General safety tips to follow when working around the calender
Jun 21, 2016
The general calender safety recommendations listed here are not all inclusive, but can be used to reinforce a mill's safety program.
- Heed warning and safety notices posted on the machine and in the area. They are installed to warn personnel of possible danger. Observe all instructions. Never remove warning signs. Replace them when worn.
- Check operation of all Emergency stops, electrical interlocks, and related limit switches on a regular basis to assure proper operation. Safety faults must be repaired and cleared by qualified personnel before resuming operation.
- Handle the equipment at the control bench with care. Do not place objects on the keyboard, color display, or pointing device (joystick or trackball). All equipment is susceptible to failure if placed in contact with liquids or excessive heat and/or humidity. Allow adequate air flow around the units at all times. Operate the keyboard and pointing device with reasonable pressure.
- Make sure that footwalks, handrails, barriers, guards, and safety fences/gates are in place and in good working order before starting the machine. They have been installed to protect personnel.
- Keep the area around the calender free from obstructions of any kind. Keep foreign articles off footwalks and out of walkways to prevent personnel from tripping and falling into the machine.
- Wipe up spilled oil, grease, water, kerosene, or other solutions which may cause a person to slip.
- Never use a rubber hose near the calender stack without a hard safety nozzle end (at least 4 inches in diameter) that cannot go into a roll nip.
- All roll cleaning equipment must have long handles to keep the user's hands and arms out of nip areas.
- Do not clean the calender stack while personnel are working on the opposite side. Loose particles may cause injury.
- Do not sand (hand dress) rolls while in the machine. Flying particles may cause injury to personnel in the area.
- Keep all parts of the body away from belt drives.
- Any nip point is a danger area. Keep clothing and all parts of the body away from the area between rotating rolls/reels and stationary objects (such as nip guards, edge coolers, frame components). There is a hazard of being drawn in or crushed by the rotating roll. Do not wear any loose clothing that could become entangled in the roll nips.
- Hazards located beyond reach from designated operator positions are not required to have guarding. Do not use ladders, stools, or other devices to reach these areas unless the entire machine has been locked out.
- Never thread closed nips by hand. Refer to the OEM or mill threading instructions.
- Do not remove broke by passing it through calender roll nips. Hands and/or body parts can become entangled in the broke and be pulled through the calender nip.
- Bring the calender to a complete stop before removing broke from nip areas.
- Do not overreach. Keep proper footing at all times.
- Avoid burns from contact with heated surfaces. Calenders have many heated components (for example: rolls, brakes, rotary unions, steam showers, the temperature control unit, hydraulic power units, piping for the above, etc.). Let heated components cool thoroughly before removing rolls or performing other maintenance.
- Do not operate any equipment until all personnel have exited specified danger areas. Where applicable, do not reset any interlocked gates or other protective devices until all personnel have exited the restricted areas.
- Avoid use of areas between machines during operation, (i.e. the area between the stack and reel/windup, or between a spare roll stand and the stack, etc.). Such areas should not be used as a general walkway and should not be entered during operation unless necessary; exit these areas as quickly as possible.
- Do not walk, stand, or reach under any moving component unless the calender hydraulics are locked out and the component is properly supported. Unexpected movements could cause serious injuries or death. Examples include, but are not limited to: moveable platforms, the bottom roll, rider rolls, roll bearing housings and web choppers.
- When using moving (threading) platforms, be aware of the proximity to machine parts such as protruding roll shafts, rotary unions, brackets, etc. Sometimes there are only a few inches of clearance. Do not reach out past the railings while the platforms are moving. Watch out for overhead objects, especially if the raise limits have been overridden. Do not open any platform gates unless the platform is stopped at a stationary platform or ground level.
- Stay away from a running web. Cuts from a running web can cause severe injury or death. Low moisture paper can build up a static charge when calendered by non-conducting rolls (such as polymer or filled rolls). A static discharge from the web or roll can cause injury.
- Do not rotate loaded polymer rolls without a web for any extended period of time. The heat can damage the polymer covers, resulting in cracks. Particles may become dislodged and cause injury. Operating personnel must not enter the calender area while running without a sheet.
- Do not enter the paper machine/unwind, stack, or windup/reel sections (except where instructed to do so in the OEM manual or in mill operating procedures) when the calender is operating above thread speed. Hazards include: flying particles from worn rolls or other sources, rotating rolls/reels, web breaks, moving components, potential for burst reels and contact burns from hot equipment.
- Do not spray calender rolls with water or steam. Sudden temperature changes may cause cracking or splitting of chilled iron calender rolls. Surface temperature changes should not exceed 50°F (28°C) within twenty minutes time.
- Check the roll heating system. Excessive contrast between the temperature of the heating media and the thermo roll surface can damage the integrity of the thermo rolls (and void warranties). Overheating will damage polymer roll covers, resulting in cracks. Particles may become dislodged and cause injury.
- Where applicable, keep temperature scanner cameras clean. Failure to do so may result in incorrect operation of cooling devices and lead to roll damage. Roll damage (for instance, the failure of a polymer roll cover), may pose a danger to anyone in the vicinity when failure occurs.
- Use appropriate personal protective equipment (PPE). With the exception of the control room, all personnel in the calender area should wear ear plugs, eye protection with side shields, and steel-toe shoes. Appropriate gloves should be worn when handling sharp items. A hard hat should be worn when doing maintenance. A full face shield and hard hat should be worn if personnel must be in the immediate calender area during full speed operation.
- Wear appropriate gloves when changing roll doctor blades. Blades become sharpened by contact with the rolls.
- Where equipped, use web break detection devices whenever operating the calender. In case of a web break, follow the recommended procedures. A broken web can wrap around a roll or other equipment. At the minimum, wrapping can damage soft rolls. More importantly, excessive wrapping can cause equipment damage, such that a roll or other equipment could fall. This is especially important in a lever-type stack.
- Do not exceed the machine specifications listed in the OEM manual provided with the calender. The equipment provided is designed only for the intended conditions. Equipment failure from exceeding specifications (speed, roll/reel sizes, etc.) could result in serious injury or death.
For more information on improving safety at the calender, consult your mill's safety manager or contact your Valmet representative for training or safety rebuild options.