[VIDEO] VFFS machine maintenance: How to set up the film brake roller
What is the brake roller and what does it do?
First, let's talk about how intermittent motion VFFS packaging machines work. Once per cycle, the packaging machine will stop the film feed to receive its vertical seal and then restart the film feed again.
The momentum of the film during the stopping motion causes slack to form in the film feed. The slack can make tracking the film difficult, especially at higher production speeds, because slack causes the film to jump around on the rollers. On intermittent motion machines like the VFFS M250, the function of the brake roller is to slow down the momentum of the film during the machines stopping motion. Proper timing of the brake roller can fix this problem and improve film tracking consistency.
How to set up the brake roller on an intermittent motion VFFS machine
CAUTION: Before performing a repair, be sure to follow your organization's Standard Operating Procedures (SOP) for safety, lockout/tag-out, and Personal Protection Equipment (PPE). Do not perform work in the machine compartment of an energized and initialized machine. Do not bypass any safety switches or relays. Failure to use caution while working on the machine by not using adequate safety procedures could result in injury or death. Only authorized personnel should perform machine repairs. Viking Masek cannot foresee every instance where possible machine damage or an injury could occur. Work on the machine at your own risk. If you need assistance, schedule a service visit by one of our authorized technicians.
Located on the back of the machine, the brake roller is stopped by a pneumatic cylinder that presses on a specialized brake pad attached to the brake roller. The timing of the cylinder’s actuation is controlled on the PLS page of the Human Machine Interface, or (HMI).
Note: Be sure the film is properly routed around your brake roller. Follow the guide stickers on the machine.
Follow these directions to turn on the brake roller and change its timing:
- Using the HMI, access the Programmable Limit Switch (PLS) settings page by touching the PLS Icon. It’s the Icon with the arrows in a circle formation.
- Turn the brake roller on by touching the on/off button.
- Set the brake on time. Touch the settings box to enter the virtual cam timing degree when you would like brake actuation to start.
- Set the off time. The off-timing mode will depend on your PLS set up: either set the duration of time in milliseconds to activate the brake cylinder; or, set the cam timing degree to deactivate the brake cylinder.
Note: If you would like to change the PLS off timing mode, touch the PLS setup button. Then touch the time/duration button to toggle the off-timing mode.
Expert tip: It may take some trial and error to find the perfect time and duration to stop the roller and minimize film slack, but in general you want the film brake to engage slightly before the pull belts stop the film and disengage before the pull belts start pulling the film again. Once you find the proper timing you will notice that the film feed will look tighter during the stopping motion of the machine and your tracking will wander less.
Maintain and clean your brake roller for optimal performance
For reliable operation, keep the surface of the brake roller clean. Regular cleaning helps the roller maintain its tackiness to grip and stop the film. Be sure to use a cleaning method consistent with your machine’s application and environment.
Also, periodically inspect the brake pad for wear and replace it as necessary to maintain roller stopping power. If you need parts for your machine, contact our certified parts department.
Watch more VFFS machine maintenance videos
Check out the other videos in our Maintenance Quick Tips series:
Follow a comprehensive preventive maintenance plan
Machine preventive maintenance is one of the most important things you can do to ensure a long, productive life for your equipment. Download our comprehensive packing machine preventive maintenance planner for daily, weekly, monthly, and yearly recommended maintenance tasks: