IN A WORLD OF SHORTCUTS, WE DON'T™
PTFE Strip Curtains
Non-Stick Strip Curtains for Coating Lines Where Silicone Contamination Ruins the Finish
PTFE strip curtains from Steel Guard Safety are built from two layers of fluorocarbon coated fiberglass with the coated face outward on both sides. They exist for one reason: silicone migrates, and in a paint or powder bake oven that migration shows up as fisheyes and craters in the finish. PTFE does not migrate.
This is not a hotter curtain than our standard build — both hold 500°F continuous. It is a different one, chosen when contamination, buildup, or cleanability is the failure you’re trying to prevent rather than heat. For the full material range, see our High Temperature Strip Curtains line.
The Silicone Problem
Silicone coated fiberglass is the default material for industrial heat curtains, and for good reason — it is durable, abrasion resistant, and inexpensive relative to alternatives. In most industrial settings it is the right choice.
In a coating environment it is a liability. Silicone migrates and outgasses, particularly at elevated temperature, and silicone contamination is one of the most common causes of fisheyes and craters in a cured finish. The defect appears downstream of the source, which makes it notoriously difficult to trace. A curtain hanging in the oven doorway is rarely the first place anyone looks.
Once silicone is in a coating line it is difficult to remove. It transfers to racks, hooks, conveyor components, and booth surfaces, and it persists through cleaning cycles. Most coating operations that have been through a silicone contamination episode enforce a strict no-silicone policy afterward, which is exactly the policy a silicone coated strip curtain violates.
What PTFE Does Instead
Our PTFE fabric is fluorocarbon impregnated through the weave and coated on the face. There is no silicone anywhere in the material, so there is nothing to migrate regardless of which way the curtain hangs or how hot the opening runs.
The surface does three further things that matter on a coating line:
- Releases. Overspray, resin, adhesive, plastisol, sugars, and cured powder do not build up on the surface the way they do on silicone or bare fabric.
- Cleans. What does accumulate wipes down rather than requiring solvent or replacement.
- Resists chemistry. PTFE is inert to essentially every industrial chemical, which matters at wash, pretreat, and e-coat stage transitions as much as in the oven itself.
Built as Two Layers
The PTFE fabric is light — 16.7 oz where our standard silicone build is 32 oz. A single layer hangs poorly: it billows in oven airflow, doesn’t recover position cleanly after someone pushes through, and doesn’t behave like a curtain your operators will accept.
We build it as two bonded layers instead, roughly 33 oz finished, which puts it in the same weight class as every other curtain we make. The coated face runs outward on both sides, so release performance is identical regardless of which way it hangs and regardless of which side the overspray comes from.
Where PTFE Strip Curtains Are Installed
Powder coat cure ovens. Both conveyor throats and batch oven doors. Cured powder does not bond to the surface, and no silicone reaches the part.
Paint bake ovens and spray booth transitions. Overspray settles on anything hanging in the opening. PTFE releases it; silicone holds it and adds a contamination risk on top.
E-coat, plating, and pretreat stage separation. Here the job is chemical rather than thermal — stopping alkaline cleaner from drifting into rinse, or phosphate into e-coat. Chemical inertness is what earns the material its place.
Adhesive and composite cure. Resin and adhesive that would permanently bond to a silicone face release from PTFE.
Screen printing and textile dryers. Plastisol ink is exactly what PTFE releases and silicone does not.
Clean-adjacent and low-particulate areas. The fabric is dimensionally stable and does not shed the way bare or lightly coated glass does.
