In-mold Labels

By Steve Katz | January 23, 2013

Durable and recyclable, IML also gives brand owners the coveted no-label look.

The no-label look has been in vogue in the labeling industry for several years, and the term usually applies to film labels, such as those adorning health and beauty products like shampoo, and some beverage and beer labels. Some people may not think of in-mold labels when they think no-label, but the reality is it’s hard to beat the technology when it comes to a achieving a no-label look.

In-mold labeling, or IML, offers more than just aesthetic appeal to brand owners and end users. And while IML’s market share when compared to the label industry at large is rather small at only 2%, there is certainly room for growth.

In-mold labeling is distinctive in how part of the process – the beginning – is quite similar to self-adhesive label manufacturing, but then takes a turn and is something completely different, involving a new set of materials and machinery.

People unfamiliar with the process, like the average consumer, may have a hard time understanding that there is indeed a label on that bottle of detergent they’re looking at. With IML, the label becomes fused to the container, thus providing a slew of advantages, including no post-labeling operations and also the energy, equipment and labor costs that would go with it.

Ron Schultz, executive director of the In-Mold Decorating Association (IMDA), an organization whose goal is to raise the level of awareness and acceptance of in-mold decorated durable products and packaging, breaks the IML process down to its core elements. He explains: “Basically, any molded plastic object can be in-mold labeled or decorated. Reduced to its most basic elements, a label (or labels) is placed into an open, empty mold, the mold closes and hot/molten plastic resin is blown, injected or inserted into the mold, fusing to the back of the label, which then becomes an integral part of the object.”

After a label has been printed, there are three pieces of equipment needed for conventional injection or blow-molded IML manufacturing. The process involves label magazines to hold stacks of diecut labels; automation or robotics to pick a label from the magazine and place it in the open mold; and finally a “pinning” system, either via vacuum ports or electrostatic charging, to hold the label in place on the mold wall until the hot resin contacts the back of the label.

Mike Dispenza, North American sales manager for IML film supplier Arjobex America, points out that IML offers a no label look, while being more sustainable and cost effective then other types of labeling. “It can add structure to the plastic package which can reduce container weight and lower overall cost. The labels are applied during the container making process, labels are inserted into the mold cavity and containers come out fully labeled – as opposed to other decorating methods that require application after the container is made. This second step can cost more,” he says.

Three processes
The three most widely used molding processes for in-mold labeling and decorating are blow molding (IML-B), injection molding (IML-I) and thermoforming (IML-T). Blow molding is used to create bottles and jugs; injection and thermoforming are used to make open top containers such as tubs and pails. IML-I is the most widely used in-mold process in Europe while IML-B is still about 75% of in-mold labeled containers in North America.

Schultz says IML-T containers are vying with IML-I containers for many of the same markets. “Each has its strengths and weaknesses. IML-I starts with resin beads while IML-T must first make a film from those resin beads. The IML-T can produce containers faster while IML-I can produce more complex configurations,” he explains.

Michael Demchinski, account executive Labels US for Taghleef Industries (Ti/AET Films), says retail food packaging continues to be the primary user of IML-I, but point-of-purchase beverage cups and mugs and also tubs, lids and tote containers are transitioning to IML from methods such as dry offset printing or PS labeling. “In IML-I, the container is labeled during the molding process which eliminates a secondary printing or labeling step for the container manufacturer,” he explains. “Once the label is molded to the container, it becomes part of the side-wall of the tub or lid, so the label cannot be removed, which is a significant feature in counterfeit prevention. Another benefit of  IML-I is the fact that one label can decorate multiple panels of a container in one step. This process also increases the durability and product resistance of the decorated container,” Demchinski says.

In-mold labels for packaging can be either film or paper, but in recent years the market share for paper IML has become increasingly small. “Most IML-B and IML-I labels are some form of polyolefin,” Schultz says. “Decorations for IMD are considerably more complex and robust, including those made of ABS, acrylic and polycarbonate. Thick inserts are often pre-formed before placement into a mold for a multi-shot molding operation.”

