Precision Roll Solutions offers two rolls that combat this common web handling issue
Wrinkles have been a major issue in web handling applications since the beginning of converting technology. While the root cause can vary, one solution for eliminating web handling wrinkles may be as simple as installing either of two specific types of rolls designed to address this challenge.
No two webs or web lines are exactly the same, which often makes identifying the root cause a process of elimination. PRS Web Control (formerly MECA) helps minimize the list of possible causes with two roll designs that focus on eliminating web handling wrinkles.
Our reverse taper roll, also referred to as a reverse crown roll, features a concave surface that has a larger diameter at the ends than in the middle. This design encourages the web to climb up to the high side of the roll, gently stretching out the web and thus eliminating wrinkles.
Likewise, grooved rubber spreader rolls help with eliminating web handling wrinkles by flexing the web outward in a spreading action that pulls the web taut. We cover the roll with very soft rubber that features grooves starting in the center and spiraling outward. This roll design is ideal for very thin substrates as it enables converters to run at lower tensions and higher line speeds.
Use this checklist for eliminating web handling wrinkles
Identifying the root cause of web wrinkles often comes down to a relatively small number of variables that exist outside the influence of roll design.
- Machines out of alignment – This should be the first detail to check when eliminating web handling wrinkles. Investing in new rollers is a waste of money if your machine stands have shifted out of alignment.
- Not enough web support – Check the space between rollers, as wrinkling tends to occur more often on longer spans. Idler rolls provide the needed support to avoid this issue. A good rule of thumb uses the width of the web as a starting point. You may need additional idler rolls if the unsupported span is 3x the width of your web.
- Poor web quality – Issues such as poorly wound parent rolls can result in web wrinkles. Likewise, excessive parent roll run-out can lead to increased vibration and web flutter.
- Inconsistent roller geometry – This issue can be the result of poor initial manufacturing of the roll, but excessive surface wear also can create problems over time.
- Web expansion – Fluctuations in temperature or moisture content can cause variation to the web material. Strategically placing a spreader roll such as MECA’s grooved rubber spreader roll may remove the tendency of the web to wrinkle.
- Roll deflection – Rolls can tend to bow under the load of the web. Eliminating web handling wrinkles in this case may require an assessment of the total system because of all the variables involved.
When ordering, make sure to share details with your supplier such as the amount of web wrap, web tension (PLI), web width, maximum line speed, and any nip load (PLI). The PRS Web Control team can guide you through these questions.