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List of Safety Standards

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Yellow Submarine Original Artwork copyright 2014

This list provides a yearly update of standards applicable to web handling. Revisions this year are shown in bold-italics.

Risk Assessment

ANSI B11.0-2015 Safety of Machinery; General Requirements and Risk Assessment

ISO 12100:2012 Safety of machinery -- General principles for design -- Risk assessment and risk reduction

ISO/TR 14121-2:2012 Safety Of Machinery - Risk Assessment - Part 2: Practical Guidance And Examples Of Methods

CSA Z1002:2012 (R2017) Occupational health and safety - Hazard identification and elimination and risk assessment and control

 

Guarding

ANSI B11.19-2010 Performance Criteria for Safeguarding

EN/ISO 13849-1:2015 Safety of machinery -- Safety-related parts of control systems -- Part 1: General principles for design

CSA Z432-2016 Safeguarding of machinery

CAN/CSA-ISO 13857:2015 (Adopted ISO 13857:2008, first edition , 2008-03-01) Safety of machinery — Safety distances to prevent hazard zones being reached by upper and lower limbs

 

Drives

IEC 61800-5-2:2016 Adjustable speed electrical power drive systems - Part 5-2: Safety requirements - Functional

 

Safety Circuit Performance

EN/ISO 13849-1:2015 Safety of machinery - Safety-related parts of control systems - Part 1: General principles for design

EN/ISO 13849-2:2012 (R2018) Safety of machinery -- Safety-Related Parts of Control Systems -- Part 2: Validation

 

Emergency Stop (E-Stop)

NFPA 79:2018 Electrical Standard for Industrial Machinery

ANSI B11.19:2010 Performance Criteria for Safeguarding

IEC 60204-1:2016 Safety of machinery - Electrical equipment of machines - Part 1: General requirements

IEC 60947-5-5:1997+AMD1:2005+AMD2:2016 Low-voltage switchgear and controlgear - Part 5-5: Control circuit devices and switching elements - Electrical emergency stop device with mechanical latching function

CSA Z432:2016 Safeguarding of machinery

ISO 13850:2015 Safety of machinery -- Emergency stop function -- Principles for design

ISO 12100:2010 (R2015) Safety of machinery -- General principles for design -- Risk assessment and risk reduction

EN/ISO 13849-1:2015 Safety of machinery -- Safety-related parts of control systems -- Part 1: General principles for design

 

C Standards

ANSI/SPI B151.2-1999 Plastic Film Casting Machinery-Manufacture, Care and Use

ANSI/SPI B151.4-1999 Blown Film Take-Off and Auxiliary Equipment -Manufacture, Care and Use

ANSI/SPI B151.5-2000 Plastic Film and Sheet Winding Machinery-Manufacture, Care and Use

ANSI/SPI B151.7-2014 Safety Requirements for Extrusion Machines

ANSI/SPI B151.20-2013 Safety Requirements for Plastic Sheet Production Machinery

CEN - EN 1034-1:2000 (+A1:2010) Safety of Machinery - Safety Requirements for the Design and Construction of Paper-Making and Finishing Machines - Part 1: Common Requirements

EN 1034-3:2011 Safety of machinery - Safety requirements for the design and construction of paper making and finishing machines - Part 3: Rereelers and winders

DIN EN 1034-5:2005 (+A1-2009) Safety of machinery - Safety requirements for the design and construction of paper making and finishing machines - Part 5: Sheeters

DIN EN 1034-6:2005 (+A1-2009) Safety of machinery - Safety requirements for the design and construction of paper making and finishing machines - Part 6: Calender

DIN EN 1034-16:2012 Safety of machinery - Safety requirements for the design and construction of paper making and finishing machines - Part 16: Paper and board making machines

DIN EN 1034-17:2012 Safety of machinery - Safety requirements for the design and construction of paper making and finishing machines - Part 17: Tissue making machines

DIN EN 1034-21:2012 Safety of machinery - Safety requirements for the design and construction of paper making and finishing machines - Part 21: Coating machines

DIN EN 1034-26:2012 Safety of machinery - Safety requirements for the design and construction of paper making and finishing machines - Part 26: Roll packaging machines

DIN EN 1034-27:2012 Safety of machinery - Safety requirements for the design and construction of paper making and finishing machines - Part 27: Roll handling systems

