Archive for the 'Composites' Category

Polypropylene Composite Materials

Rain Noe (AKA hipstomp) at Core77 ran a few articles last week that featured a rather interesting flavor of composite materials. What sounds like a contradiction in terms, polypropylene composites combine the ballistic properties we typically associate with traditional glass-fiber composites with the low density, high impact and abrasion resistance of polypropylene. Hipstomp’s first example is Tegris, a polypropylene thermoplastic composite developed by textile and chemical giant Milliken for use in lifesaving armor, NASCAR race cars and protective gear for NFL players. Baggage manufacturer Tumi is now using this material in their new Tegra-Lite collection, starting with a pair of carry-ons (above).

A few days after his initial post, Hipstomp was turned on to Pure, the same type of material manufactured by Dutch textiles manufacturer The Royal Lankhorst Euronete Group. In both products, this material starts with co-extruded tapes that consist of a highly oriented, high strength and high modulus polypropylene core and a specially formulated skin on both sides for welding the tapes together in a compaction process using a hot-press or continuous belt press. This tape can be used as-is or woven into fabric or sheets or laminated onto structural panels like foam or honeycomb substrates from which you can construct a wide range of products. But it’s this ability to mold this material by compressing and heating it so that it bonds to itself that I find so interesting.

Pure has a very nice illustration of this process:

Click to go to the Pure Technology page.

One of the key advantages to considering this type of composite is that in addition to being strong and lightweight, these materials are 100% polypropylene (the inner PP fiber core and the outer layer of PP that is heat fused) and therefore can be fully recycled. This is in sharp contrast to traditional composites using a thermoset polyester resin to lock glass or carbon fibers together and can’t be re-melted or separated. They refer to this as a “mono-material concept” since heating the material to melt temperature results in just polypropylene resin.

Of course there will be times when you don’t want your composites to soften or melt under high-heat situations, but this new technology provides new opportunities for designers who think they need a composite, but are looking for a more sustainable solution.

[via Core77 Tegris article and Pure article]

Apple Explores Metal-Ceramic Composites

Consistent with previous posts regarding its purchase of Liquidmetal and investigation of carbon fiber for the iPad, Apple is also investigating use of metal-ceramic composites to reinforce thin lightweight structural housings for personal electronic devices. According to a patent approved on March 22,

“The metal-ceramic composite component may be made of a metal-ceramic composite material containing at least one of aluminum, magnesium, titanium, zirconia and alumina.”

The composite represents yet another step in Apple’s increasing sophistication in materials and manufacturing technologies… and world domination.

[Read more at Design News.]

Apple Tests Carbon Composite for iPad Housing

In addition to investing in the LiquidMetal process, Apple also is actively investigating the potential for carbon-fiber reinforced plastics (CFRP), the same material used in the Boeing Dreamliner 787. Apple received a U.S. patent yesterday for a fiber-reinforced housing, apparently intended to replace aluminum in the iPad in response to complaints about the device’s weight. The first version of the iPad weighs just 1.5 lb, but the next version may use new materials technologies like carbon fiber to reduce its weight and make e-reading more comfortable.

The patent also covers issues that might create challenges to the design team. These additional claims address issues pertaining to the molding process to create perfect parts suitable for Apple.

[more at Design News]

In-store Display Using Hemp and Vacuum Resin Infusion

According to Jeff Casper, this is the world’s largest hemp fiber vacuum bioresin infusion. A bale of over 15 lb. of raw cannabis sativa fiber (the strongest natural organic fibers) was vacuum infused with SuperSap bioresin (derived from waste streams of rapeseed oil (from biofuel industry) along with a biproduct pine resin from paper production). These materials were combined to create a custom display for the 2010 Pointer footwear line. The backlit display was exhibited through November 25th @ Fred Segal, 420 Broadway, Santa Monica.

A more in-dept description of the project is reported here on Core77.

Plastic/Metal Composite Material Is Able To Monitor Itself

When engineers want to know how much stress mechanical components such as wind turbine blades or machine parts are subjected to, they usually do so via a series of sensors. These sensors are typically either built into components, or are glued onto them. A new polymer-metal composite material developed at Germany’s Fraunhofer Institute for Manufacturing Technology and Applied Material Research (IFAM), however, may be about to change that – components made from the material are reportedly able to act as their own sensors.

The electrical resistance of the substance changes as it is subjected to tensile or pressure loads, and these changes are sent as signals through cables to a measuring instrument. The polymer-metal composite can be made with a wide variety of plastics, and is easily processed using conventional machines such as extruders and injection molders – this means it can be custom-made for specific applications. It can also be laminated into large mats, and in the future could be sprayed onto geometrically complex surfaces.

[IFAM website]

[via gizmag]

Carbon-fiber seats by Peter Donders

Belgian designer Peter Donders developed these ultra-light seating furniture pieces made from 462 meters (for the “stone”) and 320 meters (bench) of carbon-fibre under his label morphs. The single string of fibre is twisted around a form that’s removed after forming. Check the Daily Tonic link for images of production and the Peter Donders website for additional pics and information.

[via Daily Tonic]

BMW’s new material investment in carbon fiber

Moving from concepts and piece-meal implementation, BMW AG is going to production with its 2013 Megacity vehicle (MCV). (The concept shown at top and the carbon fiber cockpit shown underneath.) Every body panel and some interior parts will be made using a carbon fiber the company will mold itself, using carbon fiber from BMW’s new joint venture plant between BMW and SGL Group in Wiesbaden, Germany. The two recently had formed a joint venture under which carbon fibers made in the U.S. at a new plant in Moses Lake, Wash., will be used exclusively to create the MCV’s cockpit structure.

BMW reported that one Megacity prototype structure has been crash-tested from three different positions: two in accordance with EuroNCAP regulations and one under U.S. side-impact rules. After the testing, the passenger cell was still intact, confirming the integrity of the composite structure.

[Plastics News story]

[Composites World story]