The need for line converging is growing every day. There seems to be more and more roll stock product being produced every year which creates a need for proper handling of the product after exiting a roll stock machine.
What are the challenges and what are the solutions?
- The first challenge is out-of-weight-range packages unless you are running catch weight product. The industry is looking at different ways to get a weight of the product prior to filling the pouch.
Solution: A unit has been developed where we can weigh prior to filling the pouch. These units are out in the field and are performing very well; however, this is only working with flowable bulk product.
2. The second challenge would be checkweighing the finished product when they are coming out 2, 3, or 4 wide, and sometimes two deep.
Solution: There are line convergers being built today that actually work. These units have progressed from gates opening at different times to units with stops that push the product off at different intervals to the new units that run with a specific number of belts for a certain number of products being discharged. The new units can singulate whatever number of products is being discharged on each cycle.
- The third challenge would be checkweighing fixed weight product and possibly sorting different weights.
Solution: There are units being built that can easily handle the speed of any roll stock unit. PPM has never really been the issue.
These units can be “Legal for Trade” and give you the ability to sort different weights into specific bins for boxing.
- The fourth challenge would be the ability to weigh price label each piece. The stability of product coming out of a roll stock unit tends to rock one way or the other making accurate label application very hard.
Solution: Use a Weigh Price Labeling unit where we control the piece from start to finish. There are two ways of doing it. One would be to use a guiding system that spans the length of the unit. The second would be to use a weigh price labeler with bottom labelers to tip each product over and apply the labels to the flat side from the bottom.
If you are currently using roll stock types of equipment and are having challenges with the finished product, talk to one of your suppliers that have the ability to handle the different options offered above.
When it comes to sortation, the product is always the most important factor. Sortation and classifying systems need to be designed in a way that handles the product with care, so that damages aren’t sustained by the product or the system itself. We’ll show how this is so important by taking a look at a loin sorting system that we recently created.
When we designed the classifier, we had to first think about any difficulties that one might run into when handling loins. These particular loins were roughly nine inches wide and two feet long. The first design decision made was that the loins would travel with the short dimension leading because this used much less floor space. If this wasn’t decided, each conveyor section would have had to be over 3-4 feet long. Orienting it like this made the system about half as long, while only increasing its width by about a foot or two.
Because the loins were traveling width first, there were a few handling considerations that came into play. The loins are generally round around the bone, so with a normal conveyor setup, it was possible that the loin could roll slightly into the gap between conveyor sections. This could cause damage to the loin, and it could cause fat to be stripped off of the loin which would cause the conveyors to accumulate buildup and cause the accuracy to be off because of added dead weight on the conveyor scale.
This was solved by cascading the conveyor sections. This simply means that each conveyor was set up a little higher than the following one. Rather than passing directly over the gap at each conveyor transfer, each loin would gently fall, bypassing the gap entirely.
The only thing to be careful with was the transfer between the infeed and the scale conveyors. A large drop between the two could cause poor weighment readings. When a scale is constantly shock loaded, detrimental effects can take place. The cascading between these two conveyors was very small, but enough to get the job done.
Finally, at the end of the system, these loins needed to be diverted. With the loins facing width-wise down the conveyor, linear thrust diverts and push/pull-off diverts would be very difficult to use as the loins might not respond ideally to outside force. We used pop-up conveyors to allow the loins to drop below the conveyor instead, which solves any problems due to orientation.
This is another example of how we are able to work out all of the little details in every system that we make.
This is a question that we often hear, and it is understandable that customers would ask such a thing. The problem is that there is no single answer. Rather, we have to answer this question with a number of our own questions.
From one operation to the next, labeling requirements vary greatly, and these requirements can cause major differences in the time needed to label.
A complex or large label is one thing that can impact the labeling process. Printers can only produce labels so fast at their current level. The preprinted route for labels can help out a lot in this scenario. If all of the labels are going to be roughly the same format, you can have them premade onto a roll of labels. You can still print dates and weights onto those preprinted labels if the machine is set up correctly, and the print time is greatly reduced.
