laminate two type of fabrics together

Have a project coming up that would involve taking two rolls of different material and spraying glue on the bottom roll and after the glue is applied then both of the fabrics be laminated together.
Boss wants us to do this with AC variable speed drives. Any professional thoughts on this. From what little talks we have had it looks like there would be some type of feed belt that would pull the fabric off the bottom roll and glue be sprayed on the fabric and then both the bottom and top roll go through some type of nip rollers to compress them together. Looks to me like you would tell the rollers to run at a certain speed which may equal feet or yards per minute and a encoder or dancer switch that would feed back into the plc or inverter to trim the speed up or down in order to ensure that both the rolls of fabric where feeding at the same rate. Anyone ever done something like this? Any suggestions on the correct approach to take.

being as the end product rolls on one roll could you not just use one roller to pull two rolls and apply glue before the two materials are feed through the nip rollers ?

IN THEORY one drive motor on finished product reel could suffice.

The finished roll will need to slow as layers build to maintain constant linear speed in the process / gluing section.

I think a braking function will be needed on the raw material rolls for two reasons
1. To maintain tension on fabric in the process. I think a dancer woould improve this.
2. To slow or stop the raw mat'l rolls when finished motor slows or stops.

In addition I assume the glue must be spread evenly and maybe to avoid overapplication to avoid "soak thru"

Another need will be to keep the material straight and parallel
OR trim the edges.

Dan Bentler

Irondesk40,

i don't believe you have thought this process out as well as you have detailed it on your post. i worked in the printing press buisness for 2 years and that's why i am advising caution.

1. how wide are your rolls of product? what is the diameter? how thick is your product? how much does the roll weigh?
what is to be done with this product after its glued together?

when the roll starts out, it feeds slowly, as the diameter reduces it speeds up. you will need brakes on the roll feed to help keep tension. how will you prevent wrinkles in the fabric?

we had a MEG dual arm roll feed and tension system for the paper rolls and a MEG pinch roller for the gripper system to maintension tension on the unit and help keep it in alignment.

2. when applying your glue, what will you do with the excess glue when the materials are mashed together? This WILL, be a problem !!

3. what is the cure time for the glue? without drying the laminated materials you will be processing materials that have wet glue and that in itself will cause a problem.

i'm sorry if i have rained on your parade or have posted something you have already thought of, but if i can help avoid heartache down the road, i think its worth mentioning.

regards,
james

Lots to think about.

Is this to be a solvent coater? - ATEX?
Spraying adhesive is messy, over-spray gets everywhere. Have you considdered other types of coating such as Gravure or reverse roll coating?

Considder drying time - you need the adhesive to be cured before you wind your laminate into a roll. Dying ovens or UV cure pehaps?

AC drives will be good, have a look at Parker 690+ or 890 series, they include winding technology blocks.

Web transport and substrate coating are two specialist fields, have you considdered contacting a third party to do this?

Nick

From what I read so far, the products will be pulled from letoff stands, not a center driven letoff. If the fabric is delicate, center driven letoffs and good tension controls may be required. If the fabric is stout then you may be able to get by with a simple brake.

James questions about roll diameter and weight defintely come into play before making that choice.

I would also be concerned with alignment as being very critical, and will there be an edge slitter to ensure end product width?

Also, the glue applier...how tightly must that operation be controlled? Can you vary the speed of the product without worrying about affecting glue quantity?

The wind-up end: Is this a center driven shaft? If so, variable speed, with diameter compensation will be needed. This might be as simple as a dancer bar with a trim pot or a diameter sensor, or just some math in a PLC.

This is one of those case where a simple sketch (side view) of the process would be very helpful.

Sounds like low speed, critical tension, at a minimum.
You need to consider the low-end speed control, or you'll never get off the ground.
AC closed loop - maybe.
DC - for sure. And, for DC applications like this, BARDAC is a really good choice..they have pre-programmed blocks of code that make an application (pun!) like this much easier.

Thanks for suggestions. No problem with anything anyone suggest. The only thing is that a lot of information i do not even know yet. All i know is the boss called some of us together and said to be doing some thinking and searching on the net at different ways that fabric is laminated together.
The only thing we know at the moment is that on a scrap sheet of paper he showed us that one of the VP's in our company suggested that we look at taking two types of fabric and spraying some type of glue to the bottom roll and then both of the rolls going through a pinch type roller to apply just enough pressure to bond the two together. as soon as i get more information i will surely post on here because this site is a great place to get information and get you to thinking in a different direction or see what you may be doing wrong.
Thanks

irondesk40 said:

All i know is the boss called some of us together and said to be doing some thinking and searching on the net at different ways that fabric is laminated together.

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Gosh I wish my boss would do that. Here, it usually a conversation like:

Boss: "Hey you coming in this weekend to help us add the new units into the old program?"
Me: "What new units?"
Boss: "We're putting two machines in, but don't worry everything is just like the old ones."

I guess it's cool being a mushroom though, no stress until Saturday morning when I find out how cluster****ed everything actually is. Someday I will have a job where I get invited to the meetings where planning and purchasing decisions take place.

Have you thought of the elasticity of the materials? Think about what happens when you stretch the base material more than the top? You get wrinkles. The same as if you pull the top tighter than the bottom.
Think of How you will do web guiding. Edge vs center.
I have done thus with 1 drive running in constant torque mode and brakes each of the 2 rolls. It was OK at best but the operator had to do a lot of the adjustments. The best thing I did was out a laser on one of the unwind reels and had it taper off the I/P for the brake roll. It was a straight linear taper but it made things a lot smother. This line was all manual. Driven hot melt glue pot. Then a AC cooling tunnel. All if these where center driven.
We did another line like this with Parker 690+ drives with common bus. Worked out nicely. What we found was that some of the material needed to be motored and not braked to make a better quality product.
I like close loop tension controls. Kieth Menges taught me more in a 30 minute phone call than any of the web handling classes did. The classes where mainly sales classes but still it was supposed to be educational.

Someday I will have a job where I get invited to the meetings where planning and purchasing decisions take place.

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Paul, been there, and it is not all a bed of roses. If you get invited to those types of meetings, it is because someone wants to ask you tough questions - either for needed information or to prove to some other top dog that you don't know what the heck you are doing. Making a suggestion in planning meetings can either make you look good, or sink your career if it does not work out. Besides, most of the time most suggestions get lost in the clutter and never see the light of day.