Up to this point in this 8-part series, we have addressed several things related to pre-wetted wipers, including the convenience and consistency of presaturated wipers, how to unlock the best wiper for your cleanroom, the powerful wetting solution of isopropyl alcohol, and most recently important wiping techniques for effective cleaning.
So, now that we’ve explored these areas let’s turn our attention to another critical part: the product packaging. This article will discuss criteria to consider when unlocking the best packaging for your pre-wetted wipers, the types of packaging used, and why.
First, let’s review several criteria to consider when choosing the packaging for your pre-wetted wipers.
- The containers must be inert to the wetting solution and not contribute extractable organic matter or ionic substances to the pre-wetted wipers. The latter requirement is usually not a problem since packaging materials for pre-wetted wipers are all constructed from plastics.
- The containers must permit the removal of single pre-wetted wipers without dragging additional wipers through the opening.
- The containers must provide good resealing capability after removing a pre-wetted wiper(s) from the packaging. The good resealing capability will ensure that the wipers do not dry out from air exposure.
- The containers may need to be small and flexible (e.g., resealable pouches) if there is limited space to store the pre-wetted wipers at their point of use.
- The label on the outside of the packaging must be inert to alcohol (i.e., no ink smearing) when you wipe the container down before introducing it into the cleanroom.
Packaging may come in various form factors, depending on the nature of the wiper fabric. However, cylindrical canisters and resealable, flexible pouches – as shown below – are most commonly employed.
Chemically inert high-density polyethylene (HDPE) is the plastic used to make the cylindrical canister shown above. Cylindrical canisters typically contain rolls of wiper fabric made from a composite of polyester and cellulose, pre-wetted to the proper degree of saturation.
The rolls of fabric are perforated to permit convenient removal of individual wipers. The wetting solution is a semiconductor-grade IPA (Isopropyl Alcohol) mixture and Reverse Osmosis Deionized Water (RO/DI) filtered through submicron filters. The appropriate amount of solution is added to the canister so that the wipers are damp (for optimum removal of particles and soils), not saturated. Products of this type are best employed in ISO Class 5-6 areas – typically gowning rooms and equipment preparation areas for wiping down articles to be brought into the cleanroom.
The flexible Satpax® pouch shown above is fabricated from a chemically inert 48-gauge/4 mil polyethylene/polyester composite with an integral peel/reseal label. The label allows the package to be opened and closed repeatedly and, when properly closed, prevents evaporation of the solution. Burst strength for the pouch seal is 213 inches H2O. (Note that the standard requirement for burst strength for medical packaging is greater than 11 inches H2O.)
Since we make our Berkshire SatPax pouch in many different sizes, it is ideal for housing a wide variety of product dimensions. Further, stacks of wipers of various compositions – hydroentangled polyester cellulose, knit synthetics, microfiber polyester, etc. – can be contained within the pouch and wetted as described above. This variety of pre-wetted wiper products in flexible pouches enables their use in all ISO Class cleanrooms. The selection, however, depends on the wiper type (knit sealed edge polyester for the most critical areas and hydroentangled polyester cellulose for less critical areas).
We hope we’ve shared some helpful insight regarding product packaging for pre-wetted wipers and why the criteria for consideration are essential to marrying the product with the appropriate vessel.
We hope you’ll join us next week when we discuss a critical and stringent application of this type of pre-wetted product: sterile pre-wetted wipers.