by Melissa Donovan
Manufacturers require durable labels in most aspects of their business, whether it be for goods they produce or an object in their own facility. Used in industrial settings and on heavy-duty consumer products, durable labels are exposed to chemicals, liquids, and extreme temperatures. Durability is essential and the label should withstand or extend past the life of the product it is adhered to. Without a legible label, there is no information to protect the user from danger or inform them on how to operate a device.
Shown: Acucote offers multiple certified film products for durable label applications, equipped with Acucote adhesive P50, which is an aggressive acrylic adhesive.
Settings and Purpose
Durable labels are used in industrial and production settings like construction and manufacturing. They are found in different locations for various purposes from wayfinding to health and safety as well as instructional and identification.
According to Kim Hensley, senior marketing manager, Mactac, the durable label segment for North America makes up about ten to 15 percent of label film. “These products are used predominately in automotive, appliance/nameplate, lawn and garden, electronics, drum/chemical, power/lighting, and battery markets.”
A majority of places the labels are placed in are what Fabrizio Mandingorra, global segment manager, labels, PPG Industries, refers to as “harsh environments,” with exposure to water and chemicals to abrasion and UV.
“One example is chemical drum labeling, including IBC bulk containers. They can contain a variety of liquids, including hazardous chemicals. Some are exposed to harsh conditions such as seagoing vessels. Here it is particularly important that the label withstand such conditions so that the warning information remains intact,” explains Richard Southward, global product manager, labels, Innovia Films.
Health, safety, and hazard warnings are commonly communicated by labels throughout industrial sites or on industrial equipment and machinery.
“These are essential to ensure people’s safety, highlighting any dangers to remove the possibility of accidents and injury,” adds Southward.
“Durable labels are used on medical devices for safety and warning information and serial or identification labeling. Appliances, HVAC, electronics, and power tools also use safety and warning labels, and may need these labels to be UL certified,” comments Paul Purdef, marketing director, durables, Avery Dennison Label and Packaging Materials.
These applications must often meet certain certifications. “They range from BS5609 certified labels for chemical manufacturers transporting dangerous goods on international waters that must meet Globally Harmonized System of Classification and Labeling (GHS) compliance and the International Maritime Dangerous Goods code, to asset tracking labels on equipment and containers. They also include hazard warning labels for OSHA, HMIS, and ANSI; any type of outdoor/weather-resistant/waterproof use; arc flash; and marine grade and industrial tank uses,” notes Mandingorra.
“In each instance durable labels ensure critical warnings and usage information remains adhered and legible to prevent costly mistakes,” advises Hensley. She says OSHA reports that the GHS standards for chemical drum labeling, for example, prevent 43 fatalities, 585 injuries, and $500 million in costs per year.
Requirements Add Up
For labels that need to withstand harsh environments, durability is a must. This feature can be broken down into further characteristics like resistance to water, abrasion, chemicals, and tearing. Beyond durability, other considerations need to be addressed as well.
“These labels rarely exist just to look pretty, and they often carry critical information related to safe usage, compliance, or product integrity. In some cases, a durable label might be all that stands between a consumer and disaster, warning of inherent product dangers or showing evidence of tampering or counterfeiting,” admits Hensley.
To protect from water, abrasion, and chemicals—which is important so that key hazard warnings aren’t erased during the container’s lifespan—labels need to be UV stable to withstand extended outdoor exposure and transportation. This includes remaining untarnished when confronted with moisture, oil, or solvents, explains Southward.
Durable labels should also withstand ripping and tearing. “Choosing a durable facestock should be a key consideration since the label needs to remain legible and intact long term. Durable labels have to stick to—and often outlast—products. Compromised labels can expose manufacturers to legal liability,” shares Hensley.
“These applications require materials that are durable in extreme environments, adhere to multiple types of surfaces, and can be imaged using both narrow and wide format print platforms,” says Joe Walton, senior application engineer, 3M Commercial Solutions.
Purdef notes that readability is an essential characteristic of a durable label—both visually and by machines that may scan the label. “This extends to the importance of the information on the label staying legible throughout the life of the product. If safety or warning information is unreadable or the label falls off and the user gets hurt, the manufacturer could potentially be liable.”
Many surfaces these labels are placed on feature low surface energy and are hard to stick to. The adhesive of the label media used in these applications requires a high tack and ultimately a strong hold.
“Tack is the initial quick stick when the label is able to grab onto the substrate, while adhesion refers to how the adhesive flows as it wets out to the surface it is bonding to. Once the label has wet out, its adhesion can be evaluated by how much peel strength it has, and whether it resists failures such as edge lift or darting as the label expands and contracts with temperature changes,” explains Purdef.
Durable labels most commonly adhere to plastics, which feature low surface energy, or even those with textured or oily surfaces. “Industrial labeling involves surfaces that make adhesion difficult—they may be uneven, coated in powder-coated paints, or may just be dirty,” advises Hensley.
