Category: PACKAGING
31. May 2012   2:59 pm
Andy Stecher

Andy Stecher
Elgin, IL

Hello again packaging professionals,

In this blog entry I will discuss the importance of cleaning glue flaps on folding cartons in order to achieve reliable, repeatable bonding results.

In the finishing area of a typical folding carton facility, you will often encounter multiple methods and products used to achieve bonding characteristics of all types of cartons.   These can include the use of multiple types of glue (i.e. special glue for poly coated material, hotmelt etc…) in addition to other mechanical modifications to the glue flap (i.e. glue assists, skiving, knocking out the coating in the glue flap area – by cutting the printing blankets).   All of these methods and materials have been developed to achieve good bonding performance that meets the end users requirements.   However, even the most diligent practices can sometimes lead to bonding failure and thus the potential for rejected pieces by the end user.   Providing a consistently clean and activated surface prior to gluing can help avoid claims and costs associated with failures.

All substrates, coatings and laminations contain internal contaminants – these could be things such as plasticizers that are used to engineer a product or materials such as fillers.   These contaminants tend to migrate to the top of a surface and hence will impede the ability of a material to be effectively bonded.   Plasma treatment can remove these contaminants allowing for a true chemical bond of the glue to the glue flap itself.

Presenting a perfectly clean surface to a glue applicator will help avoid many bonding failures.   An inline plasma treatment will accomplish just this.   Electrons and oxygen ions in the plasma beam itself allow for this type of cleaning.   The high kinetic and thermal energy of the electrons allow them to sever covalent bonds of contaminants that are typically present on the very top of substrates – this will break down those contaminants into smaller, more volatile molecules.   Oxygen ions in the plasma will then vaporize the remaining molecules into CO2 and water, leaving a perfectly clean surface to be bonded.

If such a plasma treatment is not utilized then there is always the risk that bonding could be compromised.   One such case would be if printed cartons are stored for too long.   When cartons are stored for longer time periods than normal, more contaminants in the coatings or substrate will migrate to the top of the surface.   Over time these will be much more difficult to remove than cartons processed in a timely manner.   This is the time when failures can easily occur and is a big motivating factor for customers to use a plasma treatment to achieve perfectly clean glue flaps every time.

Please stay tuned – next entry will discuss activation of the clean glue flap.

That’s it for now.

Shaun.

 

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Mikki Larner

Mikki Larner
Vice President Sales & Marketing
Belmont, CA

Editorial May 2012

Process Design Step 1:

Variables to consider when designing a surface modification program

 

I lied, partially.

I said that my next blog would be a trip report (sadly, Dyana said it was overcast) and power of plasma for modification of materials for the life sciences industry.   I’m not ready to jump into specific applications, rather want to start with some of the basics to a successful surface modification program.

I’ll start with Step 1.  Q&A.

The beginning of any lab development program typically involves a thorough Q&A session.   At the minimum, I want to know:

 

1.  Substrate

2.  Product environment

3.  Desired surface performance goal

 

The success, based on my experience, of a surface modification program relies on a thorough (if possible) understanding of these three items as 1 and 2 greatly impact 3.

For each question, there are 10s if not 100s of sub-questions that can shift outcome considerably.   I spoke about some of these recently at Hantel Technology  http://www.youtube.com/watch?v=gZemVc790oQ  and am summarizing a partial list of variables for each question below.

 

  1. SUBSTRATE.  Tell me about (I’m polymer focused):
    1. Resin selection/Metal properties
    2. Composite properties
    3. Manufacturing practice (molded, extruded, cast).  Are you starting with a machined part for R&D and then possibly considering molding for production.  We may talk about molecular weight distribution as well.
    4. Cure mechanism
    5. Cure temperatures
    6. Hardness (durometer)/crystallinity
    7. Topography
    8. Tacticity
    9. Additives (stabilizers, pigments, nucleating agents, plasticizers, etc)
    10. Propensity for migration of additives
    11. Propensity for molecular rotation
    12. Finishes
    13. Mold release materials
    14. Machining debris
    15. Moisture retain/absorption/adsorption
    16. Cleanliness (and how is the substrate cleaned prior to plasma)
    17. Manufacturing controls for said substrate
    18. Throughput targets

 

  1. ENVIRONMENT.  Once treated, please tell me about the next steps in processing and environment as these variables may impact surface performance and stability:
    1. See Item #1.9 above.  Bloom, migration of Internal impurities
    2. Adhesive technique (if bonding) and cure mechanism
    3. Potential for oxidation
    4. Chemical exposure
    5. Sterilization technique
    6. Subsequent assembly step (are you heat sealing?)
    7. Subsequent cleaning steps and techniques (are you IPA wiping part 100X times during assembly?)
    8. Handling (glove selection and practices)
    9. Storage (Packaging materials, Temperatures)

 

  1. SURFACE PROPERTIES.  What do you want as we have many variables to consider to provide the desired outcome.  Rather than listing the myriad of applications we practice, I’ll focus on variables that we consider in designing an experimental plan.

