Maxcess International -Fife, MAGPOWR, and Tidland present Converting Blog

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Filed under: General Business Topics --- khevenor @ 06:10 AM

I had the opportunity last week to attend the RadTech winter meeting in West Palm Beach, and was impressed by the passion of its members as well as their ability to come together as peers and competitors and work for the good of their particular market segment. The group is involved in diverse markets such as automotive, wood finishing, plastics, composites, and of course printing and packaging, and does a great job representing the needs and benefits of UV/EB technology across each market. In fact, the group is hosting a show/conference March 6-7 in Los Angeles and is offering a substantial discount to end users in the package printing and converting industry. You can find the details for uv.eb West 2007, and if you are interested in registering with a discount, send an email to Mickey Fortune of RadTech.
This is just one of the many active associations in our industry. Are there others that you feel your peers should be aware of? Or are there other resources you rely on? Share with us!
- Keith Hevenor
Editorial/Conference Director
CMM International

Filed under: Tensioning, Web Mechanics --- Tim Walker @ 09:00 AM

Q: Which is the best direction for a dancer roller's motion, horizontal or vertical? Also, what is better, a linear or pivot dancer motion?

A: I don’t have a strong preference on horizontal vs. vertical, but I am strongly in favor of pivoting dancers over linear dancers.

I prefer a vertical dancer arm with horizontal motion so that gravity is perpendicular to the tensioning direction, but make sure the dancer arm is hanging (as opposed to standing) with the the pivot point above the roller. Hanging dancers are 'sloped' to run stable; gravity tends to pull the roller back to its null position. Standing dancers, with the pivot underneath the roller are destabilizing with gravity trying to pull the roller away from neutral position.

My preference for pivoting over linear is based on observation of friction and sticking almost always higher in linear systems. If well-engineered, there is no reason a linear system can work great, but too often a linear dancer has more trouble holding its alignment, creating tension variations and wrinkles. A pivoting dancer can also be poorly engineered, but you have a better change to get low friction in a rotary bearing and simple structural design can translate a well-aligned pivot shaft into a well-aligned roller.

-tjw

Filed under: Winding, Unwinding, Roll Defects --- Tim Walker @ 09:00 AM

Where is the best position to nip a winding roll?
12:00 on top of the roll
3:00 or 9:00 on the side of the roll
6:00 on the bottom of the roll

12:00?
+ If you have a noodle-shaped nip roller (the L/D is over 10), the 12:00 position lets you use the roller's weight to create the nip load, avoiding the deflection of applying the nipping load from the roller's journals.
- This is a default closed system and needs to be counter balanced or other method to open the nip in case of a power loss or emergency.
- The nipping load is the combination of roller weight and external load. You may need to add or subtract from the roller weight to get the desired nip load.

3:00 or 9:00?
+ The nipping load is perpendicular to and independent of gravity, making it easy to convert pneumatic load into nip load.

6:00
+ If the nipping roller has enough stiffness, it can offset deflection in a noodle-shaped winding roll (again L/D>10) or deflection from heavy slit rolls winding on a lock-core or differential shaft.
+ In two drum surface winder, the rollers aren't at 6:00, but form a nest for the winding roll to sit and use the rolls weight to create much of the nip load.
- This position may be the most difficult to thread up.

I've seen all of these clock position used successfully. In most cases, the nip load and deflection issues can be managed with good engineering. I've lately grown fond of the bottom nip after realizing some of the best wound rolls I've seen have this orientation. Don't underestimate the value of a straight, rigid nip roller to impress its goodness into the winding roll.

-tjw

Filed under: General Business Topics --- khevenor @ 04:31 AM

A recent article in Time magazine about a company called Enfucell got me thinking about some of the hot new technology opportunities on the horizon for converters. Printed electronics and RFID represent two of those areas, and both are important in the vision of Enfucell. The company's product is a thin, paper-based battery that is extremely inexpensive and, at least in the short term, holds a lot of promise for applications such as RFID. Using coating technology to apply zinc on one side and manganese dioxide on the other, the company creates the product it calls SoftBattery. Enfucell notes that RFID tags, which do not draw constant power and lend themselves to the battery's thinness, are the perfect fit for such a power source. These are just the kinds of developments that will keep the converting industry strong moving forward.
- Keith Hevenor
Editorial/Conference Director
CMM International

Filed under: Guiding, Spreading, Wrinkling --- Tim Walker @ 02:13 PM

Contributed by Tim Walker

Several specialty rollers have spiraling patterns on their surface. Why are spiral roller surfaces so common and what is their advantage?

Some examples of spiraling roller surfaces are:
1. Spiral tape applied to a roller.
(Spirals are almost always begin at the roller's center and helix outward in opposite directions to either end of the roller.)
2. Spiral ridges cut into a roller surface, either as square or triangle waves cut into a hard metal surface.
3. Spiral grooves at angles from almost parallel to the machine direction to 45 degrees or more off MD parallel.
4. Spiral grooves cut into a rubber covering at an biased angle off perpendicular to the axis of rotation.
5. Diamond groove pattern with two spirals running the full length in both directions.

Why so many spirals?
1. The mesmerize engineers and operators into think they provide spreading, much like the optical illusion of a spinning barber's pole.
2. Grooves and ridges an effectively channel an entrained air layer, much like grooves of a car tire help channel water when driving through a puddle. In this case, the spiral shape doesn't add anything to the traction benefits.
3. Ridges can effectively break up a large wrinkle into several non-damaging micro-wrinkles, but will not have any spreading effect.
4. A spiral roller that is slipping relative to the web, such as dragging a fabric over a spiral roller with the V-shape pointing upstream is a spreader. A rotating spiral that matches the web speed does not spread, like a snow plow doesn't move snow if the truck isn't moving.
5. The angled cut in the rubber roller spreaders (such as Finzer's FlexSpreader or American Roller's ArcoStretcher) don't need to be spiraling to spread the web. The mechanics of spreading is related to the lateral flexing of the flutes between the spirals.
6. Spiral ridges and grooves will run quieter than axial ridges and grooves that may create a beat or harmonic noise (and be surprisingly loud).
7. Spiral ridges and grooves will break up wrinkles better than MD ridges or grooves that may catch and hold wrinkles, especially with thinner webs.

So spirals do have advantages, but don't let them mesmerize you into benefits that aren't there.

-tjw

Filed under: General Business Topics --- khevenor @ 05:56 AM

I don't know for sure, but I always assumed that the confetti dropped on New York's Times Square was scrap paper from somewhere saved temporarily from the landfill and chopped up to be flung through the air in celebration of the big event. I thought maybe it even came from the printer scraps of the office buildings in the area. Whatever the case in the past, this year the confetti and the messages it conveyed were deliberately produced and tied into a mass marketing campaign. Target sposnored this year's confetti drop (as well as 3D glasses to help viewers see the company's logo pop from the crystal ball dropping above Times Square) and had the confetti specially produced with themed words to be dropped in stages during the hours leading up to midnight. From what I've read, the messages--words such as "peace," "celebrate," and others--were a nice idea and brought a new twist to the evening. But in the end, the whole thing was still a marketing effort, and I just hope that Target's converting and printing partners were able to get a piece of the action. In this increasingly competitive marketing environment, converters and printers need to actively pitch their clients new and innovative ideas that can benefit everyone involved.
- Keith Hevenor
Editorial/Conference Director
CMM International