The In-mold Decorating Association (IMDA) defines the process as “labeling or decorating a plastic object while the object is being formed in the mold.” While a glue-applied or PS label is stuck on the surface of an object, the IML label is “imbedded in the wall of the object.”
“In-mold labels are printed by just about every kind of printing process,” explains Ron Schultz, executive director of the IMDA. “It’s actually a labeling method that competes against pressure sensitive, heat transfer, shrink sleeve and glue-applied.”
The printing methods include flexo, gravure, web offset, and even screen. Flexo and UV flexo have become more popular options, whereas gravure was historically the method of choice. However, the expense of gravure cylinders necessitated longer runs and high volumes of labels, and flexo offers narrow web converters more flexibility.
Schultz also notes that in-mold labeling, a process used on packaging, is not to be confused with in-mold decorating (IMD), a decoration method used for durable products.
According to AWA’s “Global In-Mold Label Market Study 2013,” Europe comprises the largest share of IML printing at 59%, while North America ranks in second with 26%. Although Asia Pacific and South America only account for 7% and 4% of worldwide IML printing. AWA anticipates that IML volume will increase from 925 million square meters in 2014 to 1.01 billion square meters in 2017, with growth rates projected to steady at around 3% by 2017.
There are a number of events designed to promote this technology. The IMDA hosts its annual Symposium & Exhibit Hall, which will take place on October 28-29, 2015, in Skokie, IL, USA. AWA hosts IMLCON & IMDCON to analyze current technologies and trends. The 2015 event took place in Miami, FL, in February and featured a keynote presentation from Standard Register.
CCL Industries, the world’s largest label company, recently announced that it is partnering with the Turkish company Korsini to construct an IML facility in Memphis, TN, USA. Internationally, Schobertechnologies serves as a leading equipment supplier for IML.
IML is also a multi-faceted industry, incorporating a number of steps in the value chain. In order to produce in-mold labels, substrates, resin and ink supplies, injection and blow molders, molding machines, and printers and converters are required. According to AWA Alexander Watson Associates, IML accounts for 2% of the label printing market, with pressure sensitive accounting for the biggest share at 51%. Of the 2%, injection molding comprises 68% of the IML market, while extrusion blow molding makes up the other 32%. Thermoforming accounts for less than 1% of the global IML market.
According to AWA, in-mold labels have the second fastest growth rate only to sleeve labels. “This is a shift just in the last handful of years, where historically cut and stack labels were the dominant label type,” says Jackie Kuehlmann, marketing manager at Inland, a Wisconsin-based label and packaging manufacturer with IML capability. “IML offers many benefits, but the durability is one of the leading pros for this labeling type. An in-mold label offers the ultimate in brand protection in that it literally cannot be removed from the container. This provides extended brand exposure, specifically when these containers are washed and reused by consumers. IML also offers improved graphics over dry offset or direct print containers.”
Printing the label can be done with any conventional press. Steinhauser, a label manufacturer in Newport, KY, USA, runs its IML labels on a Komori offset press, for example. “When we run ours, we diecut inline so that the labels come out individually, and then someone has to gather them, stack them, and then they’re weighed,” says Chris Wermes, prepress supervisor at Steinhauser. “They’re fed on the bottling process, kind of standing on their side. It’s like a clamshell that opens up and forms the bottle. There’s suction that puts the front and back label onto the clamshells, and then they close. They’re filled with plastic and they form the bottle. Then it just goes down the line with the bottle, with the label formed right into the plastic.”
“From our perspective, printing an IML label is much like any other label type, however, there are different materials and requirements that make it much more highly engineered than a standard label,” adds Kuehlmann. “We use rotary diecutting to ensure very precise cutting and exact sizes for our in-mold labels, as well as specific materials, inks and coatings to ensure our labels will withstand the harsh conditions of the molding process.”
According to Mark Keeton, vice president at Standard Register, having material flexibility is key in this market. Standard Register uses a proprietary substrate called Grafilm, but Keeton notes that polyesters, polycarbonates, for example, and other common plastics are often used. Selecting the right resin is also an important step in the process.
Inland’s Kuehlmann believes IML technology is trending upward. “The future looks great for IML. It is definitely a growing package/label type and one that we foresee continued growth in for Inland,” she explains. “From an overall perspective, we see increased global competition moving into the North American market and are seeing rapid growth for IML in areas such as South America and Southeast Asia.”
In-mold labels are typically featured on durable goods like motor oils and laundry detergents. Containers that feature warning labels or cautionary symbols often use IML. In addition, industries that feature longer run lengths on large bottles will frequently use in-mold labels. Popular brands with gallons of milk or iced tea will embed the label into the plastic jug.
In AWA’s study, the research company cited that food products account for 69% of the end use market.
There are several key advantages to the process. For one, a user cannot de-label and re-label the product, making the container tamper-proof. “Even if somebody were to put a label on top of yours, yours is part of the bottle,” says Wermes.