EN 1114-1:2011 Plastics and rubber machines - Extruders and extrusion lines

EN 1417:2014 Plastics and rubber machines - Two roll mills

EN 1539:2015 Dryers and ovens, in which flammable substances are released

EN 1570-1:2011 (+A1:2014) Safety requirements for lifting tables

EN ISO 11111-1:2016 Textile machinery - Safety requirements-Part 1: Common requirements

EN 12581:2005 (+A1:2010) Coating plants - Machinery for dip coating and electrodeposition of organic liquid coating material - Safety requirements

EN 13418:2013 Plastics and rubber machines - Winding machines for film or sheet

EN 15067:2007 Plastics and rubber machines - Film converting machines for bags and sacks - Safety requirements

 

 

Note: Please send me an email if I have missed any applicable safety standards and I will add to the list next year. In particular, I am interested in standards applicable in Asia.

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https://www.stevenabbott.co.uk/abbottapps/WBC/index.html

This week we present something entirely new. A Web-Based PID simulation Web Based Controller (WBC) app. The calculations were programmed and the page published by Prof. Steven Abbott, a long-time friend of AIMCAL and web handling. I had the pleasure of meeting him at the AIMCAL Web Handling Conference (Europe) in June. I also had the pleasant surprise of the functioning WBC in short order after the specification was prepared.

This WBC allows you to study the effect of PID regulator parameters for tuning a system. This type of control simulation has not been available on the web to date. Options for learning how to tune PID’s relied on actual controllers connected to a plant or expensive math programs with Control libraries. Using the WBC, you need only change a parameter and a trend shows the simulated step response with a few measurements such as overshoot and bandwidth. The simulation can be used with any web browsing device.

A help file with the WBC gives a very brief description of the simulation and suggests 6 learning opportunities. You may then change parameters to your heart’s content and see the trend chart change.

After completing the WBC, Prof. Abbott stated “I’ve always thought that control theory was magic, so I was rather fearful of taking up your challenge of writing this app. But thanks to your patient explanations I was able to have one of those ‘aha’ moments when it suddenly clicked. I’ll still leave control loops to real engineers such as yourself, but I’m happy that I’ve had a glimpse of some of the magic that is going on behind all those control panels.”

Thanks, professor.

Stop reading and start experimenting! Leave us your comments. Web Based Controller (WBC)

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Summer School - Combining Web Stresses

 

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What is the best tension?  How well does tension need to be controlled?  How close do you need to hold roller alignment?  What about bending of thick products around small diameter rollers?  All of these and other factors conspire to add to the total web stress that can damage and even break the web.  In the past, all these electro-mechanical issues were handled separately, often by different departments or even different companies.  This clip teaches an integrated approach to design and maintenance. 

https://www.youtube.com/watch?v=nndOBjDzShI

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Summer School - Telescoping

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Telescoping is not a single defect, but rather a collection of largely unrelated defects that happen to have a superficially similar appearance. Some happen on the winder, some on the unwind and some happen during storage.  Some are tight defects, some are loose defects and some are taper defects.

Here I show you how to tell which is which so you can set up your winder curves to minimize trouble.  Once the winder is optimized, you may need to also consider the other factors which are unique to each of the types.

https://www.youtube.com/watch?v=B5_swQrJabw

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Stop To Length

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Yellow Submarine Original Artwork copyright 2012

Of all the features of a drive system, the most popular by far is stop to length. This feature is particularly appreciated by operators of older lines in which the operator had to be vigilant to prevent winding a long or oversized roll.

Some techniques for stopping to length affect the quality of the wound roll and productivity of the slitter more than others. Slowly reducing the speed so that the targeted length may be reached is the worst method as the slitter is stopped with a varying acceleration. Slowing the slitter to a safe slow speed at a preset length count 1 is a pretty good option, but the slitter runs a long time at slow speed with resulting productivity losses. The optimum stopping method is to use a calculation to determine the optimum instant to stop the slitter and have it end at the target length.

It is quite simple to measure the instantaneous wound length of a roll. This is generally done with a surface wheel and encoder. The problem is in initiating a stop at a correct time to end the roll at the correct length. The length to be added to a roll depends on the integration of the speed as the line ramps down to a stop. Web gauge is not part of the length during stopping.

In web handling we do not use linear ramps because they introduce tension variations, so we need to integrate an S-ramp.  The S-ramp consists of 3 segments. These segments are rounding into the linear portion, the linear deceleration portion, and the rounding out to a stop. These are non-trivial and complexity is increased if the speed is too low to achieve the linear portion of the deceleration ramp.

