High-Performance Depth Filtration Solutions
Purecowater is proud to supply ErtelAlsop Pak® Lenticular Filters, the industry standard for depth filtration modules. Originally invented by Alsop Engineering, the lenticular cartridge format revolutionized liquid filtration by combining the precision of depth filter media with the convenience of a totally enclosed, leak-free system. These filters are designed to tackle complex solid and liquid filtration problems across pharmaceutical, food & beverage, and industrial sectors.
Whether you are upgrading from traditional plate and frame presses or designing a new sanitary filtration line, the ErtelAlsop Pak® offers a versatile, scalable, and operator-friendly solution.
What is a Lenticular Pak® Filter?
The Lenticular Pak® (also known as a depth filter module) is a stacked cartridge system comprised of multiple filter cells. Each cell consists of two sheets of depth filter media sealed at the edges using a patented polypropylene process. These cells are stacked on a central core to form a module that resembles a series of double convex lenses—hence the name “lenticular.”

This design maximizes surface area within a compact footprint, allowing for high solids loading capacity and efficient particle retention ranging from 0.25 to 15 microns.
Why Choose Lenticular Modules over Plate & Frame?
While plate and frame filters have long been the workhorse of depth filtration, lenticular modules offer distinct advantages, particularly regarding hygiene and ease of use:
- Totally Enclosed System: Eliminates leakage and exposure to the atmosphere, making it ideal for hazardous, volatile, or high-purity fluids.
- Rapid Change-Out: Modules can be replaced in minutes rather than hours, significantly reducing production downtime.
- Scalability: Since Pak® cartridges use the exact same media as ErtelAlsop’s filter sheets, processes developed on a lab scale or plate press can be easily transferred to lenticular housings.
Technical Specifications
ErtelAlsop Pak® cartridges are highly customizable to fit various housings and flow requirements. Below are the standard specifications available through Purecowater.
| Specification | Details |
|---|---|
| Diameters Available | 12-inch (30.5 cm) & 16-inch (40.6 cm) |
| Micron Retention | 0.25 µm to 15 µm (Nominal) |
| Number of Cells | Stacked 5 to 18 cells per module |
| End Cap Configurations | Flat Gasket or Double O-Ring (DOE) |
| Core Material | Polypropylene (Standard) |
| Gasket Material | EPDM, Nitrile, Viton, Silicone |
Filter Media Options
The performance of the Pak® cartridge is defined by the media inside. We utilize three primary media families to suit different chemical and filtration needs:
| Media Brand | Composition | Best Application |
|---|---|---|
| AlphaMedia™ | 100% Cellulose | Applications requiring no inorganic additives. Ideal for dielectric oils, coolants, and syrups. |
| MicroMedia® | Cellulose with Diatomaceous Earth (DE) or Perlite | The “workhorse” media. High solids loading, haze removal, and ultra-fine particle retention. Common in automated botanical extraction. |
| MicroClear® | Activated Carbon impregnated Cellulose | Color correction, odor removal, and decolorization without the mess of loose carbon powder. |
Common Applications
ErtelAlsop Pak® cartridges are engineered to meet the strict requirements of diverse industries:
- Life Sciences & Pharma: Removal of precipitates, catalyst recovery, and sterile pre-filtration.
- Food & Beverage: Haze removal in distilled spirits, syrup clarification, and botanical extract filtration.
- Chemical & Industrial: Filtration of silicone oils, inks, paints, and varnishes.
- Cosmetics: Clarification of perfumes, lotions, and essential oils.
Get a Quote for Your Filtration System
Purecowater provides complete support for sizing, selecting, and implementing ErtelAlsop filtration systems. Whether you need replacement modules or a full housing assembly, we are here to help.