Unicel is American’s leading manufacturer of swimming pool filter replacement cartridges and D.E. filter grids.

Unicel curved vertical D.E grids slotted collar type – Pac Fab, American, Hayward, and Sta-Rite, are interchangeable (assuming full size grids are replaced with full size and small grids with smalls). Unicel offers one all-purpose replacement series.

• Higher Yarn Count +
• Finer Denier +
• Higher Permeability +

What is the covering material used on D.E. filter grids and is this a special fabric?

The cloth used on Unicel’s D.E. grids is 100% Polypropylene. This fiber, a member of the Polyolefin family, has excellent resistance to acids, alkalis, and abrasion, in addition to being both rot and mildew resistant. The use of polypropylene cloth for swimming pool filtration was originally developed by Meissner Mfg. Co. (Unicel’s parent company) during the 1950s. Throughout the forty-year span that polypropylene cloth has been used in this application, this fabric has gone through several modifications. Improvements to critical properties such as yarn construction, weave pattern, and fabric finishing have allowed us to better control the fabric’s “permeability” in order to optimize the D.E. cake handling characteristics. Permeability is the cloth’s flow resistance, expressed in “cubic feet per minute” of airflow as measured with a Frazier permeability machine.

If D.E. grid cloth has too low a permeability, it will blind off quickly, resulting in short filter runs and frequent backwashing. On the other hand, if the material has too high permeability, D.E. can bleed back into the pool. For this reason, all polypropylene grid cloth used by Unicel (and Meissner Mfg.) is woven and finished to our exacting permeability specifications. As a result, we can assure the user the optimum in filtration efficiency, dirt holding, and cake release properties without D.E. kick back or short filter runs.

The History of Unicel
Originally Printed in Swimming Pool / Spa Age, July 1997

On a spring evening in 1956, company president and founder Dick Meissner sat down in his garage to begin work on his first sewing contract. Phil Anthony of Anthony Pools had just given him his first order to produce the Anthony McIntosh filter bag. Working alone and at night, Dick laid the foundation for the company that has grown to become the largest manufacturer of swimming pool and spa filter elements in the world.

In those early years, residential DE filtration was in its infancy. As the market started to grow, Dick received additional sewing contracts, first from Swimquip, then from Landon, Pac-Fab, and Paddock of California. By 1959 this part-time venture had grown into a full-time business. The fledgling company hired two employees and quietly moved into a 2,000-square foot building in Van Nuys, Calif. Within one year the young company doubled in size and by 1962 it occupied 6,000 square feet and had five full-time employees.

With the advent of the cartridge filter, the company saw its next opportunity. Early cartridge elements were made of a paper-type material that did not hold up well in the swimming pool environment. Realizing the future potential of cartridge filtration, Meissner set out to develop a manufacturing process to enhance this new medium. In 1964, the research and development yielded the industry’s first cartridge element made with a new spunbonded, 100% polyester material called Reemay¬. Developed by Dupont and adapted to cartridge filtration by Meissner, Reemay has become the primary filter material used throughout the pool and spa industry.

The period from 1964 to 1972 saw steady growth of the new Reemay cartridge systems. At that time, however, individual cartridge size was limited to only 6 square feet. The filter system achieved its total surface area by manifolding numerous small cartridges. These early cartridge filters worked extremely well but were difficult to clean and maintain due to the number of small elements involved. Then in 1972, Meissner, working with Purex, developed the industry’s first extended surface, single element cartridge. Meissner’s new manufacturing technology yielded a 100-square foot filter sytem using only three individual cartridges. This concept quickly caught on and single element 25-, 50-, and 75-square foot filter systems utilizing Meissner’s cartridges soon were introduced by American, Baker Hydro, Hayward, Premier, Sta-Rite and others.

Throughout the early 80’s Meissner continued to work as a supplier to the brand name pump and filter producers to develop and improve cartridge filtration. By 1984 Meissner elements, both DE and cartridges, were being utilized in virtually every major brand name filter system. To meet this growing demand, the company developed state-of-the-art high speed production equipment. Unique to Meissner, this manufacturing capability allowed the company to carve a niche for quality and delivery that is unsurpassed today.

1985 became a pivotal year for Meissner when several brand name companies began producing their own Reemay elements. Faced with a loss of business, but having tremendous production capacity, the company re-invented itself. Retaining its core OEM business under the Meissner label, the company introduced and promoted the Unicel brand of replacement filter elements. For the first time, the entire range of replacement elements built to O.E.M. specifications was made available to wholesale distribution from a single source. Dealers and service technicians could easily obtain replacement cartridges from their local distributor, even if they did not carry that particular brand of equipment.

By staying focused and specializing in filtration, Unicel has developed expertise in a very critical area of the pool and spa industry. Today, Unicel services both the spa OEM market and wholesale distribution trade. Whether it is media development or cartridge design, Unicel is recognized as the industry leader.

Technical specs

24 Sq. Ft. - Length: 12" American, Hayward, Pac-Fab, Sta-Rite, Astral

36 Sq. Ft. - Length: 18" American, Hayward, Pac-Fab, Sta-Rite, Astral, Waterway, Jacuzzi

48 Sq. Ft. - Length: 24" American, Hayward, Pac-Fab, Sta-Rite, Jandy, Astral, Waterway, Jacuzzi

60 Sq. Ft. - Length: 30" American, Hayward, Pac-Fab, Sta-Rite, Jandy, Astral, Waterway, Jacuzzi

72 Sq. Ft. - Length: 36" American, Hayward, Pac-Fab, Sta-Rite, Jacuzzi