Strawberry industry shows interest in corn-based clamshells
Strawberry industry shows interest in corn-based clamshells
The strawberry industry was among the very early segments of the produce industry to embrace the use of clear plastic clamshells for retail consumer packs. The majority of fresh strawberries now goes to market in clamshells. They are popular for many reasons: They display the product well, they protect it, they extend shelf life and reduce shrink, and they reduce labor costs at store level.
But there are downsides, one being the amount of non- biodegradable plastic waste generated by their use.
There is, however, an environmentally friendly alternative: clear clamshells made from a compostable corn-based resin. The technology is not new, but until recently, costs have been prohibitive. With recent price increases in crude oil, however, petroleum-based products, including the polyethylene terephthalate resins from which most clear plastic clamshells are made, have risen in price to the point that corn-based resins are competitive.
The California strawberry industry is showing interest in the corn-based clear clamshells, which some say are indistinguishable from the PET clams.
Crown Jewels Marketing in Fresno, CA, tested the concept last year and will pack about 90 percent of its strawberries in corn-based clamshells this year, according to Steve Poindexter, a managing partner with the company. "You can't tell them apart" from the PET plastic containers, he said.
Sunrise Growers in Placentia, CA, is doing some testing of the biodegradable clamshells, which are made from a corn- based resin known as PLA. There are two factors driving the industry's interest in clams made from the PLA material, said Sunrise President Ed Haft. One is "the increase in conventional resin prices over the last two years" by 25 to 40 percent. "When there was such a price gap between the two technologies, it really didn't make much sense to look at it," he said. "The other driver is the environmental cleanliness."
Manufacturers "have been able to achieve comparable clarity" in the product, compared to PET clamshells, said Sunrise's Christine Reker.
But Sunrise has found that there are some problems with the PLA clamshells that still need to be resolved. "I think in order to have this mainstream commercialized throughout the industry, we are still looking for a breakthrough in technology," Ms. Reker said. "Obviously, we would love to work on any kind of material that is better for the environment and satisfies the customers." But with the PLA resin clamshells, "temperature is the key hurdle."
When the PLA containers are exposed to temperatures in the high 80s and above, and particularly over 100 degrees, they tend to warp, she said. That is not a risk after packing, when the filled containers are kept in temperature- controlled environments. But when manufacturers "produce these packages" and inventory them "in order to meet our needs for peak season and beyond," she said, they are "not stored under refrigerated conditions." Summer heat can take a toll.
"There has been a lot of warping in the tests that have been conducted," said Mr. Haft, who added that the higher temperatures also reduce the clarity.
PLA containers were "the first containers made from 100 percent annually renewable resources," according to the web site of NatureWorks, which makes the resin.
But there are downsides, one being the amount of non- biodegradable plastic waste generated by their use.
There is, however, an environmentally friendly alternative: clear clamshells made from a compostable corn-based resin. The technology is not new, but until recently, costs have been prohibitive. With recent price increases in crude oil, however, petroleum-based products, including the polyethylene terephthalate resins from which most clear plastic clamshells are made, have risen in price to the point that corn-based resins are competitive.
The California strawberry industry is showing interest in the corn-based clear clamshells, which some say are indistinguishable from the PET clams.
Crown Jewels Marketing in Fresno, CA, tested the concept last year and will pack about 90 percent of its strawberries in corn-based clamshells this year, according to Steve Poindexter, a managing partner with the company. "You can't tell them apart" from the PET plastic containers, he said.
Sunrise Growers in Placentia, CA, is doing some testing of the biodegradable clamshells, which are made from a corn- based resin known as PLA. There are two factors driving the industry's interest in clams made from the PLA material, said Sunrise President Ed Haft. One is "the increase in conventional resin prices over the last two years" by 25 to 40 percent. "When there was such a price gap between the two technologies, it really didn't make much sense to look at it," he said. "The other driver is the environmental cleanliness."
Manufacturers "have been able to achieve comparable clarity" in the product, compared to PET clamshells, said Sunrise's Christine Reker.
But Sunrise has found that there are some problems with the PLA clamshells that still need to be resolved. "I think in order to have this mainstream commercialized throughout the industry, we are still looking for a breakthrough in technology," Ms. Reker said. "Obviously, we would love to work on any kind of material that is better for the environment and satisfies the customers." But with the PLA resin clamshells, "temperature is the key hurdle."
When the PLA containers are exposed to temperatures in the high 80s and above, and particularly over 100 degrees, they tend to warp, she said. That is not a risk after packing, when the filled containers are kept in temperature- controlled environments. But when manufacturers "produce these packages" and inventory them "in order to meet our needs for peak season and beyond," she said, they are "not stored under refrigerated conditions." Summer heat can take a toll.
"There has been a lot of warping in the tests that have been conducted," said Mr. Haft, who added that the higher temperatures also reduce the clarity.
PLA containers were "the first containers made from 100 percent annually renewable resources," according to the web site of NatureWorks, which makes the resin.
