CASE STUDY: Guilford Mills

Location: Greensboro (Guilford County) Industry: - Knit and Woven Fabrics (SIC 2258) Pollution Prevention Application: VOC Emission Reduction Through Solvent Substitution Annual Savings: $6,000 Payback Period: Less than 6 months Contact: Jimmy Summers, Corporate Environmental & Energy Manager (910) 316-4319

Background Guilford Mills is a leading manufacturer of knit and woven fabrics for the apparel, industrial, home furnishings, and automotive markets. Of the nearly 5,000 people associated with the company in the U.S., about 2,500 are employed in North Carolina. The company’s plants in North Carolina perform the following processes: , warping, and draw warping; circular and warp ; ; washing; ; printing; drying; heatsetting; and face . Guilford Mills sells finished fabric to customers who cut and sew it into the finished products. Waste reduction projects were conducted at three dyeing and finishing plants in North Carolina, one printing plant in North Carolina, and one dyeing and finishing plant in Pennsylvania. The dyeing and finishing plants perform the knitting, weaving, dyeing, drying, heat setting, and face finishing. The emissions survey conducted by Guilford Mills for its plants in North Carolina in 1993 revealed the majority of the volatile organic compound (VOC) emissions from the company’s facilitates were generated from the solvent- based chemical system in the heatsetting process and from the printing operation. Because of the upcoming Clean Air Act (CAA) Title V air permitting regulations, the company began to look for ways to reduce VOC emissions to stay below the permitting thresholds.

Waste Reduction Activities · The solvent-based chemical system in the heatsetting process is called the edge gum system. In the heatsetting process, dyed fabric is exposed to high temperatures (375o F) in order to lock in desirable characteristics such as width, weight, and texture. The process is performed on a tenter frame, also known as a drying oven. On some knitted fabrics, a gum is added to the edges of the fabric as it goes through the tenter frame to keep the edges from curling after the process. The gum was dissolved in a solvent and delivered to the fabric edges just prior to the high temperature portion of the tenter frame. The solvent flashed off quickly, and the gum was left on the fabric. After running many trials, Guilford Mills found that a water-based chemical system (an acrylic latex emulsion) is a suitable substitute for the solvent-based system. It was necessary to modify the gum storage pans on some tenter frames because when not being used, the evaporating water-based gum tended to leave an undesirable residue in the pans. Other than this problem, there were no other setbacks with the switch to the water-based gum system. · In the printing process, pigment dyes were delivered to the fabric through rollers. VOCs were contained in many of the chemicals and dyes used in the printing process. After being printed, the fabric went through a dryer to flash off all volatiles and lock the dye on the fabric. In reaction to business conditions

SIC 2200-2300 Case Studies - 5 - December 1995 and the potential for CAA Title V regulation, the company decided to shut down the high VOC printing process in North Carolina.

Waste Reduction Before the VOC emission reduction project, VOC emissions from Guilford Mills’ plants in North Carolina were 246.8 tons per year (1993). While most of the emissions were from the solvent-based gum system, emissions from the printing process were also a contributor. After the emission reduction project, the estimated emissions of VOCs were 93.7 tons per year. If the Pennsylvania facility is included in the figures, the company-wide reduction in VOC emissions was 67.5%. The following table summarizes the emissions data:

Actual Actual VOC 1993 VOC Emissions After Emissions Reduction Percent Plant/Location (Tons/yr) (Tons/yr) Reduction Maurice Fishman 66.2 24.1 64 George Greenberg 40.2 26.5 34 IFD (printing) 40.6 1.4 96 Friendship facility 4.2 4.2 0 Guilford East 95.5 37.48 61 Penn Dye and Finshing 116.4 24.2 79 Total NC 246.8 93.7 62 Total Company-Wide 363.2 117.9 67.5

VOC emissions were calculated from the VOC content obtained from the vendors of all dyes and chemicals used by the company and then estimating the quantity of emissions according to process characteristics. All VOCs in chemicals applied just before the tenter frames (such as the edge gums) were assumed to be emitted from the tenter frame stacks. Annual Savings The total capital outlay for the project was only a few thousand dollars. Capital was expended for modified gum storage pans for the water-based gum. As cost of the water-based gum and the solvent-based gum are about the same, operating costs have not changed substantially. The company has avoided CAA Title V air permitting at two of the plants partly because of this project and, thus, has saved at least $6,000 per year in the form of avoided permitting fees. Because of the low capital cost involved, the project cost recovery time is less than 6 months.

SIC 2200-2300 Case Studies - 6 - December 1995