Based on a current hen population of 282 million and 70% of production sold in shell form it is estimated that U.S. producers have to pack 140 million cases annually or 0.38 million cases per day. Assuming an eight hour work day and a weighted average effective processing rate of 275 cases per hour there are between 175 and 200 graders in operation in U.S. plants ranging in capacity from 100cph to 500cph per installation.

Mechanization is critical to constraining costs and improving speed and efficiency. Accordingly, the products offered by the two major U.S. suppliers indicate future trends. Over the past two decades, the standard for new egg production operations has comprised a 1 million to 1.5 million hen in-line complex.

As high-rise houses are re-caged with multi-tier belt batteries, processing rate must increase to allow for single-shift packing. It is estimated that at least 20% of eggs are packed off-line, especially with the increase in the number of floor systems operated by contractors. These installations require farm packers and in-feed equipment at the plant.

There are a number of plants which operate both off-line and in-line, requiring duplication of equipment. Some units operate exclusively off-line requiring special egg handling at the front end and installations to wash and dry reusable plastic trays.

M&A benefits industry

During the past two years there has been significant consolidation in egg packing and processing. Sanovo Technology Group has been formed following the acquisition of Staalkat based in Holland by Sanovo of Denmark. The new corporate entity will include Staalkat International manufacturing farm packers and egg graders with Sanova Technology A/S supplying egg processing equipment in association with affiliate companies involved in environmental applications.

The acquisition of Diamond Automation by Moba has resulted in the formation of Diamond-Moba Americas responsible for egg grading and packaging and OvoPro specializing in breaking and pasteurization. The rationalization and realignment of companies has contributed to synergy with respect to research and development, sales and service.

Ultimately the various mergers and acquisitions will benefit both producers and manufacturers but there will be sufficient competition to ensure technological advances and appropriate pricing.

Farm packers

Diamond produces a range of farm packers including the newly introduced FPX module with a capacity of up to 100cph. Designed for large production units supplying remote plants, the packer is constructed of stainless steel and features automatic speed control based on rate of egg flow.

The unit has a built-in egg counter and incorporates a key pad, an interactive display and auto-diagnostic capability. The farm packer can be equipped with an optional tray stacker. The new module joins a line of lower-capacity units first introduced to the U.S. market in 1960.

Staalkat farm packers are available in capacities ranging from 40cph to 200cph. The manufacturer has designed these units for ease of operation, simple maintenance and a small footprint.

Egg conveyors

Lubing of Germany offers a complete range of conveying equipment through Lubing Systems, the U.S. subsidiary. The company offers polypropylene belts and rod conveyors as approved by USDA. The Lubing Belt Conveyor System can be installed in lengths of up to 2,000 feet operating with a 7hp motor.

The company manufactures rod conveyors with a variety of curves to accommodate a wide range of house configurations. The Lubing accumulator table directs eggs from rod and belt conveyors into graders. Features include a self-tensioning interlocking polypropylene belt with variable frequency drive. Lubing claims that their conveying equipment has a 75% share of the U.S. market.

In-feed installations

Sanovo supplies the OptiLoader with a rotary system for compact installations. The unit is designed to receive a wide range of egg weights and is versatile with respect to trays. Gentle handling of eggs is achieved using electronically controlled servo gear motors.

The suction heads operate with a two-step blow-back system for optimal delivery and cleaning. Eggs are delivered by low vacuum followed by a high pressure burst after release to clear the nozzles and to prevent blocking and dropping of eggs. All internal parts of the OptiLoader can be cleaned using the integral CIP installation.

Egg washing

Generally washing equipment is supplied as a component of a complete grading and packing installation. For specific applications, Kuhl Corp. offers the WEB series egg washers ranging in capacity from 30cph to 200cph. Their SB series can process from 300cph to 1,000cph. The WEB washers incorporate oval, scalloped horizontal-action nylon brushes which are claimed to have high efficiency.

The SB series incorporates patented brushes with an upgraded self-cleaning system with sprays to achieve rated capacity. Kuhl claims a lower water temperature to achieve the same standard of cleaning as with conventional washers to expedite drying. Filtered air at room temperature is used in a double-action dryer with delivery of pressurized air through custom machine slots. Thorough drying of eggs is required for stamping which is necessary to achieve clarity of logos imprinted on specialty eggs.

Diamond now has a washer installation capable of processing 500cph. The units supplied by Diamond range from 5 rows to 18 rows with the lowest capacity rated at 50cph. All Diamond washers can be fitted with an optional presoak system and an external rotating screen to remove shell debris, yolk and white remnants and manure.


