Printing presses vary by type and size, ranging from relatively simple manual presses to the complex large presses used for printing newspapers, magazines, and books. Printing presses are often part of a larger system that also includes cutting, binding, folding, and finishing equipment. Many modern printing presses rely on computer controls, and the high speeds of such equipment often require rapid machine adjustments to avoid waste.
This section discusses amputation hazards associated with two common types of printing presses: web-fed and sheet-fed printing press systems. Web-fed printing presses are fed by large continuous rolls of substrate such as paper, fabric or plastic; sheet-fed printing presses, as their name implies, are fed by large sheets of substrate. In both types, the substrate typically feeds through a series of cylinders containing printing plates and supporting cylinders moving in the opposite direction.
As with other machines, many printing press-related amputations occur during cleaning and maintenance activities. For example, amputations frequently occur when workers get their fingers or hands caught in the in-going nip points created between two rollers while performing these tasks:
§ Cleaning or attempting to free material from the rollers.
§ Hand-feeding substrate into the in-running rollers during press set-up while the machine is operating.
| Case History | An employee was adding ink at the top of a printing press when he spotted a small piece of wood in the area of the moving rollers. He caught his hand in the moving rollers as he attempted to remove the wood and had to have his forearm surgically amputated. Source: OSHA IMIS Accident Investigation Database |
As with most machinery, you can rely on engineering, work practice, and administrative controls to protect employees against injuries when using printing presses. For example, some basic engineering controls include the following:
§ Install guarding on all hazard points, including all accessible in-going nip points between rollers and power-transmission apparatus (such as chains and sprockets), that are accessible during normal operation.
§ Safeguard nip point hazards with barrier guards or nip guards. Nip guards should be designed and installed without creating additional hazards. For example, the distance between the nip guard and the adjacent roller/cylinder should be minimized. Additionally, to prevent wedging, the angle between the nip guard and the surface the roller should not be less than 60 degrees.
§ Install fixed barrier guards at rollers that do not require operator access.
§ Use fixed guards that can only be opened with tools (to prevent tampering) at points requiring operator access once per shift or less.
§ When you need more frequent access to the press, use interlocked guards, which are designed to stop the printing press when opened or moved, instead of fixed guards. Interlocked guards should not allow normal operation of the press while open.
§ Use an inch or reverse function to perform actions such as substrate feeding, machine adjustment, and lubrication when one or more interlocked guards is moved to allow operator access. The speed and distance of the inch function should be designed to ensure that it does not pose a hazard if not otherwise guarded.
§ Require press operators to perform normal startup procedures before the press can be operated. Replacing an interlocked guard should not automatically trigger machine operation.
§ Use additional safeguarding methods such by location as well as devices for stopping the printing press such as trip bars and pull cords.
§ Remember that interlocks and stops do not stop the press immediately and that non-driven idler rollers may continue to rotate when the press is stopped and can cause injury.
All printing presses should incorporate a signaling system in accordance with ANSI B65.1-1995 as follows:
§ Make sure that printing presses attended by more than one operator or ones outside of the operator’s viewing area be equipped with visual and audible warning devices to alert workers regarding the press’s operational status — in operation, safe mode, or impending operation.
§ Install visual warning devices of sufficient number and brightness and locate them so that they are readily visible to press personnel.
§ Ensure that audible alarms are loud enough to be heard above background noise.
§ Provide a warning system that activates for at least two seconds prior to machine motion.
Work practices and administrative controls recommended for printing presses include the following:
§ Develop and implement safe operating procedures for printing presses and conduct periodic inspections to ensure compliance.
§ Ensure that all press operators receive appropriate training and supervision until they can work safely on their own.
§ Instruct workers to lubricate, align, and maintain printing presses only when presses are stopped. If this is impractical, advise employees to maintain a safe distance from any in-going nip points. Installing extended oiler tubes and adjusting screws will help in these instances.
§ Prohibit employees working with or near printing presses from wearing loose clothing and require them to secure long hair with a net or cap.
§ Perform servicing and maintenance activities under an energy control program in accordance with §1910.147.
In addition, perform minor servicing tasks using the Inch-Safe-Service procedure specified in ANSI B65.1. These include the following tasks: types of paper jams; minor cleaning, lubricating, and adjusting operations; certain platechanging and blanket-changing tasks; and, in some cases, webbing and paper roll changing. The Inch-Safe-Service procedure, at a minimum, calls for the use of a stop/safe drive push-button control. Under this procedure, the stop/safe function cannot serve as the energy control device when you are performing lockout.
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