Beli Neonpost Printer Amplop bekas (2.828)

Kondisi: siap digunakan (bekas), Tahun pembuatan: 2019, pitneybowesf700 Cjdoy R A D Tjpfx Ahrorf

Kondisi: seperti baru (mesin pameran), Fungsionalitas: berfungsi sepenuhnya, Tahun pembuatan: 2020, jam operasional: 300 h, The price refers to the machine from the demo center, including an additional tank and a second build platform. - Build volume: 250 x 250 x 250 mm - Scanning speeds up to 12 m/s - Layer thicknesses from 0.05 mm - Accuracy of +/- 0.1% over part length - Granite recirculation frame - Control of key operating parameters - Pump-fed refilling capability - High-performance vacuum recoating system Cjdpfx Ahohvim Ejrsrf - Key components from Spectra-Physics, Advanced Optowave, SCANLAB, and Panasonic. The machine features an open material platform – consumables from all manufacturers can be sourced and processed directly. Transport, commissioning, and consumables are not included in the price. The local UnionTech partner handles installation, training, and service!

Kondisi: seperti baru (mesin pameran), Fungsionalitas: berfungsi sepenuhnya, Tahun pembuatan: 2024, jam operasional: 200 h, panjang total: 2.128 mm, lebar total: 1.294 mm, tegangan masuk: 400 V, masa garansi: 6 bulan, arus masuk: 32 A, daya laser: 100 W, kapasitas tangki: 32 l, laju aliran volumetrik: 20 m³/jam, Sistem sinter laser poliamida termasuk dua wadah pertukaran dan stasiun pembongkaran. Mesin dapat dilihat dan diuji kapan saja di BIBUS-Austria-Democenter. Selain itu, sistem ini memiliki fitur quick-change system antara pisau penarik dan rol coater – sistem ini selalu berada pada standar teknologi terbaru karena pembaruan rutin telah dilakukan. Codpfx Ahsqwkyperjrf

Kondisi: bekas, penawaran super: mesin fleksografi COMEXI FP 1808 CNC, 8 warna dengan roda gigi, tahun 1999, lebar 1270 mm Crsdpfsyky Twex Ahrof

Kondisi: bekas, 1 Codpfxsw T Rwrs Ahrorf

Kondisi: bekas, Tahun pembuatan: 2011, de-hu-001 Cjdpfsxwzb Iox Ahrsrf

Kondisi: baru, Tahun pembuatan: 2022, Erittäin nopea 3D-muovitulostin Erittäin nopea 3D-muovitulostin (tulostustila 275x155x400 mm) teolliseen käyttöön ja oppimisympäristöihin, jossa on nopea materiaalinvaihto ja laaja, yli kahdenkymmenen tulostusmateriaalin valikoima. Haasta ruiskuvalun nopeus ja laatu sekä hyödynnä työkaluton ylivertainen joustavuus! Koko metallinen tulostusjärjestelmä sisältäen: - 3D-muovitulostin Cedpotucr Ijfx Ahrerf - x-Wash Tuotteiden pesu - x-Cure Tulosteiden kovetus NexaX v1 -ohjelmisto: Helppo tulostuksen hallinta ja etäohjaus, työnhallinta, jonot ja tilastot Tämä on täysi järjestelmä, johon sisältyy 3D-tulostin, pesuasema ja kovetuslaite. Materiaalit: KeyGuide, KeyModel Ultra – Ivory, KeyModel Ultra – Light Gray, KeyOrtho IBT, KeySplint Hard, KeySplint Soft, KeyTray, PRO9499 White, Saremco Print CROWNTEC, xABS3843, xDENT341-Beige, xESD, xFLEX402-Black, xFLEX475-Black, xFLEX475-White, xMODEL15-Black, xCERAMIC3280, xDENT201-Gray, xDENT341-Beige, xESD, xFLEX402-Black, xFLEX475-Black, xFLEX475-White, xMODEL15-Black, xMODEL15-Gray, xMODEL17-Clear, xMODEL35-Black, xMODEL35-Gray, xMOLD, xPEEK147, xPP405-Black, xPRO1100-Black, xPRO9400-FR

Kondisi: diremajakan ulang (bekas), Tahun pembuatan: 2021, jumlah kepala cetak: 4, de Csdpevdkdcofx Ahrorf

