China acelera la Manufactura Aditiva de piezas para misiles

China Aerospace Science and Industry Corp. (CASIC), el mayor fabricante de misiles de China, está aprovechando la tecnología de fabricación aditiva (AM) para acelerar el diseño y la producción de misiles de crucero.

Esto no tiene nada de extraño pues la fabricación tradicional de cada pieza metálica de un misil representa un coste y plazo de entrega muy elevados porque implica una sucesión de procesos de mecanizado, fundición y soldadura.

Sin embargo, las tecnologías existentes hoy día para manufactura aditiva permiten recortar los costes y tiempos necesarios para realizar cada pieza convirtiendo los meses en semanas, las semanas en días, y los días en horas.

Pero no sólo permite recortar costes y tiempos: también permite un mayor alcance gracias a que las piezas pueden ser optimizadas para manufactura aditiva, de manera tal que pesen menos pero conserven toda su resistencia mecánica.

ROSTI GROUP: YES YOU CAN

Contract manufacturing firm Rosti Group is using Ultimaker 3D Printing Technology to produce fixtures and assembly parts.

The company says it has adopted the Ultimaker S5 Pro Bundle to accelerate product development cycles and help clients get their products to market faster.

By incorporating the Ultimaker S5 Pro Bundle, which is supported by a wide materials range and has the ability to print fibre-reinforced components with the Print core CC, Rosti is replacing traditional prototyping methods where it can to save time, while also additively manufacturing fixtures and assembly components that match the strength and quality of those produced with subtractive methods. 

The results are the supply of new products to consumer markets and product samples to clients within 72 hours: “By removing traditional manufacturing methods from the development of assembly and production fixtures, the Ultimaker S5 Pro Bundle allows us to print high-strength and high-temperature materials at a fraction of the cost of previous methods and completed within a few days instead of weeks,” commented Scott Dickson, NPD Manager of Rosti Suzhou.

“Most certainly, Ultimaker is about fast first-time-right 3D prints of high visual and functional quality, but I get particularly excited when I learn how our technology serves as a transformative business solution for renowned companies like Rosti,” offered Ultimaker CEO Jürgen von Hollen. “The company recognised that it needed a rapid step change to remain competitive. Seeing that the flexibility and sustainable value derived from our 3D Printing Platform and eco-system has a strategic business impact in such a short turnaround time is what drives our teams as well our partners across the world.”

Sillines Personalizados: Vuestro Turno

Durante décadas, los fabricantes de sillines para bicicletas han confiado en la espuma. Sin embargo, después de años de mejora continua la espuma se ha estancado en términos de viabilidad estructural y de diseño.

Las tiendas de bicicletas ofrecen muchas formas, tamaños y tecnologías diferentes, pero hasta la fecha no han sido capaces de ofrecer sillines a medida para uso no profesional, a un coste asequible.

Es verdad que existen sillines adecuados para la mayoría de usuarios, pero también es cierto que ninguno de ellos puede satisfacer plenamente los requisitos personales de cada ciclista, ya que estos difieren no sólo por cada persona sino también por su actividad: no es lo mismo recorrer distancias cortas en áreas urbanas que recorrer largas distancias en carretera, o que realizar ciclismo de montaña: cada ciclista y cada actividad requieren diferentes niveles de rigidez y flexibilidad en el sillín.

Habiendo llevado la espuma del sillín tradicional a sus límites de diseño y rendimiento, ya era hora de que los fabricantes especialistas pensaran de manera innovadora para alcanzar nuevos niveles de comodidad, rendimiento y personalización. Si bien la idea de los sillines de bicicleta impresos en 3D y los prototipos impresos en 3D han existido desde hace algún tiempo, la colaboración entre las empresas atum3D, Forward AM, Hyperganic, e InnovationLab ha dado lugar a una solución que permite crear sillines personalizados de forma única, a escala de producción masiva.

El proceso comienza con un estudio de la estructura ósea del ciclista, mediante el uso de una lámina sensible a la presión: La estructura ósea del ciclista genera un mapa de presión, que indica la distribución precisa de masa y presión aplicada al sillín por el individuo. Basado en el resultado del mapa de presión, el software de Hyperganic permite el diseño de una celosía orgánica tridimensional cuya densidad varía en función de la presión a recibir, para disipar la presión que aplica el ciclista cuando monta en bicicleta. Aprovechando los beneficios de la estructura reticular, este nuevo sillín constituye una gran mejora en la amortiguación y la distribución de la presión, brindando una comodidad sin precedentes para los ciclistas ocasionales y un salto de rendimiento para los ciclistas ambiciosos.

