The spec, the annealing story, the near-isotropic design advantage, and where PET-GF actually wins · cross-checked against the manufacturer's TDS V1.0, written by the team that prints it.
PET-GF glass fibre 3D printing service · UK · quoted in 6 hours.
Stable through humidity, in six colours · the only colour-capable engineering composite we ship.
Four quick visuals. Start with which material to pick and where PET-GF works; the engineering detail is at the end if you want it.
Multi-colour engineering parts · near-isotropic load paths · enclosures and brackets where Z-direction performance matters · humid-service fixtures · functional prototypes that need to look finished
PET's repeating aromatic ring plus ester linkage is the same backbone behind PET drinks bottles. Far fewer water-attackable sites than nylon amide chains · 0.32% equilibrium water absorption (the lowest in our range). Glass fibre aligns with extrusion but gives more isotropic load transfer than carbon fibre · 1.24× XY/Z anisotropy.
1.24× tensile XY/Z (59.9 / 48.2 MPa) · the lowest of any commodity CF/GF composite we ship. Glass fibres transfer Z-axis load through the matrix more effectively than carbon fibres, and the 15% loading is gentle enough to keep matrix continuity. Z direction is only 20% weaker than XY.
"James handled the 3D printing for a functional heat resistant component we needed in batch production. He helped dial in the prototype first with their design service, then produced the final batch with really consistent results. Super fast 3D print turnaround and great quality across all the 3D printed parts. Will 100% be coming back."
"We needed a sit-in F1-car for an exhibition to showcase our new racing game. 3D Printing Express took our CAD, optimised it for strength and weight as we had no idea how it all worked! Turned out beautifully. They colour matched the finish and was looking like the real deal. On show day the cockpit ran non-stop, adults and kids jumped in. Multiple visitors asked who built it."
"We ordered a batch of 100 PA-12 parts from 3D Printing Express and could not be happier. Every part arrived consistent, dimensionally accurate, and ready for use straight from the box. The PA-12 gave us the strength and stability we needed for functional testing, with minimal post-processing required. Delivery was on time, communication was excellent, and their QC clearly made a difference."
Lowest of any commodity engineering composite we ship · 16% less directional than PA12-CF (1.48×), nearly half PET-CF (2.36×). Near-isotropic load transfer.
Lowest in our entire range · drier than PET-CF (0.53%), PA12-CF (1.5%), PA612-CF (2.2%), PA6-GF (3.33%). Holds dimensions across humidity cycles indefinitely.
Rises from 81.6°C as-printed to 133.7°C post-anneal · the phase change from amorphous to semi-crystalline PET. HDT 1.8 MPa is 71.8°C → 87.3°C. Anneal optional below 80°C service.
25% stiffer than PA12-CF (3311), 80% the stiffness of PET-CF (5481), 18% less than PA612-CF (5137). Balanced engineering stiffness without the brittleness of higher CF loadings.
The use cases where PET-GF earns its place · stiffness-critical engineering fixtures, dimensional stability through humidity cycles, hydrocarbon-resistant chemistry, and a printable lead time when CNC or moulding can't justify the cost.
Engineering materials are bought on what they can do · sold on what they can't. Pick a different filament if any of these apply to your part.
Six colour options + glass-fibre matt finish gives a working prototype that looks like a production part. Where PET-CF and PA-CF are matt black only, PET-GF is the colour-flexible engineering composite. Same engineering chemistry, brand-matched colour.
PET's dielectric strength (16-20 kV/mm) plus 133.7°C HDT plus humidity-stable dimensions match the OEM standard for automotive PET/PBT connectors. The 15% GF is itself an insulator · non-conductive across the service envelope.
Workshop jigs that live through 30-80% RH UK seasonal cycles. PET-GF at 0.32% water absorption holds dimensions year-round where PA-CF nylons swell 0.5-1%. Near-isotropic strength simplifies orientation decisions for complex clamping geometry.
For low-to-medium-volume consumer products where engineering performance and brand colour both matter. PET-GF matches the OEM colour palette and chemistry envelope that injection-moulded PET-GF parts already use across appliance and consumer electronics housings.
