Why does my web wrinkle and what can I do about it?
To fill demand during these difficult times, you may find yourself converting and processing web materials that are new to your operation. You may wonder why your webs wrinkle, you are not alone. Web wrinkles are a common challenge in any web converting application. Web wrinkles may be a new occurrence or continuing issue you have had for years. There are many reasons why webs wrinkle. I recommend reading CAC's white paper on web spreading found here: https://www.converteraccessory.com/papers/spreader2.pdf for an in depth report on web wrinkling.
Some of the most common causes of web wrinkles are:
Slight thickness variations, across your web, will create non-uniform tension profile. Measured across the web, where tension is higher, the web will tighten and "buckle" where tension is less.
Some webs are longer, in the machine direction, on one side of the machine when compared to the other side. The short (tight) side will have a higher tension than the longer side. This condition will make the web look "baggy" where the tension is less. You may encounter a bagginess in the center of the web.
Rolls that you must unwind into your process may be wound poorly and contain flaws.
Rollers may deflect under web tension. Your web will "compress" inward when rollers are not consistently linear.
In high speed applications, webs can float around rollers. When webs are not in traction with rollers, they can wander from side to side. Among other web handling issues, wrinkles will occur when webs wander.
Heavy material rolls can deflect or buckle on their supports. Webs will wrinkle where unwind or rewind material rolls are not linear due to heavy roll weight deflecting their support mechanism.
Web tension level may vary through your converting process. Webs will wrinkle due to tension variations through various converting processes.
Skewed (nonparallel) rollers are the number-one cause of web wrinkles. Remember the web handling principal that states: a web will bend out of its normal running plane to maintain a perpendicular angle to a roller, in its entry span to that roller with which it has traction. Web tension varies when webs bend out of their normal running plane and wrinkles will occur.
There are many passive and aggressive anti-wrinkle devices that can help you eliminate wrinkles in your web. Most anti-wrinkle systems provide fast return on investment by decreasing or eliminating wasted product due to defects associated with web wrinkles. In addition, anti-wrinkle systems can allow you to run your converting process at a faster linear speed. Applying proper anti-wrinkle device to your process, may even allow you to run materials you found previously impossible to run.
Expanding surface anti-wrinkle rollers, like CAC’s WrinkleSTOP®, are an excellent choice for almost any converting process where web wrinkles are an issue. This type of anti-wrinkle roller removes web wrinkles with a surface that lengthens as it rotates under your web. WrinkleSTOP® is web converting’s premier anti-wrinkle system by providing these features:
Easy install
Versatility to work with virtually any web material in almost any converting application
Works extremely well with super thin webs
This roller will not distort your web
Tension profile of your web remains constant across its linear surface
WrinkleSTOPs smooth surface that won’t mark your web
WrinkleSTOP® is an extremely aggressive anti-wrinkle device, however it is adjustable
Adjustability is with standard tools; independent from end to end
0% To 100% anti-wrinkle adjustment can be made while the roller is in motion
WrinkleSTOP can be supplied with different sleeve materials to handle adhesives, chemicals, high heat or excessive ozone
Often, WrinkleSTOP easily replaces standard idler rollers or other types of anti-wrinkle devices
Unsupported web lead-in distance and lead out distance is not critical, so this roller is easy to position in your process
FAST return on investment
WrinkleSTOPis made with pride in the USA!
Almost all anti-wrinkle rollers "work" to some extent. Some are passive and provide minimal benefits while others are aggressive and remove more wrinkles. The question is _ how will each type effect your web and process in order to get the wrinkles out of the web? Will the anti-wrinkle device mark or scratch your web? Will the anti-wrinkle roller stretch or distort your web?
WrinkleSTOPs expanding surface incorporates a smooth, linear surface. Perhaps its' best feature is that it will not adversely affect your web or process. All while providing extremely aggressive, industry best, anti-wrinkle properties.
**DISCLAIMER - A great deal of time has been invested in the development of our weekly tech tips. To the best of our knowledge, they are accurate. It is up to the user to verify all results.
THE AUTHOR ASSUMES NO LIABILITY CONNECTED WITH THE USE OF THIS INFORMATION OR THE RESULTS OBTAINED FROM IT.
