Plant manufacturer Getecha has developed an automatic screwing machine that does both and can be used at two key process-related positions: behind the blow molding line for loosely screwing the caps into the thread of the empty canisters or behind the filling machine for liquid-tight sealing of the full containers. Both blow molding companies and liquid fillers are likely to be interested in this new development.

Empty canisters, full canisters
The technological hallmark of the fully automated system is the combination of modern control and sensor technology with precisely controllable servo drives. This ensures sensitivity and accuracy when handling the screw caps and canisters. Because the torque, tightening torque, rotational speed and number of revolutions of the motors can be programmed, the capping process can be carried out with high precision, repeat accuracy, "force-dosed" and gently. This also plays a major role in maintaining the function of the PE sealing rings inside the caps.

For both applications, Getecha supplies a fully equipped system solution that can be integrated into existing processes. While the canisters enter via a short conveyor belt, the caps are separated via an ascending and a spiral conveyor and fed to the screwdriving module. Each individual canister is pneumatically fixed in the defined position and approached from above by the screwdriving module, which moves along a linear vertical axis. Screwing is fast and repeatable. Depending on the size of the canister, the total cycle time is between ten and 15 seconds. A self-monitoring system monitors the screwing process and detects defective threads. A leak test can be integrated as an option.

Changing sizes can be processed
The system can process different canisters without conversion and can be adapted to different cap types with little set-up effort. In practice, a single screw cap closing machine is able to process canisters with varying heights of 300 to 600 millimetres and widths of 150 to 300 millimetres, which come from several blow moulding or filling lines. Different process parameters can be used, for example for the screwing process. Only the footprint of the canisters is a fixed size and must be identical. An average throughput of 330 containers per hour can be calculated.

With a footprint of just under 2,000 x 3,500 millimetres, including conveyor technology, the machine is compact and can be easily integrated into the blow moulding and filling lines. The system can be connected to the customer's host computer or network and can therefore be synchronized with the cycle time of the preceding production line. The user can archive the process data of different capping scenarios in the machine's control system or in its higher-level IT system. pb