A side-by-side of the three commodity engineering composites most engineers compare against PET-GF. PET-CF wins on peak stiffness and HDT; PA12-CF wins on impact toughness; PET-GF wins on water absorption, near-isotropy, and colour flexibility.
PET-GF values from the manufacturer's PET-GF15 TDS V1.0 (ISO 527, ISO 75, ISO 178, ISO 1183 · post-anneal 120°C / 16h). PET-CF values from PET-CF17 TDS V1.0 (post-anneal 120°C / 10h); PA12-CF values from PA12-CF10 TDS. Cost reflects typical UK 2026 filament pricing.
| Property | PET-GF (here) | PET-CF | PA12-CF |
|---|---|---|---|
| Base polymer | Semi-crystalline PET | Semi-crystalline PET | PA12 (long-chain nylon) |
| Reinforcement | 15% glass fibre | 17% carbon fibre | 10% carbon fibre |
| Tensile strength XY (annealed) | 59.9 MPa | 65.9 MPa | 77 MPa |
| Stiffness (Young's modulus XY) | 4144 MPa | 5481 MPa | 3311 MPa |
| Heat deflection (HDT 0.45, annealed) | 133.7°C | 147.5°C | 131°C |
| Heat deflection (HDT 1.8, annealed) | 87.3°C | 105°C | 105°C |
| Charpy notched impact XY | 8.7 kJ/m² | 5.1 kJ/m² | 9.9 kJ/m² |
| Charpy unnotched Z | 13.9 kJ/m² | 3.1 kJ/m² | ~5 kJ/m² |
| Anisotropy XY / Z (tensile) | 1.24× | 2.36× | 1.48× |
| Equilibrium water absorption | 0.32% | 0.53% | ~1.5% |
| Density | 1.43 g/cm³ | 1.34 g/cm³ | 1.06 g/cm³ |
| Colour options | 6 colours | Matt black only | Matt black only |
| Heated chamber required? | No · 70-80°C bed | No · 70-80°C bed | Preferred |
| Post-print anneal | 120°C / 16h · optional below 80°C service | 120°C / 10h · mandatory | Optional (stress relief only) |
| Cost per kg (filament) | £45-85 | £50-100 | £90-130 |
| Best for | Multi-colour functional parts, near-isotropic load paths, humid-service fixtures | Peak stiffness and HDT in PET family, dimensional fixtures | Impact-loaded brackets, snap-fits, drone arms |
The other common engineering-composite process decision. SLS is a different machine entirely · different base polymer, near-isotropic strength, different cost structure. Pick the row that matches your job.
| Property | FDM PET-GF (here) | SLS PA12 (powder-bed) |
|---|---|---|
| Process | Filament extrusion, layer-by-layer · post-print anneal optional | Powder-bed, laser-sintered |
| Stiffness (Young's modulus XY) | 4144 MPa | 1700 MPa |
| Tensile strength XY | 59.9 MPa | 48 MPa |
| Anisotropy XY/Z | 1.24× | ~1.1× (near-isotropic) |
| Elongation at break | 4.0% | ~20% (ductile) |
| HDT @ 0.45 MPa | 133.7°C (annealed) | 163°C |
| Water absorption | 0.32% | ~1.5% |
| Colour options | 6 colours | Limited (typically grey/black + colourable powder) |
| Surface finish · as printed | Layer lines visible · sand or paint for smooth | Matt powder-grain finish, uniform |
| Min wall thickness | 1.5 mm structural | 0.7 mm achievable |
| Internal channels / lattices | Limited (support material) | Excellent (powder is the support) |
| Per-part cost · 1-off | Lower | Higher (machine + powder cost) |
| Per-part cost · batch of 100 | Comparable | Lower (efficient bed packing) |
| Best for | Multi-colour engineering parts, near-isotropic load paths, humid-service fixtures, lower lead time | Complex geometry, lattices, near-isotropic strength, batch-of-50+, food-contact certified grades |
This is 3DPE's standard process for PET-GF · the equipment and the dried-filament discipline are included, no surcharge. Slicer profile and orientation are tuned per part at quote stage.
File or sketch in. We confirm material, orientation, finish, target HDT.