Arjobex America was the first company to feature IML film in the US, and offers the IML market a medium-gauge HDPE film that is used for blow-molding. “The advantages of HDPE is that most traditional bottles are made of HDPE so the regrind content can be 100 percent,” Dispenza says. “Our film is biaxially-oriented, so it conforms better to different shape containers and sizes while holding up to drop testing. We use less resin then other types of films, thus making our product more sustainable.”

Demchinski emphasizes that Ti/AET films for the IML-I market are engineered for performance throughout the supply chain from label processing, molding and end-use functionality. The product offerings include high-yield white opaque films offering textured or smooth finish, post-molding. “We also offer high clarity transparent films for clear containers so the consumer can see the product. These films can be utilized in a wide variety of containers such as small labels for lids to large format labels for industrial pails and tubs. 

With IML-I, the labels and container are typically polypropylene, which is necessary for enhanced label bonding to the container and consistent shrink rates post-molding. “Due to the fact that the label and container utilize the same polymer, it enhances the recyclability of the container,” Demchinski says.

Of course, like any other label, the substrates require ink. Tom Socha, VP – director of national accounts, for INX International Ink Co., notes that INX offers a wide range of products for the IML market. He says, “This includes energy-curable and solvent-based inks and coatings for traditional blow mold IML, as well as the emerging injection IML market. The majority of ink products do not differ from conventional PS technologies with the exception of the coatings. IML coatings are specifically formulated to have properties acceptable for the IML process,” explains Socha.

Dedicated machinery
In-mold labels can be diecut using a variety of techniques, but the common denominator of the equipment is its ability to effectively cut the thin film substrates often used in IML.

Schober produces and supplies such thin film diecutting equipment, including offline diecutting and delivery systems for in-mold labels. The company’s RSM series of machines is for roll fed materials from 260mm up to 850mm wide. Schober’s new Sheetline system is for sheet-fed materials. The company also offers its M-Stack and S-Stack delivery systems for both machines to handle short run and long run jobs with.
Joe Lauver, Schober’s technical sales specialist, notes some of the elements distinctive to IML diecutting. “One of the big challenges in diecutting IML versus a PS label is that you are creating a discrete – and very light – piece that you now have to handle. So the key is controlling this discrete piece and putting it into a manageable stack that is ready to be put directly into a shipping carton or to be shrinkwrapped. Our new Spider delivery system is great for when you want to gang several small jobs together into one run or for large products that are difficult to handle once they are diecut,” he says.

The polyolefin films used in IML are notorious for generating static electricity, Ron Schultz points out. “The finished film in-mold labels can be very hard to control due to static,” he says. “That is why most narrow web IML printers prefer to diecut off-line, rather than slow their presses to a crawl trying to cut inline. Diecut precision, especially for injection labels, is also more demanding than for PS labels.”

When designing small objects and containers for IML, such as yogurt or drinks, static can be particularly problematic in the pinning process – where the label gets placed into the mold. Static charges can effectively be used here, to pin the label tight against the inner mold surface during injection molding.

In response to this pinning challenge, Meech has developed the 994 Hydra, a miniaturized in-mold label pinning system specifically designed for use in situations where small items are being molded. “Meech has been involved in static control technology for decades and we’ve called upon that experience to develop a product that meets the requirements of OEMs and end users, many of whom are unhappy with the in-mold labeling options currently available on the market when dealing with smaller containers and labels,” says Meech’s Business Unit Director for Static Control David Rogers.

“The 994 Hydra system provides powerful, repeatable pinning with no degradation over time,” continues Rogers. “The operational life is almost indefinite. With this system, OEMs are free to make their own label carriers, which can be produced at a greatly reduced cost compared to some other IML technologies.” 

The components of the 994 Hydra system are designed for easy mounting, as well as being straightforward to connect and disconnect during mold tool changes. “The design eliminates the chance of sparking and the possibility of expensive damage to the mold tool,” Rogers adds. “The choice of materials ensures that the problem of potential contamination of the container, sometimes seen with conductive foam-based IML systems, is removed.”

Advantage IML
One of the key benefits cited by IML proponents is how the technology measures up in regard to sustainability.

