When it comes to automatic box labelingsystems, the use of a bar
We use two separate bar code scanners to do two different jobs. The first is referred to as a “pre-identification” scanner, and the second is called a “verification” scanner.
The function of a pre-identification scanner is to scan a label that has been previously applied to a box or pre-printed on a box to let the system controller know what product is contained in the box.
The verification scanner’s job is to scan the label that the system printed and applied to the box to be sure that it is a good, readable label.
With today’s technological advances, barcode scanners are being replaced with vision-based sensors. These sensors essentially work by taking a picture of the label, and by using the processing power of the sensor itself, it is able to read the barcode on the label and send that information to the system controller.
This type of sensor offers many advantages that were not available with the laser-based scanners:
- Ability to read both 1D and 2D codes
- Ability to store every scanned image to a file on the controller
- Ability to view images from several different sensors in real time
- Ability to grade the quality of each image, which allows the controller to signal preventative maintenance
- Better ability to read damaged codes
- Allows the use of multiple filter settings
This lets the sensor look at the image in a different way. For example, if the sensor is going to have 10 chances to read the barcode, you can set up the sensor to try 8 times with a setting that works best under normal circumstances, and if it fails to get a good read, it can look at the label a different way for the last 2 chances.
With these advances in technology, this type of sensor offers a lot of added functionality over standard barcode scanners for essentially the same cost.
Automatic labeling systems have developed over the years to the point where you can label just about any surface of a box or package with minimal product movement. It has a lot of potential, but you should also know that there are limits to the design aspect.
When specifying and designing a conveyor for a labeling system, one of the most common requests that people ask is, “Can you make this conveyor shorter?” This question can get into dangerous territory.
It is always possible to make a conveyor shorter, but that does not necessarily work with the labeling system itself.
By default, a printer can only print so fast. When you add on the application time, you are left with a distinct amount of time that needs to pass between each box and each labeler. This time varies most often on your label specifics. Having a more detailed or graphics-intensive label is going to increase the necessary time between each print.
Labeling conveyors are built with this in mind. Once a package trips a photo eye, there needs to be sufficient space to allow time for the printers to prepare the necessary labels. On top of that, you also need to have a certain amount of room if you have tamping applicator arms for things like front and back labeling.
So to the earlier conveyor sizing question, we probably could shorten labeling conveyors to a minor extent, but often doing even that is a risky thing to do. If we took the conveyors down to their minimum length, that would leave absolutely no room for error. The slightest hiccup in flow could result in a severely misplaced label.
It is an understandable problem to require as much plant space as possible, but it isn’t worth trivializing the functionality of your labeling system. The best way to make them work ideally is by giving them room to “breathe”. This allows them ample space to operate efficiently in rougher conditions where things don’t always go as planned.
Navigating the issue of floor space can be rather tricky, but don’t let the temptation of an extra foot of space take away from the quality and capability of any of your systems.
If you have a need for a corner-wrap labeler, here are some important things to consider. We continue to see companies wanting a case label on the side as well as the end of each and every case. This can be accomplished in at least 2 different ways. Let’s look at both.
By using two printer/applicators, we can certainly get the same label on each case running down your line in any two locations. The first print and apply would print and apply the side label, while the second would be printed and applied by either an end apply swing arm or by running the case into an end stop where the label can be tamped onto the end of the box. We have had a request for labels on both sides of the box. This application can only be achieved with a Print and Apply
There are true corner-wrap applicators being used for this application each and every day. Instead of having a 3” X 4” label on the side and end of each case, we print a 3” X 8” label with the same information on both halves. The Print and Apply then has a swing arm that takes the label and slaps half of the label onto the leading edge of the case and rubs the label around the corner onto the side of the case. You now have a label on the leading end and on the side of the case and you have done it with just one Printer Applicator.
There are some limitations with this application method that you need to be aware of.
