1 Head (One Head or Single Head) Machines

Single head cappers are standalone, inline, screw cappers with a single capping head or chuck. A common example is the Resina Model S-30.
Inline cappers using spinning wheels for tightening are common at speeds up to 200ppm or so. These are simple, effective and relatively low cost. They have 2 drawbacks:

• If the cap tightening disks are not precisely adjusted, they can slip on the cap. When they do, torques will be inconsistent, the caps will be scuffed and the scuffing will generate rubber shreds which can get under the label making an unsightly appearance.
• Disk cappers typically position the cap in an escapement, at an angle, and use the bottle to pull it out. Guides help transition the cap from the angle to flat. If not properly set, the cap will not be straight and cocked or cross-threaded caps will result. Some caps, especially those with a large diameter relative to the cap height, can be especially susceptible.

Chuck cappers avoid these problems by using the chuck to pick up the cap from a flat position and apply it squarely to the bottle. Bottle and cap are always parallel. The chuck grips the cap positively making it less likely to slip on the cap. This eliminates scuffing and particulates as well as torque issues caused by chuck slippage.

In a capper such as the Resina, the chuck spins continuously and reciprocates up and down. Caps are oriented and fed down a track to an angled escapement for pickoff. A horizontally reciprocating transfer arm picks the cap from the escapement and positions it under the chuck. The chuck dips down, grabs the cap and moves up.

Meanwhile, the bottle has been indexed into position and held in a gripper pocket to prevent turning as the cap is tightened. As the cap arm moves out of the way, the chuck lowers the cap onto the bottle and turns it down. A clutch breaks free when the correct application torque is achieved.

The main disadvantage of these cappers is speed, generally limited to a maximum of about 60ppm maximum depending on bottle and cap. On the plus side, they are generally fully mechanical except for the drive motor and an on/off switch. A single motor drives the machine and all major components operate off cams on the main shaft. This makes them very simple for any mechanic to maintain and makes them a good choice for plants and countries where technical sskill sets are limited.