Where Contamination Costs You
Every application below runs inside the HTS-3000’s 500°F range. What separates them is how much a contamination event actually costs when it happens.
| Process | What Goes Wrong | Cost of a Contamination Event | PTFE Priority |
|---|---|---|---|
| Automotive and appliance finish | Fisheyes, craters, rework | Strip and recoat, possible customer rejection | Critical |
| Powder coat, Class A finish | Craters, adhesion failure | Full batch rework | Critical |
| Paint bake, decorative | Fisheyes, orange peel | Rework, line downtime | High |
| E-coat and plating lines | Chemical carryover, adhesion defects | Bath contamination, batch loss | High |
| Adhesive and composite cure | Bond failure, resin buildup on curtain | Part scrap, curtain replacement | High |
| Screen print and textile | Ink transfer, plastisol buildup | Cleaning downtime | Moderate |
| Powder coat, functional finish | Cosmetic defects only | Usually acceptable | Moderate |
| General drying and curing | Nothing — no finish at risk | — | Low — use our standard build |
| Bakery and food processing | FDA compliance required | Regulatory | Requires food grade — contact us |
The pattern is straightforward: the more visible the finish and the more expensive the rework, the more a non-contaminating curtain is worth. On a functional coating where cosmetic defects are tolerated, our standard silicone build is more durable per dollar and the right choice.
Not Rated for Food Contact
The FCF-1650 material carries no FDA compliance. If you need FDA-compliant construction for a bakery, proofer, or food processing oven, we build those in a food-grade PTFE fabric — contact us with your application and operating temperature.
Additional Information:
Construction
- Two bonded layers of 16.7 oz PTFE coated fiberglass, coated face outward on both sides, roughly 33 oz finished
- Fluorocarbon impregnated through the weave, not just surface coated — no silicone anywhere in the assembly
- Stainless steel thread throughout. PTFE thread caps at 600°F and fiberglass thread at 500°F
- 1000°F E-glass base fabric, with the PTFE coating determining the service rating
- Grommets on 2″ centers, with universal galvanized mounting for face mount, eave, wall, or suspended installation
- Individual strips are replaceable — replace what wears rather than the whole curtain
- Built to any opening, from 3′ x 4′ batch oven doors and conveyor slots to openings 10′ wide and larger
Overlap and Strip Width
Almost every strip curtain overlap guide is written for thin PVC, and those numbers don’t transfer to coated fabric. At full overlap someone is pushing through two layers of heavy coated fiberglass. Grommets are punched on 2″ centers to match standard strip door mounting hardware, so every grommet mates with a mount hole and strip spacing is set on a 2″ grid. We build three configurations:
- Full overlap — 8″ strips with 2″ of overlap on each side. Complete double coverage and the best heat containment. Takes the most effort to push through.
- Mid overlap — 6″ strips with 1″ of overlap on each side. Same strip count and the same hardware as full overlap, using narrower strips. Noticeably easier to walk through, still a real barrier.
- Butt joint — no overlap, strips meet edge to edge. Lowest resistance and best visibility, right for continuous conveyor passthrough where drag would mark the finish.
Full and mid overlap use the same number of strips, so moving between them changes only the fabric width and the amount of coverage — the mounting hardware and strip count stay the same.
Contact one of our experienced sales reps at 1-800-347-8368 or request a quote online. Send us the opening dimensions, your operating temperature, and what passes through, and we’ll spec the build.
HTS-3000 Material Specifications
| Property | Value | Test Method |
|---|---|---|
| Base material | Fluorocarbon impregnated and coated fiberglass | — |
| Weave | Satin | — |
| Fabric weight, per layer | 16.7 oz/sq yd | ASTM D-3776 |
| Thickness, per layer | 0.017″ | ASTM D-1777 |
| Continuous service temperature | 500°F | — |
| Intermittent | 600°F | — |
| Low temperature limit | -150°F | — |
| Base fabric limit | 1000°F E-glass | — |
| Tensile strength, warp | 423 lbs/in | ASTM D-5034 |
| Tensile strength, fill | 308 lbs/in | ASTM D-5034 |
| Trapezoidal tear, warp and fill | 25 lbs | ASTM D-5587 |
| Flame resistance | UL 94 V-0 | UL 94 |
| Vertical flame, char length | 1″ maximum | ASTM D-6413 |
| Vertical flame, afterglow | 1 second | ASTM D-6413 |
| Vertical flame, flame out | 1 second | ASTM D-6413 |
| UV resistance | 1000 hours, no change in tensile | ASTM G-154 |
| Color | Gray | — |
| FDA food contact compliance | No — food grade available separately | — |
Assembly Rating
| Property | Value |
|---|---|
| Construction | Two bonded layers, coated face outward both sides |
| Finished weight | Approximately 33 oz/sq yd |
| Continuous service temperature | 500°F |
| Intermittent | 600°F |
| Limiting layer | PTFE coating |
| Silicone content | None |
| Chemical resistance | Resistant to most industrial chemicals |
The assembly is rated to its limiting layer. The E-glass substrate holds 1000°F, but PTFE begins to decompose above roughly 660°F and is not run continuously above 500°F, so that is the number the curtain carries. Manufacturer data sheets are available on request.
