As the demands for product quality and compliance increase, so do the requirements for managing the entire product lifecycle. For many the spotlight is only ever on inspection at one point however modern quality standards demand that a container is continuously checked along all areas of a filling line.
The reality is that inspection systems fulfil a multitude of tasks in the modern filling plant. In this two-part post, we’ll look at the different areas of use and the inspection techniques used in each case with a line for processing returnable bottles as an example.
Operations that feature a filling line for returnables will have a system that offers ultrasonic measuring procedures to determine the height of the containers and to detect foreign objects in the crates. The exact inspection of incoming crates is necessary to avoid interference to the unpacking process and a high quota of foreign bottles on the bottle conveyors.
After the crate, has been unpacked it is examined to establish whether it can be used for the actual production. It must not be damaged or contain foreign objects and its colour and logo must correspond to the filled product. Today these three criteria are generally checked using cameras.
Not all the foreign containers can be rejected in the crate area because of the large assortment of bottles present at times. This means foreign bottles must be sorted during bottle transport. Generally, the most important element of the bottle sorting unit installed for this process is a camera system using an image processing technique which measures the shape of the bottle and compares it to the sample shape of the production bottle.
Empty bottle inspection is probably the most renowned process where the containers are subjected to various inspection procedures. The inspection technique used by the empty bottle inspector consists for the most part of cameras. The different areas of the bottles are generally photographed with CCD cameras and high-frequency and infrared measuring techniques. The checks that are done at this point include a base, sidewall, finish and residual liquid check.
Residual caustic solution in a bottle can present a danger to the consumer and therefore an additional residual liquid check is often installed directly before the filler as an extra safety precaution. A high-frequency measuring technique is also used here, a reliable method of identifying even the smallest amount of residual caustic solution in a bottle.
Different factors are checked during and directly after the filling process and samples taken from the production flow. The technique used for the fill level measurement depends very much on the product and container. In the simplest case a photocell suffices. A well-equipped filler management system also has an integrated sampling program so that the quality of the filled product can also be checked.
The bottle is given a final look-over after the labelling machine before it is packed in the crate. First the labels must be checked to ensure they are all present. This is generally carried out with a light scanner either in or after the labelling machine. A closure inspection can be carried out at this point instead of after the filler. A second fill level check is also often carried out at this point.
When it comes to beverage bottling Heuft is the world leader in quality inspection. Heuft offer quality inspection equipment that caters to a range of requirements. Through our partnership with Heuft, Plastic & Chemical Trading can provide South Africa with world class solutions.
Resources: Translation from a report published in the “Getränkeindustrie” journal – June 2002 edition https://heuft.com/en/actual-news/news-overview/news-archive/inspection-systems-in-the-filling-plant