While the value of product decoration is widely recognized, an imperative question that manufacturers need to answer is, “What’s the best solution for decorating my product?” The answer to this question often hinges on one important factor - the product’s durability. In other words, is the end product one that has a very short lifespan, such as disposable food containers or water bottles? Or is the product more durable in nature, lasting for years of service, such as a lawn mower or a kayak?

For non-durable products, several methods often are used for product decoration, including pressure-sensitive labels and marking technologies like pad printing, heat transfer, hot stamping, and basic painting. These methods provide the desired decoration but won’t stand up to long usage or rough handling.

When looking at durable plastic products, the lifetime is generally expected to be anywhere from three to ten years. Therefore, the decoration for these types of products is expected not only to last a longer period of time but also, to maintain the same quality as when the product was brand new. To do so, the decoration must withstand any adverse conditions that could cause the failure of the decorative elements, including

• Indoor and/or outdoor environments, such as freezing, direct sunlight, baking, etc.
• Harsh and abrasive chemicals and solvents
• Overt attempts to remove the labels

In other words, the decoration for these plastic parts must be extremely durable and permanent. While pressure-sensitive labels and other methods of product decoration can experience shortcomings in their delivery of permanence and durability on plastic parts, one type of decoration excels in these areas - in-mold decorating. This technology allows manufacturers to enhance the appearance of their products by expanding available decoration space, including products featuring curved, contoured, and textured surfaces. In-mold decoration, or IMD, actually bonds with the molded part, providing permanent, non-removable labeling that lasts the life of the product.

Manufacturers that traditionally use pressure-sensitive labels or other forms of post-mold decoration many times are unaware of IMD or assume it to be too complicated and/or too expensive. However, IMD is quite the opposite of these assumptions – producing a superior overall product at lower costs.

What is In-Mold Decorating?
IMD is the application or bonding of a decorative label during the plastic molding process. By applying the label within the molding equipment, a manufacturer is able to eliminate the post hand- or machine-applied pressure-sensitive label from the container or plastic molded part. By including the decorative label in the molding process, it becomes a permanent piece of the product that improves accuracy and durability of the finished label on the part or product.

The process begins by having a label placed inside a mold. The label can be located through robotics or by hand and typically is held in place by electrostatic attraction, vacuum ports, or other appropriate means. Once the label is positioned, the mold is closed (if required) and the molten plastic is injected into the mold. The molten plastic material envelops the label and makes it an integral part of the molded object.

The IMD Durability Factor
Recent advancements in in-mold decorating technologies have made it possible to incorporate a permanent durable label as a composite in a plastic part. By having this as an anchor, it enables printing engineers to begin evaluating various inputs to the label (such as ink systems, coatings, and over-laminates) to effectively protect the images applied to mark products.

To ensure that a product can stand the test of time, many test methods are used and continue to evolve. An IMD supplier routinely evaluates many properties when determining if a label can withstand the environment of the durable good it is marking. These properties include ink color fastness, fade resistance, scuff resistance, mar resistance, thermal shock resistance, solvent resistance, and acid resistance.

To define a durable product, internal protocols that are recognized by the printing industry must be developed and utilized by IMD suppliers. Using standard test methods allows ‘apples to apples’ communication and discussion with durable goods manufacturers. These protocols also make it possible to provide in-depth insight into the effective evaluation of durable labels, as well as insight into the future of product marking and decorating.

Putting IMD to the Test
Durability of IMD is sometimes a difficult goal to define. In the world of pressure sensitive labels, durability is frequently defined as how long a label stays affixed to the part. By its nature, in-mold labels have a different, permanent physical attachment to the molded material, so it would seem easy to say that they are all durable. But the wide-ranging uses of IMD mean that there are just as many durability requirements. Therefore, it’s important that an IMD supplier be knowledgeable about overall product durability and able to communicate it in meaningful terms.

Understanding what level of durability the manufacturer expects and what constitutes success or failure of the parts is critically important. An in-mold label may be made that is durable for many years, under any conditions, but the cost would probably be prohibitive for a product requiring minimal durability. The level of durability needs to meet the manufacturer’s expectations. So, how can durability be measured?

There is no way to test for every possible situation, but by listening to manufacturers or molders and looking for the most critical failure modes, it is possible to develop a list of ‘normal’ critical-to-quality (CTQ) factors. The testing then needs to be developed to define the durability for these CTQ factors.

Durability testing can be separated into two components:

1. Environmental exposure. This testing would be broken into two levels for labels exposed to interior and/or exterior conditions. This would include weathering and ultraviolet fade resistance. These tests usually take an extended amount of time to complete even when using accelerated aging tests. In fact, field-testing such as natural ‘sun farms’ can take years to complete.
2. Usage conditions. These are the unique conditions or requirements defined by the use of the labeled component. This testing would include chemical exposure, rub/scratch/impact resistance and temperature cycling. Most of these tests can be completed in a relatively short period of time.

It is not unusual for label suppliers to develop internal test practices based on past experience. Of course, suppliers also have to be ready to perform test procedures developed by the manufacturers. However, it is frequently difficult to correlate these test results to outside test methods.

Using established testing protocols (such as those published by ASTM International or other standards organizations) gets everyone working on the same page. The test proceeds are well defined and can be replicated by the supplier, the manufacturer, or other business partners. The downside of these tests is that they frequently require specific testing equipment. Not everyone is able, or willing, to purchase such specialized equipment. Fortunately there are several sources of testing protocols and laboratories capable of doing material testing. For example, in Dayton, Ohio, the Industramark™ business unit of Standard Register is fortunate to be close to the testing labs of the University of Dayton’s Research Institute. An example of the types of results this particular laboratory can deliver is illustrated in the above chart.

