The present invention relates to a method for inspecting the contents, such as food, of a package, particularly a light-opaque package, for degradation or the degree of degradation by means of ultra-soft X-rays (which is generally referred to briefly as soft X-rays) and an apparatus for use in practicing the method.
It is an important element of quality control, in some industries, to check the contents of packaged products, such as food contained in a pouch or other packaging container, for degradation.
In case the degradation of contents is accompanied by the evolution of gases within the package, one may readily discover the occurrence of degradation from the inflation of the container. If the container is a transparent or see-through pouch, for instance, signs of degradation can be easily detected by looking through the pouch.
These procedures are of no avail, however, where a light-opaque packaging material such as an aluminum foil-laminated film is used for purposes of an improved shelf-life, where the contents are such that they will not give rise to gases on decomposition, or where the degradation of the contents has not progressed far enough to cause gas production.
Therefore, in such cases, it has been inevitable to pick up an appropriate number of samples, destroy them, and check the contents by visual inspection.
However, the destructive inspection of packaged products is disadvantageous in that the procedure involves many steps and the sampled products, if acceptable, become loses on account of unpackaging, thus adding to the cost of products. Furthermore, while an unfailing inspection calls for many samples, there is naturally a limit to sampling size, with the result that the reliability of the inspection is compromised.
It is an object of the present invention to provide a method of inspecting packaged products, by which the contents, such as food, of a light-opaque package can be accurately checked for degradation or the degree of degradation without destroying the packaging container. Another object is to provide an apparatus for use in practicing the method.