For companies concerned about the safety of adhesives, IML offers an advantage. “A lot of companies that deal with chemicals favor the in-mold label if they can because of the kind of security that’s in the bottle,” explains Erin Dickman, business development manager, Steinhauser. “A lot of our customers, who we have pressure sensitive labels on, are always very concerned with the adhesives because they can get in big trouble – should for any reason – that label come off and not accurately label the cautionary symbols. So, I think it’s a nice plus for that kind of need.”
Once the product has been formed, IML requires no extra labeling processes. This provides financial benefits, as there is no need to add a label to an item like a plastic bottle. “IML really shines because as it applies, the object, whether it be a package or a durable product, is completely labeled but it comes out of a mold,” explains Schultz. “As opposed to a bare bottle or a tub of some sort that is molded first and then has to be labeled after it comes out of the mold. With IML, there is no post-mold labeling, no post-mold operations. There is no label applicating equipment, there is no labor, and there are no utilities or anything else associated with a post-mold operation. That’s a significant savings in terms of the labeling operation itself.”
Standard Register prints the majority of its in-mold labels for the durable goods space. These products need to feature lightfastness, as well as scuff and scratch resistance. “Really, the label has to last the life of the product itself,” explains Keeton.
According to Keeton, using flexography for IML can “significantly” lower costs. “Because we have a lower cost product and a higher capacity manufacturing method, we’ve opened up this market,” he adds.
Kuehlmann says that the process offers improved graphics over dry offset or direct print containers. “Look at the margarine industry, for example. Those containers had historically used a dry offset or direct print decoration method, which offered a few colors of low quality artwork. With IML, these brands can feature photo quality graphics on their containers, which definitely have an impact on shelf with consumers.”
The IML challenge
Converters have long dealt with how to effectively mold a label to a three-dimensional shape. When printing onto a flat substrate, two issues arise during the process: distortion and color blanching. When stretching the label to fit an object’s contours, both the color and shape of the original label will be altered.
So, for example, if a printer has a label with a red circle, the stretching of the label will transform
the red to pink and the circle to an oval. “IML has traditionally been a flat label, and for the most part, it’s been used in consumer product goods like bleach bottles and shampoo bottles,” explains Keeton.
“Many appliances have tried to use flat in-mold labels, and essentially what you see is flat label with a weird edge that has an in-mold label on the surface and a flat surface that looks somewhat like a metallic finish or a wood-grain finish,” adds Keeton. “But because it doesn’t have any curvature to it, you can tell it’s kind of like a sticker.”
Although IML’s appearance can be a challenging proposition, Standard Register has offered a solution. He says, “The direction we’re taking the technology is we’re wrapping the entire piece. If it has big broad curves or deep draws in the plastic piece, we’re able to wrap the full piece without any creases, crinkles or degradation to the image, and that three-dimensional piece now has an authentic look.”
Standard Register has developed a proprietary method featuring thermoforming to eliminate the distortion and color blanching. “You have to plan for that – that’s physics – there’s no way around that, but there are technologies we’ve been able to leverage to allow us to plan for that distortion and plan accordingly,” adds Keeton. “So, when that distortion happens in a controlled fashion, it looks like a circle when it’s done instead of an oval.”
To address cost and capacity, Standard Register has developed a flexographic solution in lieu of screen printing. “Just one flexographic press that we have can achieve print quality that, in our opinion, has a better look with the three-dimensionality you need from the inks,” says Keeton. “We’ve figured all that out, and I can run it at very high speeds. Just one flexo press can take the place of many, many screen presses.”
While IML remains a preferred printing method for many companies, Steinhauser’s Wermes believes direct printing could dissuade some converters from investing in the technology. “I think it’s taken a hit from direct print; people that print onto tubes or directly onto products,” he says.
Wermes also adds that price can be an inhibitor for IML. Even though there are no post-mold expenditures, the process itself could be cost prohibitive, depending on a given company’s volume. Steinhauser, although still active in the IML space, predominantly manufactures pressure sensitive labels. “It can be very expensive because the bottle has to be blown in a mold that contains the label,” he says. “So, generating bottles, you would really want to look at some pretty large runs before you go to the expense to set up a line specific to that bottle and label.”
One of the process’ main benefits is sustainability. Due to the package’s construction, the entire object can safely be recycled. “IML allows the entire package to be recycled, since the label and container are typically made from the same material (PP), unlike other container types where the label can cause issues in the recycling stream,” explains Kuehlmann. “Because of this, IML is appealing from a green perspective.”
By having one material, the recycling process is simplified. With objects that are made of plastic and various other substrates for the label, the process might vary for each material. “Like a water bottle, you’re technically not supposed to recycle the cap,” adds Wermes. “And the labels are really supposed to be taken off most things when they’re recycled, so that’s a sticking point. With shrink sleeves, most of those materials need to be stripped from the bottle prior to the bottle being recycled.
“That’s what makes IML greener,” Wermes continues. “It’s ready to be recycled immediately without any label removal or anything like that.”
Unlike pressure sensitive and heat transfer methods, this process omits one critical component. “IML is the most sustainable labeling method because of what it does not have,” says Schultz. “It does not require post-labeling equipment, labor or utilities. But perhaps the most important thing that it does not have is release liner. That alone is a very big plus for in-mold labeling.”