For many years now, the manufacturers of clamshells for strawberries and other fresh produce commodities have been tweaking the dimensions to satisfy both consumer desires and industry concerns.

The one-pounder is the clamshell used most often by the industry, but other sizes, including the two-pounder and four-pounder, are gaining favor. F-D-S Manufacturing Co. in Pomona, CA, has entered the two-pound arena this year with three different sizes, each of which allows for an eight-down pallet stacking configuration.

F-D-S Manufacturing Co. has three different versions of its two-pound clamshell to accommodate different sizes of strawberries.Bob Stevenson, president of the firm, said the three sizes of the clamshell and the ability to be packed in a tray that goes eight down on a pallet are equally important. While the outer dimensions of the clamshell remain the same, the inside needs to change a bit to fit different sizes of strawberries. As the season progresses, the average size of a berry changes and the inside dimensions of the clamshell must change to hit the weight advertised. Stevenson said larger berries tend to be less dense so the clamshell has to be bigger to still get to the two-pound weight. Smaller fruit utilizes the inside space better and less mass is needed to reach two pounds of fruit. The same principle holds true when dealing with one- or four-pound clamshells.

The eight down trays allow for better utilization of the cube of a semi tractor trailer. In fact, with an eight down pallet, 30-35 percent more trays can be put in a truck. That is a huge freight advantage. Stevenson said the same freight advantage applies when shipping the empty clamshells to the grower. F-D-S manufactures its clamshells in Southern California but competes against clamshells made in Asia at a lower price point. Everything the firm can do to lower its costs to the growers is a plus.

The four-pound clamshells also fit well in an eight down pallet configuration. Creating a one-pounder that offers that same freight advantage has been difficult and Stevenson said the industry is still working on it.

The clamshell manufacturing industry has evolved over the years, and Stevenson said now virtually all the pellets being used to start the produce industry clamshells process come from recycled soda bottles. Depending upon the quality of the shipment, F-D-S may have to add a small percentage of virgin material to reach the quality level needed in the resulting clamshell. But he estimated that well over 90 percent of the material ultimately used comes from recycled product. And the clamshells themselves are recyclable.

Clamshells took over for plastic baskets in the strawberry industry more than two decades ago and now they account for at least 90 percent of strawberry containers. But F-D-S still manufactures and sells “millions of baskets every year.” Because of changes in that raw product, the baskets are typically black now rather than the traditional green. He noted that farm stands are the big user of those pint baskets. Consumers looking for that farm stand experience still want to see their strawberries in that old standby container, typically holding a pint of berries.

Stevenson said clamshells for the produce industry make up about 60 percent of F-D-S’s business, with strawberry clamshells accounting for about 50 percent of those sales. Grapes, tomatoes, bush berries and a host of other products make up the other 50 percent of the clamshell business. Many retailers, such as Trader Joe’s, use clamshells as a significant merchandising aid in their produce departments.

F-D-S is also a major manufacturer and seller of single face corrugated products, most notably paper pads for tree fruit cartons. Stevenson said single face corrugated paper products have been in the company’s arsenal for half a century. In fact, Sam Stevenson, current chief executive officer and co-founder of the firm, invented the fruit box pad and launched the company with a couple of partners on the strength of that pad. Bob Stevenson said it is still a very big seller and an important aid in the packing of fruit.