Kondisi: sangat baik (bekas), Tahun pembuatan: 2016, de Codpfx Aeyly Idjhrsrf

Kondisi: sangat baik (bekas), afinia-l801-etikettendrucker-2022 Cjdpfxszaampo Ahrorf

Tahun pembuatan: 2015, Kondisi: sangat baik (bekas), Fungsionalitas: berfungsi sepenuhnya, Harga satuan per unit: 2500€. Dijual tiga unit printer inkjet merk Linx Printing Technologies Limited, model 8900, tahun produksi 2015. Printer rutin dirawat dan berfungsi dengan sangat baik. Saat membeli printer, troli roda sudah termasuk dalam paket. Csdpfx Ahjy U Utnerjrf Jika Anda memiliki pertanyaan atau membutuhkan informasi lebih lanjut, silakan kirim pesan atau hubungi kami.

Kondisi: hampir baru (bekas), Fungsionalitas: berfungsi sepenuhnya, Tahun pembuatan: 2015, panjang total: 1.290 mm, tinggi total: 1.980 mm, lebar total: 900 mm, jenis arus masuk: tiga fasa, berat keseluruhan: 658 kg, tegangan masuk: 240 V, arus masuk: 40 A, suhu: 160 °C, frekuensi input: 50 Hz, suhu lingkungan (min.): 15 °C, suhu lingkungan (maks.): 30 °C, akurasi pemposisian: 0,127 mm, sekring listrik: 40 A, akurasi pengulangan: 0,05 mm, panjang pemakanan sumbu X: 406 mm, panjang umpan sumbu Y: 355 mm, panjang umpan sumbu Z: 406 mm, persyaratan ruang panjang: 2.000 mm, kebutuhan tinggi: 2.200 mm, tingkat kebisingan: 65 dB, lebar yang dibutuhkan: 1.500 mm, Stampante 3D industriale ad alte prestazioni basata su tecnologia FDM, progettata per la prototipazione funzionale e la produzione in piccoli lotti tramite termoplastici ingegneristici certificati. La Stratasys Fortus 450mc è una piattaforma consolidata per aziende che richiedono ripetibilità, stabilità dimensionale e tracciabilità dei materiali, rendendola ideale nei settori automotive, aerospaziale, della meccanica industriale e per laboratori di ricerca avanzata. Il sistema dispone di teste di estrusione doppie in modalità materiali aperti, consentendo flessibilità avanzata di processo e compatibilità con una più ampia gamma di termoplastici specifici FDM, previa ottimizzazione dei parametri e rispetto dei limiti termici della piattaforma. Caratteristiche principali: - Camera di costruzione riscaldata (fino a ~180°C) per una superiore adesione tra gli strati e riduzione delle deformazioni - Ripetibilità a livello industriale per parti funzionali e destinate all’utilizzo finale - Ampio volume di stampa: 406 × 355 × 406 mm - Sistema di estrusione doppia (materiale + supporto solubile) - Sistema di materiali chiuso per la stabilità e la coerenza del processo - Compatibile con il software Insight per un avanzato controllo del processo di stampa Materiali supportati: 🔹 Polimeri standard e funzionali ABS-M30 → prototipazione funzionale robusta ASA → applicazioni outdoor resistenti ai raggi UV ABS-ESD7 → componenti a dissipazione elettrostatica 🔹 Polimeri ad alte prestazioni PC (Policarbonato) → resistenza all’impatto elevata PC-ABS → equilibrio tra robustezza e processabilità 🔹 Materiali tecnici avanzati Nylon 12 (PA12) → resistenza all’usura e durevolezza sotto fatica Nylon 12CF (rinforzato fibra di carbonio) → maggiore rigidità e stabilità dimensionale 🔹 Termoplastici per aerospazio ULTEM 9085 → conforme FST (fiamma, fumo, tossicità) ULTEM 1010 → massima resistenza termica e meccanica Csdpfey Ug Ecex Ahrsrf

Kondisi: hampir baru (bekas), Fungsionalitas: berfungsi sepenuhnya, Tahun pembuatan: 2024, jam operasional: 556 h, panjang total: 483 mm, tinggi total: 914 mm, lebar total: 584 mm, jenis arus masuk: Arus searah (DC), berat keseluruhan: 48 kg, masa garansi: 16 bulan, panjang pemakanan sumbu X: 330 mm, panjang umpan sumbu Y: 270 mm, panjang umpan sumbu Z: 200 mm, en Cedeydmnbjpfx Ahrjrf