The next big thing is the type of labeling and quantity of labels needed per item. Many packages are labeled on the top and bottom, which can go relatively quickly with tamping and wipe-on labelers; but what if you need to label the front or back of the box?
For back and front labels, a swing arm applicator is really the only viable method. These tend to take a lot more time and space than a tamping piston would. First of all, they need to have room between products to be able to swing out. Second, the action of their application simply takes more movement than the top and bottom labels. A tamping piston takes just a second to apply and release the label. The arm needs to rotate from the side of the conveyor, apply the label, and return to its original position before being ready again.
Corner-wrap labels are even more complex and take more time. The box is pushed into an arm that applies the label in part on the front. As the box or case moves forward, the applicator pivots around the corner of the box and pushes the remainder of the label onto the side. Products requiring this sort of finesse will take even longer as a rule of thumb.
Speed is regularly impacted by the size of your product and number of labels required. If a box has multiple labels, the system might need to run slower to make sure that they are all being placed accurately. Box size could limit the operation speed just because a heavy box might require the conveyor to move at a slower pace to reduce system stress.
There are a lot of questions to be exchanged when designing an automatic labeling system, but the benefit is worth it.
In the meat industry, new methods are being invented regularly to deal with the conflict between increasing production volume and quality control (QC). Vision systems in particular are on the cutting edge of quality control measures.
A vision system can do any number of things, but generally, they use a camera to take images of a product and make a QC decision based on a physical trait. Because they are based entirely on images, they can run into problems with lighting and color.
To demonstrate these problems, we could consider the example of grading a beef carcass based on the quality of the ribeye cut. The ribeye is used to grade the whole carcass by industry and USDA standards, so this is an important process.
There are a number of different properties to look for when grading the ribeye. Fat content/marbling is an important factor in choosing whether the meat can be considered prime, choice, or select. For certain cattle, like the renowned Kobe, this is especially important for getting top dollar.
Fat detection can be harder than one would think, as it takes precise lighting, camera angle, and camera quality. The system needs to be able to pick it up and try to match it with a database of accepted images to see which image most closely resembles it and what grade that image ultimately was assigned. This image computation happens very quickly and can be automatic.
If the lighting in the area is dim or in a certain hue, the color contrast between meat and fat can be dulled, making it difficult for a system to pick up. To solve this, some places use ultra-violet (UV) light because it makes the color white pop out in great contrast. However, other colors may be harder to determine when UV is used. The right type of lighting depends largely on the tests needing to be made.
If a test for color is required, you must use some sort of light that is very color neutral and provides high contrast. With the ribeye, this can estimate the redness of the meat to assure that the carcass is healthy and fresh. The only trouble is that color can be deceiving in certain circumstances. If a beef carcass hasn’t been exposed to the air long enough after being opened up, its meat will have a much darker hue which could be misleading to the vision system if the carcasses passed through QC too early.
Installing a vision system takes very careful and precise planning, but when all of the bugs have been worked out, it can be an invaluable asset to any plant.
Recently, we were called into a potential customer’s plant to help them look for a solution to a problem that was causing them to lose a lot of production.
This customer was running two different production lines through a small corridor with a checkweigher set up on each line that would reject any of the boxes that were out of weight range. Seemingly, the majority of these boxes were falling out of the acceptable weight range. This made the people at these two stations very busy, and it created a large bottleneck.
The boxes that were going across these scales were being filled by an automatic filling machine in a different area of the plant that was a fair distance away. This was only compounding the problem because the filling machines were so far away that it took a long time for the scale operator to relay a message to the filling machine operator that a problem existed with the amount being output. Even when the filling machine operator made an adjustment, it would take a long time for those adjusted boxes to get to the scale.
What we proposed to solve these problems was the installation of an in-motion checkweigher directly after each filling machine that would be capable of sending feedback to the filling machines when the tolerances were getting close to out–of-range. This would allow the filling machine to continuously self-adjust to changing product characteristics.
They admitted that they had thought of placing a checkweigher closer to the filling machines before but could not find a layout that would work. We showed them that by using one of our custom-designed checkweighers designed for their specific needs, we would be able to make the system fit with minimal modifications to the existing environment.
Learn more about In-Motion Checkweighers.