ErtelAlsop Pak® Lenticular Filters: Product Overview & Specifications

Introduction to ErtelAlsop Pak® Lenticular Filters

In the world of industrial liquid filtration, the transition from open plate and frame filter presses to closed systems is a significant upgrade for many facilities. ErtelAlsop Pak® Lenticular Filters, available through Purecowater, represent the pinnacle of this technology. Originally developed by Alsop Engineering in the 1940s, the lenticular cartridge format offers a sealed, hygienic, and user-friendly alternative to traditional filtration methods without sacrificing the high solids loading capacity of depth filtration media.

Whether you are filtering botanical extracts, pharmaceuticals, distilled spirits, or industrial chemicals, the ErtelAlsop Pak® line provides a scalable solution designed to meet precise retention requirements.

What is a Lenticular Filter Module?

A lenticular filter module—often referred to as a “Pak”—consists of depth filter sheets stacked in a distinctive disc format. Each cell in the stack is comprised of a pair of filter sheets (such as MicroMedia® or AlphaMedia®) with edges sealed using a patented polypropylene process. This assembly resembles a stack of double convex lenses, hence the term “lenticular.”

Unlike surface filters that trap particles only on the outer layer, these depth filter modules trap contaminants throughout the complex matrix of the media. This design allows for:

• High Solids Loading: Capable of holding significantly more particulate than standard pleated cartridges.
• Leak-Free Operation: When used with a filtration housing, the module forms a totally enclosed system, eliminating edge leakage and external contamination.
• Rapid Change-Outs: Replacing a stack of modules takes a fraction of the time required to dress a plate and frame press.

Product Variants: The Pak® Series

ErtelAlsop offers several configurations to suit specific chemical compatibility and filtration goals. The two most prominent series distributed by Purecowater include the Zeta-Pak® and the Disc-Pak®.

1. Zeta-Pak® (Micro-Media®)

The Zeta-Pak® is the workhorse of the lenticular line. These modules are manufactured using Micro-Media®, which incorporates filter aids (such as Diatomaceous Earth or Perlite) and wet strength resins into a cellulose matrix.

• Key Feature: Exhibits a positive Zeta Potential, allowing it to electrokinetically adsorb negatively charged particles (like haze or bacteria) that may be smaller than the physical pore size.
• Ideal For: Clarification of beverages, removal of haze in spirits, and pharmaceutical applications requiring high-efficiency sub-micron retention.

2. Disc-Pak® (AlphaMedia®)

The Disc-Pak® utilizes AlphaMedia®, which is a 100% cellulose product free from resins, binders, or mineral filter aids (no DE or Perlite).

• Key Feature: Extremely low extractables and high chemical purity.
• Ideal For: Applications where mineral leaching is a concern, such as dielectric oils, organic fluids, specific pharmaceutical broths, and essential oils.

Technical Specifications

Selecting the right filter module requires understanding the physical and operational specifications. Below is a breakdown of the standard configurations available.

Specification	Details
Filter Media Types	Micro-Media® (Cellulose/DE), AlphaMedia® (100% Cellulose), MicroClear® (Carbon)
Diameters	12-inch (30.5 cm) and 16-inch (40.6 cm)
Cell Configurations	Standard 16-cell stacks (ranges from 5 to 18 cells available)
Micron Ratings (Nominal)	0.25µm, 0.45µm, 0.8µm, 1.0µm, 2.5µm, 5.0µm, 10.0µm, 15.0µm
End Cap Styles	Flat Gasket (Standard), Double O-Ring (222/226 equivalent)
Core Material	Polypropylene (Standard)
Gasket Materials	EPDM (Standard), Buna-N, Viton, Silicone
Sterilization	Steam-in-place (SIP) capable or hot water sanitizable

Primary Applications

The versatility of the ErtelAlsop Pak® cartridges makes them suitable for a wide range of industries.

• Food & Beverage: Polishing filtration for wines, spirits, syrups, and soft drinks.
• Botanical Extraction: Removal of lipids and waxes (winterization) in ethanol extraction processes for hemp and cannabis.
• Pharmaceuticals: Clarification of cell cultures, API processing, and large volume parenterals (LVP).
• Chemical & Industrial: Filtration of specialty chemicals, varnishes, and dielectric oils where particulate removal is critical.

Why Switch to Lenticular Filtration?

If your facility is currently using manual plate and frame presses, switching to a Pak® Lenticular system can drastically reduce downtime.

1. Safety & Hygiene: The enclosed housing prevents exposure to the fluid and eliminates dripping.
2. Efficiency: Loading a new cartridge takes minutes, not hours.
3. Scalability: Housings can accommodate multiple modules (1, 2, 3, or 4 high) to handle increasing flow rates without changing the footprint significantly.

Purecowater is your trusted partner for sizing and supplying ErtelAlsop filtration solutions. Whether you need a specific micron rating or advice on chemical compatibility, our team is ready to assist.