Kondisi: siap digunakan (bekas), Inkjet printer for frame bending machine Length: 800 mm Width: 1000 mm Height: 1900 mm Weight: approx. 100 kg Codpfxjhzgtuj Ahrjrf

Kondisi: siap digunakan (bekas), Fungsionalitas: berfungsi sepenuhnya, nomor mesin/kendaraan: Fabr. / Serien Nr. 12.16.0072, Tahun pembuatan: 2016, jam operasional: 6.250 h, panjang total: 2.000 mm, tinggi total: 1.400 mm, lebar total: 1.100 mm, jenis arus masuk: tiga fasa, berat keseluruhan: 800 kg, tegangan masuk: 400 V, arus masuk: 32 A, panjang poros: 1.070 mm, suhu: 200 °C, sambungan udara terkompresi: 8 batang, frekuensi input: 50 Hz, daya laser: 400 W, suhu lingkungan (min.): 10 °C, suhu lingkungan (maks.): 35 °C, sekring listrik: 32 A, lebar meja: 125 mm, kapasitas tangki: 25 l, panjang meja: 125 mm, akurasi pengulangan: 0,001 mm, Perlengkapan: unit pendingin, Manufacturer: SLM Solutions GmbH Model: SLM 125 HL Factory / Serial No.: 12.16.0072 Year of construction: 2016 Weight: 800 kg Dimensions (L x W x H): 2,000 x 1,400 x 1,100 mm Documentation: Yes Accessories: Spare parts such as flanges, pipe sections, substrate plates, recoater blades, powder containers or bottles (photos available upon request) Special features: Operation requires compressed air (7-8 bar), inert gas (argon or nitrogen) at 5 bar and cooling water Used SLM Solutions SLM 125 HL system for processing reactive and non-reactive powder materials. Stainless steel and aluminum (other materials possible) have been printed on this system. Process chamber, handling station, and powder extraction are executed according to ATEX Directive II for combustible substances. Build volume (L x W x H): 125 x 125 x 125 mm (minus substrate plate height) Reduced build volume (L x W x H): 50 x 50 x 50 mm (minus substrate plate height) 3D optics configuration: Single (1x 400 W) IPG fiber laser Build rate: up to 25 cm³/h Variable layer thickness: 20 μm - 75 μm, adjustable in 1 μm steps Minimum feature size: 140 μm Focus diameter: 70 μm - 100 μm Max. scan speed: 10 m/s Average shielding gas consumption during build process: 0.6 l/min (argon) Average shielding gas consumption during purge process: 70 l/min (argon) Csdpfjy Uzciex Ahrorf Electrical connection / power consumption: 400 Volt 3NPE, 32 A, 50/60 Hz, 3 kW Compressed air requirements / consumption: ISO 8573-1:2010 [1:4:1] 7 bar

