DN Staff

May 6, 2002

3 Min Read
Innovative Materials/Adhesive Products

Cure-in-place materials ride quietly inside

Silicone cure-in-place gaskets have long stood up to the inhospitable conditions in automotive engine compartments, but they can be overkill for interior applications or as a way to stop exterior buzz, squeak, and rattle problems. For these jobs, Loctite has developed a polyether foam cure-in-place gasketing material. It can serve as a less costly alternative to high-performance silicone materials and also as a less labor-intensive replacement for pressure-sensitive foam tapes, according to Loctite Automotive Manager Dave Carbone. The polyether cures at room temperature into a soft foam(&50 Shore OO) and offers heat resistance up to 120C. And Carbone reports that it adheres to a wide variety of substrates-including hard coated polycarbonate. Loctite supplies the new gasketing material as two-component system suitable for automated dispensing-but it doesn't require mechanical mixing. Loctite Corp.: Enter 514

Conductive adhesives beat the heat

Devcon has come out with a line-up of electrically and thermally conductive epoxy adhesives. According to Market Development Manager David Bongiorni, they address a wide range of electronics applications that either can't tolerate solder or require thermal dissipation. Syon Tru-Bond 206A Conductive Adhesive Solder is a pourable, silver-filled compound with a one-to-three hour pot life and cure times of 72 hours at 75F or 2 hours at 130F. Tru-Bond 214 Silver-Filled Epoxy Adhesive is an electrically conductive, non-sagging paste used to form conductive paths on circuit boards or prepare electrodes for capacitance and loss measurements. Tru-Bond 214 also works in applications requiring high thermal conductivity and meets federal specification MMM-A-1931, Types I and II. Its pot life is 1 hour, and it cures in 24 hours at room temperature. Tru-Bond 215 Copper-Filled Epoxy Adhesive is doubly conductive-thermally and electrically. This non-sagging paste is intended as an economical alternative to silver-filled products. It can be used in place of hot solder in the preparation and repair of conductive paths on circuit boards as well as in RF-shielding and heat-sink applications. It has a pot life of 45 minutes. All three adhesives target service temperatures from-55 to 95C. Devcon: Enter 515

Dispensing tip wastes not

The EFD Mikros pen system minimizes waste in assembly processes that require precise, tiny drops of two-part epoxies, UV-cure adhesives, and other expensive assembly fluids. "Syringes and similar application tools often hold more adhesive than necessary. It's not uncommon for more to be left over as waste than goes into the assembly," explains Terrence Woldorf, EFD's business development manager. The Mikros pen system addresses the excess-capacity problem with a disposable reservoir tip whose 0.25-cc capacity allows adhesives to be mixed in small batches and consumed within pot-life constraints. Used with an air-powered dispenser, the pen produces micro-deposits as small as 0.007 inches in diameter. The silicone-free tips are available with 30-, 32- or 33-gauge dispensing needles and will block UV wavelengths between 280-390 nm. The tip attaches to a slim, lightweight aluminum handle. Applications include a variety of small medical and optical assemblies. EFD Inc.: Enter 516

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