Engineer reviewed. Lead time + per-unit cost back inside 24 hours.
Wall thickness, XY-load-path orientation, anneal-shrinkage compensation flagged before print.
Filament dried 100°C / 10h pre-print. 70-80°C bed. Hardened steel nozzle. ISO-spec adherence.
120°C / 16h anneal optional below 80°C service, required above. Sand or 2K paint to spec.
Tracked UK courier, tracking number sent the moment it leaves.
Drying adds 10 hours and annealing adds 18 hours (10h dwell + slow cooldown) to any of the above. Lead times start when CAD is signed off · CAD round-trips on rev requests can extend the clock.
Low-volume product enclosure run for a consumer electronics client. PET-GF gave engineering-grade stiffness (4144 MPa Young's modulus) in the client's brand red without secondary painting · paint-quality consistency saved against the previous unfilled-PETG route. 1.24× anisotropy meant orientation didn't have to be optimised in every direction for the variable-geometry shell.
PET-GF is 15% glass-fibre-reinforced polyethylene terephthalate · a semi-crystalline aromatic polyester filament reinforced with chopped glass fibre. The base PET polymer is the same chemistry behind PET drinks bottles and polyester fibre · the rigid aromatic ring and ester linkage backbone give PET dimensional stability and chemical resistance with very low moisture absorption (0.32% equilibrium · second only to PPS-CF at 0.225%). Glass-fibre at 15 wt% delivers 59.9 MPa tensile XY (annealed), 4144 MPa Young's modulus, and 133.7°C HDT at 0.45 MPa annealed (81.6°C as-printed). The defining wedge is 1.24× XY/Z anisotropy · the LOWEST in our composite range and approaching near-isotropic strength. Two property states are useful: as-printed PET-GF for service below 80°C (HDT 81.6°C @ 0.45 MPa); post-anneal at 120°C / 16h for service above 80°C (HDT 133.7°C). Six colour options · the only colour-flexible engineering composite we ship.
"PET-GF is the composite I reach for when a customer wants something stiffer than PETG, but in a real colour and without going matt black. The 1.24× anisotropy is the lowest we ship · for parts where the load path isn't a single clear vector, PET-GF doesn't punish you the way PET-CF does. Near-zero moisture · 0.32% water absorption against PA-CF nylons at 1.5-3.5% (only PPS-CF is drier). And the anneal is optional below 80°C service, which is faster than the PA-CF or PET-CF workflow. The trade is mechanical · PET-CF is stiffer and PA12-CF is tougher. If colour, near-isotropy, and lower lead time matter more, PET-GF earns its place."
Three questions every engineer Googles when picking PET-GF · the PET polymer chemistry, why annealing matters more than for nylons, and what the 1.24× anisotropy means in design.
PET starts amorphous off the print bed · HDT 81.6°C @ 0.45 MPa, useful for parts in service below 80°C. The 120°C / 16h anneal converts the polymer to semi-crystalline · HDT rises to 133.7°C. Unique among our CF/GF composites · the only one where both states are explicitly published and usable. PET-GF gives you the choice of speed (skip anneal) or thermal envelope (anneal).
15% chopped glass fibre (~80-200 micron length) aligns along extrusion direction. The 1.24× XY/Z anisotropy is the LOWEST in our composite range because glass fibre is shorter and stiffer in compression than carbon fibre, and the lower 15% loading lets the PET matrix transfer Z-axis load more effectively. Z direction holds 80% of XY strength · near-isotropic in practice.
PET's polar ester linkages absorb far less water than nylon amide groups. PET-GF is even drier than PET-CF (0.53%) and 5× drier than PA12-CF (1.5%), 7× drier than PA612-CF (2.2%), 10× drier than PA6-GF (3.33%). Dimensional stability holds indefinitely through UK humidity cycles.
Polyethylene terephthalate (PET) is a semi-crystalline aromatic polyester produced by condensation of ethylene glycol with terephthalic acid. The repeating unit contains a rigid aromatic ring connected through ester linkages · the same structural rigidity that makes PET films and bottles hold shape so well. PET sits in a different polymer family from the engineering nylons (which are polyamides) · the polar ester linkage absorbs far less water than the hydrogen-bonded amide linkage in nylon.
