PERMIT MEMORANDUM NO. 2007-006-TVR DRAFT 18
OKLAHOMA DEPARTMENT OF ENVIRONMENTAL QUALITY
AIR QUALITY DIVISION
MEMORANDUM December 19, 2007
TO: Phillip Fielder, P.E., Permits and Engineering Group Manager
THROUGH: Matt Paque, Supervising Attorney
THROUGH: Kendal Stegmann, Sr. Environmental Manager, Compliance and Enforcement
THROUGH: Richard Kienlen, P.E., Engr. Mgr. II, New Source Permits Unit
THROUGH: Herb Neumann, P.E., Regional Office at Tulsa
THROUGH: David Pollard, P.E., Regional Office at Tulsa
FROM: Harold Wright, Regional Office at Tulsa
SUBJECT: Evaluation of Permit Application No. 2007-006-TVR
Therma-Tru Corp.
Insulated Entry Door Systems Facility
NW ¼, SW ¼, Section 23, T11N, R26E (Lat. 35.415º, Long. 94.526º)
601 Paw Paw Road
Roland, Sequoyah County, Oklahoma
SECTION I. INTRODUCTION
Therma-Tru Corporation constructed a new plant near Roland, Oklahoma, in 2000 for production of insulated doors for residential and commercial applications, was issued Title V Permit No. 2000-009-TV in September of 2002, and has requested a renewal. The glue used on the Wood Prep/Lay Up Line has been changed, and the service on the cyclone serving Emission Point SN-08 from dust control to vacuum use has been changed to recover cardboard and Styrofoam strips from this line. These two minor modifications were authorized by Permit No. 2000-009-TV (M-1) issued July 14, 2006. Therma-Tru added a physical expansion (significant modification) to produce fiberglass door “skins” with Permit No. 2000-009-C (M-2) issued March 20, 2006. Prior to that date, fiberglass skins had been imported from a sister plant in Butler, Indiana. The plant’s SIC Code is 3442 and the primary activity at the Roland plant is the assembly and painting of insulated steel and fiberglass entry doors. This renewal Permit No. 2007-006-TVR includes the previous minor modifications and construction of the significant modification to produce fiberglass door skins. Permit No. 2000-009-C (M-2) has exceeded 18 months, and any remaining modifications on this permit that have not been started will be required to abide by the extension granted by DEQ on November 1, 2007, to continue with Permit No. 2000-009-C (M-2).
SECTION II. PROCESS DESCRIPTION
Steel Door Assembly Operations
Door skins (stamped sheet metal) are fed into a roll former, turning up the outside edges. Wood, composite and laminated stiles (side edges) and top and bottom rails receive a strip of contact adhesive, and then the door skins are sent to an oven to cure the adhesive. The frame and door skins are then mated to produce a hollow core framework. Next, doors are sent to the foaming line, where the interior cores of the doors are filled with urethane foam, for purposes of insulation, via previously drilled holes in bottom rails. The assembled doors are then machined to meet sizing specifications. The doors are then hung from an overhead conveyor and sent to a coating booth, where they are coated with a white topcoat primer by automatic rotating nozzles. Upon leaving the coating booth, the doors enter a flash-off and curing oven and are baked to dry the topcoat primer. After the topcoat primer is dried, the doors are ready for packaging and are shipped or warehoused.
Fiberglass Door Assembly Operations
Fiberglass doors are assembled from fiberglass skins, wooden, composite or laminated stiles and contact adhesive. The fiberglass skins do not pass through the roll former prior to assembly of the hollow core framework. In addition, fiberglass skins do not receive an application of topcoat primer.
Additional Operations
The facility also produces pre-assembled door and frame assemblies for new residential/commercial construction. Frames are assembled on-site from lumber. Some of these doors are fitted with glass panes (e.g., double pre-hung patio doors), requiring cutting of doors to accommodate glass installation. The principal air pollutant generated by these additional operations is particulate matter from cutting wooden framing and doors.
This permit is for maximum operation of 24 hours per day, 7 days per week, 52 weeks per year, for a maximum of 8,760 hours per year. Therma-Tru has the capacity to manufacture 1,200 doors per hour per line at maximum operating conditions. Doors range from 50 to 150 pounds, depending on the materials of construction.
In addition to wood and metal, raw materials used are paints, primers, foam products, and glues. Material Safety Data Sheets (MSDS) for these are included with the permit application.
Maximum application rates are 50 gallons per hour of white primer for the paint line.
Doors that fail Quality Control inspections are removed to a separate location within the plant where they are repaired and/or repainted to specification. Air pollutants generated include particulates and Volatile Organic Compounds (VOC) from repainting.
