Multi-Zone Foam Gasket Outgassing Oven for Insulating Glass Foam Spacer / Gasket Processing

The customer process requirement was to thermally precondition foam gasket material used in multi-pane insulating-glass windows so that trapped VOCs would be removed before the gasket was installed in the finished window assembly. This was fundamentally a downstream product-quality protection step: if the foam later outgassed inside a sealed window cavity, the glazing unit could haze or fog in the field, potentially forcing costly window replacement at the gasket supplier's expense.

APPLICATION & PRODUCT TYPE

• Product: continuous foam gasket wound onto large steel carts with multiple reel layers. Foam section approximately 3/4 in. wide by 1/4 in. thick, with hundreds of feet of material per cart.
• Process: thermal outgassing of VOCs retained from upstream salt-bath foam manufacturing. Required prior to final insulating-glass assembly to prevent window cavity fogging in the field.
• Each cart assembly weighed approximately 2,000 lb with ~95–98% of that mass attributed to the steel cart structure rather than the foam itself.

THROUGHPUT / PRODUCTION RATE REQUIREMENT

• Production target: one cart every 30 minutes.
• Carts loaded by pallet jack and transferred automatically into the system through powered transfer mechanisms.
• Cart reel length approximately 66 to 66.5 in.; load/push station sized at approximately 66.5 in. to support side loading and indexed transfer.

HANDLING / CONVEYING REQUIREMENT

• System could not rely on pit-mounted handling equipment; required above-floor automated indexing architecture.
• Equipment had to be testable at Precision Quincy's own facility before delivery.

UTILITY / BUILDING CONSTRAINTS

• Limited available make-up air in the customer's building — all combustion air for burner blower systems must be drawn from outside, routed through filtered intake above the oven.

SERVICEABILITY REQUIREMENT

• Customer required heat exchangers to be highly visible and easy to service — led to slide-out side-service arrangement allowing exchanger access and removal without major disassembly.
• Limited available ceiling height at installation constrained upper heat chamber packaging.

SAFETY / COMPLIANCE REQUIREMENT

• NFPA 86 Class A compliance required. Explosion relief incorporated into the door system.
• Process involves heated VOC-laden foam product; exhaust ventilation designed to safely remove released vapors.

The thermal process requirement was to raise the loaded carts and wound foam gasket material to outgassing temperature quickly enough to support the required production rate, then hold the product at temperature long enough to drive off retained VOCs. Because the overwhelming majority of the thermal mass was the steel cart structure, the process required front-loaded heating capacity — with the first station delivering the most aggressive heat-up and the remaining stations maintaining soak conditions.

TEMPERATURE REQUIREMENTS

• Oven operating temperature: 410°F. Maximum temperature capability: 425°F.
• Actual foam product — not just chamber air — required to reach at least 380°F.

PROCESS VALIDATION BASIS

• Total required oven time: 120 minutes. Foam must remain at or above 380°F for at least 90 of those minutes.
• Validation based on approximately 15–20 embedded thermocouples placed directly in the foam at multiple locations throughout the cart load.
• After 17 minutes of heat-up, embedded foam thermocouples may not exceed a 50°F spread. After 50 minutes / at-process condition, the spread must be within 20°F.

AIRFLOW DELIVERY REQUIREMENTS

• Zone 1 total recirculation: ~13,700 CFM; aggressive mixed-direction airflow — ~1,100 FPM vertical-up (bottom), ~1,100 FPM vertical-down (top), ~4,000 FPM side nozzles, plus air-knife at door/cart gap.
• Zones 2–5: ~10,250 CFM each; 2 in. round nozzles at ~4,000 FPM biased toward cart center and between reel layers.

HEAT INPUT REQUIREMENTS

• Zone 1: Eclipse IJ3 remote-blower indirect gas heating — 850,000 BTU/hr input.
• Zones 2, 3, 4: Eclipse IJ3 package-burner indirect gas heating — 550,000 BTU/hr input each.
• Zone 5: Eclipse IJ3 remote-blower indirect gas heating — 850,000 BTU/hr input.
• Total installed heat input: 4,150,000 BTU/hr.

