glueing PP to PE

[JayLau]

Hello there!

I have a question and I found a similar question before, but not exactly answering my question. So, I'm hoping you guys can help me.

I want to glue a PE-bag to a PP surface. [I choose to use a PE-bag because it is more flexible than a PP-bag? (correct me if I'm wrong)]
I think it needs to be delicate, because I want to fill the PE bag with a liquid - it is for medical purposes.

Is there a way to do so?

I found something about using hot air plastic welding, but how precise and delicate is this?

I hope you guys can help me out,

Best Regards,

Jay

 

[JayLau]

ow I forgot to mention that the thickness of the PP is about 0.05mm thick

 

[Demon3]

You should use PP for both bag and surface then you can try ultrasonic welding or just heat. The PP should be flexible enough for a bag.

There is not any memory with less satisfaction than the memory of some temptation we resisted.
- James Branch Cabell

 

[patprimmer]

It will be difficult to weld a PP bag that is that thin to a thick surface as there will be a tendency to blow holes in the bag before you melt the other surface.

If both were PE it would be easier as you could use different melting point PEs, with the lower melting point being the thicker material.

This approach could work with PP or PE, but you will have a wider choice of material properties to work with in PE. I would contact both PP and PE suppliers who supply to the bag industry for detailed advice.

3M make some excellent double sided tape type adhesives that glue very well to PE and to PP.

Regards

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[Demon3]

Good suggestion by Pat. An option could be to use EVA and PE. They should stick and have different melting points.

There is not any memory with less satisfaction than the memory of some temptation we resisted.
- James Branch Cabell

 

[dwightdixon]

Much more product performance data, sterilization, barrier properties, enviromental resistance. what is in the bag, how far it can drop without rupture and many other parameters must be determined before you start designing this product and choising materials. Many materials have been used for products meeting your broad discription. Many have been brought to market and some patented. My first choise would have the injection molded piece made from Co-polymer PP and the Film a Rubber modified copolymer PP with less than 15% rubber. An impulse sealer would be used. Give us more details (if you already have a patent applied for) and we may be of more assistance.

 

[JayLau]

Thank you all for your quick reply and information

Well, I can't give too much details, as no patent has been applied for yet.

This is as much I can give:
- intended to be a disposable product
- the bag should have a certain strength and flexibility, but must also easily be punctured (cannot give more detail about this)
- use for inside the body

It is still vague, my apologies.

Jay

 

[JayLau]

continuing on this problem.. Is it possible to seal PE bags to PET sheets? or is that completely impossible?

thank you in advance

Cheers,

Jay

 

[patprimmer]

It would be extremely difficult at least. Probably impossible by welding. Just maybe with 3M double sided tape type adhesives.

Also, it is easier to weld multilayer films where one surface is a tacky low temp easy to weld film and the other is a stronger higher temp film that won't melt at the welding temps of the weldable surface.

Ie if you get a nylon/polyethylene co-extruded film and weld PR to PR sides together by applying heat to the nylon sides, welding is real easy even with very thin films.

Can you get a PET/PE co-extruded film.

Even if it's PE, use metalacine PE one side (welds at maybe 80 deg C) and MDPE on the other (melts at maybe 120 deg C)

Regards

eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.