Integrated Press Systems – Achieving the Goals
On a global basis, North American stamping facilities are often faced with a cost disadvantage of high labour rates compared with their counterparts in many other countries.
To a large degree, major stamping facilities in Canada and the United States have fought the problem by replacing the labour intensive work of stand-alone presses with integrated press systems designed to set-up and produce parts at a faster pace with less labour involvement. These systems often use progressive or transfer dies to accomplish the work that used to be done in several single operations. Automated feeding and unloading systems, moving bolsters, elaborate die clamping systems, scrap removal systems etc. are commonly included in the integrated system. Unfortunately, integrated press systems often cause an increase in fixed overhead costs without achieving the anticipated production results.
These production efficiency issues can often be resolved at relatively low cost. The two problems are very often a lack of procedures and a lack of specific training. Without adequate procedures and training, set-up operators (or equivalent) are setting-up and producing parts as they see fit and very often, improperly. Supervision often does not know what the procedures should be or what is expected and therefore, cannot enforce safe efficient methods.
If your facility has purchased machinery and equipment necessary to manufacture product in a safe and timely manner at the lowest possible cost but results have not materialized, consider conducting an audit to determine the cause(s). Some of the most obvious problems and answers are as follows:
› Damage to dies and machinery occur during the set-up process. It is a good idea to develop actual set-up procedures, print them in an easy-to-read font size, and post them at the machines in a well lit area. This allows set-up operators to conduct their work as required and allows supervisors the opportunity of ensuring that set-up personnel perform the procedures properly. Ensure all set-up operators and supervisors are trained in proper set-up procedures and are capable of performing the job effectively.
› Set-up operators use various methods of locking out machinery and accidents and/or near misses occur. Very often the general lockout policy is not available or understood by set-up operators, supervisors, or others working in the press shop. Specific lockout procedures are not always available or too vague to clearly understand. In addition to knowing how and where to lock out energy sources, personnel must understand when to perform lockout. This is not a simple matter. Does the set-up person need to lockout electrical energy and install blocking devices when cleaning the bolster and bottom of the ram? Does the set-up operator need to lock out electrical energy when clamping the dies? Does auxiliary equipment need to be locked out when entering perimeter guarding? The list goes on. Lock out polices, specific lockout procedures and a clear understanding of when to lockout, need to be developed and understood by all involved to help ensure safe use of the integrated press system.
› Downtime is excessive resulting in higher manufacturing costs and/or missed deliveries. Integrated press systems are often designed to allow set-up of some auxiliary machinery at the same time the press in being set-up in order to reduce down time of the line. Often, a concerted effor
Simplifying Entrapment Rescue Procedures
If a person is trapped in a mechanical press, the rescue method must be conducted quickly without incurring additional injury.
Traditional methods of raising the ram of a press to allow rescue, are often complicated by the need to bypass modern electronic guarding devices or a need to activate a press safety valve manually near the top of the press. A couple of scenarios are as follows:
A person is trapped between the dies of a press. The press is stopped near the bottom of the stroke and no upward ram adjustment is available. The person’s arm is through the light curtain and therefore, the ram cannot cycle by electrical power to free the trapped person.
In this case, an electrician must be available to jump out the light curtain to allow the ram to move upward using electrical power.
A person is trapped between the dies of a large press. The press is stopped on the downstroke at 150 degrees. Insufficient upward ram adjustment is available to free the person. The decision is been made to jack up the ram after the brake is released manually at the press safety valve. An aerial work platform (scissor-type) is the only method available to elevate the rescuer to the press safety valve in order to release the brake.
In this case, the rescue team must use a lift truck to move materials stored near the press to allow entry of the aerial work platform. The rescuer must locate the aerial work platform, put on the fall arrest equipment, drive the vehicle to the required location, elevate the platform and free the brake. Clearly, this is a time-consuming exercise while the injured person is trapped in the press.
The good news is that entrapment rescue control systems are now available to simplify the entrapment rescue. Such devices can bypass electronic guarding devices and release the brake at floor level without requiring the skills of an electrician. Training is required to use the controls properly.
If you require more information about entrapment rescue controls or their suitability for your presses, please contact us.
The press shop personnel is required for system changeovers in order to achieve this goal. Again, set-up procedures are necessary as well as product requirement information. Press shop personnel must understand their roles to keep uptime at a maximum and should be trained accordingly.
›Scrap is excessive and eats away at profit margins. Proper set-up practices will eliminate a lot of scrap products before the production run begins. Personnel assigned to inspecting parts must be given the appropriate measuring tools and information and be adequately trained in inspection requirements.
The above information is a partial list of causes for inefficiency and unsafe work practices in the stamping facility. Resolving these issues alone, should result in a noticeable improvement if these causes exist. Please feel free to contact us for a free consultation.