Kondisi: perlu perbaikan (bekas), Fungsionalitas: fungsi terbatas, nomor mesin/kendaraan: 570115, Tahun pembuatan: 2013, jam operasional: 928 h, panjang total: 1.400 mm, tinggi total: 1.260 mm, lebar total: 1.100 mm, jenis arus masuk: AC (pendingin udara), berat keseluruhan: 430 kg, tegangan masuk: 230 V, For sale: Stratasys Objet500 PolyJet 3D printer. This machine is explicitly offered as defective / in need of repair, as several print heads must be replaced. The Stratasys Objet500 series is a professional industrial 3D printing system based on PolyJet technology. PolyJet utilizes liquid photopolymer, which is applied layer by layer through print heads and cured by UV light. The Objet500 models are designed for high-resolution prototypes, design models, functional samples, molds, jigs, fixtures, and components with fine surface quality. Once repaired, the machine is suitable for professional applications in rapid prototyping, product development, model making, design, medical technology, engineering, and small-series manufacturing. Depending on the configuration of the Objet500 series, multi-material and digital material applications are also possible. Stratasys describes the Objet500 Connex family as a triple-jetting platform with various material and color or material combination capabilities. Condition: Defective / in need of repair. To the best of our knowledge, some print heads must be replaced. Therefore, the machine is expressly sold without any functional guarantee. Commissioning or repair should be carried out exclusively by qualified personnel or an authorized Stratasys service partner. On-site inspection is possible by appointment. The machine may be of interest as a repair project, a donor for spare parts, or for recommissioning by a specialist company. Technical specifications (according to manufacturer data for the Objet500 series): Manufacturer: Stratasys Model: Objet500 / Objet500 Connex series Process: PolyJet 3D printing Build volume: approx. 490 × 390 × 200 mm Layer thickness: up to 16 microns Resolution: 600 dpi X-axis / 600 dpi Y-axis / 1600 dpi Z-axis Machine dimensions: approx. 1,400 × 1,260 × 1,100 mm Credpfx Ahjy Uwlajrjf Machine weight: approx. 430 kg Material cabinet: approx. 330 × 1,170 × 640 mm Material cabinet weight: approx. 76 kg Power supply depending on model: 100–120 V or 220–240 V, 50/60 Hz, single-phase Support material depending on system: SUP705 / SUP706B, depending on configuration and material approval The technical information is based on publicly available manufacturer and support data for the Stratasys Objet500 series. Stratasys specifies a build volume of 490 × 390 × 200 mm for the Objet500 Connex 1-2-3; weight and system dimensions are listed in datasheets at approx. 430 kg and 1,400 × 1,260 × 1,100 mm, respectively. Note on defect: The machine is not being sold as operational. Known issue: print heads need replacement. Other faults cannot be ruled out. Therefore, the sale is expressly as a defective used machine / for repair / for spare parts. Terms and conditions of sale: Sale exclusively to businesses/traders. The machine is sold as a used machine, as described and/or as viewed, with exclusion of any liability for material defects/warranty. No guarantee is provided. Subject to errors and prior sale. Inspection possible by appointment only. Sale ex location.

Kondisi: bekas, Fungsionalitas: berfungsi sepenuhnya, nomor mesin/kendaraan: ZanyTapir, Tahun pembuatan: 2025, jam operasional: 251 h, panjang total: 700 mm, tinggi total: 1.600 mm, lebar total: 700 mm, jenis arus masuk: AC (pendingin udara), berat keseluruhan: 120 kg, tegangan masuk: 230 V, Complete set consisting of Fuse 1, Fuse Blast, Fuse Sift, Mini 5-5 RG40104 and IVR 35/20-2 Sc Me For sale is a complete machinery/system set in as-new condition, comprising several precisely matched components. Scope of delivery / Set includes: - Fuse 1 - Fuse Blast - Fuse Sift - Mini 5-5 RG40104 - IVR 35/20-2 Sc Me The set is ideally suited for use in production, workshop, or industrial environments. The components are offered together as a complete set and are all in an exceptionally well-maintained, like-new condition. The nitrogen generator Mini 5-5 RG40104 is required for operation or for printing with white powder. Crsdsy Uvikspfx Ahrjf A suitable compressor is available in a separate listing if required. Condition: As new Availability: Immediately / by arrangement Collection / Shipping: By agreement All details are provided to the best of our knowledge and belief. Subject to prior sale and errors excepted. If you are interested or have any questions, please do not hesitate to contact us. We will be happy to provide additional photos or information upon request. Sales Conditions: Sale exclusively to commercial customers/businesses. The machine is sold as a used machine as described or as inspected, with exclusion of any liability for material defects/warranty. No guarantee will be provided. Subject to errors and prior sale. Inspection possible by appointment. Sale is ex-location.

