Surface Tension/Burying glass to create smoother surface

[joeprocess]

Have a customer that is concerned that too much glass on the surface of the part is causing sonic welding issues. They are in the process of quantifying this. In the mean time I am investigating test methods to collect inspection data for in process inspections. I do not want the people on the production floor to make a judgement call on "too glassy" based on visual inspection. I thought there is some sort of test for this, but I have never had to implement it on any other parts.

[brentb]

Profilimeter?

KOM

brent

[rickbatey]

Joe,
What welding process are you using? What type of resin? I ask because I've heard too much glass fiber surface complaints in the past only to find another root cause. We've had an issue with welding two parts together only to find out the resin actually had the wrong colorant package in it. The IR welder couldn't get the surface hot enough for a good bond.
I bet the part will not stay like you need it if you raise the melt or mold temps, right? I've had to flame and corona treat parts in the past to get the bond strength required. I'm just not familiar with a test to pinpoint the glass level. Maybe surface energy pens/inks to find out what it is and what works best?
Rick.

[MTUHusky]

Hey Joe,

What kind of sonic welding "issues" are they having? I run a very high glass filled ultrasonic welding operation but it took some doing. I had to have a special titanium horn made with a 2:1 stack transducer and booster on it (usually 1:1). I also had to make custom knurled tips with a special heat treatment for the horn. The bottom part that I weld has on awful appearance of glass on the surface because we cover it with the top part and dont care so I dont think the glass is your issue. If you do want to reduce the glassy ugly finish then you can definitly do that by going up on mold temperatures but be careful; your parts may not be in print at higher mold temps. Higher temperature molds equals more cooling time equals more shrinkage (and cycle time $$$).

[Suhas]

Joe,
It could even show up in a color box under different lighting. Give it a shot and see.
Suhas