El resultado es una estructura de sillín perfectamente individualizada que distribuye de manera óptima la presión ósea y muscular, maximizando la comodidad del ciclista al minimizar los puntos de máxima presión. A partir de ese resultado se diseña un sillín a medida que se imprime en 3D. Por último, se le aplica un revestimiento resistente pero flexible en una amplia gama de tonos de color personalizados. En cuanto al material de Impresión 3D se utiliza un fotopolímero altamente elástico denominado Ultracur3D® EL 150. Este material de impresión que resulta especialmente indicado para aquellas aplicaciones que requieren elasticidad y flexibilidad, brinda una dureza media y una combinación óptima de alta resistencia y excelente elongación a la rotura. Para dar al sillín un acabado estético se utiliza el material Ultracur3D® Coat F,  robusto pero extremadamente flexible, disponible en una amplia variedad de colores, así como tonos personalizados bajo pedido.

El hardware elegido para esta aplicación precisa es la impresora DLP Station 5-365 EXZ de atum3D: su plataforma de resina abierta permite ajustar la configuración de impresión para que coincida con los requisitos finales del material, minimizando así el desperdicio. Los expertos de atum3D optimizaron digitalmente el diseño de celosía para obtener todos los beneficios del proceso de impresión DLP y las propiedades mecánicas avanzadas de Ultracur3D® EL 150.

Atum3D Science & Research Excellence Pack: Poderío

Atum3D ha presentado una solución denominada Science & Research Excellence Pack, que combina una excelente impresora basada en tecnología DLP, junto con un software dedicado y unos materiales de grado industrial.

Esta solución está basada en la Impresora 3D DLP 5-405 de grado industrial, que permite imprimir con precisión, repetitividad y velocidad gracias a su fuente de luz de 405 nm de alta potencia.

Asimismo, cuenta con una bandeja de resina que presenta una muy alta resistencia química y un recubrimiento patentado que evita que se pegue el material. De esta manera, los usuarios pueden utilizar una amplia gama de materiales y controlar una amplia gama de variables con el software de edición Operator Station Creator.

Más información:

https://www.atum3d.com/industry-science-research.php

MEX vs MIM: Todo es posible

La fabricación aditiva mediante extrusión de materiales metálicos (MEX, por Material Extrusion) es uno de los procesos de Impresión 3D que ha ganado más interés en los últimos años debido a su óptima combinación de economía y sencillez.

El proceso MEX es muy similar al proceso convencional de moldeo por inyección de metal (MIM, por Metal Injection Moulding) basado en la deposición capa a capa de un material compuesto por metal en polvo y polímeros aglutinantes; acabada la impresión, la pieza debe someterse a un proceso de eliminación de aglutinantes y finalmente a un sinterizado para consolidar las partículas metálicas.

Debido al rápido desarrollo reciente de las tecnologías MEX, les importante revisar el trabajo de investigación actual sobre este tema al objeto de comprender mejor el proceso, los parámetros, y las propiedades físicas y mecánicas de las piezas obtenidas. A tal efecto, está ya disponible en Internet un estudio que considero relevante, y al que podrán acceder a través de este enlace:

https://www.mdpi.com/2075-4701/12/3/429/pdf

Additive Manufacturing for 3D Printed Implants: This is a must see

This video highlights the 3D Printed PEEK Implants with Apium M220:

https://www.youtube.com/watch?v=H6e74YOBQAQ

The implants were printed using Apium M220 by Lucid Implants and Skåne University Hospital.

Lucid Implants is an Implant manufacturer based in India. They worked closely with surgeons in multiple hospitals.

Till date they have performed more than twenty surgeries with 3D Printed PEEK Implants.

Skåne University Hospital performed the world's first surgery in which a 3D Printed PEEK Implant is directly manufactured in an hospital.

3DGence Industry F421: Go!!!

Industrial 3D printer manufacturer 3DGence has announced the launch of its latest High-Temperature 3D printing system, the INDUSTRY F421.

