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Filed under: General Business Topics --- Yolanda Simonsis @ 11:15 AM

As a first-time blogger, the burning questions I have on my mind beg for converters to respond . . . although converter suppliers' answers wouldn't be unwelcome.

The biennial CMM Show just concluded on April 21st at Chicago's McCormick Place. I gotta tell ya, I was bafffled by the lack of attendance, still many suppliers said they weren't displeased with the sales they negotiated on the show floor. The show was significantly smaller and the number working pieces of equipment was definitely in the minority.

The show is moving to Rosemont, IL (just outside of O'Hare Airport's boundaries). My first reaction was this new venue will hopefully attract more converters who want to get in and out quickly from Chicago. Other's say visitors want the "Chicago experience." I say that can always be addressed with shuttles.

The bigger question is, will the new location attract suppliers with working equipment?

We need to inject some excitement into this industry!

PFFC Editor/Associate Publisher
Yolanda Simonsis

Filed under: Rollers, Traction --- Tim Walker @ 10:45 AM

As an engineer, sometimes you trip across something that gives you that "best invention since slice bread" feeling. Well, there is one at CMM that your should take a peak at.

Laser gyro roller alignment.

The Paralign(tm) from Pruftechnik looks like it could fly a helicopter. You "sweep" one roller as your reference, send the date wirelessly to a laptop, then continue "sweeping" other rollers in your web line to get tram and level errors from the reference roller. Their literature says it is accurate to 0.4 mils per foot, which should exceed most converters needs. The system is fast, so you can do many, many rollers with minimum downtime. Whether the cost of this service can be justified for you operation is based on what downtime costs you.

The folks at Pruftechnik has brought this new device to the US. They are back in a corner booth at the show, so you may not have notice them, but please do. Also, get info at their website:
http://www.pruftechnik.com/alignment/products/paralign/paralign.htm

Filed under: Winding, Unwinding, Roll Defects --- Tim Walker @ 07:36 AM

I often advocate the benefits of controlling entry to a winding roll with a nip or gap roller. Both options will reduce wrinkles and improve the entering web's alignment. Nipping rollers provide three benefits beyond gap rollers. Winding nips will squeegee air entrained by moving web and roll. Winding nips will press down on large diameter lanes and let air in small diameter lanes, promoting a more cylindrical roll (if the winding nip is held parallel to the roll's axis of rotation). Winding nips will increase the tension of the winding roll's outer wrap above the upstream handling tension, increasing roll tightness. Definitions: Gap roller, gap winding - In center winding, a roller is held in close proximity, but not touching the winding roll. Winding nip roller, nipped winding - In center, surface, or combination winding, a roller is pressed with against the winding roll to squeegee entrained air, promote cylindricity, and increase roll tightness through nip-induced-tensioning. -tjw

Filed under: Rollers, Traction --- Tim Walker @ 07:35 AM

If you come from the world of paper products and are moving into films, one of the first things you'll fight is scratches. You relatively rough, high tension paper could drive you old overly-greased rollers, but the smooth, low tension film - no way. The result - scratches. When I run in this, I recommend a dual action plan. 1) Improve you idlers to be easier to turn (a whole topic in itself), and 2) switch to rough rollers. Many people balk the idea of rough rollers, since they assume a rougher surface will create more scratches. Are they right? Sure, if you put in a rough sand-blasted roller and keep the old high-drag bearings, you may increase your scratches, but that not the goal. If the rough roller prevents air lubrication and keeps a roller speed-matched to the web, then you will be scratch-free. I can rest my eyeglasses on a piece of sandpaper without scratching them. Abrasion requires two things: normal force and relative motion. It's the relative motion that underlies scratching.

Continue reading"Should you be afraid of rough rollers?"

Filed under: Coating, Laminating, and Printing --- Tim Walker @ 03:31 PM

Like the song says "I don't know much about chemistry", but what I do know is that these processes, coating, laminating, and printing are all an interesting interaction of chemistry and mechanics. It's the mechanical part I bring to the table.