Diamond washers incorporate a patented side-to-side brush motion and the complete manifolds with their nozzles can be removed for cleaning. Temperature can be controlled accurately using multi-tube heat exchangers fabricated from stainless steel. Washers incorporate CIP equipment. The new high efficiency dryer comprises a single blower system designed for reduced energy use and low noise level.


Staalkat is able to supply imported graders with capacities of up to 300cph. The Ardenta range is constructed of stainless steel and incorporates electronic control. Currently upgrades are undergoing design and development for the U.S market to achieve capacities up to 500cph with a full range of crack, dirt and blood spot detection.

The Diamond range of Innova egg graders is available in 100cph to 500cph capacity with 6 wide to 18 wide accumulators, in-feed conveyors, loaders and egg washers. Innova installations are modular and can be upgraded in capacity. Innova systems incorporate automatic candling involving leak, dirt and crack detection.

The range is designed for ease of cleaning and maintenance. The in-feed is totally compatible with washing and the digital egg scales are mounted on pull-out trays for ease of foam cleaning. Touch-screen control with traceability software can track each flock of eggs from production to consumer. Servo packers ensure gently handling of eggs and correct positioning in the cells of packs.

Diamond-Moba Americas have adopted the policy of supplying either Diamond or Moba equipment depending on individual client’s requirements. Accordingly the Moba Omnia range can be delivered in the U.S. with capacities ranging from 85cph to 500cph. Installations incorporate the usual modules including accumulators, dirt and leak detection, electronic crack detection, weighing, blood detection and case packers.

As it is a European unit, there are no factory-supplied washing modules. For the U.S. market installations would be fitted with Diamond modules as they are for international markets. Moba offers color detection to identify and reject brown eggs with visual shell defects as pre-determined. Again in consistency with the EU market, an interface is provided for inkjet printing of eggs which is required in many nations in the European communities.

Diamond has introduced a new control system for the Innova grader range. The DC2 is fitted standard on recently released 18W graders. Features include icon based software with a direct link to the servo packing. The previously used circuit cards have been replaced and the system offers improved reports and auto diagnosis.

Based on the combined technological resources of Diamond and Moba, Diamond Vision brown and white dirt detection modules are now available for new installations and for retrofitting to some recently supplied graders. Brown eggs can be screened for adherent dirt and there is no requirement for re-adjustment when changing from white to brown eggs. It is possible to run both brown and white eggs simultaneously in split-lots.

The Vision system incorporates high resolution cameras and special illumination to detect surface manure, blood, yolk and feathers but can also detect pin holes. When grading brown eggs, the system can distinguish between defects and “freckles.”

For off-line plants, Diamond now offers the FW-10 plastic tray washer and dryer which operate in as a single unit with an automatic spin drying cycle capable of processing 2,000 trays per hour representing a throughput of 165cph.


For 2010 Diamond-Moba Americas will offer the Auto Pack robot system developed in association with Motoman a subsidiary of Yaskawa of Japan. This leading world manufacturer of robotics produces over 175 models suitable for a range of industrial applications. The robots have been adapted for operation in egg plants with specially designed peripherals including the pick-up heads and special software for efficient operation.

The MR30 robotic system can be configured to transfer consumer packs into cases, crates, display pallets or baskets. The robot can pick groups of packs from two locations for distribution into the shipping containers. In the MR40 configuration the robotic installation will palletize both plastic packs and fiber trays onto wooden pallets and insert interleaf sheets. The system is capable of manipulating empty pallets and also weighing palletized product. The MR40 installation can handle up to 300cph.

Massman Automation Designs offer robotic packers to palletize loads. Installations can be configured to a variety of applications with a variety of in-feed and discharge patterns. The unit is capable of handling different sizes of boxes and can insert slip sheets as required. Massman manufactures case packers capable of processing up to 25,000 eggs per hour (70cph) and a variety of models allowing dual-line operation with different products.

Moba accessories available through Diamond-Moba Americas include a tray stacker, tray palletizers, case packers with two individual modules in one compact frame to combine throughput of 70 cases per hour. The Diamond Multi-caser can handle foam, PET and fiber cartons and egg trays. Carton labeling, pack splitting, label inspection and custom design conveyors are available for specific configurations of packing lines.

The bottom line

Innovations in electronic control and product handling will increase the efficiency of plants to cater for larger complexes, reduce labor cost and minimize injury. These are important considerations in a highly competitive industry with increasing concern over environmental and labor issues.