Containers key to blueberry grower’s success

With a 4- to 6-week harvesting window to pick blueberries at their peak of ripeness, Sweet Berry Farms of North Carolina relies on automation and error-free packaging lines to bring in its 600-acre crop. The grower is able to get fruit from the field to the stores in as little as two days, thanks in part to a new container design that runs smoothly on its packaging lines at a rate of 240,000 pints of blueberries per day.

Fabri-Kal of Kalmazoo, MI, developed a one-pint container with snap-fit lid which solved some major problems for Sweet Berry Farms. A formulation of crystal polystyrene blended with CPChem’s K-Resin styrene-butadiene copolymer (SBC) provides the strength, durability, clarity and hinge flexibility needed to run on the customer’s production lines.

“Originally, Sweet Berry Farms was using an oriented polystyrene (OPS) container,” explains Bill Keely, a regional representative for Fabri-Kal. “But every 10 containers or so, one would crack when it met the pinch roller that guides the container. We worked with staff at the plant to design a container that would be cost-effective, increase production rates due to consistent machineability, provide a secure fit from body to lid, and provide the “shelf-appeal” supermarkets demand.”

The formulation for Fabri-Kal’s containers uses K-Resin KR-03, a resin suitable for sheet extrusion where gels must not be visible in the finished part. The material also contains a microcrystalline wax, which acts as an antiblock.

“One of the most attractive facets of this copolymer,” says Steve Shelby of CPChem, “is its ease of processing. It actually can be extruded into very high quality sheet with equipment normally used for high-density polyethylene or polystyrene.”

Fabri-Kal’s Dave Armstrong adds that “K-Resin is the ideal substitute for PET” in some containers. “We look to use a K-Resin SBC grade first in applications where clarity is an issue, such as with our cups, trays and food containers.”

CPChem 866 KRESIN1