Fiberglass Door Skin Production in the New Plant Addition
In 2006, Therma-Tru submitted an application for a significant modification to Title V Permit No. 2000-009-TV for an addition to the facility and future installation of ten fiberglass mold presses. The resulting Construction Permit No. 2000-009-C (M-2) was issued on March 20, 2006. Four presses have been installed and are operational. This permit authorized 18 months to construct the addition, including the 10 presses, and since construction had commenced and then stopped, an extension of the permit was granted by DEQ on November 1, 2007. The Company stamps fiberglass skins on-site from its own proprietary blends of fiberglass.
The fiberglass door production operation in the new addition is described in greater detail by the five steps below.
1. Material Receiving Area
All incoming materials and goods for production of fiberglass door skins arrive in this central area. All incoming Sheet Molding Compound (SMC) material arrives on refrigerated trucks to prevent material spoilage. Upon receipt at Roland, all containers are visually inspected for defects, retains are collected and stored and quality audits will be conducted. Samples of the material are tested to verify that the viscosity is within parameters.
2. Material Storage
Upon receiving and initial inspection, all incoming SMC material is moved to the Maturation Room to age. The Maturation Room is comprised of two separate areas; Area I is central storage and Area II is for warm-up of material prior to use. The Maturation Room (Area I) is an environmentally controlled space with a design temperature of 45-55 degrees F. The different recipes of SMC are stored here until needed by production. Under these conditions, the material can be stored for up to 30 days. When necessary, the bins of SMC material will be moved to Maturation Room Area II to warm up to process temperature. This area is an environmentally controlled space, with a design temperature of 65-75 degrees F. The material remains in this room for 24-28 hours prior to use.
3. Press Operations
Based upon production scheduling, the appropriate recipe of material is taken from the Maturation Room to the appropriate press. The material is drawn from the shipping container onto the cutting table, where the width and length is shot. The shot is then loaded onto the press and the cycle started. Upon completion of the cycle, the newly created fiberglass sheet is removed from the press and staged on the deflash table. All excess material (flash) is removed from the skin. All flash material is collected into a central vacuum and dust collection system for proper containment and disposal. As each sheet is deflashed, it is stacked on the printed label stack with any necessary dunnage between the sheets (usually cardboard strips attached to styrofoam blocks).
4. Cutdown Operations
If the skins require resizing for any reason, they are moved to the cutdown saw station where they are resized according to production needs. All dust and scraps created from this processing step are collected through the use of filter banks and a vacuum/dust collection system. The exhaust from this processing step vents through new Donaldson Torit filter booths, which are enclosed units that discharge to the plant interior. Filters are cleaned by pulsed compressed air at the end of each shift. Dust bins (two per machine) are periodically emptied.
5. Storage for Door Plant Use
Upon the completion of all skin manufacturing steps, the fiberglass door skins are moved into storage bays within the existing door plant.
A total of 17 roof-mounted fans remove fugitive press VOC emissions from the press room. These roof fans are collectively identified as emission point SN-14. The door plant is currently permitted as a Title V facility on the basis of HAP emissions from coating and gluing operations. The proposed presses will generate a maximum of 58.83 additional tons of VOC and HAP (styrene) emissions annually.
In addition to the process operations described above, the facility uses a maximum of 660 gallons per year (gpy) of mineral spirits mold release annually. Insignificant VOC emissions (2.33 TPY) result from this product.
A small (insignificant source) 165 MBTUH gas flame treater has been installed in the fiberglass door assembly area. The “gas flame treater” is a small natural gas device used to heat up the fiberglass skins to open up the porosity and let the PUR (polyurethane resin) adhesive glue provide better adhesion between the skin and the stile of the door put on further down the line.
SECTION III. EQUIPMENT
EU ID # EU-06, and its Point ID # SN-08 are deleted due to previous modifications.
SN-03 and SN-04 represent two exhaust fans on one paint booth.
EUG #1 – Facility-Wide
EU ID #
/ POINT ID # / EU Name/Model /Construction/
Modification DateEU-01
/SN-02
/Foam Machine
/2000
EU-01
/SN-10
/Foam Machine
/2000
EU-02
/SN-03
/Paint Coater Exhaust Fan
/2000
EU-02
/SN-04
/Paint Coater Exhaust Fan
/2000
EU-03
/SN-05
/Flash-Off & Drying Oven
/2000
EU-04
/SN-06
/Steel Door Sizing Machine
/2000
EU-05
/SN-09
/Fiberglass Door Sizing Machine
/2000
EU-05
/SN-07
/Door Component Fabrication
/2000
EU-07
/SN-13
/Off-Line Door Cut-Out Area
/2001
EU-08
/SN-11
/Steel Door Line Curing Oven (removed)
/2000
EU-08
/SN-12
/ Fiberglass Door Line Curing Oven (removed) /2000
EU-09
/SN-14 *
/Fiberglass Mold Presses (4 currently)
/2006
* Permit No. 2000-009-C (M-2) authorized ten (10) presses, if needed.
