Visitors and readers of this page are invited to submit questions and/or problems concerning winding and finishing. The topics can deal with operation, design, productivity or any facet of the finishing operations. The Finishing & Converting Page will act as a moderator in this venture and at times offer comments concerning the questions posted by the readership. Readers of this page are encouraged to offer solutions, opinions or comments to the questions posted. Some questions may be referred to the misc.industry.pulp-and-paper newsgroup for comments by their readership.

TOPIC #1 AUTOMATIC SLITTER POSITIONING SYSTEMS
TOPIC #2 LOOKING FOR PETER WATERHOUSE
TOPIC #2 REEL SPOOL WRINKLES
TOPIC #3 LOOKING FOR A ROLL HANDLING SYSTEM
TOPIC #4 DISHING ON A JAGENBERG VARI-DUR 2 DRUM WINDER
TOPIC #5 REWOUND ROLL VIBRATION DURING WINDING

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POSTING #1 AUTOMATIC SLITTER POSITIONING-- On May 28 we received the following E-mail: "Convince the boss to buy an automatic slitter section." We do not have permission to use the writer's name. The E-mail is on file.

Response: Here is some ammunition to assist you in convincing your boss!

There are several reasons for a mill to retrofit or purchase an automatic slitter section. They could be safety, consistency of shipping roll width, better slitting, reduced dusting, etc. The main reason and the one that will determine the ROI (return on investment) is improved cycle time. Whether or not there is an appreciable gain in winder productivity to justify your mill's investment can be determined by a careful analysis using one of the numerous software programs available. Before launching such a study, it may save some time and money to establish if the potential gain is in the ballpark. The following steps may establish your position.

• Determine the AVERAGE number of slitter set-up changes the winder makes in a 24 hour period. Establish how long a time period it takes to make a slitter set-up. You can do this by timing a number of slitter set-up changes and averaging the time required. Don't forget to put in a factor for rethreading the winder in about half of the slitter set-ups. No rethreading is required with automatic slitter positioning.
• Automatic slitters are effective from a cycle standpoint not only because they can reset fast but also that the actual resetting procedure takes place during a set change or jumbo change There is no time allowance required when changing slitter setup using an automatic slitter positioning system. Machinery builders may suggest using ½ to 1 minute time allowance per slitter set-up for automatic positioning systems change.
• Now how do we find if we are in the ballpark? Multiply the number of slitter set-ups in 24 hours by the number of minutes it takes to make a set-up. This is the time saved per 24 hours. If you want to be more conservative use .5 minutes for an automatic slitter set-up time. If the average slitter set-up time is 6.5 minutes and your winder operation averages 10 slitter set-up changes/day, your calculation should look like this:(6.5 x 10) - (.5 x 10) = 60 minutes time saved
• It may be more meaningful if the saving is expressed as number of sets per day. Divide the savings in minutes by the time to wind a set including the set change time. If it takes 7.5 minutes to wind a set and .7 minutes for a set change, the result of the automatic slitter improvement is the equivalent of 7.3 sets per 24 hours through the winder.
  

Readers are welcome to add or comment to the this response.RETURN TO "INDEX OF TOPICS"

POSTING #2. LOOKING FOR PETER WATERHOUSE & REEL SPOOL WRINKLES--This E-mail received June 3. "I am an ex-coater/super/winder superintendent and I am looking for an address/phone # for a Peter Waterhouse I used to work with him. He is a Canadian. Any info.-he is a winder consultant. Are you familiar with "accordion(sp.?)"wrinkles at the rereeler. I am working with an LWC mill who runs into this problem at their rereeler past the OMC on lightweight/very smooth grades. It generally only happens close to the reel spool at the windup (around 10 inches from core). Any suggestions? Great web site, I'll spread the word, looking forward to hearing from you."

RESPONSE: PETER WATERHOUSE I know Peter Waterhouse who has been a consultant in North America for many years but unfortunately not his phone number or address. Do any of our readers know how to contact Peter?

PETER WATERHOUSE FOUND! (He probably didn't even know he was lost)-August 1 received an e-mail from Everett Harriman of Falmouth Associates Inc. who was good enough to look up PW in the CPPA Directory and found his listing. We are reluctant to put this information on the net without Peter Waterhouse's permission. Please contact The Finishing & Converting Page at lbagnato@citicom.com and we will be happy to give you the contact information.

RESPONSE: WRINKLES-Regarding the wrinkles down near the spool of the windup, there isn't much information to go on. I have heard of "accordion type" wrinkles that go full width in the CD and "accordion" wrinkles near the edges of the roll in the machine direction and sometimes accompanied by a break, the type that will happen on a duplex winder near the core. Perhaps one of our readers can shed some light on this. Many mills are adding centerwind assists to their rereelers to get improved structure control at the rereeler. You may want to review TIP #2 on the "Winder Operation Tips & Shortcuts" link" of the Winder Home Page. There is also a good paper available and listed In the "Technical Publication Directory" link that you can request. This paper deals with reels which are very similar to those of the rereeler, making to large a jumbo, to small a reel spool, poor structure control. etc. This paper discusses areas that can be a contributing factor to the problem you describe.

FOLLOW UP RESPONSE: Number 1 June 16 Use a "J" line

RegWal@aol.com writes: "Use a line from reel spool to O.D. of reel on face of reel and check with strobe light while running. This will show any slippage due to tension or caliper variations in the parent reel. If there is slippage present then I would look at winding tension as a starting point."