“I think one of the great advantages is in IML products’ recyclability,” says Schober’s Joe Lauver. “Both the label and container are 100% recyclable. Then, add in the fact that you no longer require silicone release liners, and you have made another major step towards sustainable packaging.”

Ron Schultz feels that IML is arguably the most sustainable labeling method – primarily for what it does not have. “IML has no post-mold labeling machines, flame treaters, additional floor space, energy, labor or release liner. The in-mold labeled container is ejected from the molding machine ready to receive product. Containers in-mold labeled with polyolefin labels are completely recyclable, unless they have large areas of very dark print.”

Future forecast
At just 2% of the total label market, it’s fair to say that there’s nowhere to go but up for IML. And the experts agree. However, the technology has its fair share of challenges.

According to Schultz, the IML-B market has been impacted by competing labeling technologies, especially sleeve and heat transfer labeling, and recent increases in prices for HDPE and PP resins have caused users of these materials to shift to PS labeled PET for products such as refrigerated citrus juices.

Perhaps the most persistent challenge to IML-B is brand owner fear of pre-labeled container inventory. Schultz says, “With the exception of a few ‘through the wall’ installations, IML-B is done at major blow molders some distance away from the product filler. Consumer product manufacturers will order large quantities of in-mold labeled bottles to fill high volume orders from big box retailers. When one of these large retailers changes an order, the FMCG manufacturer can be stuck with millions of in-mold labeled bottles that cannot be re-purposed for another product. To guard against this risk, brand owners have adopted ‘late stage product differentiation’ by PS, heat transfer or shrink sleeve labeling right on the filling line. In the event of a cancelled or changed order in the midst of a production run, the worst that can happen is the loss of some labels.”

Despite these challenges, Schultz says, “IML is still the lowest unit cost and highest quality of any labeling method for plastic containers. It is also the most sustainable labeling process, an attribute that is so strongly advocated by retailers such as Walmart.”

INX’s Tom Socha notes large consumer product companies trending towards high end, special effect IML that includes the use of cold foil stamping. He says, “This is especially true for new product launches in the household products category. I’d look for injection IML to gain momentum and market share in North America over the traditional form of blow mold IML.”
Demchinski, of Ti/AET Films, continues to see growth in the IML-I market in Europe and North America with major global brands showing interest. “The demand for lower cost, high performance films continues in mature markets as the supply chain asks for thinner or down-gauged materials. There is an increased demand for IML-I packaging to be functional in barrier and retort packaging, as well as an increase in sustainable films with either recycled polymers or bio-resins.”

Getting educated
Education is a prevailing issue in the IML community. At AWA Alexander Watson Associates’ IMLCON conference held prior to Labelexpo in September 2012, the topic of educating the supply chain was stressed.

Clare Goldsberry, a contributing editor for Modern Plastics Worldwide, spoke at IMLCON about education being a key factor in mainstreaming IML. She said the supply chain, which includes mold makers, molders, brand owners, label suppliers and automation suppliers, could all benefit from enhanced communication.

“Mold makers typically build the type of mold they are asked to build and seldom try to educate OEMs and brand owners on available mold technology,” Goldsberry said at the conference. “Mold makers need to educate and be educated in IML technologies and be prepared for innovation and collaboration.”

Goldsberry emphasized that brand owners need to let their mold makers know of their packaging goals in regard to size, shape and eye-catching designs, and all parties need to work with the label suppliers. “Label suppliers need to educate brand owners and mold makers on label materials for IML, new technologies in inks and sustainability options,” she added.
Getting a proper IML education is readily available. AWA holds regular conferences on IML, geared toward the entire supply chain. On April 17, AWA will host its “In-Mold Technologies Seminar” in Amsterdam. For more information, visit www.awa-bv.com.

The IMDA is another great resource for both education as well as networking. Through a variety of activities and promotional events, including the annual IMDA Awards Competition, the Association showcases advances in technology and design across the IML value chain. “We are continually adding programs that provide value and benefits for our member companies,” Schultz says.

For those interested in learning the basics, on March 28, the IMDA will host a conference titled “ABC’s on IML: A Basic Course” in Skokie, IL, USA. For more information, go to