Just as cleanroom wipers, cleanroom gloves, and cleanroom garments are essential in every controlled environment, cleanroom sticky mats remain an vital tool for capturing particulate upon entry into a clean room. They are placed on the outside of the clean room, making them one of the first contamination control points.
The need to keep contamination from entering certain areas is not a new concept. According to this article http://www.tested.com/science/608153-history-cleanroom/ the concept of the modern-day cleanroom was first seen in 1962. Willis Whitfield, working for Sandia National Laboratory invented the cleanroom after being tasked with keeping nuclear production facilities as clean as possible.
Tools for controlling particulate have advanced over the years. There are however some products that remain mostly unchanged since the days of the first cleanrooms. One of those products is the cleanroom sticky mat – a simple multi-layered mat made with thin sheets of sticky surface polyethylene.
First Uses and the Evolution of the Tacky Floor Pad
The Tacky Floor Pad was patented Jan 15, 1974 (US 3785102 A). A summery of the invention states: The pad of this invention employs a polyethylene or polypropylene sheet which can be walked on and wheeled over without tearing or destruction. A pressure-sensitive adhesive advantageously has been found to remove dirt from shoes and wheels while at the same time it readily releases the polyethylene or polypropylene sheet which covers it to enable presentation of a fresh adhesive surface for use.
Cleanroom sticky mats are also known as Tacky Mats® since the Liberty Industries, Inc trademark in 1978. These mats are exactly what their name implies, adhesive top coated mats. To be more descriptive, cleanroom sticky mats consist of multi-layered adhesive top coated plastic film sheets that are designed to capture dirt from foot and cart traffic. The mat is attached to the floor with an adhesive backing. Once the top layer is contaminated and no longer tacky, the sheet is peeled away to reveal the next clean sheet. Sticky mats are a cost-effective way to remove dirt.
In addition to keeping dirt and dust out of cleanroom, Sticky floor mats are also widely used in several other industries. They can be found court-side at basketball games and in gyms. They are also used in residential settings, service-based industry, and construction industry.
Attempts at Improvements
The have been many attempts to find cost-effective and efficient ways to remove dirt from shoe in the medical and cleanroom industries. In such example is an air blast system which ultimately proved to be expensive and inconsistent. Additionally washable adhesive mats lose effectiveness after washes and prove to be labor intensive when compared to traditional stick mats. Lastly, disinfectant wash troughs are messy and impractical for cart wheels.
Cleanroom sticky mats typically come 30 layers per mat and four mats per case. There is also a variety of colors including white, blue and gray.
Article by High-Tech Conversions, Inc., a manufacturer of cleanroom supplies