Investors gobbled up shares of Potbelly Corp. Friday, and the sandwich chain's shares more than doubled in their debut on the Nasdaq.

The company's initial public offering was another win for food companies going public. Shares of Sprouts Farmers Market Inc. rose 123 percent in the natural and organic grocery's August IPO. Restaurant chain Noodles & Co.'s stock more than doubled in its June debut.

Potbelly's stock rose $16.77, or 120 percent, to close at $30.77, after the IPO raised $105 million — more than the company had expected.

Potbelly began in 1977 as a small antique store in Chicago. The original owner started offering sandwiches and homemade desserts to customers in an effort to boost sales.

As of September, the company had 288 sandwich shops in 18 states and the District of Columbia. Its franchisees have seven shops in the U.S. and 12 in the Middle East.

Its net income in 2012 came to $13.6 million on revenue of $274.9 million.

In the IPO, 7.5 million shares priced at $14 each, above the revised projected range of $12 to $13. The company had initially expected shares to price from $9 to $11 each. Most of the stock came from the company. Early investors also sold about 150,000. Potbelly won't receive any money from the selling stockholders.

Potbelly plans to use the money from the IPO to pay a previously declared dividend, to pay off debt and for working capital.

Its shares now trade under the "PBPB" ticker symbol.