Hello loyal blog readers, 

I am often asked what makes Plasmatreat different than other companies selling similar equipment.

Please allow me to explain a bit about Plasmatreat as a company and the plasma equipment we produce.

Plasmatreat is the inventor of atmospheric plasma and currently holds approximately 130 international patents on the design.

Our equipment is manufactured in Germany, and I am sure you can appreciate the quality of both the engineering and manufacturing associated with this.

 Plasmatreat’s philosophy of sales is to provide our customers with a solution to their bonding challenges and not just sell a commodity.  As such, we have a full lab, accessible to our customers, in our Ancaster Ontario, Elgin Illinois and Belmont California locations.

We provide service and stock spare parts for North America from our Ancaster location so next day delivery of parts is certainly possible.  24hr service support is available 7 days a week.

 

I would like to highlight a few of the features that are included in our plasma systems.

 

Our generators constantly monitor the plasma voltage, plasma current and sir supply to the jet in order to maintain consistent process parameters.  The limits for each of these parameters is software programmable so the allowable variation in plasma output is determined by the end user.

 Although the process parameters are monitored as noted above, Plasmatreat has developed an independent method to ensure, and obtain QS9000 compliance, that plasma is actually being generated in the jet.  This is accomplished through the use of an optical focusing lens that looks directly at the plasma and this signal is sent to the generator, via a fibre optic cable, where it is monitored in real time to ensure 100% feedback that the plasma is present.

Through our control panel, the voltage, frequency and duty cycle of the plasma can be varied allowing the system to be set up for ideal processing parameters.

The incoming power supply from any customer normally has some degree of fluctuation throughout the day.  Our generators have a power regulator that ensures that the plasma voltage remains constant regardless of the incoming voltage. (95-250VAC is the allowable fluctuation with our smallest systems and 340-500VAC for our three phase systems)  Without this feature, the plasma intensity would vary with the incoming voltage affecting the treatment of the part.

All of our cables contain multiple layers of electrical shielding to ensure that no EMI is present to interfere with other sensitive electronic equipment or possible operator safety due to shock or pacemaker interference.

I have listed some of the features that set us apart from the other plasma equipment you may find on the market and I suggest you become curious as to whether these features are also available on the systems you are comparing ours to. Some of these features have safety concerns attached to them.

I feel very confident that once you have a chance to compare, you will be able to make the correct decision for your company.

Tim

 

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I am often asked how can a company verify, in a production environment, that a part has been treated successfully with plasma?   How can they verify post-treatment surface activation?  I will answer these two questions separately as they have two very distinct answers.

Most plasma applications utilize some form of automation to treat a part and some form of fixture to hold the part in a known location while it is being treated.  These systems also run, sometimes for months at a time, without human supervision.

Let’s break down the three key parameters that will ensure that the part has been successfully treated using plasma. 

1- The Plasma

2 – The Robot Path

3 – The Part Fixture

The Plasma

As discussed in my last blog, Plasmatreat equipment has the ability to monitor the voltage, current, frequency and duty cycle of the plasma as well as the incoming and internal jet (optional) air pressure.  In addition to the control and monitoring of all of these parameters, the LCM option allows for the independent verification of the presence of plasma allowing for QS9000 rating.  If all of these feedback signals are present then it can be assured that plasma is present, with the correct operating parameters, at the plasma jet.

The Robot Path

Once a robot has been programmed with a treatment path, it cannot vary from this path without triggering some sort of error.  It is safe to assume that a robot will follow the proscribed path exactly each time and if for some reason it does not, then an error will be indicated.

The Part Fixture

A part fixture must hold the part in an exact location to ensure that the plasma jet, when being moved by the robot, will maintain a fixed and repeatable distance from the part that is to be treated.  The part fixture usually includes some form of mechanical clamping or vacuum to ensure that the part sits properly in its nest.  Through the use of proximity or optical sensors, it can be verified that the correct part is seated in the correct position within the part fixture.

With the abovementioned three parameters verified; the correct plasma, the correct robot path at the correct distance from the desired part, it can be safely assumed that the part is receiving the proper plasma pre-treatment.

Post Treatment Surface Energy Verification

The above steps ensure that the part has been successfully treated with plasma but does not verify that the plasma has been successful in raising the surface energy to the level expected.  One of the largest varibles in pre-treatment that has not been mentioned so far is the substrate itself. 

Even if you have very tight control over your resin manufacturer and supplier, there may be variations in the molded part due to molding machine parameters, mold release agents and/or the environmental conditions present at the time of molding or during part storage after molding.  If you don’t have tight control over the resin you are using then the variation in the properties of the finished part can be even more significant.

These variations due to the substrate can have a negative overall effect on the surface energy of the product before and after plasma treatment.

In order to verify that the post treatment surface energy is sufficient, the only practical method that I have seen, for use on the plant floor, is to use dyne test inks.  The frequency of this testing is usually dictated by the Quality Control department. A part is taken off of the line, its dyne level is measured and checked against the level required and, assuming that the level is sufficient, the part is usually re-introduced into the assembly line for further processing.

To recap, by verifying that the plasma treatment is correct and by further verifying that the resultant surface energy is as expected, a manufacturer can rest assured that their process is performing properly.

Tim

 

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I thought I would produce a series of blog entries outlining some of the most common technical questions I receive regarding Plasmatreat equipment. 

The internal electrode in the plasma jet and the nozzle at the tip of the jet are wear items.  The plasma arc begins at the inner electrode and ends at the nozzle and because of this, over time, some material is removed from both. 

In addition to the above wear, the nozzle experiences the plasma stream blasting through the opening at end of it and this causes the nozzle orifice to increase in diameter.

The normal life of each of these components is approximately 3000-5000 hours depending upon the amount of plasma energy being used and the quality of the air being fed to the system. 

Plasmatreat has developed an ingenious method for monitoring this wear and indicating to the operator or maintenance staff that the nozzle is in need of replacement.  The air pressure developed inside of the plasma jet will drop as the diameter of the exit orifice on the nozzle increases.  By monitoring this pressure and comparing its value against predetermined limits, a warning can be displayed indicating nozzle wear. 

So by keeping the air supply to the Plasmatreat equipment clean and dry, (three stage filtering to 0.3 um is sufficient), you can obtain the maximum life out of both electrode and nozzle. And by incorporating the pressure feedback option, you can have the system indicate to you when it is time to change the nozzle. 

 

 

 

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