Carbon nanotubes eliminate polymer manufacturing headache

Aug 14, 2004
Carbon nanotube polymer

Researchers at the National Institute of Standards and Technology (NIST) have discovered that the addition of carbon nanotubes to a common commercial polymer, polypropylene, leads to dramatic changes in how the molten polymer flows. This process eliminates a widespread manufacturing headache known as "die-swell" in which polymers swell in undesirable directions when passing through the exit port of an extruder (a machine for producing more or less continuous lengths of plastic sections).

Researchers have been adding small amounts of nanotubes--tiny tubes of carbon about 1,000 times thinner than a human hair--to polypropylene in hopes of dramatically enhancing the material's strength and other properties. Once realized, this enhanced polymer could be processed at high speed through extruders for use in manufacturing.

NIST materials scientists were concerned that because nanotubes make the polypropylene rubbery, the material would be difficult to process or its enhanced properties would be lost. To their surprise, the opposite proved true. When sheared (forced) between two plates, the polymer normally separates the plates. However, when nanotubes are added, the plates are pulled together.

The scientists discovered that this "pulling-together" completely alleviated die-swell. Industry currently uses various time-consuming trial-and-error solutions to deal with the problem.

Eliminating die-swell should help manufacturers improve their time-to-market by simplifying their die design processes and enabling the controlled manufacture of smaller components.


Explore further: Better memory with faster lasers

Related Stories

Getting cars onto the road faster

Feb 08, 2011

Auto manufacturers are looking for shorter production times, faster logistics processes, new materials and technologies. A novel software platform will help companies to achieve these goals by reducing not ...

Recommended for you

A stretchy mesh heater for sore muscles

1 hour ago

If you suffer from chronic muscle pain a doctor will likely recommend for you to apply heat to the injury. But how do you effectively wrap that heat around a joint? Korean Scientists at the Center for Nanoparticle ...

Polymer mold makes perfect silicon nanostructures

5 hours ago

Using molds to shape things is as old as humanity. In the Bronze Age, the copper-tin alloy was melted and cast into weapons in ceramic molds. Today, injection and extrusion molding shape hot liquids into ...

Better memory with faster lasers

Jul 02, 2015

DVDs and Blu-ray disks contain so-called phase-change materials that morph from one atomic state to another after being struck with pulses of laser light, with data "recorded" in those two atomic states. ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.