United States
                     Environmental Protection
                     Agency
Air and Energy Engineering
Research Laboratory
Research Triangle Park, NC 27711
                     Research and Development
EPA/600/SR-93/161   November 1993
&EPA       Project Summary
                     Initial Assessment of  Emissions
                     from  Heat Setting Carpet  Yarn
                     B. McMinn and D. Ocamb
                       The report gives initial results of a
                     project to determine the nature of emis-
                     sions resulting from the heat setting of
                     carpet yarn and to identify possible con-
                     trol options. Two Georgia yarn manu-
                     facturing facilities—World  Carpets in
                     Dalton, GA,  a yarn and carpet manu-
                     facturing facility, and Diamond Mills in
                     Rome, GA, a yarn spinning  facility-
                     were  visited to collect the necessary
                     technical  information  to  identify the
                     nature of the heat set emissions and to
                     suggest possible  emission  control
                     strategies. During the  visits, informa-
                     tion on the yarn spinning and heat set-
                     ting operations was  gathered,  the
                     carpet  manufacturing process was
                     viewed, and  (with input from the plant
                     technical staff) opportunities were iden-
                     tified  for preventing and/or controlling
                     the heat setting emissions.
                       This Project Summary was developed
                     by EPA's Air and Energy Engineering
                     Research Laboratory, Research Triangle
                     Park,  NC, to announce key findings of
                     the research project that is fully docu-
                     mented in a separate report of the same
                     title (see Project Report ordering infor-
                     mation at back).

                     Introduction
                       The face fibers currently used  in pro-
                     cessing carpet yarn include nylon, polypro-
                     pylene (olefin), polyester, and wool, with
                     the first three accounting for all but 0.6%
                     of the face fibers used. These fibers may
                     be supplied to the yarn  plants either as
                     staple  fiber  (which  must be  blended,
                     carded,  drafted,  spun, wound, and heat
                     set) or  as bulked continuous filament
(which must be twisted, wound, and heat
set) prior to being shipped to  the carpet
manufacturing mills. The output of the car-
pet mills is tufted, knitted, needle punched,
felt, or braided carpet for both contract
and residential markets.
  During the production  of the fiber and
the processing of the yarn, several chemi-
cals (e.g., finishes and tints) are added TO
increase the fiber processability. It is pos-
sible that the elevated temperatures dur-
ing heat setting in either the Suessen or
Superba systems  release  these chemi-
cals, resulting  in significant visible emis-
sions. Additional potential emitted species
from heat setting operations include steam,
materials used to clean the heat set equip-
ment, and fiber degradation products or
unreacted monomer. At  the time of this
report, speciated stack test results identi-
fying the emissions resulting  from heat
setting operations were unavailable. How-
ever, industry efforts are currently under-
way to quantify the amount of caprolactam
released from the Suessen heat setting of
nylon 6.
  Without specific vent stream  character-
istics, it  is  difficult  to  accurately assess
heat  set emissions and to develop emis-
sion  control strategies. However,  based
on an initial review of the  heat set sys-
tems, only two possible control strategies
appear applicable:  condensation and ab-
sorption. Although the installation of a con-
denser would likely control emissions by
nearly 90%, it might also result in fouling
of the exchange media and contamination
(requiring further treatment) of the facility s
wastewater discharge to the publicly
owned treatment works (POTW). Installa-
                                                                       Printed on Recycled Paper

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tion of an absorber would result in a con-
trol efficiency  of 80 to  95%,  but  it  too
would potentially require additional treat-
ment of wastewater discharges. Initial data
suggest that the lowest cost control alter-
native is the absorber.
  More information is  needed before a
control device can  be recommended and
installed. This information would include
details of fiber production and processing,
fiber degradation products and/or residual
unreacted monomer, and applied finishes.
Such  information  may be  available from
fiber manufacturers (particularly those cur-
rently  investigating heat setting emissions),
trade associations, heat setting equipment
manufacturers, and local university textile
schools.
  B. McMinn and D. Ocamb are with  TRC Environmental Corp., Chapel Hill, NC
    27514.
  Chester A. Vogel is the EPA Project Officer (see below).
  The complete report, entitled "Initial Assessment of Emissions from Heat Setting
    Carpet Yam," (Order No. PB93-229862; Cost: $ 19.50; subject to change) will be
    available only from:
          National Technical Information Service
          5285 Port Royal Road
          Springfield, VA 22161
          Telephone: 703-487-4650
  The EPA Project Officer can be contacted at:
          Air and Energy Engineering Research Laboratory
          U.S. Environmental Protection Agency
          Research Triangle Park, NC 27711
                                                                                     *U.S. Government Printing Office: 1993 — 550-067/80119
United States
Environmental Protection Agency
Center for Environmental Research Information
Cincinnati, OH 45268

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EPA/600/SR-93/161

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