How weighers and graders improve product quality for poultry processors

Desirable bird weights will vary from market to market. In some markets the heavier the bird the better, as each bird takes up a shackle and processing heavier birds does not necessarily involve more people. In other markets, particularly those where cut portions in fixed weight/fixed price packs predominate, growers aim to achieve a weight profile suitable for these packs. In each case, processors must be able to check that birds arriving at the processing plant are of the weight expected. If not, plant management will have to take prompt remedial action. The sooner therefore they have this information, the better. Once in the process, optimum processor profitability depends on the allocation of each product to the downstream process where it can earn the most money.

A different process

The ability to weigh products at various stages in the process is important for another reason too. Unlike other manufacturing processes, which assemble products from individual parts, processing chicken is all about disassembly. Carcasses bleed out, their feathers are removed, their feet cut off and all innards taken out. In many plants, cut and deboned products now account for the majority of production. The disassembly process can result in too much weight being lost and quality compromised. The processor needs to know as soon as possible if something is wrong and exactly where the problem is happening.

Let us now look by department at what weight and quality information we ideally need and why.

Weighing live birds

Although they give the total weight of birds delivered by flock, conventional crate weighing systems do not weigh birds individually and cannot therefore show a flock’s weight distribution curve. If this information were also available, it would help plant management manage better, as they would spot any unwelcome variances at the beginning of the process, giving them extra time to come up with solutions.
The ability to weigh live birds accurately is important for other reasons too, such as grower evaluation and a baseline reference for downstream yield checks.

First quality check

The first opportunity to check the health status of a flock is in the lairage/hang-on area, where vets can remove DOAs and damaged birds. A second check after plucking allows the removal of obviously sick, undersize or poorly bled carcasses unsuitable for proceeding to the next stage in the process. To ensure the correct allocation of the cost of such damage, the ability to determine whether damage to a product happened on the farm or in the processing plant would also be very welcome.

Evisceration checks

The next step in the process is evisceration. Being able to compare live and eviscerated weights on a carcass-by-carcass basis would give plant management invaluable information on the performance of automatic evisceration equipment, allowing prompt reaction to any unacceptable variances. This check would also serve as the basis for monitoring chiller performance.
Immediately after evisceration, the quality grade of each product will already be obvious. In many plants, however, the first quality check happens after chilling in the whole product distribution line. It would be helpful to know the quality profile of a flock before it enters the chiller, as in some plants products can spend two to three hours in the chill process. Once again, this would give management more time to react to any unexpected situations.

Decision time

It is in the whole bird distribution line where accurate weighing and quality grading really begins to count, as it is at this point that the precise allocation of each product to the correct downstream process will largely determine a processing plant’s profitability.
Being able to grade not just the whole product but also each anatomic part is particularly important in those plants where most are cut into portions. As we have already noted, a single downgraded part still means seven premium grade parts. As the downstream process for “A” grade and downgrade parts is likely to be different, a technique to keep their flows separate would also be a benefit.

Accurate grading is important for another reason too. Blemishes acceptable for one customer are not always acceptable for others. Being able to measure the size of a bruise or the length of a scratch would be a huge advantage in such situations.

Enter Marel

Marel has the answer: its SmartWeigher and IRIS systems controlled by class-leading Innova PDS software.
SmartWeigher can weigh products in kill, evisceration, whole bird distribution and cut-up lines. IRIS vision systems can assess individual product quality at the same points in the process. Both systems will operate at today’s highest line speeds.
Innova PDS software manipulates data received from both systems and presents key information to plant management on a minute-by-minute basis.
A summary of Marel's possibilities in chronological process order now follows.

Kill line weighing

Installed at the beginning of the killing and de-feathering line, SmartWeigher, which works with standard kill line shackles at 6” pitch, weighs live birds after either electrical or controlled atmosphere stunning.
SmartWeigher has several advantages. Unlike conventional crate weighing systems, the system weighs stunned live birds only, no droppings and no stones. As the system weighs each bird individually, it can show the weight distribution curve of each flock. In an ideal situation, all birds should be of the target weight and the curve should be flat. SmartWeigher is also supremely accurate. Innovative and highly effective self-learning techniques neutralize friction and vibration, two traditional enemies of accurate in-line weighing. SmartWeigher is also supremely easy to live with. Once set up during installation, regular re-calibration is unnecessary.

First IRIS check

Installation of the IRIS vision system in the kill line is after plucking. The system, which looks at the breast of each product, can differentiate between machine damage and damage caused during grow-out. IRIS uses shape, color and texture to assess products. Installed in the kill line, it will pick up undersize products, poor bleed-out, broken limbs and residual feathers and is a useful aid to vets in safeguarding downstream process hygiene, particularly at today’s high line speeds. Innova software instructs the first Marel re-hanger transferring products automatically to the evisceration line to unload those rejected.

Data collection

Innova software ensures that weight and quality information on each product, collected by SmartWeigher and IRIS at various stages in the process, stays with it until its release as a whole product or cut portions. Comparing weights allows processing plant management to keep a close check on yields throughout the process.

Evisceration line options

In an evisceration line, SmartWeigher and IRIS can follow the last process machine. Both systems provide plant management with an effective early warning system, should product quality or weights not be as expected. SmartWeigher looks both backwards and forwards, allowing the performance of both evisceration and chilling equipment to be monitored minute-by-minute.

Focus on weighing accuracy

Ultra-precise weighing and quality grading is particularly important when the time comes to allocate products after chilling.
SmartWeigher systems installed in whole bird distribution and ACM-NT cut-up lines feature the auto-taring of shackles/carriers each conveyor circuit. Turning shackles at 8” pitch in the distribution line mean that wings can no longer touch. Differing shackle weights and touching wings can therefore no longer negatively affect weighing accuracy.
Carriers in the ACM-NT are at 12” pitch. Installed in this cut-up system, SmartWeigher can weigh either whole products, back saddles or both.

Focus on quality too

Shackles/carriers in distribution and ACM-NT cut-up lines are at a wider pitch than on primary process lines. With all wings stretched, an IRIS system installed in the distribution line can inspect both breast and back, in effect having an all-round view of each product. IRIS will pick up residual feathers, broken limbs, bruises, scratches and red tails and can even detect the size of a bruise or length of a scratch.
Whether installed in distribution or cut-up line, IRIS grades both the whole product and its individual anatomic parts.

Other important benefits

Besides helping ensure products are always put into their profitable form, SmartWeigher and IRIS, linked to Innova software, contribute to overall operating efficiency in numerous other ways too.
In plants equipped with two or more ACM-NT systems, weight information from a SmartWeigher installation in the distribution line can help users optimize yields by narrowing the range of weights allocated to each cut-up system. Information from SmartWeigher, installed in either distribution or cut-up lines, can help lift breast meat yields too. This involves the installation of additional modules to cut lighter and heavier front halves and breast caps for distribution to twin FHF-XB and AMF-i lines, each set to handle a limited weight range.
Information from IRIS can save inspection labor and lift overall packing efficiency by identifying downgrade whole products or portions and then releasing them automatically onto/into a separate conveyor or container.

Easy access

Innova presents information from SmartWeigher and IRIS installations on easy-to-read dashboards located centrally, giving processors complete control over the two attributes of each product, weight and quality grade, which will largely determine a plant’s profitability. In a plant equipped with both technologies, information on each carcass builds up as it moves through the process. Plant management can access this information at any stage, allowing them to spot potential problems as early as possible. Quality and yield loss and product wrongly allocated all cost money. Avoiding these pitfalls is the best answer.