Web Handling & Converting

Your supplier has provided you with a pretty crappy wound roll.  Captured inside the roll for weeks, the web is just waiting to misbehave.  Let it loose and it will misbehave at the first opportunity; the first roller.  However, if you tame the web at that first roller; it might make it the rest of the machine without trouble.

That first roller should conform to the Shelton ‘Big and Slippery’ Law.  What we are doing here is to kick in the flattening effect because spreading might be either overkill or impractical due to the changing geometries of an unwind.

This art and craft has yet to be learned by most machine builders.  Over and over again we find them putting traction enhancers such as grooving on the first roller.  Over and over again the savvy web-handler puts Teflon tape on that roller to ‘grease’ it a bit to provide tolerance for a web that is less than perfect.

Of course, tricks like this do have limitations.  If the web is too crappy, no amount of effort will save it.  Also, getting it by the first roller doesn’t mean you can drop your guard after that.  Roller design problems such as excessive deflection, diametral profile and misalignment can still do you in.  Even so, the machine will run just a bit better if this first roller is treated differently.