Technical Update
Welcome to the PPMAs new technical area, which will keep you up to date with the latest issues, as well as providing in depth information, free downloads and links to other relevant websites.
Watch out for UK Measuring Instruments Regulations!
Following the agreement of the Measuring Instruments Directive, the National Weights and Measures Laboratory (NWML) has published separate UK Regulations for each of the different types of instrument covered by the Directive. The Regulations that are likely to affect PPMA members are as follows:
The Measuring Instruments (Automatic Catchweighers) Regulations 2006 SI 2006/1257
The Measuring Instruments (Automatic Gravimetric Filling Instruments) Regulations 2006 SI 2006/1258
The Measuring Instruments (Beltweighers) Regulations 2006 SI 2006/1259
The Measuring Instruments (Automatic Discontinuous Totalisers) Regulations 2006 SI 2006/1255
The Measuring Instruments (Automatic Rail-weighbridges) Regulations 2006 SI 2006/1256
These Statutory Instruments are available to download free of charge from the Office of Public Sector Information website at: www. opsi.gov.uk/stat.htm
The Regulations come into force on 30th October 2006, but watch out, because the provisions in these Regulations only apply to the UK, because with the MID, unlike other European Directives, countries can choose which instruments require regulation and which not and so the UK Regulations will be significantly different from say the German Regulations.
For further information please contact: anna.jenkins@nwml.gov.uk
New US Packaging Machinery Standard is Based on ISO and EN Standards
The American equivalent of PPMA, the Packaging Machinery Manufacturers Institute (PMMI) has just published a new safety standard for packaging machinery. Known as "ANSI/PMMI B155.1-2006 safety standard for packaging and packaging-related converting machinery", this revised version, approved as an American National Standard, has been harmonized with the international (ISO) and European (EN) standards by the introduction of hazard identification and risk assessment as the principal method for analyzing hazards to personnel and achieving acceptable risk.
The requirements of this standard apply to new, modified or rebuilt industrial and commercial machinery that performs packaging functions for primary, secondary and tertiary packaging. The standard describes procedures for identifying hazards, assessing risks, and reducing risks to an acceptable level over the life cycle of the packaging machinery.
This edition of the standard integrates the requirements of ISO 12100 parts 1 and 2 (formerly EN 292), and ISO 14121 (machinery risk assessment), as well as U.S. standards. Suppliers meeting the requirements of ANSI/PMMI B155.1-2006 should conform to the requirements of these three ISO standards.
PMMI anticipates that a large number of US customers will ask for machines to comply with this standard and because of its compatibility with the Safety of machinery series of standards, European companies should find it easier to comply with this version of the standard than its predecessors.
"ANSI/PMMI B155.1-2006 safety standard for packaging and packaging-related converting machinery" is available for $65 and is located under Shop PMMI at www.pmmi.org
New EN standards keep pace with current technology
One of the challenges facing the authors of European safety standards for packaging machinery has been to keep pace with technical developments in general and the increasing use of industrial robots and other software synchronised mechanisms in particular.
For instance it is increasingly common for case and tray loading machines to be based on an industrial robot and for the guards around the robot to be positioned to suit the programmed limits of movement of the robot, rather than the mechanical limits of movement of the mechanism.
This raises some significant safety issues because most robots are quite capable of demolishing a set of guards if they are inadvertently programmed to move to a point outside the guards or deviate from their programmed area of movement for some reason.
The new standard that covers case loaders EN 415-7: 2006 Safety of packaging machines Part 7: Group and secondary packaging machines, offers four methods of tackling this problem. The first is to position the guards outside the maximum area of movement of the robot. This solves the problem but typically means that the footprint of the machine is much bigger than necessary which is never popular.
The second method is to fit mechanical stops to the robot that prevent it from moving in certain areas even if programmed to do so. This technique works well to limit the rotational movement of a robot but is not usually practicable for limiting the reach of the mechanism.
The third technique is to fit an interlocking device to the robot head that can stop the mechanism if it encounters resistance. Such a mechanism is unlikely to prevent damage to the machine's guards if it connects with them at full speed but will almost certainly prevent the head from breaking out from the guards, since the stopping time of most industrial robots is now very short.
These three solutions represent the traditional approach to machinery safety which takes the view that electronics and software cannot be trusted but you can rely on mechanical devices and hardwired electro-mechanical controls. However the fourth solution offered by EN 415-7 recognises that electronics and software can be very reliable if they are designed in accordance with a standard like IEC 61508-3 and that the most likely reason for the robot trying to break out of the guards is not component failure or electromagnetic interference but operator error. Consequently the fourth solution which relies on programming alone requires that the software for altering the movement of the robot is password protected so that only competent people are allowed to make alterations.
Changes in technology also had to be taken into account when drafting " EN 415-6 - Safety of packaging machines Part 6: Pallet wrapping machines ". With this standard the particular focus of attention was the ubiquitous rotary turntable pallet stretch-wrapper. When drafting first started a distinction was drawn between semi-automatic machines which do not have to be guarded provided certain requirements like having a 500mm gap between the mast and the load were satisfied and fully automatic machines that did have to be guarded because of their additional mechanisms and higher output speeds.
However halfway through the drafting process new fully automatic, but low speed machines produced by Lantech and Robopac called this distinction into question. The line now between machines that need to be fully guarded and machines that do not is no longer semi or fully automatic but is based on the speed of rotation of the turntable and the hazards presented by the various mechanisms that can be found on both types of machine.
The following standards will be published by BSI Standards during September 2006.
BS EN 415-5 - Safety of packaging machines Part 5: Wrapping machines
BS EN 415-7 - Safety of packaging machines Part 7: Group and secondary packaging machines
The following standards will be published later this year. BS EN 415-6 - Safety of packaging machines Part 6: Pallet wrapping machines
BS EN 415-8 - Safety of packaging machines Part 8: Strapping machines
For more information Click Standards
PPMA EMC Experts
The new version of the Electromagnetic Compatibility Directive (2004/108/EC) which has some significant changes for equipment that is intended to be part of a fixed installation,. is currently being transposed into UK law.
If you are interested in EMC and could spare some time to read the new Directive we would like to know how you think this new Directive will affect your company and how you think it will affect the PPMA EMC Code of Practice.
For more information Click EMC
PPMA e-Library
The PPMA e-Library includes Information Sheets on Legislation, Conformity, Directives and General Working Practices.
For more information click e-Library