The commercial pedigree is everywhere. PET is the polymer behind drinks bottles, polyester fibre (from clothing to ropes), packaging films, and automotive engineering connectors (PET/PBT family is the OEM standard for electrical connectors). The same hydrocarbon resistance and dimensional stability carries through to the FDM-printed grade · engineering fixtures, electrical insulators, and metrology mounts inherit the chemistry's pedigree.
PET exists in two states that matter for 3D printing. Amorphous PET is transparent or opaque, lower stiffness, formed when the polymer cools too fast for crystallites to form · this is the state PET takes coming off a standard FDM nozzle. Amorphous PET has useful printability and decent mechanical properties (HDT 81.6°C @ 0.45 MPa, useful for parts at service ≤80°C). Semi-crystalline PET is opaque, higher stiffness, higher HDT, higher chemical resistance · reached when cooled slowly through the crystallisation window (~120-200°C) or when annealed.
PET-GF is the only commodity composite in our range that the manufacturer explicitly publishes BOTH states for · 81.6°C HDT 0.45 MPa as-printed, 133.7°C annealed. Skip the anneal for parts at service ≤80°C (HDT 0.45 MPa is the cosmetic ceiling, HDT 1.8 MPa is 71.8°C the structural one). Add the 120°C / 16h anneal for parts above 80°C service · HDT rises to 133.7°C (0.45 MPa) / 87.3°C (1.8 MPa). The TDS publishes critical handling for the anneal cycle: parts supported during anneal, thin walls under 4mm need ribs, slight colour shift post-anneal is normal (crystallinity affects transmittance).
Our stocked grade is 15% glass fibre by weight, chopped to short segments (80-200 microns long). The fibres orient along the print-head direction as the molten filament extrudes. That orientation would normally drive high anisotropy, but PET-GF sits at the LOWEST 1.24× XY/Z ratio in our composite range · the most-isotropic CF/GF composite we ship. Two reasons: (1) glass fibre is shorter and stiffer in compression than carbon fibre, so it transfers Z-axis load through the matrix more effectively; (2) the 15% GF loading is lower than the 17% in PET-CF, leaving more continuous matrix material to bridge layer interfaces.
Practically, this is the composite we recommend when CAD load paths are ambiguous, when geometry forces Z-direction loads, or when a part is being designed for multiple use cases at once. PET-CF would punish that design freedom · PET-GF lets the design choice take priority over the print orientation.
Values measured to the ISO standards cited in the right-hand column, on the manufacturer's own injection-moulded test specimens · directly comparable to other engineering thermoplastics.
| Property | XY · print plane | Z · build axis | Wet · XY / Z · post-immersion | Unit | Standard |
|---|---|---|---|---|---|
| Mechanical · post-anneal status (120°C / 16h) | |||||
| Tensile strength | 59.9 | 48.2 | · | MPa | ISO 527 |
| Young's modulus | 4144 | 3429 | · | MPa | ISO 527 |
| Elongation at break | 4.0 | 2.6 | · | % | ISO 527 |
| Flexural strength | 104.2 | 80.3 | · | MPa | ISO 178 |
| Flexural modulus | 3705 | 2998 | · | MPa | ISO 178 |
| Charpy impact (notched, XY) | 8.7 | · | · | kJ/m² | ISO 179 |
| Charpy impact (unnotched, XY) | 27.2 | · | · | kJ/m² | ISO 179 |
| Charpy impact (unnotched, Z) | · | 13.9 | · | kJ/m² | ISO 179 |
| Thermal | |||||
| Heat deflection (HDT @ 0.45 MPa) | 133.7 (annealed) · 81.6 (as-printed) | °C | ISO 75 | ||
| Heat deflection (HDT @ 1.8 MPa) | 87.3 (annealed) · 71.8 (as-printed) | °C | ISO 75 | ||
| Glass transition temperature (Tg) | 59.5 | °C | DSC, 10°C/min | ||
