Apple apparently considering carbon fiber for portable computers

Patent filings indicate that Apple is considering use of carbon fiber composites to take as much 100g off the weight of its popular MacBook Air portable computer.

According to patent filings made by Apple Inc. (Cupertino, Calif.), the computer-maker appears to be considering use of carbon fiber enclosures on future MacBook computer products.

In the filings, Apple describes use and manufacture of composites by laying sheets of carbon fiber material into a mold that is the shape of the desired product, followed by application of a thermoset resin that is cured and hardened.

There appears to be some concern by Apple that the weave of a carbon fiber, if visible to the user, could be an aesthetic liability: "In addition, the fibers (either as a unidirectional, woven, or nonwoven substrate) are typically variable in their construction and therefore are variable in their surface presentation. As a result, the resulting carbon fiber composite can have cosmetic imperfections that reduce the aesthetic appearance of the molded article formed therefrom. Further, carbon fiber composites, often being black, provide a narrow range of surface appearance to the molded article and therefore may give a 'tired,' unexciting look."

Apple's solution, according to the documents, is to use scrim layers to manage aesthetics: "Since scrim absorbs resin of the composite, scrim takes on the cosmetic properties and color of resin. Also [...] scrim is very thin, and it is translucent, and the underlying fibers of composite are partially visible therethrough. The combination of resin and scrim-forming scrim layer imparts a depth to surface of composite laminate, thereby providing an improved cosmetic surface of a molded article formed therefrom that is not only consistent in appearance, but is also aesthetically pleasing."

Use of carbon fiber would reportedly increase production costs but reduce total weight of the MacBook Air by 100g, reducing its weight from just more than 3 lb/1,363g to 2.78 lb/or 1,263g.