Most S-ramps begin with acceleration. This is a segmented curve in the shape of a trapezoid. The sloped portions cover the rounding time. The S-ramp integrates the acceleration to produce a speed reference in the shape of a tilted “S”. In order to stop to length, the speed is integrated over the 3 segments to get the total length.

Your drive controller is capable of this calculation in the hands of the right programmer.

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Some spreaders are or should be driven.  However, tuning the motor is not a simple matter of matching speed as commonly thought.  From web handling we know the competing demands for the total available traction include overcoming bearing drag (cover hysteresis, inertia etc) as wellas spreading.  Knowing this tells you how to tune the drive for optimum spreading performance.  Find out how to make your motors and spreaders sing.

https://www.youtube.com/watch?v=UycaHZpMrdE

 

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Video Recording and Drives

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Yellow Submarine Original Artwork copyright 2012

Years ago, I was plagued with web breaks on a large high-speed paper coater. In the motor control room, we had a full time, 8 channel chart recorder. It was set to chart at slow speed continuously at all times and chart at a faster speed for every splice.

The chart recorder showed that tension ran along steadily and then suddenly dropped to zero suddenly just at the time the web broke. Most of the breaks occurred at the second coating station.

It didn't take a genius to determine that the problem clearly was the drive system creating the breaks. I spent hundreds of hours monitoring everything on the drive system.

Finally, we upgraded the drive and made progress with solving the web break problems. The drive upgrade consisted of purchasing 4 high-speed video cameras and recorders.  These recorders were coordinated with web speed and simultaneously showed the same section of the web at different points along the web path. Of particular interest were the cameras at the two coating stations.

The first day the cameras showed a small web defect (hole) passing successfully through the first coater. The hole would then tear apart at the second coater.

The drive system was fixed! The effort then moved to the paper machine which produced the defects and the web inspection system which ignored the defects.

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The Second T in TNT

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Yellow Submarine Original Artwork copyright 2012

The TNT’s associated with the quality of winding are Tension, Nip Loading, and Torque2. Torque2 is the second T and is used when control of Tension and Nip Loading is not enough to produce a roll without defects. Each of the TNT’s contribute to the wound in tension in a wound roll. Tension requires a drive at the winder. This can be a center or surface drive. Nip loading is a surface function. It relies on controlled nip pressure. The nip roller may be driven or undriven.

Torque2 (as used in TNT) requires two drives. The first drive is used to establish web tension into the winder. The second drive is used to modify the wound in tension with torque2 control. At least one of the drives must be a surface drive. Zero or one center drive can be used.

Once the first drive establishes the web tension into the winder, a base wound in tension is produced. The units are N/m or PLI. The nip load then adds to the wound in tension. Finally, the Torque2 produced by the second drive adds to or subtracts from the wound in tension. That’s correct, a negative Torque2 can reduce the wound in tension. Torque2 is the only tool in the TNT toolbox that can either increase or decrease wound in tension.

A design strategy is required to use Torque2 effectively. Torque2 is often described in “%” or “% split”. Does anyone know what a 60%/40% split in Torque2 means? I suggest that each of the TNT’s be calibrated in N/m or PLI. Then the contributions of each of Tension, Nip Loading and Torque2 can be controlled independently and added to give an indication of the wound in tension. Advice from winding and process experts may be sought at this time.

Next, a drive control strategy is required to implement the design requirements. I mentioned that Tension and Torque2 could be controlled independently. This is not quite true. To maintain web tension (correct speed), the total torque of both drives must be summed to the correct value. If one drive provides more load, the other drive’s load must decrease or the web tension will vary. In general terms, one of the drives (surface drive) is used to hold speed with a speed regulator. The speed regulator will then automatically adjust the torque for that motor to regulate speed. The second motor can be given a torque2 reference. The more Torque2 the second motor provides, the less torque will be required from the first motor. This is oversimplified and you will need help from your drive designer.

We must also consider what happens during a speed change. An acceleration torque is required to change the speed of the winder. We expect that the wound in tension due to TNT should not vary when the speed is changed. Inertia compensation should be applied to the drives to accelerate the winder in such a way that Torque2 does not vary. Again, your drive designer will be required to control Torque2 during speed changes.