| Melting temperature (Tm) | 231.6 | °C | DSC lab figure · not the print temperature or the in-service softening limit (see HDT/Tg) | ||
| Crystallisation temperature (Tc) | 201.4 | °C | DSC, 10°C/min | ||
| Vicat softening temperature | 232.6 | °C | ISO 306 | ||
| Decomposition temperature | 422.8 | °C | TGA, 20°C/min | ||
| Physical | |||||
| Density | 1.43 | g/cm³ @ 23°C | ISO 1183 | ||
| Glass-fibre content | 15 | % by weight | manufacturer spec | ||
| Equilibrium water absorption | 0.32 | % | manufacturer absorption curve | ||
| Melt flow index | 36.9 | g/10min (270°C, 2.16kg) | ISO 1133 | ||
| UL94 flame rating | HB at 1.5mm | · | UL 94 | ||
| Surface resistivity | >10¹² | Ω/sq (insulator) | ANSI ESD S11.11 | ||
| Processing | |||||
| Recommended print temperature | 280-310 | °C | manufacturer spec | ||
| Recommended bed temperature | 70-80 | °C | manufacturer spec | ||
| Chamber requirement | Room temperature (no heated chamber required) | · | manufacturer spec | ||
| Drying conditions | 100°C / 10h before printing | · | manufacturer spec | ||
| Annealing | 120°C / 16h post-print · OPTIONAL for service ≤80°C, required above for full spec | · | manufacturer spec | ||
| Nozzle material | Hardened steel or ruby (brass ~9 hours life) | · | manufacturer spec | ||
Tensile load > 30 MPa: orient with load in the XY plane. Z bonds are 20% weaker · 48.2 vs 59.9 MPa, anisotropy 1.24×. PET-GF is the LEAST orientation-sensitive composite we ship · ambiguous load paths and complex geometry are tolerable in a way they aren't for PET-CF (2.36×) or PA-CF nylons (1.48-2.0×).
PET-GF's near-isotropic 1.24× anisotropy lets it use the standard 1.5mm structural-wall minimum (vs 2mm for PET-CF). 0.8 mm is cosmetic only. For heavy-duty load-bearing service step up to 2mm or add ribs.
Above 45° from vertical needs support material · plan part orientation to keep critical surfaces support-free.
Tight-tolerance ±0.1 mm achievable on small parts with calibration · ask before finalising CAD.
Removes 0.1-0.3 mm per surface · pre-paint prep or stand-alone hand-feel polish.
Manufacturer explicitly recommends as-printed PET-GF for service below 80°C (HDT 81.6°C @ 0.45 MPa is sufficient) and annealing only when higher HDT is needed. The TDS publishes both states · choose the workflow that matches the part's service envelope. Optional anneal costs ~0.5% XY and 0.2% Z shrinkage.
Adds 0.05-0.15 mm per surface · sand 800 grit first, primer + topcoat · for colour-matched exterior parts. Often skipped for PET-GF · the 6 in-filament colours already cover most brand applications without secondary painting.
Vapour fuses the matrix without flattening exposed glass · glossy but textured · sand + paint instead. Or skip both and accept the matt + glass-fleck as-printed finish, which already looks engineering-grade.
Every value on this page traces to an ISO test method. We don't quote derived numbers without naming the standard. The annealed-state caveat is clear on every spec figure.
No offshore subcontracting. Files, prints, and couriers all stay in the UK.
Send three things: peak load (N or MPa), peak service temperature (°C), and service environment (humid / outdoor / chemical). our team come back inside 24 hours with material, orientation, and post-process recommendation · if PA12-CF, PA6-CF, PA612-CF, or PPS-CF fits better, we say so.
our team review every brief before quote. No ticket queue, no account managers.
According to the Fiberon PET-GF15 TDS, PET-GF15 reaches Young's modulus 4144 ± 133 MPa (XY) per ISO 527 with HDT 133.7 °C @ 0.45 MPa (annealed) and Tm 231.6 °C · low-anisotropy glass-fibre PET.
