Pressure-sensitive tape is a great way to make the mounting of extruded parts and profiles quick and simple. Extrusion means shaping a substance like metal or plastic by forcing it through a die. Weather stripping, decorative trim and seals are all examples of extruded parts that you’re probably most familiar with.
In the past, extruded parts like these needed to be fastened with screws, nails or glue. Mounting required tools and took a lot of time. Because this process was not fast or simple, pressure-sensitive tape was seen as a better solution upon its invention. Manufacturers of extruded parts soon found that they could easily apply a double-coated tape to their parts, which not only added value, but could also save time and money.
Today, tape manufacturers supply the extrusion market with double-coated tapes in almost any width and length. Long-length formats such as large pancake rolls and spools help reduce downtime and scrap associated with frequent roll changes.
When you are searching for the best tape to bond extruded parts, there are several things to think about. First, consider the extrusion material. Next, consider what the extruded part will adhere to, what the end-use conditions are, and what’s needed to efficiently run the material through your process or subsequent processes.
Here are a few guidelines that will help you figure out what tape is right for your project:
- Rubber adhesives bond quickly and provide a strong initial bond. Rubber adhesives also bond well to other rubber materials, along with most plastics and metals. They are often more cost-effective than other adhesive systems, too. Some of the drawbacks of rubber adhesives are they are not well-suited for outdoor applications where sunlight and temperature variations are present and moisture resistance is needed. In addition, rubber adhesive systems can get brittle over time and lose performance ability.
- Acrylic adhesive systems can be formulated to provide a wider range of performance properties and are therefore suitable for more applications. Acrylic adhesives have long-term performance properties along with good UV resistance, moisture resistance and resistance to wide temperature fluctuations. These properties make acrylic adhesives a great choice for outdoor applications, high or low temperature applications and chemical-resistant applications. Acrylic formulations likewise can be customized for specific requirements. The main drawbacks of using these systems include the dwell time of 24 hours for acrylic adhesive to achieve full performance and a generally higher cost than rubber adhesives.
- The greatest benefit of silicone adhesive is its ultra-high temperature performance. It’s also good for bonding to other silicone materials when certain adhesives can’t manage to do so. Drawbacks of silicon adhesive include its high cost and poor performance in vertical holding applications.
Double-coated tapes are most commonly used for bonding extruded parts. They can be easier to cut into small rolls and are better for making narrow-width, long-length rolls or spools. The carrier in the double-coated tape adds dimensional stability and often increases the overall strength of the part. The carrier also helps keep the adhesive from flowing and sticking to roll edges. Unsupported transfer tapes can be used in some applications, but they don’t provide the dimensional stability of double-coated tapes.
All types of carrier materials can be used in double-coated tapes, with each kind providing different properties. For example, a foam carrier will offer cushioning and gap filling. Polyester films have good heat resistance and provide tensile strength. Meanwhile, tissue carriers are low cost and easy to cut. Lastly, polyethylene and polypropylene are extensible and will conform to bends and corners.
Release liners should also be considered for your work. Paper release liners are the most popular and the most cost effective. Nevertheless, paper liners are susceptible to moisture damage, resulting in cockling/wrinkling or liner shrinkage/expansion. This is an important point to keep in mind because these defects can result in problems in processing and other areas. Film release liners are great for extrusion applications. They don’t absorb moisture, which prevents cockling and allows parts to be stored for long periods of time. Film liners provide greater strength, are less likely to tear during removal and usually cut more cleanly.
When in doubt, talk to your adhesive tape professional for help with selecting the right tape for your extrusion application.