All Evergreen models can be equipped with Extended Shelf Life (ESL) and Extended Long Life (ELL^®) features. Read more to learn about what you might need to preserve the shelf life of your fresh products.

Evergreen Packaging ESL Technology

We offer ESL capabilities as options so the equipment can be customized to meet your specific needs. Nearly all Evergreen machines are shipped with at least some basic ESL components. While packaging configurations and materials also affect the shelf life of refrigerated products, machine technology is fundamental for maintaining product quality.

Form, Fill, and Seal Environment

Enclosures for the basic machine are combined with High Efficiency Particulate Air (HEPA) filtration system for the form, fill, and seal sections of the machine to create a cleaner environment. The environment is pressurized to assure an outward flow during normal operations and when doors are opened.

Metering Bowls

ESL machines generally utilize hermetically sealed metering bowls. A positive displacement metering system used on most ESL machines floods product into the area surrounding the fill valves and pistons. A double-diaphragm, self-draining system, used on recently developed filling machines, separates the product to be filled from the outside environment by use of a vacuum between a double diaphragm. HEPA- filtered air occupies head space in the product tank for additional protection.

Pre-Production Sanitation

All Evergreen machines are designed to accommodate pre-sanitizing by circulating 195–205°F hot water or sanitizing chemicals through the product contact piping. The practice can extend refrigerated shelf life up to 28 days—the limit for High Temperature Short Time (HTST) processed dairy products, before they begin to degrade because of microbial factors.

Auto Sanitization

The auto-sanitize system protects against contamination by periodically spraying sanitizing solution on critical product contact surfaces. This system can be used in an automatic or manual mode.

Requirements to Ensure ESL Success

In addition to machine technologies, to ensure desired shelf life, specific plant practices are also required. Experience has shown that the higher the sanitation standards of the entire plant, the higher the prospect of ESL success.

Minimal Process Requirements

HTST processed with Standard Plate Count (SPC) to the filler not to exceed 50–100 cfu/ml.

Minimum Packaging Machine Requirements

The basic requirements begin with good sanitary practices, including system Cleaning in Place (CIP) and careful cleaning of product/container contact surfaces according to machine specifications. In addition, the filler area should be enclosed to reduce potential contamination via ambient plant air.

Minimum Distribution Requirements

Maintain product temperature at 45°F (7.0°C) or below—the colder, the better.

Evergreen Packaging ELL Technology

Evergreen Packaging Extended Long Life (ELL) machines represent the ultimate in sanitary packaging machine design. ELL machines, through the use of aseptic technology, allow an ultra pasteurized low-acid product to achieve maximum refrigerated shelf life.  Evergreen ELL machines utilize advanced ISO 5 (Class 100) HEPA filtering technology to provide a dual barrier between the outside environment and the filling process. This environmental control, coupled with carton decontamination, hot-water sterilization of product piping, and auto-sanitize systems, allow Evergreen ELL machines to maintain the quality of the finished product. Packaging configurations and materials do contribute to the keeping quality of refrigerated products, but machine technology is critical.  To achieve expected product shelf life from ELL machines, at a minimum the ultra pasteurization process should be utilized yielding a <1 cfu/ml SPC value to the filler.

Benefits of ELL

• Increases plant efficiency through longer production runs.
• Allows for a larger distribution area from a single facility.
• Reduces product returns from expired short-term pull dates.
• Increases retail sales—longer pull dates encourage retailers to increase facings and equate with freshness in consumers’ minds.

Minimum Packaging Machine Requirements

ELL machines leave nothing to chance in the packaging environment. ELL machines include all the following integrated technologies:

Environmental Control Systems

• Dual ISO 5 (Class 100) HEPA filtration acting like a double self-contained clean room with continuous ultraviolet decontamination of plenum surfaces.
• Auto sanitize system of product contact surfaces.
• Sterile Air Blanket for product tank and vent system.
• Condensate control system.

Self-Contained CIP/SIP

• Hot-water/steam sterilization (for product piping system at 250°F for 30 minutes).

Carton Decontamination System

• Hydrogen peroxide (H₂O₂) carton interior decontamination.

• Hot incinerated air chamber to evacuate peroxide to or below legal limits.

Hermetic Filling System

• Positive barrier provided in the fill bowls.

ELL Packaged Products

When used to package ultra pasteurized processed dairy products in standard packaging, ELL features combine to provide up to 45 days of refrigerated shelf life for dairy products. When selecting advanced packaging configurations and materials, product quality can be maintained beyond 60 days. For juice, the microbiological quality of refrigerated products can be sustained beyond 90 days with ELL technology.

For more information, check out our white paper “Extending the Shelf Life of Refrigerated Fluid Dairy Products Packaged in Paperboard Containers.”