PET-GF is unique in our composite range · the manufacturer explicitly publishes both as-printed (HDT 81.6°C @ 0.45 MPa, 71.8°C @ 1.8 MPa) and annealed (HDT 133.7°C / 87.3°C) properties. Skip the anneal for parts in service below 80°C · the as-printed properties are sufficient and lead time is faster. Run the 120°C / 16h anneal for parts above 80°C service, parts in long-term load above ~60°C, or parts that need the full chemical resistance envelope. The phase change from amorphous to semi-crystalline is the same as for PET-CF, but PET-GF gives you the choice.
PET-GF15 sits at 1.24× tensile XY/Z (59.9 / 48.2 MPa) · among the lowest anisotropy of any composite we ship (PA6-GF25 is near-isotropic in tensile at ~1.0×). PA12-CF is 1.48×, PA612-CF 1.90×, PET-CF 2.36×. Two factors: (1) glass fibre is shorter and stiffer in compression than carbon fibre, transferring Z-axis load through the matrix more effectively; (2) the 15% GF loading is lower than PET-CF's 17%, leaving more continuous matrix material to bridge layer interfaces. Practically, PET-GF is the composite we recommend when CAD load paths are ambiguous, when geometry forces Z-direction loads, or when a part needs to handle loads from multiple unpredictable directions.
Yes · 0.32% equilibrium water absorption per the TDS V1.0 absorption curve. That's second only to PPS-CF (0.225%) and far below every nylon · 3× drier than PA12-CF (1.5%), 4× drier than PA612-CF (2.2%), 6× drier than PA6-GF (3.33%). PET's polar ester linkages absorb far less water than nylon amide groups. The practical result: PET-GF parts hold dimensions and properties across UK ambient humidity cycles (30-80% RH) where nylon-CF parts swell and lose stiffness. For outdoor fixtures, marine brackets, humid workshops, and parts stored for months · PET-GF is the right CF composite.
PET-CF wins on tensile strength (65.9 vs 59.9 MPa XY), stiffness (5481 vs 4144 MPa Young's modulus), HDT (147.5 vs 133.7°C at 0.45 MPa). PET-GF wins on anisotropy (1.24× vs 2.36× · half as directional), ductility (4.0% vs 2.4% elongation), Charpy notched impact (8.7 vs 5.1 kJ/m²), water absorption (0.32% vs 0.53%), and colour options (6 colours vs matt black only). Pick PET-CF for peak stiffness and HDT in a dimensional fixture. Pick PET-GF for colour-flexible engineering parts and near-isotropic load paths.
PET-GF wins on stiffness (4144 vs 3311 MPa Young's modulus XY · 25% stiffer), water absorption (0.32% vs 1.5% · 5× drier), and HDT (133.7 vs 131°C at 0.45 MPa). PA12-CF wins on tensile strength (77 vs 59.9 MPa XY), impact toughness (Charpy notched 9.9 vs 8.7 kJ/m²), and ductility (4.2% vs 4.0% elongation). For dimensional fixtures and near-isotropic load paths, PET-GF. For impact-loaded brackets and snap-fits, PA12-CF.
Tg is 59.5°C per the manufacturer TDS V1.0 (DSC, 10°C/min). This sits below the bulk PET literature range (67-81°C) and below PET-CF's 79.3°C · suggests a co-polyester PET base or a different DSC scan protocol. Above Tg, amorphous regions soften · but the as-printed PET-GF still holds HDT 81.6°C at 0.45 MPa, and the annealed semi-crystalline state holds 133.7°C. For unannealed parts, do not load above 60°C. For annealed parts, the HDT figures govern service.
No heated chamber required · the TDS specifies room-temperature chamber. However, PET-GF prints with a hotter bed (70-80°C) than the PA-CF nylons (40-50°C) to manage PET's crystallisation behaviour during cooling. Standard industrial FDM hardware with a 300°C-capable hotend and hardened nozzle handles the material · no PEEK-class equipment needed.
Hardened steel or ruby. Glass-fibre at 15 wt% destroys a brass nozzle in roughly 9 hours of print time. Ruby-tipped nozzles extend life to hundreds of jobs. We run hardened-steel on every GF print as standard, included in the quote · no surcharge.
