Adhesive Seepage from Die Cut Parts Edge

[somashekar]

We use a lot of discrete die cut parts of single coated polyethylene medical tape. They are supplied packed loose in zip lock pouch.
Within days of supply we observe adhesive seepage from the edge of parts and the parts are sticky and therefore not convenient to remove each and use.
Is the convertor missing any process in the manufacturing that will make these parts be crisp and free from any adhesive seepage...

 

[Miner]

Possibly, but it is more likely that this problem is caused by the particular adhesive selected. Adhesives have many different properties that vary by the type and formulation of adhesive. Processing variables such as thickness of adhesive applied can exacerbate the issue, but the ability of the adhesive to flow is inherent in the type/formulation.

 

[try2makeit]

Temperature/Climate may also come into play. Adhesives tend to run or expand more in hot temperatures then in cold. I don't know if your facility is climate controlled where it is stored. But I would check with the Supplier as to what the normal storage conditions are for the tape and then possibly adjust accordingly. Sometimes storing adhesive tapes in a cooler environment eliminates the seepage or running of the adhesive.

 

[somashekar]

Possibly, but it is more likely that this problem is caused by the particular adhesive selected. Adhesives have many different properties that vary by the type and formulation of adhesive. Processing variables such as thickness of adhesive applied can exacerbate the issue, but the ability of the adhesive to flow is inherent in the type/formulation.

The reason why I am inclined towards the converter and the process is that with the same material (3M) use, supplies from one converter (USA) never exhibited this, while in the one from the second source (INDIA) it is showing up.
Our storage and plant temperature is maintained within 23'C to 28'C.

 

[Miner]

I would start by looking at the applied thickness of the adhesive.

 

[try2makeit]

As Miner suggested start with the applied thickness of the adhesive between the 3M product and your second source. Technical data sheets should give you some idea.

Not sure if you have done that, but I would also check with the Supplier on their die cutting process.

 

[Miner]

The reason why I am inclined towards the converter and the process is that with the same material (3M) use, supplies from one converter (USA) never exhibited this, while in the one from the second source (INDIA) it is showing up.

To clarify: You have two suppliers (USA/India) that both use a 3M tape and the only value-add performed by either is to die cut this tape?

 

[somashekar]

To clarify: You have two suppliers (USA/India) that both use a 3M tape and the only value-add performed by either is to die cut this tape?

Perfect ... They both use the same 3M material (1526)

Not sure if you have done that, but I would also check with the Supplier on their die cutting process.

This is what I am looking for. The correct Technical Process.
Is it just die cut and pack., or is there something after die cut, to make the parts flat and crisp. The parts from USA are like fresh $$ bank notes.

 

[Miner]

I have seen a few die cutting operations for labels, which I presume would be similar. Typically, the very small margins drive very efficient operations with no secondary ops. I suspect that any difference would be found in the design of the die itself, such as, do any portions of the die other than the cutting surface contact the tape. Are there differences in the geometry of the die cutting surface between suppliers? What are the surface characteristics of the plate the die closes against? What speeds and pressures are involved?

Regarding the laying flat, one supplier may feed the tape through an in-line straightener as part of the die cutting op.

 

[try2makeit]

Can you compare processes between the two Suppliers?

One could be die cutting on a Rotary Fabricator, the other on a Punch Press. That would also determine what kind of tooling is being used to cut the parts.

Are both adding a secondary liner to the 3M product? Is that different? Just my