Introduction to ErtelAlsop Pak® Lenticular Technology
ErtelAlsop Pak® Lenticular Filters represent a significant advancement in depth filtration technology, offering a user-friendly, totally enclosed alternative to traditional plate and frame filter presses. Designed for critical purity applications across pharmaceutical, food and beverage, and industrial sectors, these lenticular modules combine the superior filtration efficiency of depth media with the convenience of a cartridge format.
At Purecowater, we supply these robust filtration solutions to help facilities utilize premium depth media—such as MicroMedia®, AlphaMedia®, and MicroClear®—without the leakage risks or labor-intensive changeouts associated with older press designs. Whether you are filtering distilled spirits, botanical extracts, or dielectric oils, the Pak® module ensures consistent, scalable results.
How the Pak® Lenticular Module Works
The term "lenticular" refers to the lens-like shape of the stacked filter cells. A standard Pak® cartridge is constructed from multiple filter cells stacked vertically. Each cell consists of two precision-cut circles of depth filter media, sealed around the edges using a patented polypropylene process, and separated by an internal slotted core.

Fluid enters the housing and flows from the outside of the module stack into the media cells. Particulates are trapped within the tortuous path of the depth matrix (fibers and filter aids), while the clarified liquid passes into the center core and exits the housing. This design maximizes filtration surface area while maintaining a high solids-loading capacity.
Key Technical Specifications
ErtelAlsop Pak® cartridges are renowned for their versatility. They are manufactured in standard industrial sizes to fit most 12-inch and 16-inch lenticular housings.
| Specification | Details |
|---|---|
| Module Diameters | 12-inch (30.5 cm) & 16-inch (40.6 cm) |
| Number of Cells | Typically 5 to 18 cells per module (customizable based on cake space requirements) |
| Micron Ratings | Nominal ratings from 0.25 µm to 15 µm |
| End Cap Architectures | Flat Gasket (Standard), Double O-Ring (222, 226 styles) |
| Core Material | Polypropylene (Standard), Stainless Steel options available |
| Gasket Materials | Buna-N, EPDM, Viton, Silicone, PTFE Encapsulated |
Available Media Formulations
Selecting the correct media is critical for optimizing throughput and retention. ErtelAlsop offers several distinct media series integrated into their Pak® modules:
| Media Series | Composition & Characteristics | Primary Applications |
|---|---|---|
| AlphaMedia™ | 100% Cellulose. Contains no resins, binders, or inorganic aids. High purity. | Dielectric oils, perfumes, essential oils, pharmaceutical liquids. |
| MicroMedia® | Cellulose mixed with high-performance filter aids (Diatomaceous Earth or Perlite) and wet-strength resin. | Food & Beverage, haze removal in spirits, gelatin, chemical clarifying. |
| MicroClear® | Immobilized Activated Carbon media. | Color correction, odor removal, decolorization of syrups and APIs. |
| Zeta-Pak® | Media with high Zeta Potential (positive charge) for removing sub-micron particles and haze. | Biopharmaceuticals, endotoxin reduction, fine chemical filtration. |
Advantages Over Plate & Frame Filters
Many industrial operators are upgrading from traditional plate and frame presses to lenticular Pak® modules for several operational benefits:
- Sealed System: The lenticular housing is a closed vessel, preventing liquid loss, oxidation, and exposure to the environment. This is crucial for volatile solvents in botanical extraction or sterile pharmaceutical processes.
- Rapid Changeout: Replacing a stack of Pak® modules takes minutes compared to the hours often required to dress and clean a filter press.
- Scalability: The same media grades used in small laboratory discs are available in 12" and 16" production modules, allowing for linear process scaling.
Industry Applications
Botanical Extracts & Distilled Spirits
Specifically useful for “chill haze” removal and polishing, the MicroMedia® Pak cartridges utilize Diatomaceous Earth to capture waxes and lipids without stripping essential flavor profiles. The EPDM gaskets and Polypropylene supports offer excellent compatibility with ethanol and other solvents.
Industrial & Utility Oils
The Disc-Pak® configuration using AlphaMedia™ is a standard for filtering transformer oils (dielectric fluids), lubricating oils, and coolants. The cellulose-only media ensures that no inorganic material leaches into the oil, maintaining dielectric strength.
Need help selecting the right micron rating or media type for your process?