In every processing plant that has in-motion box weighing or automatic box labeling, box indexers can play a vital role in spacing and merging the thousands of boxes that pass through the system in a single day.
In-motion scales are an integral part of any automatic box labeling system. These scales help to ensure that any box leaving the facility has been filled with the correct amount of product. In order for these box scales to get accurate weights, product spacing is extremely important.
Product spacing is also very important for merging multiple lines into single lines. Most box lines have areas in the plant where multiple lines feed another line to combine the product into a single line. There are several methods to index boxes, but not all of those methods are created equal.
One method is to squeeze the box from the sides. This method requires that the mechanical component holding the boxes is sized just right so it can squeeze the box tight enough to hold it but not crush it. It also must have enough squeezing force to hold back any accumulated boxes behind the box being held. A potential difficulty with this method is dealing with varying box sizes.
Another method is to start and stop conveyor belts. For best operation, a clutch brake is needed on the conveyor gear motor so the motor can keep running but just disengage from the drive. A major drawback of this method is that it doesn’t allow for much, if any, box accumulation.
Another method is to have a plate of some sort either pop up between boxes or come down from overhead between boxes. This method allows for better accumulation of boxes. Coming down from overhead is the least desirable way to index due to the potential pinch hazard to employees and the potential of crushing boxes. The pop up plate method works pretty well, but when the boxes are heavy, it puts a lot of force on the plate and the structure holding the plate.
A method which we have had very good success with and would highly recommend, involves making the conveyor pivot up and down and having a stop at the end of the conveyor. In this method, there is a part of the rigid conveyor frame that holds boxes back when the conveyor drops down.
The conveyor is mounted with a pivot point on the frame at the beginning of the conveyor. When a box needs to be stopped, the conveyor simply drops down, pivoting at the entrance end. The pivoting action is done with a short stroke pneumatic or hydraulic cylinder. The piece that holds the boxes back does not move and is mounted just below the top of belt height of the conveyor belt, so any boxes that do not need to be stopped simply pass right over it.
This conveyor is typically about the length of 1-1/2 to 2 boxes and has a roller top belt to allow for box accumulation.
When looking at box indexers, remember to keep in mind varying box sizes, the need for accumulation, and that not all box indexers are created equal!
Learn more about Box Indexing Conveyors.
When setting up or running a box line in a production environment, spacing between boxes becomes critical when those boxes need to be weighed or sorted.
In many production environments, there are several lines combining together so all the boxes can go across a single scale or labeling line.
When those lines converge, spacing typically becomes very inconsistent.
Add in surges in each of the various lines and the boxes may be back-to-back or spaced far apart.
If the boxes are back-to-back, it can be very difficult to separate them so they can be spaced properly.
One method we have implemented many times and been very successful with uses anindexing conveyor with a speedup roller.
The indexing conveyor uses a roller top belt to allow for product accumulation when the boxes arrive back-to-back.
A sensor located at the end of the indexing conveyor senses boxes as they travel down the conveyor.
A speedup roller is mounted directly on the indexing conveyor after the roller top portion.
This speedup roller has friction top belt and is running substantially faster than the roller top belt so it grabs the leading box and pulls it away from the box directly behind it.
This action pulls a gap between boxes so the sensor sees the gap and can sense the next box in the line.
If the time measured between boxes is too short for the desired spacing, the indexing conveyor holds back the next box so the desired spacing is created by dropping the tail end of the infeed conveyor so the box stops against a bulkhead.
A simple controller easily handles controls involved in receiving inputs from the sensor and activating the indexing conveyor box stop. This simple design is low maintenance and proven to be very effective.
Next time you need to space the boxes in your production line, consider a Vande Berg Scales indexing conveyor with speedup roller!
The role that a robust Automatic Case Indexer plays in an Automatic Case Weighing and Barcode Labeling system can hardly be overstated.
Without proper spacing of boxes, your weights will not be accurate.
To rely on an operator or the normal production rate to create enough space between boxes or cases, is in all actuality, dependent on luck.
It is only a matter of time before your luck will run out.
The approach we take is to place a photo eye at a box stop to sense the arrival of a box. This box stop section consists of a powered section on the conveyor that drops down to hold back the boxes accumulated on the in-feed conveyor. At a settable time or length interval, the indexer rises, allowing a box to progress down the line.
As soon as a box reaches the midway point over the stop, the indexer drops again to detain the trailing box or boxes. This process continues unless box spacing is great enough that detaining box is not necessary.
An Automatic Case Indexer puts you in control of the vital function of proper spacing of your boxes, while eliminating the labor expense associated with staffing someone to perform this function!
Box Indexing Systems Designed to Fit Your Plant’s Specific Indexing Needs
Box Indexing Conveyors are designed to create space between boxes as they are conveyed between stations. In-Motion Box Indexing Conveyors are used to automatically space boxes and to eliminate the cost of having your personnel manually space them for you. Box indexing conveyors will enhance productivity and efficiency in your production processes.
Like any other conveyor systems, Box Indexing Conveyors are designed to save you money by eliminating the need to manually space boxes entering:
- In-motion weighing scales
- Automatic labeling stations
- Scanning stations
- Palletizing stations
- As they converge with other lines
Box Indexing Conveyors are configurable for several different type of applications. If you are not sure of which Box Indexing Conveyor System will best fit your needs, you can contact one of many conveyor manufacturers such as Vande Berg Scales for answers to your questions.
There is a need for box indexing conveyor equipment to automatically index an object, whatever it is, for whatever the purpose is. It is being done in many ways everyday. Some are successful, some are not, and it all depends on how much work was put into the planning.
Indexing can be done in many ways; it is almost unlimited. Depending on the product, you can do it by using a start/stop conveyor belt and photo eyes.
It can also be done with a series of conveyor belts with each belt pulling a larger gap.
Indexing can be done with a line converger where multiple objects are being discharged at the same time. Then, there are pop-up indexers and drop down indexers and the list goes on and on.
Where the challenge lies is understanding what works for what.
If you need to index cases of product perhaps a pop-up or a pop-down indexer would work best. If the case weight is really light, the case will fly off the line if a pop-up hits it.
You possibly need a start/stop conveyor for light cases. If your belt is too smooth, the cases may slip all over the place. You may need a conveyor with a friction top belt for no slipping of the cases.
Now let’s say you need to index packages, you need to properly space them for labeling. Pop-up’s and pop-down’s more than likely will not work. Most often we would use a belt with photo-eyes to detect product and space. You can do it by time-base or with a second photo-eye measuring the package and the space. Weight of the product comes in here as well.
Each application always has a catch and will require some work on your part making sure your supplier knows all of the details on what is needed to be indexed. If your supplier does not ask specific questions in regards to just about everything related to the product needing indexing, find another supplier.
Ask your supplier if they are doing your specific application in other places. Can you see the system working and/or could they supply video of the process. Do your homework and you will increase the odds into your favor!