 

    1. Type of equipment (Corona, Atmospheric, Low Pressure)
    2. Steps and type of process (Cleaning, Etching, Activation, Functionalization, PECVD, Grafting, Crosslinking)
    3. Chemistry (gas, liquid vapor, sublimated solids, combinations).
    4.  Temperature of substrate, chamber, liquid/solid
    5. Pressure (flow driven, throttled, pumping capacity)
    6. Fixturing and fixture materials (does it contribute to dark space?)
    7. Power (continuous, pulsed, duty cycle, frequency)
    8. Time (3o seconds or 10 minutes)

BUT WAIT.  There is more!

VALIDATION TECHNIQUE/SURFACE ANALYSIS

Even the choice of how to validate the surface can impact the results.  Our chief technologist, Steve Kaplan, loves to say “don’t throw the baby out with the bathwater.”   It is not unusual for a customer to overlook the success of the process by improper selection of the validation method.    Test the product in the ultimate application.  Techniques used and considered at our laboratories include:

 

  • Surface energy testing
  • Dyne-cm, contact angle
  • fluid choice
  • Adhesion testing
  • Wear and abrasion testing
  • Friction testing
  • Hardness testing
  • Surface analysis
  • X-ray Photoelectron Spectroscopy (XPS)
  • Scanning Electron Microscopy (SEM)
  • AFM Atomic Force Microscopy
  • Fourier Transform Infrared Spectroscopy (FTIR)
  • Chemical resistance
  • Gas permeation / vapor barrier testing

 

This list isn’t to overwhelm.   I don’t expect answers to all of these questions nor do we screen every possible combination of variables.  We know where to start if you can provide us with the basics about  1 (Substrate), 2 (Environment of use) and 3 (Desired surface performance) so that we can design efficiently and effectively the best surface for your application.

Next blog…no promises.

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17. May 2012   1:35 am
Jeff Leighty

Jeff Leighty
Elgin, IL

After recently installing a Plasmatreat application in a customer’s manufacturing line his parting comment was, “Thanks. I’ll sleep better tonight.”

The worst type of adhesion problem for a manufacturing engineer or quality manager is a sporadic one. One where there is no single, clear root cause–no “smoking gun”. Maybe it only happens when the humidity in the plant is just so or the part is a little too cold or the moon is full. Or, even worse, it looks fine when you ship it but fails in the field. Too many of today’s high-tech adhesives, primers, inks and coatings have narrow operating conditions giving the production process very little wiggle room. Plasma treatment can balance that out. Sure, our systems go right in the assembly line, are very fast and extremely cost-efficient to operate but the real benefit of plasma treatment is that it can make the rest of your process more forgiving.

Sometimes we get so caught up by the art and science that is plasma treatment that we forget the best part—it works! Sweet dreams…

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Category: SOLAR
15. May 2012   4:28 am
Wally Hansen

Wally Hansen
Belmont, CA

First Solar has announced a $250 million warranty charge for defective panels.  For about a year  First Solar had a “Manufacturing Excursion” that resulted in a 4%-8% field failure rate after only a couple of years of service.

First Solar has not commented on the exact nature of the “Excursion.”  Since it occurred over a period of a year and at three different  manufacturing facilities, I would not call this an “Excursion” but a misunderstanding of acceptable process tolerances or allowables.

This is especially troubling because First Solar is the largest and most successful US solar manufacturer.  They have the best equipment, the smartest  scientists and engineers, and probably the best understanding of their products.

“We thought everything was OK.  Our modeling was good.  Our in-process controls were good.  Our accelerated testing and certifications indicated no problems. We  inspected 100% of the modules. Everything is OK.” ……Followed several years later by, ”I think we may have a problem. We didn’t know,” You could hear some upset engineer or scientist say.

Solar modules are exposed to the harshest environmental conditions and are warranted to reliably produce power for decades. Solar materials, can continue to react and degrade with heat over time. Wind and structural loads mechanically stress  panels. Sealing and prevention of moisture ingression into the module is a key factor in preventing field failure. Understanding and improving environmental reliability was a manufacturing issue. Now it is a real financial issue.

I think that we can help. Plasmatreat’s Openair technology and production treatment systems have become an important tool for automated, reliable solar product manufacture.

  • Openair® Cleaning of glass and metal surfaces for reliable J-box attach, rail bonding and edge sealing
  • Openair® Activation of plastic junction boxes for critical and long-lasting potting adhesion
  • AntiCorr® Coatings for corrosion protection and adhesion promotion.

Avoid the Excursions and stay on the path.  Keep the water out and the smoke in.

As always, comments, opinions and ideas are welcome.

-Wally

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Tim Smith

Tim Smith
Vice President Operations
Ancaster, Ontario

Editorial May 2012

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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