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In our previous post on the topic of labels, we covered the importance of labels, essential questions to ask when considering the type of label for the product, and what machinery is needed to label primary and secondary packaging. We also took a deeper dive specifically into a popular type of label, pressure sensitive. Now, we’ll cover two other types of labels—shrink and stretch sleeves. While shrink and stretch sleeves are both commonly used for decorative labeling and do share some label similarities, they are different types of labels which will be explained in this review.

Unlike a pressure sensitive label, which is affixed on the product by an adhesive, shrink and stretch sleeves use no adhesive. Rather, with 360⁰ coverage, they are placed around a container from overhead or from the side and are held in place by some form of sleeve contraction.

Starting with shrink sleeves, they can be a desirable decorative label option because they have 360⁰ coverage and can also reach from the top to the bottom of containers, allowing maximization of available real estate on products. Shrink sleeves used on plastic bottles containing sports drinks, for instance, can cover the neck and shoulder and all the way down to the perimeter of the bottle’s base. Shrink sleeve labels add shelf appeal to the product, as the label can display a wide variety of colors and graphics, designs, and finishes from matte to gloss. Additionally, the product’s temperature or environment in which it is stored, such as a beverage stored in a refrigeration unit, is less of a concern compared to other label alternatives.

Shrink sleeve labels are typically made of polyethylene terephthalate glycol (PETG) film, because the film has a high shrink rate and conforms well to a multitude of different container contours. This film also works well with the most common container materials, such as metal, glass, and plastic. A vast range of products use shrink sleeve labels, including:

• Ready-to-drink beverages, such as sports drinks, energy shots, carbonated beverages, etc.
• Craft beers, wine, and spirits
• Condiments
• Processed foods
• Nutraceuticals
• OTC pain relievers, cough & cold remedies
• Cosmetics and personal care products
• Household cleaners, such as laundry treatments and fabric softeners
• Lawn & garden products

Shrink sleeves used as decorative labels have three general variations: full-body sleeves, full-body over-the-cap sleeves, and partial sleeves.  A standard shrink sleeve (or full-body sleeve) covers much of the package but not the neck or cap. These labels are typically seen on plastic or glass bottles, metal cans, and more. As mentioned earlier, there are many reasons to use these, and it is also worth noting they can be a good alternative to printing directly on containers, as is the case with craft beer where blank cans can be purchased at bulk price and can then be used for any number of beers.  A full-body over-the-cap sleeve covers the neck and cap of the package, as well as the perimeter of the bottom. Typically, this sleeve is used for plastic bottles like energy shots, ready to drink beverages that require a seal, personal care products, OTC cold remedies, and any other product that requires tamper evident coverage for security or consumer safety at the top of the container, in addition to a full body graphic sleeve. Partial sleeves, as the name suggests, covers only a portion of the container and are a cost-effective label alternative that mimic standard cut and stack, roll-fed, or even clear pressure sensitive labels. Partial sleeves are attractive for those who are environmentally conscious as it uses less plastic than traditional full body sleeves and can also highlight the color or contents of the product inside the container.

The process of shrink sleeving can be a relatively quick process. The PETG sleeve film is printed and measured to the exact size of the bottle with consideration for the extra room needed for shrinking and label distortion that occurs when shrinking. A conveyor delivers the bottles or containers down a line and places the package underneath the sleever. A sleeve is then positively applied on to the container vertically from above or horizontally from the side, with some machines running as fast as 800 containers per minute. From the sleever, the container gets conveyed to a heat tunnel where, in a matter of moments, the sleeve gets shrunk tightly to the contours of the container. This process is the same for all shrink sleeve types.

There are multiple types of heat sources that can be used in a heat tunnel: convection (forced air), infrared, and steam are the most common. Factors that should be considered when deciding on which heat to use for the label application include film type used, container material, product inside the container, environmental concerns, and product temperature at the time of sleeve application. Convective tunnels, the most popular due to their ease of use, utilize forced hot air and usually include a fan of some type to force air through a heat source, resulting in a heated air stream. Infrared tunnels utilize radiant heat to provide the energy required to complete the shrink process and utilize various energy sources from quartz panels or tubes. Infrared tunnels are normally used in conjunction with other types of tunnels as a finishing unit. Infrared is like steam in that it provides a consistent temperature and a high heat energy transfer. Steam tunnels use live steam to provide the energy required to complete the shrink process. The heat transfer is higher for steam and the shrink process occurs at a low, consistent temperature. Steam is recommended for most applications in which a sleeve is applied to a liquid-filled container, especially glass. *

Turning attention to stretch sleeves, while similar to shrink sleeves in being able to apply 360⁰ full color graphic labels without the use of adhesives, the material, application technology, and markets where they are used are different.

