Ultrasonic welding Nylon 33% glass
Ultrasonic welding Nylon 33% glass
(OP)
Does anyone have experience ultrasonic welding Nylon with 33% glass? Specifically, what effect will humidity of the environment have on weld integrity? I know that the material is extremely hydroscopic, but can the material absorb enough moisture as to degrade the weldability? Any comments welcome. Also any references or links to sites with info really appreciated!






RE: Ultrasonic welding Nylon 33% glass
Best results will be obtained if you can weld within a few hours of moulding.
the parts can be stored longer in plastic bags, or in a dry environment.
If the nylon is wet you will nee to dry it in an oven.
You can do a real rough test by rattling the parts together. A clinky rattle means dry, a dull thud means wet Once you have heard wet and dry mouldings, it is quite easy to tell.
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RE: Ultrasonic welding Nylon 33% glass
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RE: Ultrasonic welding Nylon 33% glass
There is not any memory with less satisfaction than the memory of some temptation we resisted.
- James Branch Cabell
RE: Ultrasonic welding Nylon 33% glass
RE: Ultrasonic welding Nylon 33% glass
If you could weld the parts right after they are made that would be best because they would still be dry. To dry a "wet" part will take a long time.
The weld line will always be far weaker than the rest of the part because of the way the polymer and glass flows. Basically at the weld line there will be an area with more or less zero glass and areas with too much glass. In addition, the orientation of the glass will be poor and will not give much strength. This effect can not be avoided.
There is not any memory with less satisfaction than the memory of some temptation we resisted.
- James Branch Cabell
RE: Ultrasonic welding Nylon 33% glass
Is consistent welding of this high glass content nylon even possible.
Thanks for the help.
RE: Ultrasonic welding Nylon 33% glass
This is caused by any of or a combination of the following.
Insufficient melt temperature.
Insufficient hold up pressure.
Insufficient hold up time.
Insufficient injection speed.
Insufficient mould temperature.
To small gate size.
Insufficient cushion.
Worn check valve.
Wet material.
Basically, for glass filled nylon, you need quite hot material (generally about 300 deg C).
You need maximum fill speed, dropping down just short of full.
You need to hold up with pressure just short of flash.
You need to hold up until the gate freezes.
The smallest dimension on the gate should be at least 1/2 and ideally 2/3 maximum section thickness of the part.
You need a mould temperature of at least 90 deg C.
You need the machine to hold a stable but small cushion for the entire hold up time.
You need the material to be dry before moulding. If material bubbles and spits from the nozzle between shots, it is probably to wet.
If your moulder does not appreciate all the above, you probably need a new moulder.
What type of nylon is it.
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RE: Ultrasonic welding Nylon 33% glass
RE: Ultrasonic welding Nylon 33% glass
RE: Ultrasonic welding Nylon 33% glass
If in doubt try someone like Ticona, BASF, Solutia, DuPont, DSM, UBE or Emserwerk to test their prime grade materials and see if the standard improves. Some compounder's do a very good job at high quality consistent materials, but some do to much horse trading.
It still sounds like poor control of moulding conditions to me. Also Both myself and demon3 have recommended welding very soon after moulding. You should try that to see if it improves things.
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RE: Ultrasonic welding Nylon 33% glass
While it has excellent properties in prime condition when properly moulded, it is more sensitive to degradation and is harder to mould and weld than is type 6.
35 to 40% GF type 6 might do better for you.
Are they failing at the weld or elsewhere.
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RE: Ultrasonic welding Nylon 33% glass
Again, thanks pat and demon3. for all of your information.
RE: Ultrasonic welding Nylon 33% glass
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RE: Ultrasonic welding Nylon 33% glass
They have quite a few handles with varying levels of glass, depending on design.
The weld is to hold the bottom side in so the beam is fully boxed in. They use small bolts on some models to reinforce the joint at the highest loaded point.
They also have a step in the fit so as to give some mechanical assistance to shear.
When tested to destruction, it is normally the bronze drive dog that fails, not the plastic.
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RE: Ultrasonic welding Nylon 33% glass
Thanks for the reply.