The dual-extrusion FFF machine is designed specifically for high-performance applications in sectors such as aerospace, enabling users to print with engineering-grade filaments such as PEEK, PEKK, and ULTEM.

According to 3DGence, the launch is intended to help its customers transition from functional prototyping to full-fledged end-use production. To complement the INDUSTRY F421, the firm has also announced the launch of a new Material Management System and an AS9100-certified PEEK Aero filament.

“At 3DGence, we are supporting our customers across industries in expanding the use of high-temperature and composite materials for end-use applications,” said Ron Faruqui, CEO of 3DGence Americas. “The aerospace industry has the most stringent requirements for material performance due to demanding application environments and critical safety imperatives.”

Based in Poland, 3DGence has been manufacturing high-performance Extrusion-Based 3D Printers since 2014. The firm’s INDUSTRY 3D Printer range has already seen extensive use in sectors such as automotive, aerospace, and medical with over 1000 global installations to date. The new F421 is intended as a successor to the firm’s previous flagship INDUSTRY F420. Much like the newer model, the system is compatible with a plethora of engineering filaments.

For customers on a tighter budget, the company also offers the INDUSTRY F340 and INDUSTRY F350 3D printers. The former is designed for cost-efficient rapid prototyping and provides users with a 260 x 300 x 340 mm build chamber, while the latter features a maximum nozzle temperature of 500°C and a build volume measuring 340 x 340 x 350 mm.

The company’s latest product was designed with productivity in mind. Sporting a large-format 380 x 380 x 420 mm build volume, the INDUSTRY F421 provides ample workspace for both large part and small batch series production. The machine also offers a maximum print speed of 400 mm/s and travel speeds of up to 1 m/s, meaning throughput is a major focus here. Much like the rest of the 3DGence portfolio, the INDUSTRY F421 also boasts an impressive list of material capabilities: With a maximum nozzle temperature of 500°C and an actively heated chamber capable of 180°C, the system can process a wide variety of high-temperature thermoplastics and fiber-reinforced composites. This includes ASA, PC, PEEK, PEKK, and carbon fiber filaments. Specifically, the machine is perfectly suited for the firm’s new PEEK Aero filament. The high-strength polymer combines heat and corrosion resistance for end-use parts in aerospace. Faruqui adds, “Our customers can now rapid prototype and produce proof-of-concept end-parts in PEEK, without doubt of compliance and qualification of the material.”

Of course, when working with engineering materials, it’s also important to consider user safety. The INDUSTRY F421 comes complete with an advanced emissions control system capable of filtering macro dust, nano dust (VOC and UFP), solvent vapor, noxious gases, and other foreign particles. With the help of 3DGence’s new Material Management System, customers also now have a place to store their filaments with the confidence that they’ll be maintained in optimal temperature and humidity conditions. As a cherry on top, the INDUSTRY F421 even has a new three-year warranty policy in select European markets. Sebastian Sczasny, CEO of 3DGence, adds, “With the launch of our new F421, we wanted to make our commitment clear to our users about our quality and service with this new industry standard in warranty. As the market has progressed in requirements and complexity of applications, we designed our printers to meet these enhanced expectations in build quality, component integrity, and ease of use and maintenance.”

(Source: 3D Printing Industry)

Manufactura Aditiva con Fibra de Carbono: Los clásicos nunca se olvidan

La impresión 3D con fibra de carbono permite obtener piezas con una resistencia a flexión similar a la de ciertos metales, pero con un peso mucho más reducido y una resistencia mucho mayor a los productos químicos y la corrosión.

Aunque la fibra de carbono ha sido un material de fabricación muy utilizado desde la década de 1960, como material de impresión 3D es relativamente nuevo. Mezclada con otros materiales, incluida una amplia gama de plásticos de alto rendimiento, la fibra de carbono mejora las características de estos materiales base y amplía sus aplicaciones.

Hoy en día, las piezas de fibra de carbono impresas en 3D se utilizan preferentemente para reemplazar piezas metálicas de uso final, aunque también para obtener utillajes de alto rendimiento y peso ligero. Sin embargo, no todas las impresoras pueden imprimir con fibra de carbono pues hacen falta unas características más ajustadas a este tipo de materiales. 

