The closure process of PET bottles is one of the most critical because it is performed at a very high speed. What are the applicable checks and how does the “application angle” check work?
In a PET bottle, the cap-bottle coupling is a step that must be inspected accurately to avoid placing on the market bottles with excessively tight closures or on the contrary, bottles that leak. Only checking the height of the cap with a vision system may not be enough as closures have intrinsic height variability that would lead to false rejects. The “application angle” check is used to prevent this event, and make sure that the cap is correctly applied to the bottle. How does it work? The producers of caps and preforms place markers on the finish at the base of the bottle neck and on the screw-on cap to allow the bottling customer’s Quality control department to spot-check closures. The Application Angle check produced by FT System inspects the two markers and their angle from the top. For correct closure, the two markers must be at a specific angle to one another. If the two markers fall within a specific angle, this means that the bottle is correctly closed. Otherwise, if the angle is too narrow it indicates that the caps have been closed too tightly, whereas if the angle is too wide it means that the bottle might leak.
FT System has patented a system to make this inspection very accurate. What are the advantages of this system compared to similar checks?
During the filling process, droplets of liquid may easily remain on the bottle which, during the application angle inspection, may easily be mistaken for a marker, thus distorting the check and placing non-conforming bottles on the market, or generating false rejects.
To prevent that, we have developed and patented a system that makes it possible to eliminate this eventuality and recognise the marker without a shadow of a doubt, thus performing the inspection correctly and avoiding false rejects.
Our “application angle” check also makes it possible to perform the check in line on 100% of the production. Other inspection systems perform the check on bottle samples from the line, hence with spot checks. What is more, our system works regardless of the cap colour and size.
What other advantages does the “application angle” patented by FT System offer to the producer?
The experience of FT System in the inspection sector is very extensive, therefore the Application Angle system can be integrated with a number of other inspections, including a lateral vision cap check system. We also have the expertise and skills to collect the huge amount of data produced and manage the capper set-up through a feedback mechanism. Through the analysis, data correlation, study of the primary causes and thanks to artificial intelligence, it is also possible to automatically forecast the efficiency of the production line as well as perform preventive maintenance operations aimed at streamlining production processes.