Vision systems integrator Olmec-UK, has developed a novel multi-camera, multi-illumination high speed inspection system for checking the integrity of the foil seal on plastic lids used to seal a wide range of glass and plastic containers in the food, healthcare and pharmaceutical industries.
Designed for use by production engineers rather than vision experts, the new Quality Station system features Olmec’s new modular user-interface for Windows, which provides multi-level security and allows easy review of images from failed components, and can also be set up for remote diagnostics if required.
In order to capture all possible defects, the foil needs to be illuminated from different directions and imaged by three cameras positioned at different angles to the foil.
The lighting runs in a sequence of three illumination combinations for each of the three cameras, thereby producing nine individual images for each lid inspected.
Full frame images are captured using Genie HM 1400 cameras from Teledyne DALSA, allowing the nine images to be captured for analysis in just 48 milliseconds for high volume inspection.
Easy integration
The new system can be readily integrated into a production line environment, with an air knife mechanism or similar used to fire rejected lids from the line.
Olmec technical director Robert Pounder says: “Olmec is frequently asked to provide solutions of this nature by a wide range of customers who need to integrate vision into their production lines.
“For this reason, we have very recently developed our Quality Station product. This can be configured for a wide range of inspection applications and features an integral transport and reject mechanism.”
With a small footprint of 1.2m x 0.7m, the Quality Station can be easily added to the manufacturing environment to provide in-line inspection, Pounder adds.
Critical step
The foil seals used inside plastic lids provide an air-tight seal to protect against contamination, humidity, tampering and leakages, in order to maintain product freshness and increase shelf life.
This type of lid and seal are used on a wide range of products from milk bottles to sauces such as ketchup, powdered drinks and tablet containers.
With the Quality Station system, the foil is inspected – in a critical part of the quality control process – to make sure there are no blisters, dents or creases, and that it has not lifted from the rim before the lid is sent to the induction heated container sealing station.
The lids are produced with the foil sealed into the lid ready for subsequent sealing to the container. Damage to the foil can occur during transit.
According to Olmec, the challenges faced in designing a high speed vision solution included the highly reflective nature of the foil material, the variety of possible defects and their random orientation, as well as the depth of the foil inside the lid.
Olmec foil inspection example
