Our competition has been promoting nitrogen plastic welders with "pre-set flow" -- as if that's an advantage.
Using the "pre-set flow" on thin plastics might cause you some trouble!
All of Polyvance's nitrogen plastic welders allow you to adjust the flow to suit the job.
This video will show you how to set your flow rate to suit the thickness of the plastic.
Most car bumpers are in the range of 3 millimeters thick.
For the typical car bumper, set the flow on your Polyvance nitrogen plastic welder
to about 12 liters per minute.
In other words, float the metal ball between the 10 and 15 mark on your flow meter.
This is your "baseline" flow setting.
It will give you enough heat to melt the bottom surface of the welding rod
and the top surface of the bumper without overheating it.
Using the same flow setting on a thinner plastic substrate will cause problems.
If you overheat the substrate, it will lose its structure.
This is exactly why Polyvance's nitrogen plastic welders have flow control.
Here, you can see this mounting flange is 2.3 millimeters thick,
and the edge where it mounts to the bumper is less than a millimeter.
So, if the plastic is less than 2 and a half millimeters,
turn the flow down to about 10 liters per minute.
Here, you can see we are welding this rectangular slot tab at 10 liters per minute,
precisely controlling the amount of heat we are inputting to the plastics.
We are not overheating the substrate and causing it to lose its structure.
As a result, after it's cooled off and we do a strength test, the slot tab itself is so strong,
it actually rips the flange off the bumper before the slot tab fails.
If this same slot tab is welded with too high a flow setting, the substrate begins to lose its structure,
resulting in a weld that is not as controlled and accurate.
As you can see, after it has cooled off, the slot tab tears at the edge where the substrate had been overheated.
Polyvance's plastic welders give you the control to prevent this failure mode.
What if you're welding on a thick plastic, like this Freightliner side skirt?
This plastic is over 4 millimeters thick.
In this case, you can turn up the flow to 15 liters per minute
and use the R02-06 thick polypropylene welding ribbon.
This will provide enough flow to melt the plastics efficiently for a faster repair.
Thick plastics are easier to weld since you don't have to worry about distortion of the base material.
In these cases, just turn up the flow and temperature to make a fast, strong repair.
This table shows our recommended flow settings for various plastic thicknesses.
In normal situations, keep the welder set at 12 liters per minute, or your "baseline" flow setting.
Adjust down if you're welding a thin plastic, and up if you're welding something thicker.
Flow is not the only variable in the nitrogen plastic welding process.
If you want to learn more about plastic welding and plastic repair in general,
check out one of our live, instructor-led training courses.
Our PR-01 is a three-hour course delivered live in your shop,
and our PR-02 is a two day course held at our factory.
Look for the training link on our website at polyvance.com, or give us a call at 800-633-3047.
Polyvance wants to be your partner for greater plastic repair profits!
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