The company agreed to return 5 percent of its savings to a county fund used to promote economic development.
Fifty-seven people now work at the company's facility at 2190 Summit St. According to the application, the company might not be able to keep pace with customer demands without the added capacity. The new equipment could be purchased next month and operational by early 2014.
CSC, headquartered in Bedford Park, Ill., announced its expansion into New Haven in 2005. The company provides paperboard sheets primarily to small-and medium-sized independent box makers within a 250-mile radius.
Its original New Haven expansion also received a variety of incentives from state and local governments.
The phase-in request could be considered by New Haven City Council next month.