After five years in development, Monadnock Non-Wovens has developed a unique bonded composite of meltblown Halar and polypropylene. It combines the unique characteristics of polypropylene and Halar in one intimately bonded composite.
“It will have filter applications worldwide where the combination of high-dirt holding, relatively low cost and extreme inertness for use where chemical or radioactive attack is expected,” said Monadnock’s technical cirector Rowland Griffin. “Although primarily developed to meet demand in the liquid filtration market and the chloro-alkalis chemical, electronic and pharmaceutical industries, it has other potential uses in Homeland Security as personal barrier protection or other replacement for expensive membranes such as PTFE.”
Halar E-CTFE is a fluoropolymer that has chemical resistance properties similar to PTFE in that it is highly unreactive to acids, alkalis, ozone, heat and radiation. Its ability to resist permeation by aqueous solutions is unmatched versus other commonly used surface webs (i.e. carbon, polyester and glass). It also has exceptional electro-negativity and offers a very smooth structure that discourages biofilm formation. For several applications Halar`s properties, including its tolerance to pH 1-14, makes it more suitable than both PVDF and PTFE. The polypropylene layer extends the service life under particle challenge saving time at the filter fabricator and ensures a constant bond between the media. This breakthrough overcomes some of the challenges of forming layers with Halar with its “non-stick” behavior without addition of glues or other
extractables. “This could lead to other possible uses including back-washable filter bags or elements or even
water impervious structures that allow air to pass in battlefield equipment,” said Mr. Griffin
Monadnock Non-Wovens, a supplier of roll goods to the filtration industry, plans to supply the unique composite in rolls up to 42 inches wide, with roll diameters up to 40 inches, and nominally rated to filter between 1-20 micron.