“A variety of adhesives are designed for unique surface adhesion. Texture, contamination, and temperature are all part of the adhesive selection process when it coms to the right product for a specific application,” shares Earl Curran, VP business development, Acucote Inc.
Traditionally, solvent-based adhesives were favored for industrial-level labeling applications. “This is due to their ability to resist chemicals like gasoline or acid and to standup to high temperatures. But with sustainability concerns, suppliers look to alternatives,” notes Hensley.
Other options include emulsion acrylic, UV acrylic, and rubber adhesives.
Modified acrylic adhesives are normally used to achieve an adequate bond to hard-to-stick-to surfaces, according to Julie Levins, market development manager, Tekra, LLC. “These adhesives are modified to allow the adhesive to flow and achieve their ultimate bond.”
“Acrylic adhesives are a great choice as they exhibit strong chemical/environmental resistance and tend to stick well on coated metal surfaces,” adds Hensley.
Commenting on rubber adhesives’ strengths, Hensley says “they are compelling in certain circumstances due to quick tack, aggressive holds, and the ability to fill voids for lasting adhesion—but high temperatures and chemical exposure need to be avoided.”
Durable labels are designed with longevity in mind. Many labels found in harsh environments and on industrial machinery or consumer products are designed for long term use, although some are considered medium or short term as well. This influences media selection.
“Facestock selection is critical to the lifecycle of the label,” admits Curran. For short-term applications he suggests paper, medium term paper with an overlaminate or film, and long-term lifecycles utilize film or vinyl.
UV stable media is used for medium- to long-term applications, whereas typical BOPP is preferred for short-term applications of about three months or less, according to Southward.
Synthetic paper, on the other hand, is suited for a label placed indoors that may not experience temperature extremes or have exposure to chemicals.
“It might still have some exposure to UV light if placed by the window, but the synthetic paper might be a fit with good legibility but without unneeded additional functionality,” shares Purdef.
Hensley says most applications in this category are long term, since the message being conveyed is about product usage, dangers, or compatibility and label needs to last as long at the object it is adhered to. She gives an example of consumer goods requiring durable labels, such as a lawnmower or washing machine, with information on operation, safety, and ratings.
“Because these items are meant to last and may even be resold or handed down, it is important that warnings and instructions stay adhered and legible for the lifespan of the units, necessitating a durable label,” continues Hensley.
Purdef admits that there are some durable label applications considered short term, but these are instances of harsh conditions. He gives an example of a point of purchase tire label, which must withstand oils coming out of the tire and channels on a tire tread. However, the label is removed after purchase and not intended to remain on the tire for the life of the product.
Depending on the label media used, a laminate may be necessary to add further durability. Also, where the label is placed dictates if the extra protection of a laminate is needed.
According to Walton, since durable labels need to perform in extreme environmental conditions, a film laminate helps to prolong the performance of the inks used in the imaging process. He suggests a film overlaminate for maximum graphic performance.
Mandingorra says lamination probably isn’t necessary if a synthetic label stock is used, especially if that stock offers durability benefits like water, abrasion, and chemical resistance on its own. However, he points out that some users who opt for laminate synthetic label stock use a laminate for added resistance in extreme handling and abuse environments. Floor labels for warehouses where labels must standup to damage from skid loaders is one example.
Depending on the conditions the label is exposed to, a laminate might be required. “A laminated paper, for example, lasts longer in areas with moisture,” shares Curran.
Outdoor environments are another example of when an overlaminate is favored. “It is a good match for applications that withstand some of the harsher environmental conditions—freezing on the surface, particles blowing in the wind, and direct UV exposure,” notes Purdef.
What Digital Can Do
Digital printing continues to influence the use of labels in industrial and production settings, especially when compared to more conventional label printing methods.
“The shift is definitely moving towards digital printing. It allows for shorter runs and makes it easier to incorporate variable data,” says Levins.
Mandingorra believes an ideal example of digitally printed color labels growing rapidly in industrial settings is track and trace as well as brand authentication labels. “Because these require specific information be printed, the adoption of on demand printers for industrial labels has increased dramatically.”
“Digital print has grown enormously and offers fantastic scope for bespoke short-run print jobs versus the traditional screenprinting process,” notes Southward.
For manufacturers looking to print labels in house, digital offers a smaller footprint and at times a lower cost than say flexographic printers. This allows companies to purchase and run onsite versus outsourcing their labels, admits Curran.
Inventory reduction is a major benefit. “With traditional methods, labels might be flexographic printed with standard information and secondary variable information added later. Digital printing allows the use of blank labels with 100 percent of the information printed on demand. This is a benefit if regulations change, because labels with preprinted information would not have to be disposed of,” explains Purdef.
For those looking to digitally print their own durable labels—whether for internal use or on the goods they manufacture—there are a number of options. When paired with the correct adhesive, they are constructed to withstand some of the harshest environments a label can encounter. In most scenarios, the label must last as long—or longer—than the object it is adhered to. If not, the manufacturer is subject to liabilities from employees and/or customers. IPM
Sep2020, Industrial Print Magazine