Curtain Construction
| Component | Specification |
|---|---|
| Thread | Stainless steel |
| Grommet spacing | 2″ centers |
| Strip widths | 6″ or 8″ |
| Overlap options | Full 50%, Mid 33%, or butt joint |
| Mounting hardware | Universal galvanized — face mount, eave, wall, or suspended |
| Maximum size | No limit — built to opening |
| Replacement strips | Available individually by width and length |
Material Composition Note
PTFE is a fluoropolymer and belongs to the PFAS family of compounds. Facilities operating under a PFAS reduction or elimination program should factor that into material selection. For applications where contamination control is the requirement but PTFE is not acceptable, contact us to discuss alternatives.
Because of what silicone does, not because of temperature — both materials hold 500°F continuous. Silicone migrates and outgasses, and silicone contamination is a leading cause of fisheyes and craters in cured finishes. If you run a coating line, a silicone coated curtain hanging in the oven doorway is a contamination source. PTFE contains no silicone, so there is nothing to migrate.
Effectively yes. Teflon is DuPont’s original brand name for polytetrafluoroethylene, now owned by Chemours. PTFE is the material itself, and it’s the term we use because our fabric comes from an industrial supplier rather than under that brand.
Silicone migrates from the coated fabric at elevated temperature and transfers to whatever it contacts — parts, racks, hooks, conveyor components, booth surfaces. The defect shows up downstream in the cured finish, which makes it difficult to trace back to the source. A curtain in the oven doorway is rarely the first thing anyone suspects.
Yes. We build the curtain as two bonded layers with the coated face outward on both sides, so release performance is the same regardless of which way it hangs or which side sees the overspray. The fabric is also fluorocarbon impregnated through the weave rather than only surface coated.
Weight. A single layer of PTFE fabric is 16.7 oz where our standard silicone build is 32 oz. At that weight a strip billows in oven airflow, doesn’t recover position after someone pushes through, and doesn’t behave like a curtain operators will accept. Doubling brings it to roughly 33 oz, in line with every other curtain we make.
Not this material. FCF-1650 carries no FDA compliance. We build FDA-compliant strip curtains in a food-grade PTFE fabric — contact us with your application and operating temperature.
500°F continuous and 600°F intermittent, on a 1000°F E-glass base fabric. PTFE begins to decompose above roughly 660°F, and decomposition products are hazardous, so this is a real ceiling rather than a conservative derate. Do not specify PTFE for any opening where the curtain face could exceed 600°F.
Far less often than silicone or bare fabric, and when it does, it wipes down. Overspray, resin, adhesive, plastisol, and cured powder release from the surface rather than building up. That is a significant part of the value on a high-overspray line — cleaning time is downtime.
PTFE is inert to essentially every industrial chemical, which is why the material also works at wash, pretreat, and e-coat stage transitions where the job is stopping chemical carryover rather than containing heat.
Yes. PTFE is a fluoropolymer within the PFAS family. Facilities operating under a PFAS reduction program should factor that into material selection, and we’d rather you know before ordering than after. Contact us if contamination control is the requirement but PTFE is not acceptable.
Stainless steel throughout. PTFE thread caps at 600°F and fiberglass thread at 500°F, which would put the thread at the same limit as the fabric.
Yes. Order by strip width and length. Strips wear at different rates depending on position in the opening, so replacing the few that have degraded beats replacing the whole curtain.
Any opening. We regularly build 3′ x 4′ batch oven doors and conveyor slots as well as openings 10′ wide and larger. Every curtain is made to your dimensions in our own facility.