- Cases per min drops down to approximately 15 – 20 cases per minute, depending on the size of the label. It is a matter of just how many inches the printer can print per second and the time it takes to apply the label.
- The size of the label really comes into play here. If you are currently applying a 5” X 6” case label, with a corner-wrap you would have a 5” X 12” label. Compare the total square inches with a 3” X 8” label, and you will have 60 sq. in. vs. 24 sq. in. This is a huge difference.
- You need proper indexing with each and every case. There needs to be enough room between the cases for the applicator arm to rotate out and return. This can be easily accomplished by pulling a gap on the labeling line.
All of the above being said, feel confident that you can have case labels on any and all sides of the cases you are producing. Pursue your idea with a supplier that knows what they are doing and that already has experience with different methods of label application.
Auto box labeling systems need attention just like every other piece of equipment you have in your plant.
- Is your box labeling system doing what it was intended to do?
- Are you getting the boxes per minute needed through your unit?
- Label quality problems?
- Are the box weights accurate?
These are just a few of the challenges I have run into over the years on auto case labeling units. Let’s look at a few of these:
Not doing what it was intended to do:
- What has changed from when you bought the unit?
- The label size?
- The label content?
- Possibly you are now printing a label in a foreign language?
- What about the size of the boxes?
- The environment in the plant?
Not getting the boxes labeled per minute you need:
- What has changed?
- Bigger boxes?
- Bigger labels?
- Was your in-motion scale built to meet the current box sizes?
- Is the scale and conveyor system level and boxes transferring smoothly?
- Are the boxes indexed properly?
- Is your controller fast enough to process the information and still send the label format to the printer in time to be auto applied?
- Are your boxes in the correct position to be labeled?
Accurate case weights? What has changed?
- The size of your cases?
- The weight of your heaviest case?
- The speed of the line?
- Are the cases transferring correctly onto the scale, not being pushed or pulled on or off?
- Is the scale level?
What we have attempted to do here is to make you aware of the fact that an “Auto Case Labeling System” needs attention to all of the above and more.
Take a moment right now, go out and look at your system, how many of the above items do you see that could be affecting your current system?
Address these issues or ask us how we can come in and analyze your current system for improvement.
If the printer/applicator is holding things up, there is generally a couple of things to look into. The first and most important is label length, you need to be sure that the label is as short as possible so that the label is out of the print engine and ready to be applied when the box arrives. The other possibility is the speed that the label is fed out of the printer. 6-6.5 inches per second is usually as fast as you would want to go before the quality of the printing starts to suffer to the point that you will be getting no reads on the bar codes. The speed can sometimes be pushed to seven or seven and a half, but the printer will need to be kept extremely clean, especially print heads and print rollers, and the label stock will have to be of a high quality.
If the In-motion conveyor scale is causing the bottleneck you will have to be sure that the scale system was properly engineered to give you the best possible results for the size of your box and desired throughput. We take many factors into consideration when designing a box labeling system. What is the length of the boxes to be weighed? Will the boxes all be of uniform length? Or will the length vary? What is the weight range of the boxes? And of course, how many boxes per minute need to go through the system?
We recently were able to help a large company increase throughput on their box labeling system by going to work and re-engineering the scale section of their system. They were weighing and labeling a very large and heavy box. We were able to reduce the length of the scale by 25% and this allowed for nearly 25% more throughput because just prior to a box leaving the scale the weighing process is complete and the next box can begin entering the scale at this time.
You might ask, “Why not just use a very short scale?” And the answer is “because you will not get accurate weights!” The reason for this is when a package first enters the weighing platform it jars or shocks the scale and the weights fluctuate up or down. So we design systems that the weighing platform is of adequate for the weight to stabilize and gather accurate in motion weights before the end of the scale.
In conclusion, you can see that scale length is an important consideration to get the most throughput out of your system. Keep in mind that if you have a heavier package or too much belt speed the shock or jarring to the scale will be greater and it may not have time to settle down before the end of the scale.