He aquí el listado de las impresoras CF más adecuadas para uso industrial:

https://all3dp.com/1/carbon-fiber-3d-printing-a-guide-for-decision-makers/

REFORM + 3DGence: Gol Position

The development of modern, versatile, and economical special vehicles that can withstand continuous use under challenging conditions requires a high level of specialist knowledge and experience.

Growing product portfolios and variations require greater flexibility in shorter periods. For an innovative company like REFORM, additive manufacturing processes for product development were a logical step.

The 3D solution provider Prirevo quickly emerged as a suitable partner, able to provide the best hardware for the specific requirements and support the implementation with extraordinary expertise.

The implementation of 3D printing enabled the rapid and flexible creation of many vehicle parts in the development phase, leading to cost reductions. The company now manufactures complete interiors, trim parts, roofs, fenders, and bonnets. It optimizes fittings ergonomically, quickly, and inexpensively. Larger pieces are glued, filled, and painted.

The years of successful cooperation are reflected in the increasing use of additive manufacturing processes at REFORM. Currently, REFORM owns two 3DGENCE F340 printers and one 3DGENCE ONE 3D printer. The company also uses Prirevo’s 3D printing services at peak times and benefits from its regional proximity: “Using additive manufacturing processes allows us to create excellent prototypes that save us both time and money. We have found an excellent and reliable partner in Prirevo for the implementation of our high standards”, said Dominik Haas, design engineer at REFORM.

REFORM thus benefits from Prirevo’s strict focus on quality, user benefits, and on-site service attributes that many other satisfied customers have been relying on for years. Prirevo has already manufactured more than 8,000 components in 2021 alone for these satisfied customers.

(Source: 3D Printing Media Network)

3D Printing and its Effect on the Fashion Industry: It's More Than Just About Intellectual Property

When most people think about 3D Printing and the fashion industry, they immediately focus on the intellectual property consequences.

While there certainly are a myriad of intellectual property issues that must be addressed right now, there are several other areas that will be equally affected.

This paper will discuss how 3D Technology will affect the supply chain, employment opportunities, entrepreneurialism, tariffs, and other subject matter.

Since the technology is in its evolutionary cycle, many of the concerns to be discussed are forward-looking and of-the-moment; consequently, a deep dive into any given area is impractical.

Rather, this paper will address topics from a bird’s eye view and conclude with

thought provoking and sometimes unanswered (or even unanswerable) questions that readers should store in the back of their minds as they watch the technology improve and unfold.

(Read more...)

Free Jewelry 3D Printing Models for Download

2.189 free 3D Jewelry models ready for 3D printing with FDM, SLA, SLS and other types of 3D printing technologies.

https://www.cgtrader.com/free-3d-print-models/jewelry

Yeggi: El Google de la Impresión 3D

Creada en abril de 2013 por Sebastien Karpp, Yeggi reúne ya más de 2.3 millones de Modelos 3D en una sola plataforma que ha estado creciendo constantemente desde que entró en funcionamiento.

Puedes elegir el Modelo 3D que más te convenga, pues Yeggi te enviará directamente a la plataforma desde la que podrás descargar el modelo: Cults3D, MyMiniFactory, Thingiverse, etc.

Yeggi ofrece tambien la posibilidad de crear una cuenta gratuita a la que asociar una lista de Modelos 3D y seguir palabras clave específicas para estar informado cada vez que se publique un nuevo Archivo 3D sobre el tema en cuestión.

Anisotropy of additively manufactured AlSi10Mg: threads and surface integrity

Implementing Additive Manufacturing in an industry, particularly for critical applications of lightweight aluminum (AlSi10Mg), requires part properties that are both accurate and precise to conform to the intent of a robust design. In this experimental study, the objective was to evaluate anisotropy in part properties (i.e., flatness, surface roughness, surface porosity, surface hardness, pre-hole shrinkage, drilling thrust force, and thread-stripping force) when the part orientation (i.e., print inclination and recoater angle) was independently changed. This study developed and investigated an innovative procedure for determining anisotropy in part properties.

(Read more)

The Top-10 3D-Printable Gadgets for Xbox One

Hi gamers! Tired of confinement by the Covid-19? If you have the XBox One and a 3D Printer at hand, here I show you some gadgets for XBox, ready to download and print in 3D.

Xbox One S/X Wall Mounts

There are 3 different bottom mounts. A bottom left and right that has side tabs to keep the Xbox from sliding and one without tabs. The bottom wall mounting holes should be 8 1/4" apart for the Xbox One S. This prevents the mounts from blocking any of the air vents.

