Emerson 2000IW, 2000X Troubleshooting

Technolog

Ultrasonic Welding Trouble Shooting Guide

PROBLEM PROBABLE CAUSES SOLUTIONS

Overweld Too much energy into the part. Reduce pressure, trigger force and/or down speed

Weld time too long. Reduce weld time/energy/ collapse.

Too much collapse. Change to lower ratio booster to reduce amplitude.

Digitally reduce the amplitude %.
Use Amplitude Profiling.
Reduce down speed.
Change to lower gain horn if lowest booster is already in use.

TL-24

Absolute distance too high.

Underweld Insufficient energy into the part. Increase pressure, trigger, and/or down speed.

Insufficient weld time. Increase weld time/energy/ collapse.

Insufficient amplitude. Use higher ratio booster to increase amplitude, if horn allows.

Energy loss into fixture.

Presence of mold release.

Absolute distance too low.

Moisture absorption by
hygroscopic material.

Non-uniform Warped part(s).
weld around
the joint

Non-uniform horn face amplitude.

Lack of parallelism between horn,
fixture and part.
Insufficient support in the fixture.

Recalibrate absolute distance and adjust.

Change to higher gain horn if highest booster is already in use.

If fixture is urethane, change fixture to rigid material such as
aluminum, stainless steel.
Evaluate part fit in fixture.

Eliminate use or clean parts after molding.

Increase absolute distance.

Dry parts as required.

Check part dimensions and flatness
Check molding conditions.
Use higher trigger pressure.

Have horn tested (and modified if needed) to establish uniformit

Shim fixture where necessary, or level adjustable plate.
Check part dimensions/flatness.
Check part fit with horn using carbon paper.
Improve support in critical areas.
Change to a rigid fixture.
If large sections of urethane are deflecting, add rigid backup

y.

PROBLEM PROBABLE CAUSES SOLUTIONS

Non-uniform
weld around
the joint

(continued)

Inconsistent energy director height.

Wall flexure.

Knock-out pin location in joint area.

Improper alignment.

Non-uniform horn contact.

Part tolerance.

Mold release.

Correct mold to ensure uniform energy director height.
Check molding conditions.

Add internal ribs to part.
Increase wall thickness.
Modify fixture to prevent outward flexure.

Move knock-out pin location from joint area.
Make sure knock-out pin marks are flush with surface.

Check for part shifting during welding.
Check alignment features in mating parts.
Check for parallelism of horn, part, and/or fixture.

Check fit of part to horn.
Check part fit with horn using carbon paper.
Check for sinks.
Check for proper support in fixture.

Tighten part tolerances.
Check molding conditions.

Clean mating surfaces.
If mold release is required, use a paintable/printable grade.

Inconsistent
weld results
part-to-part

Accumulation of fillers in one area.

Moisture in joint area.

Mold release.

Part tolerances.

Cavity-to-cavity variations.

Regrind/degraded plastic.

Check molding conditions.
Reduce the amount of filler.
Use only short fiber fillers

Dry parts as required.

Clean mating surfaces.
If mold release is required, use a paintable/printable grade.

Tighten part tolerances.
Check part dimensions.
Check molding conditions.

Run statistical study to see if a pattern develops with
certain cavity combinations.
Check part tolerances/dimensions.
Check for cavity wear.
Check molding conditions.
Centralize gate location.

Check with molder for percentage of regrind
Check molding conditions.
Reduce percentage of regrind (maintain below 10%).
Improve quality of regrind.