The automated slaughter-line
Read our theme on the automated slaughterline, which poses new requirements to everybody.

Af Kjeld Neve Andersen, Hans Henrik Bondegaard, Peter Andersen, Carsten Jensen

New technology at the slaughterhouses - increases the demand on everyone

'In the good old days' the horses found the way home even if the coachman fell asleep; the motorcar cannot manage this - yet!

A similar parallel can be drawn between the traditional and modern slaughterhouse. Earlier, many problems were solved because the operators corrected faults, but with the entry of the robots onto the slaughter-line it is necessary to make certain to maintain the equipment so that the machines perform optimally. Nozzles must be kept clean, and knives must be changed before they become blunt. Faults must be corrected quickly, the engineer must not be far away and cooperation about the required solutions is necessary.

The use of robots makes new demands on management, operatives and suppliers. It is necessary to train the employees in the new functions and to cooperate across trades and companies.

 

Starting new robots - new functions for the employees

Although the robots have received basic adjustment by the supplier, experience shows that an adjustment is always required for each slaughter-line. It is for example important for the eviscerator whether the carcasses are flame treated or singed. Flame treatment results in a softer carcass and the front legs hang slacker. The position of the front legs is very important for how the tools in the eviscerator are placed, and this requires a special adjustment of the robot.

Practical start
DMRI Consult from the Danish Meat Research Institute cooperates with the supplier about the practical commissioning on the line. In the beginning a few carcasses are treated in the robot. The quality is then evaluated, the requited adjustments are carried out and the number of treated carcasses is slowly increased. During this process the operators and service staff are taught how to adjust the robot.

Training
The production employees are trained as operators or super users.

An operator must know how the robot treats the carcass. He must be able to evaluate whether possible faults on the carcass means that it must be sent for manual treatment or whether the fault is so minor that the carcass can be sent through the robot.

A super user must be able to evaluate whether the carcass quality at each robot is satisfactory. If it is not, he must be able to evaluate where on the line an adjustment must be made; whether it is just a small change he can do himself or whether he must call in service staff for a more thorough adjustment.

The service employees are trained to basic level or expert level.

One robot, many robots
It is of course complicated to commission several robots simultaneously. It should ideally happen at a low slaughter rate, and the adjustment of the robots must be done in sequence starting from the 'black' end of the line, so that all processes are checked systematically from there. In the real life this is rarely possible, and the commissioning therefore becomes difficult.

In practice continuous adjustment is carried out, and each adjustment can influence many of the subsequent operations. It is therefore very important to be able to consider what each change can result in.

Three tests must be passed
Three approvals are required to ensure that the robots operate satisfactory.

The first test is the 'dry' test, where the functions of the robot are tested without carcasses. The next test is the operating test that evaluates the slaughter rate and 'operating time', i.e. the part of the production time where the robot is running correctly. Finally the transfer test is done; here the carcass quality is also included and evaluated.

The success has been achieved when all three tests have been passed, but between the three tests lay many adjustments and adaptations.

Process control - the quality is monitored on the modern slaughter-line

'Process control' is a tool for daily monitoring and registration of the quality for critical slaughter processes. The system tells when the quality is reducing in order to ensure quick fault finding action thus reducing the financial loss.

The first commercial system for process control is being commissioned in cooperation with Danish Crown at Saeby. It includes measuring equipment for manual checks of the position of the sticking wound and carcass splitting quality plus automatic registration of the quality of fin cutting.

The Danish Meat Research Institute supplies the system, which has a preliminary basic price starting at approximately DKK 100,000. 

The automated slaughter-line is ready in 2007 - the last robots are now being developed

In 2007 it is expected that the last four robots for the slaughter-line are completed. This provides the possibility to establish the automated slaughter-line. The last four robots are:

Removal of heart pluck and loosening of jaws
A new robot will ease the work and improve the hygiene

At the moment the robot is a complicated test installation, but it is expected to become a robot for heart pluck removal with the tongue cut loose and transfer of the heart pluck to the pluck conveyor; at the same time the jaws will be cut loose.