Kondisi: baik (bekas), Fungsionalitas: berfungsi sepenuhnya, nomor mesin/kendaraan: G1850438, jam operasional: 675 h, panjang total: 1.400 mm, tinggi total: 1.100 mm, lebar total: 1.260 mm, jenis arus masuk: AC (pendingin udara), berat keseluruhan: 430 kg, tegangan masuk: 220 V, arus masuk: 7 A, lebar meja: 390 mm, panjang meja: 490 mm, Stratasys J850 Digital Anatomy – Professional PolyJet 3D Printer for Medical and Anatomical Models For sale is a Stratasys J850 Digital Anatomy, a high-quality industrial PolyJet 3D printer for the production of realistic medical, anatomical, and functional models. This machine is ideal for clinics, medical technology companies, research institutions, universities, dental/medical labs, as well as 3D printing and prototyping service providers. The J850 Digital Anatomy enables the printing of complex models with multiple materials, colors, and Shore hardness levels in a single print process. This allows for the highly realistic representation of anatomical structures such as bones, vessels, tissues, organs, and transparent areas. Typical applications include surgical planning, training, demonstration models, product development in medical technology, and patient-specific models. Technical Specifications / Additional Information: - Total printing time: 675 hours - Technology: PolyJet / Multi-material 3D printing - Layer thickness: down to 14 µm - Multi-material printing with up to 7 base materials - Full-color and transparent printing possible - Software: GrabCAD Print / GrabCAD Voxel Print - Network connection: LAN / TCP-IP - Suitable for Digital Anatomy materials including TissueMatrix, BoneMatrix, GelMatrix, and other PolyJet materials Condition / Storage Notice: The machine is currently dismantled. Before disassembly, it was professionally flushed by Stratasys to prevent clogging or drying out of the print heads. Therefore, the machine has been properly prepared for transport and storage. Special Features: - Realistic haptics and appearance of anatomical models - Very high level of detail and fine surface quality - Printing of flexible, rigid, transparent, and colored areas within a single model - Ideal for medical training, surgical preparation, and product development - Industrial Stratasys quality - Large build area for complex models and small batch production - Professionally flushed and prepared for transport/storage The machine is particularly well-suited for users looking to produce high-quality medical models, demonstrators, implant/instrument prototypes, or highly realistic training models. Crjdpsy Urwwofx Ahrsf Sales Conditions: Sale exclusively to commercial customers/businesses. The machine is being sold as a used machine, as described or as inspected, with all liability for material defects and warranties excluded. No guarantee is provided. Errors and prior sale reserved. Inspection by appointment possible. Sale is ex location.

Kondisi: bekas, Fungsionalitas: berfungsi sepenuhnya, Tahun pembuatan: 2016, panjang total: 100 mm, tinggi total: 100 mm, lebar total: 95 mm, berat keseluruhan: 570 kg, tegangan masuk: 230 V, arus masuk: 8 A, frekuensi input: 50 Hz, sekring listrik: 16 A, daya: 1,7 kW (2,31 hp), EOSM100-2016 Crsdpfsy Szv Rex Ahrjf

Kondisi: diremajakan ulang (bekas), Fungsionalitas: berfungsi sepenuhnya, nomor mesin/kendaraan: 140L-C, Tahun pembuatan: 2022, jam operasional: 5.854 h, panjang total: 1.450 mm, tinggi total: 1.040 mm, lebar total: 1.250 mm, jenis arus masuk: AC (pendingin udara), berat keseluruhan: 380 kg, tegangan masuk: 400 V, arus masuk: 12 A, frekuensi input: 50 Hz, suhu lingkungan (min.): 10 °C, suhu lingkungan (maks.): 40 °C, sekring listrik: 16 A, lebar meja: 500 mm, kapasitas tangki: 140 l, panjang meja: 700 mm, daya: 8,3 kW (11,28 hp), kecepatan perjalanan (maks.): 24.000 mm/menit, jumlah kepala cetak: 2, Refurbished industrial fused filament fabrication (FFF) 3D printer Includes: - 140L-C printer - Vibration-dampened platform - License for slicing software (Simplify3D) Original price €73,800 General Technical Data: Model..... HAGE 3D-140L-C Year of manufacture..... 2022 Operating hours..... 5,854 h Printing technology..... FFF (Fused Filament Fabrication) Filament diameter..... 1.75 mm; open material system Build area (L x W)..... 700 mm x 500 mm Build height..... up to 400 mm Build volume..... up to 140,000 cm³ Dimensions and Weight Length..... 1,450 mm Width..... 1,250 mm Height..... approx. 1,040 mm Weight..... approx. 380 kg Temperature Maximum printhead surface temperature..... 300°C (optionally 450°C) Maximum build plate surface temperature..... 180°C Maximum build chamber temperature..... 85°C Minimum operating temperature..... +10°C Maximum operating temperature (ambient)..... +40°C Electrical AC input..... 400 V / 50 Hz Power supply..... 24 V DC Connection..... USB 3.0 / Ethernet Printing Features Cjdpfoxuh Nyox Ahrerf X-axis speed..... up to 400 mm/s Y-axis speed..... up to 400 mm/s Z-axis speed..... up to 300 mm/min XY-plane accuracy..... < 0.1 mm Print control..... Industrial control (Sigmatek) Software..... HAGE3D All documentation available Platform: 1,450 x 1,250 x 600 mm (LxWxH) Includes storage compartments Includes machine feet with vibration damping

