Product Overview
Convenient Assembly and Re-Assembly for Automotive Trim
Ideal for attaching automotive OEM trim components, our 3M™ Dual Lock™ Reclosable Fastener SJ3209 provides a high-strength closure that is easy to assemble and just as easy to open and reclose in high cycle applications. Moreover, the pieces audibly snap together with a satisfying click to form a secure, dependable and repeatable attachment.
Designed with hundreds of interlocking mushroom-shaped stems, Dual Lock fasteners can replace conventional attachments such as screws or adhesives, which can be time-consuming to fit and assemble, may weaken the part, or are susceptible to vibration and weather extremes. Dual Lock fasteners are constructed of polyolefin and hold tight regardless of high heat, cold, moisture or humidity. These fasteners are also an excellent attachment solution when vibration is an issue – not only do the fasteners hold tight, but actually reduce vibration and rattling.
Additional Features include:
- Fast assembly with no drilling or additional tools required
- Hidden attachment avoids unsightly mechanical fasteners on the show surface
- High temperature and solvent resistance
- Mushroom heads that allow flexibility in alignment for easy attachment of components
- Can be used to attach components before they enter the final assembly plant, thus helping to reduce the number of parts and the length of assembly time
- Combinations of stem densities and the engaged area provide adjustable and proportional engagement and disengagement forces
- An audible snap confirms that the part is correctly installed with minimal insertion force required by the assembly worker
- Can be opened and closed hundreds of times – allowing easy access to areas behind closeout panels, headliners and trunk liners
How It Works
This pop-in fastener has a polypropylene post on the back designed to be inserted into a round hole where attachment is desired. Its “pine tree stems” grip the inside of the hole and hold tight. The fastener can be snapped to a second Dual Lock fastener attached to another part – forming a secure, dependable and repeatable attachment.
When two pieces of 3M™ Dual Lock™ Reclosable Fasteners are pressed together, the stems flex and the mushroom heads slide past each other. After passing the opposing mating piece, the stems snap back into their original position and the opposing mushroom heads interlock. These fasteners can provide high tensile strength but can be opened by simply cleaving or peeling open the closure.
Alignment and re-alignment are easy and no special tools are required. This means that the fasteners can be used to attach components before they enter the final assembly plant, thus helping to reduce the number of parts and the length of assembly time.
Stem Densities
3M™ Dual Lock™ Reclosable Fasteners allow customers to combine different stem densities and engaged areas to create adjustable and proportional engagement and disengagement forces to suit their application. Dual Lock fasteners are offered in three different densities (stems per square inch): 170, 250, and 400. Our Dual Lock fastener SJ3209 has 250 stems per square inch and mates to Type 170, 250 or 400. Types 170 and 400 should not be mated with another fastener of the same density.
Applications
3M™ Dual Lock™ Reclosable Fasteners can replace conventional mechanical fasteners in a wide range of assembly and attachment applications where reclosability or serviceability is desired. Dual Lock fasteners are used primarily to secure rigid and semi-rigid surfaces such as trim or door panels, instrument panel bezels, headliners, and other automotive interior and exterior trim. Some examples of applications include:
- Headliners
- Trunk liners
- Door panels
- Toll transponders
- Vehicle headliners
- Sunroofs
- Interior lighting
- Window and door trim
- Vibration and sound dampening control
- CHMSL – Center Height Mount Stop Lamp – cover plates
- Center console flanges
3M Science Delivers Closures You Can Count On
3M™ Dual Lock™ Reclosable Fastener are ideal for many applications where a high strength, reclosable fastening system is required. 3M engineers have uniquely combined physics and materials science to bring the automotive industry reliable fasteners that supply high performance even after exposure to ultraviolet radiation, high moisture levels and wide temperature ranges. For applications that require a pop-in piece and multiple closures, look no further than the long-lasting durability of our 3M™ Dual Lock™ Reclosable Fastener SJ3209. It is yet another outstanding example of how 3M technologies advance operations in the automotive industry, providing both ease of use and superior results.
