START OF THE CLOSURE THREAD
In order to make the measurement of application angle easier and faster, the closure with diameter of 28mm (AB1881CSD8), that we produce for the bottle neck/finish of the PCO1881, already has the mark with the position of the start of the closure thread (it is located on the side wall of the closure, as shown in the following pictures). 1881 с already has the mark with the position of the start of the closure thread (it is located on the side wall of the closure, as shown in the following pictures). (it is located on the side wall of the closure, as shown in the following pictures).
DIFINITION:
The application angle (expressed in degrees) is defined as the rotation in application of the start of the closure thread around the bottle finish from the start of the bottle thread.
HOW TO MEASURE THE APPLICATION ANGLE:
1 – mark with a coloured line the position of the start of the bottle thread as it is shown in the following picture.
2 – mark the position of the start of the closure thread in the same way as it is shown in the following picture
3 – place the closure on the bottle so as to align the mark on the closure with the mark on the bottle, as it is shown in the following picture.
4 – screw the closure on the bottle finish by rotating it clockwise manually or by means of capping machine (head) till closure reaches the sealing position.
The application angle corresponds to the total number of degrees the start of the closure thread has been rotated from the start of the bottle thread. The measurement is performed by means of a goniometer as it is shown in the following picture.
The goniometer must be kept perfectly horizontal and not inclined to avoid reading errors.
The zero position of the goniometer is placed in correspondence of the start of the bottle thread (the line on the bottle) and the distance in degree from the start of the bottle thread and to the start of the closure thread is measured. The received value in degrees must be added to 720° and you can get the total application angle of the closure.
HOW TO MEASURE THE APPLICATION ANGLE OF THE CLOSURE ON THE BOTTLE
If the closure was applied onto the bottle without having previously marked the start of bottle and closure thread, it is still possible to measure the application angle, as follows:
1 – make a line (straight line) that connect closure and bottle as it is shown in the picture below:
2 - unscrew the closure completely and mark with a line the start of the closure and bottle thread as described above.
3 – reapply the closure onto the bottle so that the line of the start of the closure thread and line of the start of the bottle thread coincide, as it is shown in the picture below.
Screw the closure until the lines coincide (the straight line on the closure and the bottle).
Having done this operation, the closure goes back to the initial position, as it was before unscrewing.
4 – measure the application angle in the same way (as it is reported in the procedure above).