With stretch sleeves, no heat is required as part of the overall application process. Rather, each sleeve gets expanded and then slipped over the top of the product, being released at the point of desired height placement in one smooth motion. Therefore, the material used must have some elasticity to expand and then contract onto the contours of the container. A monolayer polyethylene (LDPE) material is commonly utilized. This material is resistant to moisture and chemicals, so if spillage occurs outside the bottle, the product won’t get trapped in the sleeve-like it could on a shrink sleeve. It also holds up better to product exposure which can be particularly important in cases where the product contains harsher chemicals.

Overall, stretch sleeving is a simple, flexible, and economical method of container decoration that is capable of covering round, square and rectangular containers. Like shrink sleeves, stretch sleeves can also cover a lot of container real estate, though, not as much as the full-body over-the-cap shrink sleeves. However, stretch sleeves are a good option for covering large containers like 2.5-gallon bleach bottles. Stretch sleeves are a popular label option for:

• General large bulk items
• Chemicals and cleaners
• Laundry detergents and bleach products
• Pet care, such as kitty litter
• Automotive fluids

Typically, stretch sleeves are not as snug as shrink sleeves, and because adhesives are not used, products that use this label type are less concerned with minor label movement around the container. Additionally, while heat tunnels are not needed, stretch sleeving is normally slower compared to shrink sleeving with production rates at less than 150 bottles per minute on the high-speed side.**

Providing support to businesses needing or considering a shrink or stretch sleeve labeler is what Axon, a ProMach product brand, excels at. Axon manufactures machine applicators for just about every shrink and stretch sleeve label requirement and can determine which labeling machine will best suit the situation and desired outcome. With speed capabilities from high to low, from complete shrink sleeve lines to stand alone tamper band sleevers and heat tunnels, Axon’s robust lineup of solutions have made them a stand-out in this niche segment of the labeling industry. The link below provides more about Axon, the industries they serve, and more information on the technology behind shrink and stretch sleeving. Depending on your product’s size, label type, and speed requirements, there’s likely a shrink or stretch sleeve solution that can do the job.

* https://files.axoncorp.com/axon-tunnel-vision-selecting-the-right-heat-shrink-device.pdf

**https://redimark.com/packaging-primer-101-stretch-shrink-sleeve-labels/?=454038380603&=&=b&gclid=CjwKCAjwwab7BRBAEiwAapqpTLZmVdkU_8NW1W-zhdnKHPwvQcSMmrs-RD0xWLyY_EOT1aCxt4VEOhoC17cQAvD_BwE

Labels are one of the most important aspects of the packaging industry. Labels are essential because not only do they provide information, but they showcase a brand and help it move across the supply chain. An effective label will creatively highlight what the product is, provide necessary information for the consumer, and will stand out from other products on the shelf. A label should fit the product, fit the package on which it is adhered to, and be able to withstand the rigors of the packing and shipping process.

There are questions one should ask when considering the correct type of label for the product, as there are a range of variables. Questions such as:

• What is being labeled? For instance, what is the size, shape, and material of the product?
  • How many labels will be applied to the product? To the case? To the pallet?
  • Where is the label being placed on the product? On the case? On the pallet?
  • Where is the labeling machine going on the production line?
  • What is the product environment, such as, is there moisture or residue on the surface of the application?
  • What is the temperature and climate where the label is being applied?
  • Are there any regulatory requirements that each label must follow?
  • Are there shipping guidelines or requirements that the case or pallet must follow?

Once these questions have been answered, the next step is to determine the correct type of machinery to label the primary and secondary packaging. ProMach has multiple product brands that offer labeling machines to meet a wide range of needs. Chances are, if you have a container, package, case, tray, or pallet, a ProMach product brand can label it. To show just how broad the ProMach labeling equipment portfolio is, we’ve created a labeling matrix of our comprehensive capabilities from each of our product brands. Due to the extent of available solutions, with each having its ideal use case scenarios, we will be featuring a series of blog posts highlighting these labeling capabilities to ultimately help as a guide to those in need. The first type of labeler we will be highlighting is the most prominent and popular on the market – pressure sensitive.

Pressure sensitive labels, also known as self-adhesive labels, are one of the most popular labels because the adhesive material allows for a label to be pressure applied to almost every kind of glass, plastic, paper, or corrugated packaging surface. The label itself is made of five layers: the liner, release coat, adhesive, facestock, and topcoat. There are options to choose from for these layers, such as paper or film for liner, paper, film or foil for the facestock, and topcoat material which can come in gloss, UV coating, or laminates. Adhesives also come in a variety of different options which can be chosen depending on the requirements of the label, such as permanent, removable, cold temperature-resistant, or water soluble. The methods of applying pressure sensitive labels include direct transfer (roll-on or wipe-on), tamp application, and air-jet (air-applied, air-blow, etc.). Because of all these specifications and variations in label and application, it is important to take into account the size, material, and shape of what is being labeled, what speed is needed to apply the label, and what length of time the label adhesive will be needed to stick to determine the exact machine that will adhere the label to the product.

ProMach product brands offer various types of pressure sensitive labeling machines: stand-alone labeling heads, linear and linear trunnion labelers, rotary labelers, print and apply labelers, weigh price labelers, as well as digital printing. Which is chosen is based on necessary labeling requirements for the product and its desired output.

