Considerations for Cold Temperature Labeling Solutions
The combination of low temperatures and condensation can wreak havoc on your adhesive labels, causing problems with application and durability. Whether you’re applying barcode labels prior to shipping a product or you require cryogenic labels in a healthcare setting, cold temperature labeling solutions can be a source of great frustration.
How do you address issues with your label design? Do you need a different label substrate, or can you solve cold temperature labeling problems by changing your production process?
Points of Failure in Labeling Due to Cold Exposure
You may associate cold products with refrigerators and freezers. However, cold resistant labeling doesn’t only encompass freezer labels. There are three points where low temperatures interfere with custom labels:
- Cold exposure during the labeling process
- Extreme temperatures in refrigerators, freezers and storage environments without climate control
- Severe temperature shifts during storage and transport
Why am I Having Problems with My Package’s Labeling and Storage Environment?
Low temperatures stiffen and freeze materials, making them brittle. And, applying labels to cold containers extends wet out time for glues and keeps labels from bending as they wrap around containers.
To further compound the issue, as the air gets colder, it holds less moisture. Excess moisture gathers on nearby surfaces, creating condensation, which interferes with adhesion and breaks down label materials.
Why Do Labels Fail on Cold Temperature Products as they Reach Consumers?
Adhesives and labels can become stiff in freezers, causing them to separate and fall off of the container.
Changes in temperature can make the label separate from the container as it expands and contracts. This causes the label to flag or fall off entirely. Flagging is common for refrigerated and frozen goods that warm up as they’re transported from the store to the home. It’s also a problem for containers kept in environments that fluctuate with outdoor temperatures. (For example, chemical pails can sit for months in a warehouse or storage building before being used. Over this time, they will experience repeated expansion and contraction as temperatures rise and fall each day.)
When beverages move from coolers to outdoor environments, they become coated in condensation. This problem is particularly troublesome in hot, humid weather, because water can saturate standard labels, damaging the paper or adhesive.
How do you address these problems? Select the right label material, the right adhesive, and the right operating conditions.
Adhesive Challenges in Cold Temperatures
There are two types of freezer grade adhesives commonly used for cold temperature labeling. Rubber adhesives can be applied at temperatures ranging from 35 to 120°F, and they can handle storage at temperatures from 0 to 120°F. However, they degrade quickly when exposed to solvents.
Emulsion acrylic adhesives can be applied at temperatures as low as 0°F, and they can withstand temperatures ranging from -65 to 200°F. However, these adhesives aren’t as tacky as rubber, so they don’t work well on frosty or moist surfaces.
When you’re selecting an adhesive, you need to take into consideration the temperature during the labeling process, as well as the storage conditions immediately after labeling and throughout the product’s lifetime. You will see three terms used to refer to adhesive performance in these situations:
- Wet-out time is the amount of time it takes for the adhesive to cure fully. There are several factors that can affect wet-out time, including temperature, moisture and container materials.
- Minimum Application Temperature (MAT) is the lowest temperature at which the adhesive will work during labeling and wet-out.
- Service Temperature Range (STR) is the temperature range the adhesive can handle after it cures.
Face Stock Considerations
Face stock makes up the bulk of a pressure sensitive label.
Most standard temperature labels are made from untreated paper, which fails when exposed to moisture. While there are several face stock materials available, most cold temperature labels use these three materials:
- Polyester Labels – this is the best material for cold storage, staying pliable in extreme temperatures. It also isn’t affected by moisture, and it works with direct thermal and thermal transfer printers. However, it has low UV resistance, and it’s expensive.
- Polypropylene – this plastic is less resistant to low temperatures, but offers good all-around performance.
- Coated paper – paper with gloss and semi-gloss coatings are temperature resistant, and they don’t absorb surface moisture as readily as uncoated paper.
Addressing Common Labeling Problems Related to Temperature
In some cases, the problem with your labels may not be the materials they’re made from, but how they’re handled. Before you spend money creating new label designs, make sure you’ve addressed these common temperature-related issues.
Are your labels and containers clean? If you’re storing them in a warehouse, they could be picking up oil, dust and other debris over time, which can interfere with adhesion. This compounds cold-related issues.
Are your labels too cold to function properly? Adhesives are brittle and less tacky at low temperatures. In the winter, store your labels in a climate-controlled environment. If you need to apply labels in a cold environment, only keep as many labels as you need next to the machine. Only move replacement reels into the area when it’s time to load them into the machine.
Are your labels getting wet in storage? Seasonal changes can dramatically affect humidity, making labels that work fine in dry months suddenly fail in rainy months. Likewise, moisture exposure is more likely if the labels are kept near loading docks. Constant air movement exposes the labels to outside air, speeding up degradation.
Are your containers dry? Water interferes with adhesion, and it breaks down paper labels. An air knife can blow off moisture before your containers reach the labeling machine. If this isn’t enough to stop condensation, look into adhesives that are designed for wet surfaces.
Do your labels have time to wet out before cold storage? Depending on the adhesive, it can take up to a half-hour before the glue fully sets. Rapid temperature changes interfere with drying, which weakens the bond between the label and the container.
Choosing Label Applicators That Work With Cold Products
For the best results, your labels must be applied consistently and evenly to get maximum contact with the container. We’ve developed several machines that get the results you need, no matter the size or shape of your containers.
Our vertical trunnion roller labeler is designed with glass bottles in mind. It uses rollers to capture containers, enabling fast, accurate label application. This shortens product pitch while nearly eliminating label skewing and is a great choice for labeling wet and frosty bottles.
Our 360a label applicator supports tamp blow application, which lowers the label down to the product surface and pushes it on with a gust of air. Tamp blow application evenly applies labels on hard-to-reach surfaces, like recessed lids, maximizing surface contact.
Our pail labeling system lets you use a 360 label applicator or a 3600 print and apply applicator with attachments designed around handling industrial pails. By using a large vacuum grid and a series of O-ring belts, this system keeps consistent pressure on the label as it wraps around the pail. (This maximizes surface contact and minimizes flagging so that your labels have the best chance of staying put, even in long-term storage.)
Get a Labeling System That Works With Your Production System
Do you need a cold-resistant labeling system that works in unusual operating conditions without slowing down your production line? Contact CTM Labeling Systems. Our local distributors will work with you to come up with a solution that delivers the results you need, no matter what you’re labeling.