Kondisi: bekas, Fungsionalitas: berfungsi sepenuhnya, nomor mesin/kendaraan: 570150, Tahun pembuatan: 2015, jam operasional: 10.018 h, stratasys-connex-500-2015 Crsdpfxsy S Rp Ho Ahrsf

Kondisi: baik (bekas), Typ: Overture ES Spannung: 230 V (50 Hz) Hergestellt in: USA Transportmaße: 600 x 400 x 500 mm Gewicht: 15 kg Codpfod Ig S Aex Ahrorf

Kondisi: siap digunakan (bekas), Tahun pembuatan: 2019, fujifilm-uv-flachbett-rolle-hu Credoy Tav Espfx Ahrof

Kondisi: baru, SLS-materialen voor industriële & compacte SLS 3D-printers Hoogwaardige SLS-poeders voor professioneel 3D-printen — compatibel met een breed scala aan industriële en compacte SLS 3D-printers zoals EOS, Formlabs, Sinterit, Sintratec, Nexa3D en Raise3D systemen. Onze SLS-poeders worden uitvoerig in eigen huis getest om een betrouwbare verwerking, uitstekende mechanische eigenschappen en constante printkwaliteit op diverse machineplatformen te waarborgen. Ontworpen voor zowel industriële productie als compacte SLS-systemen leveren IM3D-materialen professionele prestaties zonder beperkingen van gesloten ecosystemen. Beschikbare Materialen PA12 Balance — €45/kg Kostenefficiënt allround PA12-poeder met uitstekend verfrisgedrag en betrouwbare mechanische eigenschappen. PA12 Performance — €49/kg Verbeterd PA12-materiaal met verhoogde rek bij breuk en grotere slagvastheid voor veeleisende functionele toepassingen. PA12 Glasgevuld (PA12-GF) — €44/kg Stijf en maatvast PA12-materiaal, versterkt voor gereedschaps- en constructiedelen. TPU88A — €45/kg Flexibel SLS-materiaal met uitstekende elasticiteit, duurzaamheid en impactbestendigheid. Machinecompatibiliteit Compatibel met een breed scala aan SLS-systemen, waaronder: EOS / EOSINT: P100, P110, P350, P360, P380, P385, P390, P395, P396, P450, P500, P700, P730, P760, P770 Formlabs: Fuse 1, Fuse 1+ Sinterit: Lisa, Lisa Pro, Lisa X, Suzy Sintratec: Kit, S1, S2, S3 Nexa3D: QLS230, QLS236, QLS260 XYZ Systems: MfgPro230 xS, MfgPro236 xS Raise3D: RMS220 SLS4All Innova MK1 Crsdpfx Asy Til Aehrsf Loopzizo K-100 Meer compatibiliteitsinformatie: im3d.shop/printer-compatibility OEM Materiaalalternatieven Wij bieden alternatieven en/of plug-and-play vervangingen voor materialen van Formlabs, Sinterit, Sintratec en Raise3D, waaronder: Formlabs PA11, PA12, PA12 Tough, PA12-GF, TPU90A Sinterit Flexa Performance, PA11 Onyx, PA11.5, PA12 Eco, PA12 Industrial, PA12 Smooth Sintratec PA12, PA12-GF, TPU88A Raise3D PA Next, PA Next GB, PA11, PA12, PA12 GB, TPU86A, TPU90A OEM vergelijkingsoverzicht: im3d.shop/compare/oem Waarom kiezen voor IM3D SLS-materialen? - Brede compatibiliteit met industriële en compacte SLS-systemen - Uitstekende refresh rates en lage kosten per onderdeel - Stabiele verwerking en consistente printkwaliteit - Industriële prestatie zonder vendor lock-in - In-house getest en gevalideerd voor productie - Technische onboarding en support beschikbaar - Snelle levering vanuit Nederland

Kondisi: bekas, Used 3D printer EOSINT M 270 with low operating hours (4910) Cjdpfx Ahjwd Ulvorsrf