3M™ Dual Lock™ Reclosable Fastener SJ3768, Roll Good with Rigid Back, Stem Density 250, Black, 6 in x 50 yd, 1 Roll/Case

Convenient for Automotive Trim

The 3M™ Dual Lock™ Reclosable Fastener SJ3768 is an ideal solution for attaching low surface energy (LSE) polypropylene automotive trim components. These fasteners have a thicker backing compared to standard plainback Dual Lock reclosable fasteners, which enhances the capability and robustness of the ultrasonic welding process. With easy open and reclose features, these fasteners are perfect for high cycle applications. When engaged, the pieces audibly snap together, providing a secure, dependable, and repeatable attachment.

Designed with hundreds of interlocking mushroom-shaped stems, this polypropylene fastener offers a reliable alternative to conventional attachments like screws or adhesives. These traditional methods can be time-consuming to fit and assemble, weaken the part, or be susceptible to vibration and weather extremes. The Dual Lock fasteners, on the other hand, are constructed with polyolefin stems that hold tight regardless of high heat, cold, moisture, or humidity. In fact, these fasteners not only provide a secure hold but also reduce vibration and rattling, making them an excellent choice for applications where vibration is a concern.

How It Works

The 3M™ Dual Lock™ Reclosable Fastener features a thicker polypropylene backing, which enhances the ultrasonic welding process and reduces the number of welds required per piece. This thicker backing provides a more rigid fastener, minimizing lifting or flexing during disengagement and ensuring a firm hold through multiple openings and closings. The ultrasonically welded piece can be easily snapped to a second Dual Lock fastener attached to another part, creating a secure, dependable, and repeatable attachment.

When two pieces of the Dual Lock fasteners are pressed together, the stems flex and the mushroom heads slide past each other. Once they pass the opposing mating piece, the stems snap back into their original position, and the opposing mushroom heads interlock. These fasteners offer high tensile strength but can be opened by simply cleaving or peeling open the closure. Alignment and re-alignment are effortless, requiring no special tools. This means that these fasteners can be used to attach components before they enter the final assembly plant, reducing the number of parts and assembly time.

Stem Densities

The Dual Lock fasteners are available in three different stem densities: 170, 250, and 400 stems per square inch. The Dual Lock fastener SJ3768, specifically, has 250 stems per square inch (25mm), offering the tightest hold. It can be mated to Type 170, 250, or 400 for adjustable and proportional engagement and disengagement force to meet specific application requirements.

3M Science Delivers Closures You Can Count On

3M™ Dual Lock™ Reclosable Fasteners are the go-to choice for applications that require a high-strength, reclosable fastening system. These fasteners have been developed by 3M engineers using a unique combination of physics and materials science to deliver reliable performance even after exposure to high moisture levels and wide temperature ranges. For applications that require an ultrasonically bondable piece and multiple closures, the 3M™ Dual Lock™ Reclosable Fastener SJ3768 is the perfect solution. It exemplifies how 3M technologies advance operations in the automotive industry, providing both ease of use and superior results.