Controller Wall Hanger

A standard wall-attachable mount for hanging 2 console controllers. It can be attached to the wall either via 1/16" holes for pushpins or with an adhesive such as Command strips. Designed to be printable on a 7x7" build plate with no supports.

Xbox One Riser

These console risers are intended to lift an original Xbox One safely above a Playstation 4. When your entertainment center is crunched for space, placing the PS4 on top of the Xbox One may seem like the obvious solution... WRONG! Most of the air vents on the Xbox are directly on top and blocking those is begging for you console to overheat. The inverse (Xbox on top of PS4) isn't the most stable of stacking situations. So, the Xbox risers are simple solution to a simple problem.

Xbox One controller mini wheel

Rack and pinion steering for your xbox controller. 100 degrees of rotation. Enjoy finer control in racing games.

Xbox One Controller Stand

This is just an Xbox One controller stand but with the Xbox logo.

Xbox controller and headset wall mount

https://www.thingiverse.com/thing:3045545

XBOX ONE Thumbstick Controller Extension

Thumb stick for a standard XBOX ONE controller.

Desk Clamp Xbox Controller Holder

This is a desk holder for the controller clam grips (also works for controllers without the grips).

Modular controller stands for multiple consoles

Current set includes stands for Xbox 360, Xbox One, Gamecube, Nintendo Switch Pro, Steam, and Playstation 4. They're designed to snap to each other, and work in almost all combinations. The Steam controller is the only one that cannot be behind a Gamecube controller due to the unusually large size of the Steam controller. A spacer is included for wired Gamecube controllers, so there's space to place the coiled up cable and rest it besides the controller.

Xbox Power supply wall mount

YouMagine: More than you imagine

YouMagine is an online community of 3D Printing Enthusiasts who wish to work together to share, remix and make better 3D Printed Things.

YouMagine facilitates this community, empowers and gives you the tools you need in order to improve, invent & make.

Uniquely YouMagine is primarily a vehicle for supporting open source creation and wants to be a force multiplier for the entire 3D Printing Community. 

Uniquely they are focused on building the entire end to end open source software toolchain to make things malleable.

YouMagine wants CAD & 3D Files to be as easy to create, adapt, share and change as text is nowadays.

The Top-7 3D Model Sources from A to Z

If you are not a professional or a designer, you may need a lot of time to design 3D Models since it involved a lot of imagination, creativity, and skills to build from scratch.

There are tons of online websites available that provide 3d Models free to download. You can download the models for free and feed directly into your printer, or you can customize to meet your need.

To make your life easy, I am listing the top-7 websites to download 3D Models for 3D Printers.

GrabCAD

GrabCAD, from Stratasys, helps engineers get products to market faster by connecting people, content and technology. GrabCAD Workbench makes it easy for engineers to share files, work with partners and complete projects on time.

NIH 3D Print Exchange

The NIH 3D Print Exchange provides models in formats that are readily compatible with 3D printers, and offers a unique set of tools create and share 3D-printable models related to biomedical science.

Pinshape

A curated collection of 3D-printable designs. Some are free and some require payment to download.

Repables

3D printable file repository.

SketchFab Cultural Heritage (Creative Commons)

A collection of public domain cultural heritage 3D models. 

Thingiverse

The grandaddy of 3D model sites, Thingiverse has over 100.000 models and is easy to add to and "remix" your own versions. There are groups you can join, rating systems for models, and challenges where you can compete to complete a task.

YouMagine

A community to share, remix and make better 3D Printed Things.

Take advantage of quarantine time discovering useful free applications to learn how to model in 3D with your iPad

There are many iPad applications made for 3D Design out there. However, things get even more complicated when you realize that most 3D Design applications are targeted towards visualization or fun rather than 3D Printing. Fortunately, there are some of the best 3D Design apps for iPad that actually fit into a 3D Printing Workflow. Alright then, time to jump head-long into the world of mobile 3D Printing. Find out now some interesting applications to discover:

Sculptura: An app that hopes to satisfy all your virtual clay-morphing cravings. The simple set of tools available makes it most suitable for creating base meshes, which are then exported to desktop modeling software for more granular edits.