I don't expect to post much in this section of convertingblog.com, but I thought the blogsite would be lacking without this subtopic. You can only make so much money unwinding, transporting, slitting, and winding (alot of money for some folks), but if you coat, laminate, or print, you can go further.

For all you wet-end converters, please drop in and give us your converting challenges, victories, and oddities.

Thanks tjw+

Filed under: Tensioning, Web Mechanics --- Tim Walker @ 03:12 PM

In preparing for my seminar at the CMM show this month, I was working up the list of what creates tension variations. Most people focus on machine direction tension variations without giving much thought to crossweb variations.

Why are crossweb tension variations snubbed? Probably several reasons. Unless the web goes slack, you many not see a crossweb tension variation. It rare and difficult to measure crossweb variations beyond slackness or left-right transducers.

What creates the biggest crossweb variations?

Continue reading"Crossweb tension variations"

Filed under: Rollers, Traction --- Tim Walker @ 12:55 PM

Handling smooth films or papers on smooth rollers is like driving through puddles of water with bald tires. You can do it slowly, but its hazardous at even moderate speeds.

Many converter never run into this problem. If you product is porous (like many nonwovens) or rough (like abrasive-coated papers), you have a way to prevent air lubrications. But if you run smooth, non-porous webs, you have to manage the lubricating air layer with roller roughness.

What is your favorite rough roller?

Continue reading"What's your favorite rough roller?"

Filed under: Guiding, Spreading, Wrinkling --- Tim Walker @ 12:44 PM

Maybe this is obvious. Traditionally, I've grouped these three web handling sub-topics into 1) guiding and 2) wrinkling/anti-wrinkle. Guiding is about lateral registration of the web, whether with active automatic web guides or passively with crowned, tapered, and skewed rollers at one topic. Wrinkling is about keep the web from buckling, either laterally or in the machine direction, and the use of spreader or anti-wrinkle rollers (not the same thing) to prevent them.

Why group them together?

Continue reading"Why group guiding, spreading, and wrinkling together?"

Filed under: General Business Topics --- Sean Craig @ 09:08 AM

During a recent CMM International exposition in Chicago I was asked "What makes a product ergonomic and how does your new line of products qualify?" Here is my response.
A product is ergonomic, or an ergonomic solution, when it aids employers in matching human capabilities and limitations with the tools they are required to use in the workplace. Use of such products reduce the risk of Work-related Muskuloskeletal Disorders (WMSDs) which is the goal of ergonomic solutions.

Continue reading"What makes a product ergonomic?"

Filed under: Slitting, Cutting --- Reiny Schable @ 08:59 AM

To determine the cause of slitter blade wear, look for the tell-tale signature wear patterns on blades that will help you differentiate between blade-to-blade wear, and web-to-blade wear.

Once the distinctive patterns of wear are classified, the solutions will be easier to recognize and implement without resorting to "taking a stab in the dark"' or applying an unnecessarily costly solution to a relatively simple problem.

Continue reading"Determining the cause of slitter blade wear"

Filed under: Winding, Unwinding, Roll Defects --- Tim Walker @ 10:05 AM

Rubber covered rollers are common in almost any nipped process. Without a compliant covering on one or both rollers, the nip pressure will vary greatly from roller misalignment, diameter variations, uneven loading, roller deflection, and web thickness variations. Steel just doesn't deform much, so even variations as small as 2-10 mils can create larger nip pressure variations.

The compliance of a rubber covered roller is forgiving. The rubber (or elastomer) will deform from the nip load, often as much as 30-100 mils. If the rubber covering is deflection 50 mils, a 5 mils error from product variation or deflection will create a 10% pressure variations. The same 5 mils error in a steel nip will likely cause a gap in the nip. In some cases, a 5 mil thick lane in the product could end up carrying 100% of the nip load, creating what could be a 100-1000% pressure change. Whew.

So what about winding nips. Should they be elastomer-covered or hard?

Continue reading"When should winding nips be rubber covered?"