With the onset of winter in the midst of an Ecommerce boom and the public hearing news about vaccines requiring a super-cold environment as low as -80 degrees Fahrenheit, many facilities are learning for the first time the importance of temperature in the printing, application, and storage of labels.
If your products will get cold or be exposed to extreme temperatures, it’s vital that you choose the right label materials, adhesives, and printing processes for your situation. Not planning properly in this regard can lead to label failure and damage to your brand's reputation.
Understanding the Environment for Cold Labels
When it comes to product labels, different environments call for different applications. Even with cold product labels, there are many subcategories. Some are for dry and cold applications, and others deal with moisture and frost.
If you use a standard label on a product that will be subject to cold or freezing temperatures, you can run into several issues. Among these are:
- Labels that don’t adhere to the surface or fall off
- Labels that wrinkle or pucker during shipment
- Labels that curl
Labels Don’t Adhere to Surfaces
Cold conditions can impact your labels even if they were applied at room temperature. If your labels are stored in an unheated room or left on a shipping dock in freezing temperatures, you’re likely to experience issues.
Assuming your labels are kept in a controlled environment but the surface you need to apply them to is cold or freezing, label application and durability is likely to be a problem. In short, you can eliminate many challenges by controlling the environment. If the labels or the products will be subject to extreme temperatures, you’ll want to choose a different application.
Labels Wrinkle or Pucker
When products are shipped or stored in cold conditions, it’s not uncommon to find labels that are wrinkled or puckered. Low humidity levels, or dry air, can contribute to these issues. If labels were stored in a cold and dry environment, you can prevent these problems by allowing the labels to acclimate for up to 48 hours before application.
Low humidity levels can contribute to a common problem known as “label curl.” Your label doesn’t come off entirely but instead curls up at the edges. To prevent labels from curling, products and labeling material should be stored at humidity levels between 35% and 65%.
Before you choose labels for your cold product, you’ll need to ask and answer a few simple questions.
- Where do you plan to apply the labels?
- What surface will the labels be applied to?
- What temperatures and humidity levels will they be subjected to in each environment?
Label Materials for Cold Applications
There’s a common misconception that all labels are made from paper. Not anymore. When applying labels in the cold or exposing your products to freezing temperatures, there are two categories of labels - those for “dry” conditions and those for “wet.”
For dry conditions, you may wish to use paper labels, which work well under cold, yet dry, exposure. For wet conditions, other label materials are better choices. Some options include polyester, vinyl, and polypropylene (PP) or polyethylene (PE).
Choosing the Right Label Adhesives
Various types of label adhesives are suitable for different applications. You might have the perfect adhesive for your cold or freezer products. But, apply it in the wrong environment, and the labels might not stick, will fall, or eventually curl.
If you apply a label outside its recommended temperature range, it may not have the adhesion or tack necessary to stay on your product. With cold applications, the minimum application temperature (MAT) is a vital consideration, which is the lowest temp at which your adhesive will work effectively when applied.
The first question you’ll want to answer is whether your product will be subject to cold temperatures or freezing. What’s the difference, and which adhesives work under each condition?
Cold temperature labels that are applied with hot rubber adhesive will be effective at temperatures as low as 35 degrees F (MAT) and can withstand transportation and storage as low as 0 degrees F.
When using an emulsion acrylic adhesive, your cold temperature labels can be applied in temperatures as low as 0 degrees F (MAT) and can withstand transportation and storage as low as -65 degrees F. This type of adhesive is economical and works well for various applications.
Products like ice cream, frozen food, and certain pharmaceuticals need to be packaged and sold in freezer-grade or cryogenic settings. Freezer grade labels using hot rubber adhesive can be applied in an environment as low as -15 degrees F (MAT) and will maintain adhesion to temperatures as low as -65 degrees F.
If you wanted to store a vaccine at subzero temperatures, such as the Pfizer COVID vaccine that requires -80 degrees Fahrenheit, what would you use? Presently, the best solution is cryogenic labels, which are composed of woven polyester, nylon, or polypropylene materials and are designed for use in environments as cold as -384 degrees F. A solvent adhesive is often used in these applications because it is designed for glass and plastics, is permanent, and can withstand extreme temperature conditions.
Don’t Forget to Consider Label Varnishes
With cold and freezing temperatures, you often get ice, frost, and moisture. A varnish or laminate on a product can protect it if it will be exposed to harsh conditions. Label varnishes are essential choices when dealing with cold temperatures since they are a factor in the ink adhering to the label and staying readable.
For extreme temperature applications, VGE-7031 varnish is a commonly-used product. It bonds to a variety of materials, has a fast tack time, and can be used in cryogenic conditions.
Label Printers for Cold Environments
Depending on the material of your cold or freezer label, different kinds of printers can be used effectively. In an industrial setting, thermal transfer printing is most typical. Commonly used thermal transfer label printer brands include Zebra, DuraLabel, Brady, and TSC.
Other options for these types of labels are flexographic, digital, and screen printing. If you are printing for extreme applications, it’s also a good idea to use a high-grade resin ribbon.
There’s a lot more to your product’s labels than just the design. If they will be exposed to extreme temperatures, you’ll need to consider which label applications will best meet those performance needs as well as be able to stay within budget and engage your customers.