Removing Static in Pharmaceutical Packaging

Static Eliminators
Variety of Static Eliminators from EXAIR

A pharmaceutical company contacted EXAIR about static issues in their packaging area. When static is created, it can become a real nuisance.  For this pharmaceutical company, it was greatly affecting the tablet filling station.  They actually had four major areas generating static in their process.  The first area was the preformed plastic trays at the start of their process.  They would purchase many sheets of plastic from their supplier and as they started to unpack the sheets, a large amount of static would shock the operators.  Another area was when the blister pack was being thermally formed.  As for the tablets, they too were generating static when they were being separated from the forming process and transferred to the delivery chute.  Like the same poles on a magnet, static charges with the similar polarity, will repel each other; causing the tablet to be rejected from the blister tray.   The fourth area that had static was at the rotating brush.  The brush was used to knock down any raised tablets inside the blister cavity.  As the plastic bristles were rubbing against the tray and tablets, static was being generated.  In order to keep this process running smoothly, they had to eliminate the static.

In evaluating the target areas to remove the static, I recommended the following solutions:

  1. Unpacking of the preformed trays: As the operators started to unpack the plastic trays, they would get a big shock. Static is being generated as the sheet are moving and sliding across each other. I recommended the model 111224 Super Ion Air Knife Kit.   The Super Ion Air Knife blows ionized air onto the surface. It can remove static and dust as far away as 20 feet. The operators could still perform their operation as the Super Ion Air Knife could perform its job. This will remove the static and also remove any plastic fragments or debris off the surface. Dirt and contamination is attracted to the material by static, and if the tray is not completely clean, the company has a potential to lose an allotment of product.
    Plastic sheets before EXAIR
    Static on Plastic sheets before EXAIR is 13,300 volts
    Tablet packaging after
    Static on Plastic sheets after EXAIR is 100 volts

     

  2. At the thermal forming machine: This machine uses a heated die to press cavities into a plastic film. As the tray is being made and pushed along, static is being created. I recommended the model 7012 Ionizing Bar.   This would neutralize that static before the tablets are being inserted.
    Thermoformed trays before EXAIR
    Static on thermoformed trays before EXAIR is 4,900 volts
    Tablet forming trays after
    Static on thermoformed trays after EXAIR is 200 volts

     

  3. At the tablet chute: As the tablets are being moved and transferred, a static charge is being generated on the surface. When the tablets are about ready to be dispensed, the repulsion forces would cause either a delay by sticking to a prior tablet or a shift in alignment; both causing the tablet to miss the cavities of the blister pack. I recommended the 7012 Ionizing Bar to mount near the end of the chute. The Ionizing Bar creates both positive and negative ions to remove any type of static that passes underneath it.
  4. The rotating brush: After the tablets are placed in the blister pack and before the foil is applied to enclose the package, a rotating brush with plastic bristles would rub on the surface of the plastic tray and the tablets. This would ensure that the tablets are lying flat in their cavities. This operation would regenerate the static. As you can see with the picture below, it was creating 1.5 Kilovolts of static electricity on the surface. I recommended another model 7012 Ionizing Bar to remove this buildup of static.
Tray/tablet after brushing before EXAIR
Static on Tray/tablet after brushing is 1500 volts
Tray/Tablet after brushing after EXAIR
Elimination of Static after using EXAIR results in no static charge

With any type of static issues, it is best to have a quantitative result of your process. The EXAIR model 7905 Static Meter can do this.  This pharmaceutical company was able to determine how much static was being generated in their process, and how effective in removing the static.  They were so happy with the results of the EXAIR Static Eliminators, they sent pictures to show.  As you can see, we were able to remove all static before their last step of applying the foil.  The rejection rate went way down and their process ran very smooth.  If you start seeing issues with static in your process, you can contact EXAIR and speak to one of the Application Engineers.  We have a large range of Static Eliminators that can help you.

John Ball
Application Engineer
Email: johnball@exair.com
Twitter: @EXAIR_jb

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