A Spicy Kick to Plastics

Chile plants are being used in wood-plastic composites
Chile plants are being used in wood-plastic composites.

Plastics have always been a hot venture but now they get spicier. Researchers at New Mexico State University (NMSU) are looking at combining the chile plant with plastics. If they get it to work, the venture will bring in money to New Mexico.

The New Mexico State University’s Chile Pepper Institute specializes in crossbreeding and combining chile varieties. Researchers from the university’s Department of Industrial Engineering decided to look into how to make most of the chile plant once its chiles are used.

Wood-plastic composites (WPCs) are a mixture of wood fibers and plastics, as well as small amounts of additives to help the material hold together. They are also known as natural fiber plastic composites or natural fiber reinforced plastics. The wood behaves as reinforced fibers running through the material to give it strength, and the plastic acts like a matrix to hold the fibers in a mesh.

The material is becoming more popular, especially in decks and rails. The product is environmentally friendly, resists decay and insects, and holds up better than wood in bad weather.

Senior Communications Specialist Mark W. Cramer of NMSU Communications says:

Companies use both recycled and virgin plastic to combine with wood products like pallets, furniture waste, recycled oak wood flour, oak and pine from millwork and reclaimed cedar wood chips, among other sources. Over time, researchers have investigated high levels of wood and plastic combinations with functional additives, such as coupling agents, UV stabilizers, antimicrobials and antioxidants.

Delia Valles-Rosales [link is ours], associate professor in NMSU’s Department of Industrial Engineering, believes manufacturers in New Mexico could cash in on this growth by using chile plants for the composite material.

About 60% of a fully grown chile plant’s weight is in its stems, leaves, and roots. These parts are usually thrown away or used as cattle feed. If that material could be used in WPCs, local manufacturing facilities could be established to make the product because New Mexico is a leader in chile production in the U.S.

Valles-Rosales’ team is exploring the ratios of wood and plastic for the WPCs, and also different grain sizes. The plastics are recycled.

The work falls into the broader context of research into plastics made from chicken feathers, fruit, and dandelions. It reduces the dependence on petroleum and turns potential waste into something useful.

The red chile is seasonal, so Valles-Rosales and colleagues are also looking into other potential local resources to make WPCs, such as cotton plant byproducts, pecan tree branches, and pecan shells.

Source: “Eye on Research: Could chile be used to reinforce plastic?,” Las Cruces Sun-News, 05/16/11
Image by jonboy mitchell (Jon Mitchell), used under its Creative Commons license.

Rajendrani "Raj" Mukhopadhyay is a science writer and editor who contributes news stories and feature articles on scientific advances to a variety of magazines. Raj holds Ph.D. in biophysics from Johns Hopkins University.