Infranor USA recently completed the successful retrofit & integration of a BLP 192 servomotor for tension control on a CMF printing press & inline sheeting machine.  The customer, a major manufacturer of paper wrapping sheets for the food industry, requested that Infranor provide a complete technical solution for placing the sheeting machine in-line with the printer.  This would reduce the amount of time taken to produce the final product by integrating two processes into one, and also increase product throughput.

Infranor project manager Ray Groyer explains:

We are faced with the challenge of integrating two individual electrical systems into a single control system.  The initial machinery consisted of 1) A 6 color CMF printer with both unwind & rewind DC drive systems 2)  A stand alone sheeting machine, with unwind stand & SC Drive system.  The customer requested that both the printer rewind system, and the sheeter unwind system be completely removed.  The sheeter would be moved in-line with the printer (in place of the printer rewind unit).  It would also be necessary to accurately control the paper film tension between the printer and sheeter, allowing smooth material control in all modes of operation.

System Solution-Harware

The continuous operation and high torque requirements of this system proved to be an ideal application for the BLP 192 motor.

Combined with a 400V SMTBD1 Option E Amplifier, the motor drives the entire sheeting machine including nip rollers.  Tension is maintained between the pinch point of the sheeter nip rollers and the printer chill roller.

A Shaft encoder fitted to the printer main drive-shaft provides electronic line shafting.  This allows the sheeter to follow the linear speed of the printer with a software position-lock.  Tension is applied by varying this base ratio while ensuring feedback from the pre-loaded dancer.

Safety Aspects

With safety a primary concern, Infranor opted to disable tension control with the machines in the jog or setup modes.  This would allow the sheeter to follow the speed of the printer while printer/sheeter jog modes were operational. When the machine is place in run mode, tension control is automatically activated.  In the case of material breakage, tension is also disabled.

Dancer Bar for Tension Control

A dancer bar situated between the CMF press and the sheeting machine applies small variations in the electronic gear ratio thru the amplifiers analog input.  This compensates for the slip, roller wear and other mechanical inaccuracies.  On the application, up to 3% speed variation is allowed.

Motor Mounting

The customer provided an adjustable base & mounting flange for the 192 motor, allowing belt tension & alignment.

System Benefits

The resulting system yields impressive results:

• Speed-Increased from 250 sheets/min to 500 sheets/min.
• Efficiency-With two processes integrated into one machine operation, it is possible to operate the entire line with just one operator.  In addition, the lengthy process of moving & storing rolls of printed material between production processes is eliminated.
• Less material length variation, due to extremely smooth tension control.
• Servo Reliability-The powerful BLP 192 runs cool and at low idle currents, ensuring extended life operation.
• A satisfied customer-the ultimate goal!!

Infranor USA Team
Ray Groyer, Jim Kubis, Mark Brochu

For more information vist. www.automotioninc.com