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If you align rollers too closely, you cost your company money.  If you align rollers too sloppily, you cost your company even more money.  How much is too much?  Find out here how to avoid web path (registration) problems, web breaks and wrinkling by using science to determine maintenance standards.

https://www.youtube.com/watch?v=5OBQIKP9NQM

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Summer School - Roller Alignment How To

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Rollers need to be aligned close enough to avoid problems such as path control, wrinkling, web breaks and others.  This clip summarizes how to design rollers and frameworks to be alienable and how to align rollers upon construction, installation and periodically as needed.  In the next clip we will answer the more interesting question of how close must roller be aligned.

https://www.youtube.com/watch?v=0ZJtjj0iJhc

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Length Measurement

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Yellow Submarine Original Artwork copyright 2012

Producing rolls of a fixed length is a great selling point and may even be a requirement. Web length measurement is normally accomplished with a length or footage counter. This is a wheel of known circumference (1 foot or .25m) that rides along the surface of the web on a roller near the winder. The length counter can signal the winder to perform an index and cut at a specific length. Slitters may be signaled to slow at a certain length and then stop at the target length.

How accurate can this be? It cannot be exact. There are too many assumptions.

  • The web may shrink or expand after being measured.
  • The thickness of the web affects its length – do we measure on the roller or the outside of the web?
  • Does the web ever travel in the reverse direction (ex. roll back before starting after a cut).
  • We assume the measuring wheel doesn’t slip.
  • We assume the measuring wheel is the same temperature each day.
  • The length counter wheel may wear.
  • The PLC has a scan time which introduces error.

I have made very accurate rolls for some customers. That would be +80mm/-0mm on a 30 m roll. These were calibrated by rolling them out on the floor and measuring with a tape. Helping to achieve this accuracy involved a slow line speed, and stopping to make a square cut (no serrated knife cut a full speed). The roll was also shorter than the building so we could unroll it in the aisle.

The next question to ask is how does your client know your roll is too long or too short?

The length measurement can be improved, but error cannot be eliminated. Other technology such as laser interferometers promise higher accuracy at the time the web passes the sensor. Please see my article Achieving precise roll-length measurement and control in Converting Quarterly 2018 Quarter 2 pp. 46-52.

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Port Expanders

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Yellow Submarine Original Artwork copyright 2012

It is quite difficult to maintain some older electronic devices used in web handling. Many of these devices used serial RS232 communications protocols. They may also use DOS or old Windows programs. I am speaking of setting up old PLC’s, drives, weigh scales, resin systems, temperature controllers and many other devices.

Most new notebook computers do not even have a serial port. RS232 dongles which plug into a USB port on the computer may work, but my experience is these are difficult if not impossible to set up for all applications.

A practical solution is to use the port expander option available for most new notebook computers. These port expanders will often have the missing RS232 serial port.

The program to perform the device configuration may not be compatible with the operating system. In this case, read my previous blog on Virtual Machines.

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Production Data Storage

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Yellow Submarine Original Artwork copyright 2012

The controllers used in web handling have a lot of data, but not much storage capacity. Many manufacturers recognize this and collect and retain the data from the drive controller using programs typically including the word “Historian”. This may be used for equipment maintenance and to track customer orders and shipments.

The drive system controls speed, tension, roll lengths and diameters. Generally, the same controller regulates other roll quality parameters such as nip loading and torque split. It may also contain information related to product ingredients, treatments and coating formulations.

The drive controller has a short memory. That is all that is required for control. Long term data storage must be done on another computer. The computer may be the operator HMI, but will probably be a database on a corporate server. Special software and network communications equipment are required to communicate between the database and the controller.

Control engineers often think of data vs. time. It may be more useful to store data by roll # or order #. This is possible with correct programming. This requires programming work by database and control personnel.

The amount of data collected is truly amazing. When problems or complaints occur, it takes a long time to review the historian data to determine the fault. Analytics properly applied could help sort through the data to seek problems causing customer complaints. Eventually, the analytics may even help with preventative maintenance and in preventing defects from reaching the customer.

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Sharing Web Handling Tech

I am of a mind that “if you can’t sell it, give it away.”  Thus, much of my writings and other products, aside from my published books and Web101 school, I share freely.  Merely email me at DrRoisum@aol.comwith your completecontact information and “Best of Dr Roisum” in the subject line.  Then I will share via Dropbox a folder of goodies that I own copyright to.  These dozen documents are shared via a creative commons licensingthat means that you can use them with fair attribution, share them, but not sell it or change them.