Excellent against hydrocarbons (petrol, diesel, oils, greases), alcohols (IPA, ethanol, methanol), dilute acids, detergents, and cleaning products · PET is the bottle-grade polymer behind food and beverage packaging. Limited against strong alkalis (PET hydrolyses in hot caustic), sustained hot water above 80°C (hydrolysis), and phenols. Fails against concentrated sulphuric or nitric acid, chlorinated solvents long-term, and high-temperature steam.
| Chemical / family | Resistance | Notes |
|---|---|---|
| Petrol / gasoline | Excellent | PET fuel-rail return lines are OEM specification |
| Diesel | Excellent | Including biodiesel and E85 ethanol-blends |
| Engine oil, gear oil, hydraulic oil | Excellent | All standard service grades |
| Brake fluid (DOT 3 / 4 / 5.1 glycol) | Excellent | DOT 5 silicone also fine |
| Coolant / antifreeze (ethylene glycol) | Excellent | Including diluted service coolant |
| Methanol, ethanol, IPA | Excellent | Cleaning + assembly OK |
| Detergents, soap, weak alkalis | Good | Workshop wash-down OK · hot caustic hydrolyses |
| Sea water / saline solution | Excellent | PET marine-grade chemistry · long-term immersion OK |
| Hydrogen peroxide ≤ 6% | Excellent | Stronger H₂O₂ attacks long-term |
| Acetone | Good | PET more solvent-resistant than amorphous PETG |
| MEK, toluene, xylene | Limited | Brief contact only · long soak attacks PET |
| Strong alkalis (NaOH > 10%) | Fails | PET hydrolyses in hot caustic · alkali attack |
| Weak organic acids (acetic, citric) | Good | Cold + dilute is fine · hot conc. degrades over weeks |
| Hot water (sustained > 80°C) | Fails | Hydrolytic attack · PET hydrolyses progressively |
| Strong acids (sulphuric, HCl, nitric) | Fails | Concentrated acid attacks PET backbone |
| Chlorinated solvents long-term (TCE, DCM) | Fails | Solvent crazing + dissolution |
| Phenols | Fails | Strong PET solvent |
| High-temperature steam | Fails | Combined heat + moisture · hydrolyses repeatedly-autoclaved parts |
Ratings reflect long-term immersion / sustained exposure. Brief contact (cleaning wipes, splashes) is more forgiving. For mission-critical chemical service, request a 7-day immersion sample before committing the design.
Standard PET-GF15 is rated UL94 HB at 1.5mm wall · the lowest horizontal-burn rating. For UL94 V-0 / V-2 self-certification (electrical enclosures, transportation, aerospace), step sideways to PPS-CF (V-0 at 1.5mm) or PA6-FR (flame-retardant nylon).
No · standard PET-GF15 is insulative. Surface resistivity is >10¹² Ω/sq per the TDS (rated OL · overload, beyond ESD-safe range). The 15% GF loading is non-conductive · glass fibre itself is an insulator. For ESD-sensitive electronics handling jigs and PCB fixtures, use PETG-ESD or PA612-ESD (dedicated anti-static grades).
Short-cycle yes, repeated cycles no. 121°C steam sits above PET's Tg (59.5°C) but below the annealed HDT at 0.45 MPa (133.7°C). Single autoclave cycles are mechanically workable on annealed parts. However, PET hydrolyses under combined heat plus moisture, so repeated autoclave cycles progressively degrade the polymer chain. For routine repeat steam autoclave (clinical, lab), PEEK or PPSU are the correct materials. Dry-heat sterilisation, EtO, UV-C, gamma, and IPA wipe-down are all compatible with PET-GF.
Continuous service (annealed): -20 to ~100°C (HDT 1.8 MPa is 87.3°C). Short-term load: up to ~147°C (HDT 0.45 MPa). Outdoor: moderate UV tolerance, better than PA-CF nylons but coat with 2K paint for multi-year exterior service. Humid environments: yes, the headline application · 0.32% water absorption means dimensional stability holds across humidity cycles. Not for steam autoclave (repeated), not for ESD service, not for flame-rated applications, not for sub-2mm thin-walled bending parts.
You'll hear back from our team within 24 hours · with material-fit check, ISO-referenced spec, and lead time on every quote.