Fastening systems

There are also mechanically fastened systems where large sheets are laid over the substrate and seamed together. The mechanical fastening system to hold the membrane to the deck is placed at the appropriate density either over the membrane to fasten the system to the deck or under the membrane to which it is affixed. 

EPDM is by far the most widely used material in the ballasted roofing system constmction. Because of EPDM s flexibiHty, very large sheets of up to 10,000 square feet (929 m ) can be deHvered to the job site in compact roUs that offer reduced labor on the roof in the seaming process. The typical EPDM sheet size used in ballasted systems is 12 by 30 m and 1.1 mm thick. EPDM is also widely used in both the fully adhered and mechanically fastened roofing systems. In these constmctions, both 1.1- and 1.5-mm thick material is used with widths from 2.1 to 15 m. A majority of the installations use nonreinforced sheet, although reinforced membrane can also be used in all of the system types. The majority of the reinforced sheets go into mechanically fastened systems. 

Despite unfavorable mechanical properties of polyethylene compared to polypropylene, PVC, ABS, and Nylon, HDPE is the most popular plastic in WPCs. Polypropylene is too tough and makes difficult to use nails and screws as fasteners at a deck installation. Polypropylene-based composites require special fastening systems. PVC is typically considered as not environmentally friendly. Other polymers are not weather stable, brittle, or expensive. 

Amanda Olesky has mastered the nuts and bolts of engineering. She is the application engineer for Acument Global Technologies, which manufactures nuts, bolts, screws, and other fastener systems. Acument s products hold everything together from automobiles to aeronautics. 

In the aerospace industry its uses include oil cooling and ventilation systems fans, fuel tank covers, door handles, radomes, fastening systems (nuts, bolts, inserts and brackets), pipes and convoluted tubing (a barrier against chemicals and moisture), wiring and cable clamps. 

Where temperature variations are encountered in the service of an item containing dissimilar materials, adhesives perform another useful function. Flexible adhesives are able to accommodate differences in the thermal expansion coefficients of the adherends and therefore prevent damage that might occur if stiff fastening systems were used. 

Invisible zippers Invisible zippers are usually coil zippers. They are also seeing increased use by the military and emergency services because the appearance of a button-down shirt can be maintained, while providing a quick and easy fastening system. 

If new drywall, paneling, etc. was used to enclose lead surfaces, the fastening system is dust-tight. ... 

An easier way to maintain a preload is to determine first how much, if any, is needed. In this example there was no option to change the fastening system, but in less-demanding applications, where little force is required to obtain continuity, such alternatives as downsized bolts, Belleville washers, and locking treaded fasteners may be the best way. 

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