Simulated divided lites are a popular design option for residential and even light commercial windows. The design intent is to create the look of individual panes of glass by applying muntin bars or grilles internally (called “G-B-G” for glass/bar/glass) or externally by using foam bonding tapes. Muntin bars attached with high performance tapes having a pleasing visual appearance, have secure bonds if installed correctly, and save production time.
Types of Foam Tapes for Muntin Bar Attachment
The two most common types of foam tape used for bar attachment are acrylics and polyolefins.
Acrylic foams include the popular VHB brand from 3M and the Norbond brand from Saint Gobain. Other suppliers of high quality acrylic foam tapes include the AS series from Scapa, the ACX series from Tesa, and the SFB series from Avery Dennsion.
These tapes can be monolithic meaning the adhesive and foam core are extruded in simultaneously in a single layer or they can be multi-layer where an extruded acrylic foam core is coated with the acrylic adhesive system. In either case, these tapes exhibit excellent viscoelastic behavior. This means the “viscous” behavior allows the tape to absorb and damp energy that occur from sudden wind gusts or other forces while the elastic behavior allows the tape to recover (think of stretching a rubber band and then letting it come back to its normal shape).
Saint Gobain A7300 Series Performance Data
Polyolefin Foam Tapes
Polyolefin foam tapes are made from a foam core extruded from polyethylene that is often modified with varying amounts of EVA and polypropylene. Additional coatings can be extruded onto the foam core to create a very smooth surface onto which the acrylic adhesive will be coated. High quality polyolefin foams are produced by Adhesives Research as well as Berry Plastics, Adhesive Applications, and others.
The polyolefin foams don’t have the same viscoelastic behavior of the acrylic foam tapes but they exhibit very good dynamic shear and tensile (T block) values along with a very favorable price that can make them worth considering especially for lighter weight muntin bars made from cellular PVC and other lightweight materials.
Adhesives Research 8645 Muntin Tape Performance Data
Foam Core Stress /Strain Capabilities
The chart below demonstrates the capabilities of each basic type of foam core and how they differ.
Want to know more about muntin bar tapes? Contact Tom Brown, Inc. today for samples, technical data, or to discuss your application further.