22 Aug 5 things to know about labelers
5 things to know about labelers
Buying a new labeling machine can be a big investment depending of your production requirement. We hope to be able to demystify the different types of labeling systems and help you make a sound decision.
In this article, we will discuss automatic labelers, which are normally part of a production line and located after the capping machine or sometimes before the filling machine. If your interest is for semi-automatic labelers, the information below may not be applicable.
1- Inline VS Rotary Labelers
As a general rule, inline labelers are perfect for simple applications and rotary labelers are perfect for complex or high speed label application. For example, if you need to apply a wrap label to a round bottle at 50 bottles per minute, this could easily be done with an inline labeler. The same is true if you need to apply front & back labels to a straight wall rectangular bottle at 80 bottles per minute.
On the other hand, if you need to apply 4 different labels on a wine bottle and align the label with an embossed logo in the glass, this sounds like a job for a rotary labeler. Generally speaking, high speed application is also a good fit for a rotary labeler because of the way we handle the bottles and also because we can offer non-stop labeling capacity in a small footprint.
The main difference between an inline labeler and a rotary labeler is the bottle handling. The bottles stay on the conveyor during label application with an inline labeler, but with a rotary labeler, the bottles are transferred on a turret during label application. On the turret, each bottle is positively held between a bottle plate at the bottom and a centering bell at the top. Each bottle plate can rotate 360⁰ in any direction to achieve optimal bottle position to apply the label.
The turret size will vary in diameter depending on speed requirement and how many labeling stations will be integrated to the machine. The circular design allows to integrate several labeling station (up to 9 on larger machines) in a relatively small footprint, when compared to an inline labeler. One important difference between an inline labeler and a rotary labeler is the bottle change parts. Typically, an inline labeler will have mechanical adjustments like sliding rails and height adjustment depending on the size of containers. A rotary labeler will have dedicated bottle change parts, such as infeed and outfeed starwheels and guiding rails.
2- Labeling technologies available
If you are familiar with bottling lines and packaging machinery, chances are you have seen many labeling machines during your career. In North America, pressure-sensitive labelers are very popular and many people have some degree of knowledge about them. However, there exist other labeling technologies that could be very beneficial in terms of label cost and performance depending of your products.
Pressure-sensitive labeling is certainly the most popular today when it comes to bottle decoration in many industries. The labels come in rolls and the labeler will peel-off the labels from the backing paper and apply it to the bottles or containers. The main benefit is the versatility when it comes to size and shape of labels, which requires minimal change parts and quick changeovers. Another benefit is machine cleaning, which is limited to removing dust or some glue residue on the label applicator once when needed.
Hot Melt Cut & Stack labeling (also called pre-cut labels) is perfect for full wrap applications on round or square bottles. A stack of pre-cut labels without adhesive is placed in a magazine and a hot melt glue system will spray glue dots on the bottle and trailing edge of the labels prior the label application on the bottles. The main benefits of a hot melt cut & stack labeler is the low cost of labels and non-stop production capacity of the system. Basically, the operator can add stacks of labels in the magazine at any time during production without stopping the machine.
Hot Melt Rollfed labeling is popular with beverage companies around the world; it is used to apply thin film labels on round or shaped containers. The labels are supplied on a roll without backing paper and the film is cut with a knife located on a vacuum drum. The cut labels are transferred to another vacuum drum and glue dots are applied to both ends of the label prior application on the bottles. The main benefits of the hot melt rollfed labeler is the low cost of labels and non-stop capability with a second roll of label support and automatic splicer system.
Cold glue Cut & Stack labeling (also called pre-cut labels) is popular with breweries, wineries and to a lesser extend, food companies. A stack of pre-cut labels (paper or foil) without adhesive is placed in a magazine and glue is applied to the complete surface of the label with glue palettes. Those labels are than applied to the bottles with a gripper/sponge and wiped with brushes. Besides the low cost of labels, another benefit of cold glue cut & stack labelers is the possibility to apply both a body label and neck label from the same label dispenser. For beer bottles, it is also possible to apply “over-the-cap” foil and for wine or spirit bottles, tax strip can be applied as an inverted “U” shape on top of the cap.
