【文章內容簡介】 the strength, stability and low maintenance characteristics of fiberglass. These windows resemble traditional painted wood windows with factory applied exterior colors. Quite recently, manufacturers have also introduced a line of windows in which the fiberglass production process enables plex profiles required for the look of painted wood windows on the exterior, bined with a natural wood interior. Better options in this category feature furnituregrade, clear, verticalgrain Douglas fir, mahogany or other species on the interior unmarred by nail or staple holes, a powdercoated exterior finish and builtin systems to increase both energy efficiency and window longevity. FIBERGLASS: WHAT IS IT AND HOW IS IT MADE? Fiberglass is a posite structural material that consists of fiber reinforcements, typically glass, that are bound together in a resin matrix. Unlike mon fiberglass used in pools, boats, and storage tanks, fiberglass frames are produced via pultrusion, a process in which glass rovings and mats are pulled at tremendous force through a resin bath and a series of dies where the resin sets to the desired shape and the materials bine and catalyze to provide high tensile and torsional strength. These dimensionally stable fiberglass lineals are then assembled into window frames, which can be filled with foam insulation and glazed with highperformance lowE insulating glass for higher performance. Fiberglass window frames are produced similarly to vinyl, however where fiberglass is pultruded, or pulled, vinyl is extruded, or pushed, through a form tocreate a similar shape. ATTRIBUTES OF FRAMING MATERIALS The window frame which makes up some 20 percent of the total window area,is an important factor in window39。s total performance. Wood Wood is a readily available frame material, and the most mor choice for homes. Strong and easy to work with, wood is a natural insulator and plements many forms of traditional home architecture. It can either be painted a solid color or stained and sealed to show off the wood grain. Some significant downsides to wood windows have driven a switch to other frame materials. Wood frames require considerable maintenance to the exterior, with frequent touchups and occasional refurbishing, sanding and applying new coats of paint on a regular basis. Wood windows are also prone to rot, which can damage their integrity and make it difficult for the frames to hold paint. Some manufacturers of wood windows will offer cladding. However some cladding materials can conduct heat and cold while others offer limited color options and cannot be painted. In addition to the inherent problems caused by varying expansion rates of two dissimilar materials, the wood beneath all cladding is susceptible to water damage that seeps behind the cladding material and rots the wood. Wood39。s characteristics include Available in custom colors and designs Providesexcellentinsulation Traditional look fits many home styles Susceptible to rot and water damage Vinyl A vinyl window can be inexpensive, durable and energyefficient when designed properly to minimize thermal transfer. While early vinylwindows had problems with thermal expansion (the vinyl sash would expand or contract at a different rate from the glass and cause leaks) and stability in very hot environments, modern vinyl windows are much more durable and dimensionally stable. Vinyl window frames with heatwelded joints are stiffer than mechanically joined vinyl frames and thus provide better resistance to temperature stresses. Interior webs also strengthen the frame and improve its thermal performance Vinyl windows are made primarily from polyvinyl chloride (PVC) which is virtually maintenancefree. Vinyl frames can39。t easily be painted, but are often available in white and various neutral colors that plement many design schemes. Because