Your closure supplier sets the torque and your glass supplier sets the finish. The capping head is where those two meet, and it decides how repeatable the result is across a shift.
The 3 Head Types and What They Give You
| Head | How it stops turning | What you get |
|---|---|---|
| Friction chuck | A clutch slips at a mechanical setting. | Simplicity, and a setting that drifts as the clutch wears. |
| Magnetic | A magnetic coupling releases at a set point. | Consistent results and easy adjustment, the common workhorse. |
| Servo | A motor drives to a controlled angle and force. | Tight repeatability and a torque record for every bottle. |
Why Servo Heads Change Your Quality Data
A servo head does not just apply torque, it records it. Every closure carries a measured value, so a drift shows as a trend rather than as a complaint.
That matters most where your seal is critical. A vacuum jar or a carbonated 330 ml (11 oz) bottle benefits from knowing which pack was outside the window, and no other head type tells you.
Why Glass Jams Where Plastic Squeezes
Plastic containers deform and recover, so a dimensional variation passes through a star wheel with a squeeze. Your glass bottle does not deform, so the same variation becomes an interference.
Three dimensions cause most of it. Body diameter or width, overall height, and base flatness, since a bottle that rocks presents its finish at an angle. SGSBOTTLE gauges all three at the cold end on all 14 lines in Shandong and Xuzhou.
Your head meets the finish the drawing promised. SGSBOTTLE holds tolerances across 14 lines in Shandong and Xuzhou.
What Your Finish Drawing Has to Carry
Your capping head is set from paper before samples arrive, so the drawing has to carry more than a designation. Thread profile, finish height, sealing surface and their tolerances all feed the setup.
Ask for them explicitly. SGSBOTTLE issues the finish drawing with every quotation for glass from the 14 lines in Shandong and Xuzhou, so your closure supplier and your engineer work from the same numbers.
What a Format Changeover Actually Involves
Changing bottle format is not a setting change. Your star wheels, guide rails, chuck inserts and head height all follow the new dimensions, and your torque window follows the new finish and liner.
Plan it as a job. A line that runs several formats benefits from choosing bottles that share a finish, since a 500 ml (17 oz) and a 750 ml (25 oz) bottle on one designation cut your change parts considerably.
What Goes on Your Enquiry
Your closure and liner, your capping head type and line speed, the format in ml and oz, and the other formats running on the same line. SGSBOTTLE comes back with the finish drawing, its tolerances and bottles for a capping trial.