EUG # 2 Door AssemblyEU ID #
/ POINT ID # / EU Name/Model /Construction/Modification
DateEU-04 / SN-06 / Steel Door Sizing Machine / 2000
EU-04 / SN-09 / Fiberglass Door Sizing Machine / 2000
EU-05 / SN-07 / Door Component Fabrication / 2000
EU-07 / SN-13 / Offline Door Cut-Out Area / 2001
EUG # 3 Foam Machines
EU ID #
/ POINT ID # / EU Name/Model /Construction/Modification
DateEU-01 / SN-02 / Foam Machine / 2000
EU-01 / SN-10 / Foam Machine / 2000
EUG # 4 Coater (one Paint Booth with two exhaust fans)
EU ID #
/ POINT ID # / EU Name/Model /Construction/Modification
DateEU-02 / SN-03 / Paint Coater Exhaust Fan / 2000
EU-02 / SN-04 / Paint Coater Exhaust Fan / 2000
EUG #5 Combustion Unit
EU ID #
/ POINT ID # / EU Name/Model /Construction/Modification
DateEU-03 / SN-05 / Flash-Off Drying Oven / 2000
EUG # 6 New Electric Units
EU-ID # / Point ID # / EU Name/Model / Const/Mod Date / Serial No.
PR-1 / SN-14 / Mold Press No. 1 / 2006 / 2006628-PPM2500-1
PR-2 / SN-14 / Mold Press No. 2 / 2006 / 2006628-PPM2500-2
PR-3 / SN-14 / Mold Press No. 3 / 2006 / 2006628-PPM2500-3
PR-4 / SN-14 / Mold Press No. 4 / 2006 / 2006628-PPM2500-4
Emission Stack Parameters
EmissionPoint / Source Emission Point Data / Diameter
(inches) / Ht. above ground
(feet) / Flow Rate
(CFM) / Temp
(oF)
SN-02 / STL Line Foam Machine / 30.5 / 28 / NA / Amb.
SN-03 / STL Paint Line Coater Exhaust / 19.5x19.5 / 29 / 1,500 / Amb.
SN-04 / STL Paint Line Coater Exhaust / 19.5x19.5 / 29 / 1,500 / Amb.
SN-05 / STL Paint Line Drying Oven / 28 x 28 / 30 / 6,000 / 150oF
SN-06 / STL Door Machine Sizer / 36 / 18 / 30,000 / Amb.
SN-07 / Door Component Fabrication Area / 18 / 15 / 9,000 / Amb.
SN-08 / Wood-Prep Glue/Lay-up Lines / 30 / 35 / 8,000 / Amb.
SN-09 / FG Door Machine Sizer / 45 / 20 / 38,000 / Amb.
SN-10 / FG Line Foam Machine / 36 / 37 / 18,000 / Amb.
SN-11 / STL LUL Glue Dry Oven (removed) / 16 x 24 / 30 / 7,000 / 120oF
SN-12 / FG LUL Glue Dry Oven (removed) / 25 / 35 / 8,500 / 120oF
SN-13 / Off-line Cut-out Area / 46 x 92 / 9 / 14,000 / Amb.
SECTION IV. AIR EMISSIONS
The principal air pollutants resulting from automated door manufacturing operations conducted at this facility are particulates from cutting and drilling lumber, and VOCs from glue adhesive, urethane foam, white topcoat primer, fiberglass mold press (door skins) operation, and combustion by-products from one natural gas-fired oven (EU-03). Estimated maximum potential emissions of 2-Butoxyethanol were estimated at 10.95 TPY in the original Title V Operating Permit. The new glue emits an insignificant amount of methylene bisphenyl diisocyanate (MDI) annually. Methylene diphenyl diisocyanate (MDI) and methylenebis (phenylisocyanate) (MBI) are apparently chemical synonyms for the same compound with a CAS No. of 101-68-8. The product is a HAP under either name. MDI is a constituent of the replacement glue that Therma-Tru uses. The MDI replaces the 2-Butoxyethanol in the previous glue used at SN-08. To avoid a potential future emission exceedance, Therma-Tru will move these 10.95 TPY of VOCs to the Paint Line, which has two exhaust fans, SN-03 and SN-04.