Shapr3D: Allows you to create concepts on the go, all of which can be exported to desktop software for more granular editing at any time. One of the most functional and reliable mobile apps out there for parametric modeling.

uMake: An application that takes advantage from the touch input to offer an easier approach to modeling. A nice bonus is the ability to view your 3D designs in augmented reality.

¿Could Chinese Cyber Army use 3D Printing to cheat The Pentagon?

“Biometrics are not an Achilles heel,” said Craig Williams, director of Cisco Talos Outreach. “Biometrics are something that makes it very, very easy to use. You don’t have to remember a password. You don’t have to enter a password, which makes it very fast and easy. You don’t have to carry anything around with you. And so I think for most users, it’s still perfectly fine.”

However, it’s possible to use 3D printing technology to create “fake fingerprints” suitable to cheat most fingerprint scanners from Apple, Microsoft and Samsung mobile products: Researchers with Cisco Talos created different threat models that use 3D printing technology, and then tested them on mobile devices (including the iPhone 8 and Samsung S10), laptops (including the Samsung Note 9, Lenovo Yoga and HP Pavilion X360) and smart devices (such as a smart padlock).

The fake fingerprints achieved an 80 percent success rate on average, where the sensors were bypassed at least once. Researchers did not have success in defeating biometrics systems in place on Microsoft Windows 10 devices (though they said that this does not mean they are not necessarily safer; just that this particular approach did not work).

Revoluciona la Automoción con HP 3D Printing

HP 3D Printing en colaboración con SERNAUTO ha organizado una serie de seminarios técnicos en Madrid, Barcelona, Valencia y Vigo, bajo el lema “Revoluciona la Automoción con HP 3D Printing”, cuyo objetivo es dar a conocer a fabricantes y proveedores de componentes la nueva tecnología 3D de HP que permite la fabricación digital directa de piezas de uso final, fijaciones y utillajes de montaje, prototipos funcionales, y modelos de concepto.

Importante: Las jornadas van a celebrarse en distintas ciudades españolas, y aunque la  asistencia es gratuita el aforo es limitado; es por ello que debes registrarte para reservar tu plaza. Para cualquier duda, puedes contactar con Laura Prous, Marketing Manager de Integral Innovation Experts, en el teléfono  637 070 666 o mediante el correo-e lprous@integralplm.com

¿Quieres reducir peso en tus misiles? Descubre cómo

HP 3D Printing ha organizado un Webinar para explicar cómo la fabricación aditiva puede mejorar los procesos de fabricación a lo largo del ciclo de vida del producto. Naturalmente, HP se centrará en su tecnología Multi Jet Fusion y creo, por lo que conozco esa tecnología y por lo que conozco del resto de tecnologías de Manufactura Aditiva, que puede ser muy interesante para fabricar misiles más ligeros mediante la sustitución de piezas metálicas por piezas de plástico: Esa reducción de peso traerá como consecuencias un menor consumo de combustible, así como un incremento de la velocidad máxima y el alcance.

Otra de las ventajas que veo super interesante para los fabricantes de misiles, estriba en la alta productividad de esta tecnología, que supera con creces al resto de tecnologías competidoras. ¿Más ventajas? El diseño absolutamente libre: Si queremos producir misiles más pequeños, más ligeros, más veloces y con mayor carga explosiva, forzosamente deberemos rediseñar sus componentes para que encajen. Pero fabricarlos puede ser luego imposible por las limitaciones que impone la fabricación tradicional mediante CNC. Sin embargo, con la manufactura aditiva ese problema desaparece, y más aún con la tecnología de HP gracias al elevado nivel de isotropia que presentan las piezas impresas mediante la tecnología Multi Jet Fusion.

En definitiva, creo recomendable apuntarse a este evento: descubrirás los beneficios de la tecnología HP Multi Jet Fusion y conocerás casos de éxito de OEMs que están reinventando la forma en la que se fabrican sus productos. Por tanto, si deseas reducir el peso de tus misiles no te pierdas esta oportunidad única de conocer en profundidad las posibilidades de esta tecnología sin precedentes.

Más información e inscripciones:

https://hp.zoom.us/webinar/register/2015650146868/WN_Zh7KVtKZTuqFSX-KOxG04g?utm_source=BenchmarkEmail&utm_campaign=Webinar_HP_diciembre_2019&utm_medium=email