Test robot
In its present form the robot consists of a fixing part, a section for cutting the jaws loose and a station removing the heart pluck with tongue. The carcass is measured anatomically from the underside of the gambrel to the elbow. This measurement is used to be able to hold the carcass correctly from the dorsal side. The jaws are cut loose from the dorsal side, but the heart pluck with tongue is cut loose and pulled out from the ventral side.

Difficult tongue
The difficult task is to cut the tongue loose. Various cutting tools have been tested. At the moment a process is tested where a central pull in the larynx is combined with cutting from both sides to loosen the tongue. The process is expected to be ready in a couple of months.

Jaws OK
Loosening of jaws from the dorsal side functions well. When the process for cutting out the tongue has been decided and the heart pluck can be pulled out, the robot will be optimised to handle the carcasses at the required cycle time and with the required yields.

 

Figure 1. Test robot for removal of heart pluck and loosening jaws.

Advantages
The heavy lifts, which are required today for heart pluck removal, will be eliminated. The same is the case for the difficult pulls and cutting operations, often in awkward positions, when the tongue is taken out and the jaws are cut loose.

The hygiene is improved when tongue and jaws are cut automatically. The mouth and neck regions contain many microorganisms. By replacing the manual handling with a robot whose tools are disinfected, the risk of spreading bacteria between carcasses is reduced considerably.

New simple robots for pluck separation
Success with a combination of robots and manual operations

When using automatic evisceration, the liver pluck is taken out with the gut set while the heart pluck is removed traditionally and hung on a hook conveyor.

Since the summer of 2004, two new robots separating and sorting the two pluck sets have been commissioned at Danish Crown in Blans. The commissioning period has shown both strong and weak sides of the robots, which today functions in a simpler way than originally expected.

The capacity is 400 pluck sets per hour for the robot for separating liver pluck and 800 per hour for heart pluck. A double slaughter-line will therefore require two liver pluck robots and one heart pluck robot, see Figure 2.

 

Figure 2. Layout sketch for separation of liver and heart pluck.

Robot for liver pluck
The machine pulls the liver off the diaphragm, see Figure 3. According to the quality requirements, the weight percentage of liver on the diaphragm must not exceed 1%. Danish Crown has checked this and found that the robot leaves less than 0.07%.

In the original version, the robot also cuts off the kidneys. Today the kidneys are cut off manually. The time for this work was found by utilising the spare time for the operator minding the robot. In this way the robot has become simpler and cheaper.

The robot for heart pluck
Due to the considerable variation in the pluck, the fault rate of the ability of the machine to accept, orientate and position pluck was so high that the machine couldn't be used in production. However, the quality of the parts cut from the pluck set was so good that a simpler version of the machine is being developed.

The simplification is that the orientation of the pluck sets is done manually. It has also here been possible to utilise the 'free time' for the operators.

Criterion for success
Automatic pluck separation for the two types is profitable if the manning in the pluck area can be reduced from four to two persons per shift. With the present solutions this appears to be possible.

The liver pluck machine is installed and commissioned on both lines at DC Blans. The new simplified version of the robot for separation of heart pluck is expected to be introduced at the same plant during the late summer of 2005.

 

Figure 3. Liver pluck on its way into the robot. In the background a diaphragm after liver removal hangs on the hook.

Automatic neck cleaning and cutting off front feet is nearly ready

The prototype robot that was tested at Danish Crown Saeby last year is now being altered in order to be able to be used for carcasses with split heads. During the autumn the robot will be moved to the slaughterhouse for final test.

Robot will remove leaf fat residues, sawdust and spinal cord by suction

The development has reached a stage where the method has been decided, and the tools are being tested in an industrial robot. The tools will be combined with steam suction in order to improve the hygiene.

/August 2005