FOLLOW UP RESPONSE Number 2 June 19, 1996 Increase reel amps

Anne Campo writes "In regards to the reel wrinkles in posting #2, we encountered what we called crepe wrinkles near the spool on our #2 paper machine which is a 630 cm (248") newsprint machine that was converted to a soft calendar machine. These wrinkles showed up as our smoothness went up as we increased gloss and added more clay filler. They were always on the front of the reel (a good part of our reel), about 9-12 cm (3.5" - 4.75") from the butt. We felt the paper on the reel was running ahead of the wind on the bottom so we increased out reel amps. To make a tighter wind on the reel and it worked for us".

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POSTING #3 LOOKING FOR A ROLL HANDLING SYSTEM. Louis Wong writes-"Any roll handling system manufacturers consultants suppliers out there? Or can anyone recommend a good company? We are a boxboard mill in Hong Kong. Capacity 800 tons a day. We need an efficient roll handling system that can move rolls and pallets quickly in a rather confined space. Open for quotation. Companies with an Asian support office a plus. Concordia Paper Limited, 67-73 Fuk Hi Street, Yuen Long, NT, HONG KONG T: (852) 2486-6100 F: (852) 2477-9478 "

Readers should contact Louis direct at louisedp@hkstar.com If you would like your response posted on the FINISHING ROUNDTABLE-Copy to lbagnato@citicom.com . RETURN TO "INDEX OF TOPICS"

POSTING #4 DISHING ON JAGENBERG VARI-DUR 2 DRUM WINDER Anne Campo's E-mail of June 18 is as follows: "I work on a 850 cm (340") wide Jagenburg Vari-Dur winder. We run 45 gm. to 52 gm newsprint (27.5 to 32 #/3000 sq ft). We have always had a problem of dished rolls both front and back. The dishing is bad enough to cause a recess in the core. This recess can be up to 15 mm .(6"), resulting in a culled roll. In the past we have noted that the dishing is worse when reel condition is poor (the humpier the parent reel, the worse the shifting), top sets are worse than lower sets, the more rolls we run per set, the worse the shifting. We are now having trouble with shifting even on 45 gm yet we have some of the best cross machine profiles for caliper and bone dry and moisture that we have ever had. Alignment on the winder has bee checked. Any suggestions?

RESPONSE BY WINDER HOME PAGE It is generally accepted that in order to have dishing the winding roll must move sideways during winding. In order for this sideways movement to occur, there must be a cross machine thrust force present that is greater than the forces restraining the roll. Thrust forces in excess of 10,000 pounds have been experienced. This thrust can be caused by winder alignment, mechanical play, binding, looseness, mechanical restraint of the core slide cross tie, non-cylindrical web or nip rolls, excessive deflections of components, web basis weight, caliper and elasticity profiles and incorrect adjustments of TNT. Admittedly, this is a long laundry list but offered only to indicate that dishing is a complex problem and not easy to solve.

Anne, there is an excellent technical paper by Robert G. Lucas titled Dishing in winding rolls of paper. It was reprinted in the TAPPI Journal, Vol. 60, No. 7, Copyright 1977 by TAPPI. This paper discusses 6 types of roll dishing, one type being the symmetrical dishing about the machine centerline that you describe. If you can't locate a copy, TAPPI may be able to assist you. In your particular case, this reprint is well worth tracking down.

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POSTING #5 WOUND ROLL VIBRATION ON BOND GRADE Jeff Comer writes, "We are getting wound roll vibrations on some bond grades. The wound roll vibrates and sometimes has a slight rumble. Because this has just happened in the recent past we suspected the mechanical winder and tightened and aligned.. Have any of your readers experienced this?"

RESPONSE: Wound roll vibration has been with us a long time. It is particularly present with grades that have a low coefficient of friction and layer to layer grip is high under conditions of little or no calendaring, tight winding, high moisture or high percentage of Kraft. Some of the things that may reduce bounce are run more calendar nips, less tight winding, more uniform hardness profile and lower moisture. From a mechanical standpoint, experimenting with torque distribution and acceleration rates can be helpful. Tractionizing the front winder drum also appears to be beneficial in reducing bounce. If the drum has been previously tractionized and is worn smooth you may want to consider re-spraying.

SAFETY ALERT! If a winder has vibration or wound roll bounce, check and make sure the winder is well guarded. Sets have been known to bounce out of both shafted and shaftless winders onto the operating floor. The winder should have ample guarding to completely encapsulate the winding roll during operation. The rider roll program should be such that the rider roll never completely unloads or raises from the winding roll during operation. Be cautious making changes. Make changes in small increments and fully evaluate each change before continuing to the next change.
ADDITIONAL RESPONSE: Received the following e-mail July 17 from Graeme Everett who writes "I noticed Jeff Commer asking about winder vibration. We've had a fair bit of experience with that so if you like you can suggest he contacts me. Also he should get a copy of Alex Olshansky's article about Roll Bouncing (Beloit)."Jefff: You can contact Graeme at <r&d@taspulp.co.nz>.

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Notice: Any comments contained in the Roundtable are made in the interest of imparting information only. Any changes to the equipment or process should be checked with mill experts and the machinery builders of the equipment in question. The Finishing & Converting Page or Luigi Bagnato assume no responsibility for the information or how it may be used.

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