Why Use In-Mold Decorating?
In addition to durability and permanence, manufacturers can benefit in a variety of ways by using in-mold labeling on their plastic components. These include adding value to the product, promoting and protecting the brand, and ensuring proper safety messaging.

Adding Value to Plastic Parts. There’s no end to the decorative possibilities for plastic products when a manufacturer uses IMD to add colorful, photo-quality images. By adhering to the shape and texture of a product, the decorative label allows manufacturers to add high-quality color graphics as well as textured metallic-like finishes to areas where decoration previously was impossible, all without image distortion.

A good example can be found with appliance manufacturers, where most large and small appliances use decorative trim and exterior designs, all of which could be incorporated into the plastic piece, eliminating the need for post-production labeling, printing, and/or painting.

IMD also works superbly with appliance backsplashes. Typically, these backsplashes are covered with an expensive stainless steal, brushed chrome, or graphite overlay. With IMD, these and many additional finishes can be replicated right into the backsplash component. Plus, with the proper scoring of the mold, these parts also will take on the proper texture, giving it the feel and look of a genuine finish.

Promoting and Protecting the Brand. The value of a recognizable and respected brand is nearly impossible to assess. The fact is, next to employees, manufacturers have no greater asset than their brand image. Thus, they want to avoid promoting their brand with labels and imprints that fade, chip, peel, or otherwise deteriorate.

IMD protects a manufacturer’s valuable brand with a process that is unmatched for durability, image sharpness, and color accuracy. Just like the previously mentioned product decoration, in-mold branding labels adhere to the shape and texture of a product without image distortion.

For example, according to Bob Freund, an entrepreneur and inventor, “In-mold decorating and branding allow me to significantly improve the value of my products and give me a competitive advantage. My customers love the premium graphics and are willing to pay a premium price for product that really stands out from the competition.”

Ensuring Proper Safety Messaging. There’s no question that responsible companies want the people who use their products to do so safely. That’s why they put prominent safety warnings on potentially dangerous items. Due to increasing legislation, safety warnings are increasing even on innocuous products.

What happens when a well-intentioned company places a warning label on a product that later peels, chips, or wears off to the point that the safety message is unreadable? Not only can product users become injured, but in today’s litigious society, the financial impact and damage to a company’s brand image also can be devastating.

In addition to product decoration, IMD integrates colorful safety messages into a manufacturer’s plastic product with no fear of peeling, cracking, or wearing off. Incredibly sharp, picture-perfect images are fused into the plastic during the molding process without adhesives, allowing the graphics to become part of the product itself. Plus, the elements of nature, rough handling, cleaning solvents, and many other chemicals will not alter the safety message.

All of these features help provide peace of mind for manufacturers, according to Mark McCarthy, a partner with Tucker & Ellis, a Cleveland law firm specializing in defending manufacturers from product liability actions. “User safety is a huge concern. We want everyone who buys products to have a completely safe experience. That’s why it is so important that safety warnings and other information remain legible and easy to read for the life of a product. You can’t always get that with labels that peel, scratch, or tear. And messages molded into plastic without contrasting color aren’t very readable. With [this] system, there can be colorful safety messages that are hard to ignore – and stay that way, helping to protect companies from product liability.”

Moving to In-Mold Decorating
Based on the information reviewed here, manufacturers should consider incorporating IMD into their plastic products and components to take complete advantage of this sophisticated product and process. In addition to providing a cost-effective and secure method of fusing product decoration, branding, and safety messages into a plastic product, IMD provides the following advantages:

• Works with existing molds and tooling. IMD lets manufacturers add colorful, high-definition decoration to molded products without modifying existing molds or tooling, saving time and money. Plus, the technology works in both automatic and manual insertion processes.
• Automates the process. For high-volume applications, film placement can be automated easily with robots.
• Exceeds FDA and child safety requirements. In-mold films, such as those provided by Industramark™, a Standard Register business unit, comply with all child safety regulations for hazardous materials and exceed FDA requirements for food contact.
• Is competitively priced. The IMD process is competitive with other decorating methods, including pressure-sensitive labels.
• Is compatible with virtually all molding materials. With an IMD system, there’s no need to carefully match the material composition of the label to the molded material. In-mold technology is proven completely compatible with all thermoplastics, including polyolefins, ABS, polycarbonate, PVC, PET, TPO, TPE, elastomers, vinyl, glass-reinforced nylon, and styrene. It also has been molded into thermosetting polymers and rubber during vulcanization. Decorative images can be molded into non-rigid items because the image will flex or stretch with the product.
• Conforms to product shape or texture. The graphic image in an in-mold application assumes the texture and shape of the mold surface. The image actually molds around curves and over steps to create a continuous graphic that enhances the quality of the finished product. IMD works in injection, gas-assist, structural foam, blow, compression, injection-compression, and extrusion applications, as well as some thermoforming and rotational molding applications.
• Provides incredible durability and fade resistance. In-mold images actually fuse into the surface of a product during molding and shrink with the product as it cools without blistering, thus becoming inseparable. This process results in a graphic image that is highly fade-resistant and virtually impervious to the effects of nature, dishwashers, autoclaves, gamma radiation, rough handling, gasoline, and other abuses.

David Coughlin is director of operations for Industramark™, a Standard Register business unit specializing in functional and decorative labels, technical literature, and in-mold labeling. Joining the company in 2004, he has served as plant manager, senior manager of Lean Six Sigma, and most recently, director of in-mold labeling technologies. Dave Washburn is director of engineering for Standard Register and is responsible for new product development engineering support. With the company for over 28 years, he has held the positions of senior project engineer, carbonless technologies manager, and production equipment development manager. For more information on Industramark™ products and services, call (800) 755-6405 or visit www.standardregister.com/industramark.