New Applications for High-Strength Tapes

1. New Applications for High-Strength Tapes Manufacturers today are trapped in a perennial race to get products assembled and out the door in less time and at lower cost while maintaining high quality. They must also adjust to constant change in the materials they use. These challenges have many companies rethinking their default use of fasteners and liquid adhesives as the best ways to attach metal, plastic and glass. One alternative that is increasingly—and justifiably— gaining engineers’ attention is high-strength bonding tape that contains acrylic foam or glazing. Many Benefits There are several advantages to using high-strength bonding tape for assembly. The most important is that the tape bonds instantly. It also is quicker to use than structural silicone, for example. For assembling commercial window units, structural silicone sealant takes approximately 24 hours to 21 days to fully cure. In contrast, pressure-sensitive acrylic foam bonds two substrates together on contact with no drying time. And a structural glazing tape, such as VHB made by 3M, takes approximately 30 minutes to apply, with zero wait for curing. High-strength tape is more resilient than the general-purpose foam tape purchased at the local home building supply store. To be sure, the latter is great for sealing, mounting and insulating. But, it’s not so good at withstanding rigorous applications and conditions, such as extreme heat or cold, moisture, wind and flexing. Acrylic closed-cell foam tape remains flexible to accommodate material expansion and contraction caused by temperature extremes. Specialty bonding tape also allows for differing expansion and contraction rates of dissimilar substrates, such as plastic bonded to metal. These types of bonding tape are designed to absorb shock and distribute stress over the entire length of the joined surfaces through a continuous bond. Acrylic closed-cell foam, for instance, has specific properties that absorb shock and impact. It comes in a variety of thicknesses. Equally important, viscoelasticity gives the bonding tape cohesive strength, allowing it to resist dynamic stresses, absorb static stresses and spread stresses over a large area to reduce stress concentration. The ability to do this allows manufacturers to use thinner, lighter, lower-cost materials than the thicker materials needed for screws or rivets. Finally, high-strength bonding tape maximizes design flexibility to minimize assembly time. Much of this type of tape is used with precision die-cutting, so that it can fit any shape, size or profile. The tape can

2. also provide full coverage on the back of any item if desired. Recommended Applications There are four types of applications where viscoelastic high-strength bonding tape works best. High-strength bonding tape is great at joining panels to frames. Bus manufacturers sometimes use tape to bond the outer roof and side metal skin to the vehicle frame. The benefits of this approach are speed and ease of attachment, instant holding, and the durability to withstand dynamic stress such as wind and weather. Bonding tape is equally effective at adhering a stiffener, external element or structural glazing to a panel, such as the exterior sidewall of a trailer. Besides speed and ease of use, this approach avoids read-through. The tape foam also reduces vibration and noise caused by flexing of the thin-gauge panel material, such as a commercial baseboard air conditioning unit. Other recommended applications include applying decorative materials to a firm surface, and bonding lenses or windows to a housing. A common decorative application is adhering a company’s brand label to a household appliance. Tape allows this to be done quickly and easily with long-term reliability. In some cases, the high-strength bonding tape also provides dynamic strength, depending on the substrate. Manufacturers are increasingly using tape to secure cell phone screens, LCD displays and windows in electrical enclosures. In these applications, the benefits of tape include speed, ease of use, impact absorption, sealing (if die-cut) and aesthetics (thin bond).