EXHAUST REQUIREMENTS

• Process exhaust: 2,000 CFM total (400 CFM per zone) for VOC vapor removal during heating.
• End-hood exhaust: New York Blower 15 hood fan rated 3,000 CFM — alternates extraction between ends based on door-open condition; runs only during door-opening events.

To deliver the required outgassing cycle without pit-mounted conveying, Precision Quincy developed a multi-section automated cart-handling architecture consisting of an infeed conveyor, a heated middle conveyor spanning the five heated stations, and an outfeed conveyor. Although the system functionally served as one indexed transport path, the conveying hardware was separated into three mechanically independent servo-driven conveyor sections — because continuous through-shaft arrangements would have interfered with the cart wheel path and because the indexed spacing had to be collapsed within the oven body.

OVERALL CONCEPT

• Five-station, single-path conveyorized batch-indexing oven with automated infeed, heated middle, and outfeed conveyor sections.
• Above-floor pit-free cart handling architecture; carts side-loaded via pallet jack and transferred automatically through the indexed conveyor sequence.
• Equipment designed for full pre-shipment testing at Precision Quincy's facility.

HEATING ARCHITECTURE

• All zones: Eclipse IJ3 indirect natural gas heat exchangers with external combustion air drawn from above the oven through a filtered outside-air intake system.
• Zone 1 and Zone 5: remote-blower burner arrangements at 850,000 BTU/hr input each. Zones 2, 3, 4: package-burner arrangements at 550,000 BTU/hr input each.
• Heat exchangers designed for high visibility and slide-out side-service access — each exchanger can be withdrawn from the oven for inspection or removal without major disassembly, using a support rail positioned in front of the zone.

AIRFLOW / DUCT ARCHITECTURE

• Zone 1: aggressive mixed-direction airflow with bottom, top, and side ducting plus an air-knife concept at the door/cart gap — generating ~1,100 FPM vertical-up, ~1,100 FPM vertical-down, and ~4,000 FPM side nozzle discharge.
• Zones 2–5: lower-airflow heated holding with 2 in. round nozzles at ~4,000 FPM biased toward cart center and through reel layers.
• Recirculation duct attached directly to each zone's access door so the duct moves with the door when opened — improving service access and integrating explosion relief into the door system.

CONVEYOR / CART HANDLING CONCEPT

• Three separate servo-driven conveyor sections: 86.25 in. infeed, 204.5 in. heated middle, 124 in. outfeed. Total conveyor length: 437.75 in.
• Independent left/right drives on each conveyor side due to cart wheel path constraints.
• Side-loaded by pallet jack onto engineering chain, then transferred by pusher/extractor arm into indexed sequence; carts discharge off outfeed conveyor onto wheels for pallet-jack removal.
• Approximately 2,000 lb per cart load capacity.

SHELL / CONSTRUCTION ARCHITECTURE

• Structural steel frame; 16 ga aluminized formed interior pans configured for thermal expansion and contraction; 6 in. thick 6 lb density mineral wool insulation; exterior skins with two-part epoxy blue finish.
• Interior construction in pressurized zones sealed to maintain airflow control and thermal containment.
• Each heated zone has a door on each end; explosion relief integrated into door system.

EXHAUST / VENTILATION ARCHITECTURE

• Process exhaust: New York Blower 15 GP fan — 2,000 CFM at 3 in. w.c., 2 HP motor.
• End-hood exhaust: New York Blower 15 hood fan — 3,000 CFM; alternates extraction end based on which doors are open; only operates during door-opening events to minimize building air removal.

CONTROLS ARCHITECTURE

• Allen-Bradley CompactLogix PLC with Allen-Bradley servo drives for all conveyor sections.
• Remote-mounted NEMA 12 control enclosure. Dungs-related flame-safety hardware with Honeywell actuators.
• Zoned burner control plus alternating hood exhaust logic integrated in controls.