Universities and other organizations are also following similar patterns with open access documents.  This makes sense as they are in large part publicly funded so we the public own at least part of the product.  This year, the Web Handling Research Centerat Oklahoma State University has also seen the trends. They have begun to put up the IWEB proceedings beginning with IWEB2019and will work backward 30 years to upload previous biennial conferences and then their dozens of masters and Ph.D. theses.  The URL routing is ShareOK.org / Handle / filename.  The search engine is rudimentary, so you may want to also supplement your searches using the RoisumLibraryavailable above or as an AbbottApp.

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Pneumatic Accumulators Calibration

Yellow Submarine Original Artwork copyright 2012

Pneumatic accumulators are designed to take up slack and maintain web tension if a drive stops. The need may come up during splices, cut-overs or due to equipment jams. Because the accumulator is part of the tension control system for the web handling line, it must be calibrated.

The first step is to cancel the tare weight of the moving roller assembly. This tare weight is a bulk property of the accumulator and is balanced with fixed air pressure. With web removed from the accumulator, adjust the pneumatic air pressure to balance the tare of the moving roller assembly. When properly balanced, it should be possible to raise or lower the accumulator by hand. Please be aware of the hazards associated with a sudden movement of the accumulator when pressure is increased or decreased. Record the pressure needed to tare the accumulator.

Calibrating the pressure difference needed to establish tension is more complicated. Thread a non-stretching rope or cable through the accumulator following the web path. Tie the rope down on the side toward the line pacer. A weight corresponding to the design tension needs to be tied to the other side of the accumulator. Be aware that the accumulator and the weight will travel during calibration - love your toes.

As shown in the attached diagram, the accumulator acts as a block and tackle pulley system with a mechanical advantage on the moving side. Very little web tension will raise or lower the accumulator, even though it has a considerable mass.

Determine the pneumatic pressure change required to balance the weight. You can expect that the pressure for full tension may be less than 10% of the pressure required for taring the accumulator. You may find a different pressure is required at the full vs. empty position (non-linear). You may find quite a bit of difference in pressure required to fill and empty the accumulator (hysteresis due to stiction of the cylinders). No one said this would be easy! Find the best value for the pressure difference needed to balance the weight corresponding to the design tension of the line.

This pressure difference must be scaled into web handling units of tension. That is N/m or PLI. This value will be needed in the controller programming or on a chart understandable by operators if manual regulator knobs are used.

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Is Web Handling STILL a Thing?

The answer is yes if you have trouble with baggy webs, curl, length and width control, position control or registration, web breaks, winding defects, wrinkling and more.  While research and new publications has decreased since its peak about the year 2000, application is as strong and steady as ever.  Web handling was a shiny new tool 30 years ago.  Now it is dented and scratched from daily use in 10,000 plants around the world.

https://www.youtube.com/watch?v=R4_kGm8nAeU

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Do YOU need Web Handling?

The answer is yes if you have trouble with baggy webs, curl, length and width control, position control or registration, web breaks, winding defects, wrinkling and more.  If you do need web handling, don't try to learn the hard way.  Go to school.  My last public school in the US is in Milwaukee, June 18-21, though I will be in Stockholm in late November if you can get your boss to spring for the ticket.

https://www.aimcal.org/web-handling.html

https://www.aimcal.org/web-winding.html

https://www.youtube.com/watch?v=tOBd-8S5M2E

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Why Drives Aren't Tuned

Yellow Submarine Original Artwork copyright 2012

Whine, Whine, Whine. Life is full of excuses.

Last week I was responsible for a drive upgrade. The day ended, the line is running and the drive with Out-Of-The-Box parameters and is not tuned. Let me list the excuses.

Installation took a long time.

  • The 3 phase cabling had “incorrect rotation”. These were big cables.
  • The drive had a fault.
  • It got late.
  • The process had leaks.
  • The contractors and electricians went home.
  • Management had production requirements.
  • The drive ran well enough.

I consider myself the preacher and the choir. I want drives in our industry tuned. Didn’t happen. Hopefully next time.

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AIMCAL is hosting my award winning and trademarked Web101 school on June 18-21 in Milwaukee.  This training has been taken by 5,000 students just like you.  As a bonus this year, the course will include a facility tour of Faustel where we will see web handling in action.  Details below.

https://www.aimcal.org/web-handling.html

https://www.aimcal.org/web-winding.html

Faustel will be hosting a facility tour and reception on Tuesday evening for those interested. The tour will begin after the conclusion of the class and will focus primarily on the Technology Center at Faustel's facility. At least two machines will be running as part of the demonstration to provide the opportunity for a close up display and explanation of Faustel's equipment. Join other attendees for this exciting opportunity and learn more about the Converting School classes!

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