Combination machines are available by combining any of the above-described technologies on the same machine frame to provide flexibility and let you achieve your needs.
3- Printing variable information on the label
These days, pretty much all industries will require you to print variable information on your products. Now, depending on products and regulations, you may have to print directly on the container or on the labels. Printing variable information on the label will certainly impact the way the labeling system will be designed as well as its operation and price. The most common way to print information on labels is with a thermal transfer overprinters (TTO), which are available from different OEMs. Ink jet coders and laser coders are also used to print on labels, but are usually used to print directly on the bottles or caps.
When variable information is printed on the labels, this will be done prior the labels are applied to the bottles. Therefore, the TTO needs to be integrated to the label applicator itself, somewhere between the roll and the peel-off plate. This will require a mounting bracket and possibly a slide mechanism for the whole label applicator assembly to facilitate access to the coder to change the ribbons and maintenance. The coding system is also an important point to discuss if your goal is to have a non-stop labeler operation; you might need to consider a single label applicator with splicing system rather than have two label applicators running in redundancy.
4- Label inspection & traceability
Traditionally limited to the pharma and medical products industry, a growing number of manufacturers are now considering label inspection for various reasons. A basic request that we see frequently with large companies is to have a system in place to make sure the right labels are going to the right products. The idea is to avoid human mistake of loading the wrong labels on the machine. Basically, a barcode scanner is used at the beginning of a run for a given product, and a camera mounted on the labeler will inspect every barcode to make sure the right label is applied.
Other camera systems can be used to inspect the variable information printed by the thermal transfer overprinter (TTO) and make sure the information printed is readable and accurate. Cameras can also be used to validate label presence on the bottle and also proper positioning on the bottle. Any faulty bottle/label combination not meeting desired criteria are rejected after the labeler for downstream inspection by the operator.
In order to avoid counterfeit products and to provide data to consumers and brand owners, more and more products have a unique serial number (unique identifier) printed on its package to provide unit-level traceability. In addition to integrating proper TTO on the labeler, we need to have camera system to verify and aggregate the printed information and specialty software package to manage the date and traceability process.
5- One machine will not do it all
Yes it is true that some labeling machines are very versatile, but no machine will work well if your range of products is too wide. Even so called modular rotary labelers, where you can switch from a pressure-sensitive label station to a hot melt label or cold glue station have serious limitations. The bottles, the products you are filling, the labels and the speeds all have a major impact when choosing the right labeling machine. It is never too early to discuss your challenges with labeling machinery experts and involve your label supplier as well.
For example, if you are planning to use round, square or rectangular bottles, the label length and the label material will have an impact on the choice of labeler. Applying a clear plastic label to a glass bottle will be different than applying an opaque paper label to the same bottle. Clear labels will tend to enhance imperfections of the bottles; a price example would be the seam in glass bottles. The label length is also an important consideration. Applying a full-wrap label to a 6’’ diameter bottle means the label is 19’’ long! Keep in mind that we are working against gravity and this long strip of material will tend to go down and create a skew label on the container.
As mentioned before, most bottles and containers are labeled after the filling and capping, but in certain industries, it is easier and better to label prior filling. Beer is a good example of product that can be labeled before or after filling. The benefit of labeling before filling is we have a dry bottle, which is perfect for pressure-sensitive labels. If you are labeling beer bottles after filling, the bottles will condensate and be wet and make it more challenging to get good label adherence to the bottle, even with cold glue applied labels. Another huge factor is product temperature at the time of filling; hot filled products will have a different effect on bottles than products filled at room temperature or cold filled. Dusty products may represent another challenge because the bottles get covered with products and makes it difficult to apply labels in a nice way.
Here are key questions to determine what type of labeler you need:
- What kind of bottles will run on the labeler
- What label goes on each bottle
- Speed requirement for each bottle
- Do you need to apply multiple labels to the same container
- Do you need to perform bottle orientation prior label application
- Do you need to print variable information (date, lot #) to the label
- Do you need to inspect the information printed on the label or the label placement
- Do you know if pressure-sensitive labels are the best option compared to other technologies like hot melt applied labels or cold glue applied labels