Skip to main content

Trim removal on slitters

A trim fan attached to a slitter.
As discussed previously on this blog the process of slitting (at its most basic) can be reduced to the one-line description of 'a big roll is loaded on one side of the slitter rewinder, and smaller rolls are loaded off the other side' and that's fine... most of the time.

Here comes the example!
If a 1000mm wide roll is loaded onto a rewinder and is slit down into rolls that are 212mm wide then four rolls would be produced.  If your mental maths is up to scratch you might have noticed that 4x212 does not equal 1000, and that means that from the original / master / jumbo roll there will be roughly 117mm left over.    Sometimes this happens because the edges of jumbo rolls are discarded due to damage, print reasons or simply because the material being slit isn't coated all the way to the edges of the roll.

So what happens to this waste material?
Waste material can be wound onto cores in the same way 'correct' rolls are, but sometimes it is preferable to discard this waste rather than collect it, and that's where trim removal comes in:

A quick look at a couple of slitter trim removal methods:

  • Trim winders
    Trim winders do exactly what you would expect them to, they wind trim on a part of the machine set apart from the rewind section of the slitter.  The advantage of using trim winders is that trim can be collected in such a way that operators only need to remove the collected waste once every few jobs, rather than at the end of every job.  Trim winders can also help maintain web tension.
  • Trim blowers
    Trim blowers do in fact work by sucking... sort of.  By using a venturi pipe or a suction tube waste trim is simply sucked away from a position close to the point of slitting and carried to a central collection point or dropped into a bag that looks like a big fishing net.  A venturi pipe is a 'Y' shaped pipe that creates a vacuum effect when air is passed through it.
All methods of trim removal have their upsides and downsides, so choosing the most efficient method for your own processes is vitally important, and we're here to help.

Comments

Popular posts from this blog

We need to talk about how you're handling this...

At the risk of sounding like I'm marketing for them instead of Universal I'd like to mention  Package Print Worldwide ( @PackPrintWorld ) again.  We contributed to the safe materials handling article in the new issue of Package Print Worldwide, with particular focus given to our roll handling trolley .  We have recently expanded the range of material handling attachments for the trolley and have seen the number of enquiries rise considerably.  Sadly safety is a subject that is sometimes (thankfully only rarely) overlooked by some companies, and when it comes to safe roll handling the risk of personal injury is one that is easy to minimise with the correct equipment.  We have priced our materials handling equipment at a level that should be easily affordable to all, so there's no excuse for lax safety! More roll handling information: Find out more about our roll handling trolley... Reducing roll handling risk and increasingly productivity...

Slitters save money (and energy)!

If you look in the new issue of Package Print Worldwide ( @PackPrintWorld ) you'll spot a photo of our rather handsome X3 Slitter Rewinder on page 18, the reason this slice of cool blue is on page 18 is because it is a good example of one of our energy (and money) saving slitters.  A large part of my job at Universal Converting Equipment involves working on press releases and talking to editors and journalists, and while this bit of coverage is one of many I thought I'd mention it here on my own blog because energy efficiency is a topic we've been talking about a lot recently. Reducing energy usage has long been a hot topic in our factory (and equally importantly in our design suite), and over the last few months we've started to let the world know what our machines can do to reduce energy consumption.  I'm particularly proud of this aspect of our machinery as reducing energy consumption is something of a personal mission of mine (I even cycle to work!), so I t...