A pressure sensitive stand-alone labeling head is a budget friendly, versatile labeler that can be a stand-alone feature or can be integrated into a complete packaging system. Typically, labeling heads are mounted on a portable stand, enabling them to move quickly and easily from one location to another as needed to maximize productivity. These labelers have vertical and horizontal capabilities and can still run labels at wide range of speeds. These labelers are a great option for production lines with space concerns, start-up companies, or production lines that already have efficient product handling.

Pressure sensitive linear (or inline) labeling systems are broadly used across the packaging line and consist of two main features, a conveyor that moves the product in one direction and one or more labeling heads. They may also incorporate a feature to effectively stabilize products as they are labeled while moving on the conveyor, such as feedscrew and trunnion roll systems, spacing wheels or belts, and aligning belts or chains. Linear labelers are effective at achieving lower speed targeted production goals compared to rotary labeling systems and are the most commonly used system for basic labeling needs. Linear labeling systems label items such as bottles, jars, or vials in primary packaging, as well as sealed trays, cases, and other packages in secondary packaging. Because the design of the system is less complex and typically does not run as fast (with a few situational exceptions), when compared to rotary labeling systems, linear systems are generally often less expensive, easier to maintain (with less change-parts), and have a smaller footprint.

As mentioned above, linear labelers can be a competitive alternative to rotary for high-speed labeling applications in certain situations. For instance, high-speed linear labelers have more upside when handling small, round containers such as pharmaceutical vials. Because containers have the potential to be spaced closer together with linear labelers (when using a feedscrew or trunnion), in comparison to a rotary machine, similar output is achievable with smaller containers while going at overall lower machine speeds.

Pressure sensitive rotary labeling systems are the most robust option especially when it comes to decorative label applications in primary packaging. They are generally the way to go for products with demanding or complex labeling specifications. If the product needs orienting, multiple labels, and/or requires fast speeds to meet high output, the rotary labeler is the machine for the job. In a rotary labeler system, bottles enter a star wheel and are transported on a continuously rotating carousel where the product is turned on bottle plates and labeled at different position points. These machines can run at high-speed rates, some in the range of 600-800 packages per minute (ppm) depending on the situation, with servo motors aiding in the orientation process. Rotary labelers can be equipped with up to eight different labeling stations and can apply labels at different positions such as spot, neck, belly, back, and top. Consequently, these machines are often much larger than linear machines and have a more substantial footprint within a packaging line.

Pressure sensitive weigh price labelers are an attractive option for flexible, accurate, and simple labeling for high-speed continuous motion weight labeling of items such as meat and cheese, as well as other price-by-weight primary packaging items. These machines are modular and can be easily upgraded to fully automatic equipment, offering flexible machinery for production. These labelers can come in a variety of sizes, which can be used for grocery retailers in the meat or bakery departments or can be included in a robust packaging line.

Pressure sensitive digital printing, also called print on demand, is a compact stand-alone system for primary packaging that offers flexibility and control, designed specifically for demanding print requirements. Full labels are printed entirely on demand from blank label rollstock in full color or simple black and white in desired quantities at time of need, omitting changeovers for limited runs and excess storage for numerous SKUs. For companies who have multiple products to label, multiple label configurations, multiple languages and more, digital printing can simplify logistics and offer quick turnaround time for printing.

Pressure sensitive print and apply labelers are best used for secondary packaging, such as cases, trays, stretch-wrapped pallets, etc. The labels are printed from a roll as the product is labeled which allows for variable information such as time specific applications, bar codes, and shipping information to be changed or swapped easily. Print and apply labels typically do not include any branding and are usually standard black and white. Print and apply labelers have a higher speed capability to keep up with more secondary packaging situations.

Pressure sensitive labeling machines are chosen for many major packaging lines because it’s an efficient way to label a product. These labels can be simply created with many custom designs of colors and shapes, making them perfect to display branding, information, and nutritional facts on standard or irregular shapes, from small to large sizes. There are many different materials a pressure sensitive machine can apply labels to across many industries, including processed food products, beverages, fresh produce, nutraceuticals, personal care, pet food, household, red meat, poultry packaging, and more. You’ll see pressure sensitive labels on plastic and glass bottles, jars, clam shells, and other packaging in all retail settings. Look around at any grocery or convenience store and you will see many labels that have been printed and applied with a pressure sensitive label. You’ll also find pressure sensitive labelers tailored specifically for the pharmaceutical industry, which require government regulations, and ProMach product brands NJM and Weiler Labeling Systems specialize in labeling these specific products such as vials, syringes, bottles, and more.

ProMach product brands have labeling equipment options for most pressure sensitive needs. P.E. Labellers, PackLab, ID Technology, EPI, Ossid and pharmaceutical product brands NJM and WLS, each have a labeling application that can outfit a need for pressure sensitive applications, as shown in the graph above. Depending on the specific requirements when labeling a product, any of these ProMach product brands can assist in creating the perfect labeled product.