocked at an angle due to cross threading
- Caps not tightened fully
- Tamper evidence ring damaged or missing
- Missing nozzle top or dust cover and
- Fill height