[go: up one dir, main page]

CO2017012225A1 - Blindaje transparente multi impacto - Google Patents

Blindaje transparente multi impacto

Info

Publication number
CO2017012225A1
CO2017012225A1 CONC2017/0012225A CO2017012225A CO2017012225A1 CO 2017012225 A1 CO2017012225 A1 CO 2017012225A1 CO 2017012225 A CO2017012225 A CO 2017012225A CO 2017012225 A1 CO2017012225 A1 CO 2017012225A1
Authority
CO
Colombia
Prior art keywords
layers
materials
pattern
integrated
volume
Prior art date
Application number
CONC2017/0012225A
Other languages
English (en)
Inventor
Astete Mario Arturo Mannheim
Pierre Mezeix
Original Assignee
Agp America Sa
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Agp America Sa filed Critical Agp America Sa
Publication of CO2017012225A1 publication Critical patent/CO2017012225A1/es
Priority to PCT/IB2018/056404 priority Critical patent/WO2019038720A1/en

Links

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B17/00Layered products essentially comprising sheet glass, or glass, slag, or like fibres
    • B32B17/06Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material
    • B32B17/10Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin
    • B32B17/10005Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing
    • B32B17/10009Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing characterized by the number, the constitution or treatment of glass sheets
    • B32B17/10128Treatment of at least one glass sheet
    • B32B17/10146Face treatment, e.g. etching, grinding or sand blasting
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B17/00Layered products essentially comprising sheet glass, or glass, slag, or like fibres
    • B32B17/06Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material
    • B32B17/10Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin
    • B32B17/10005Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing
    • B32B17/10009Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing characterized by the number, the constitution or treatment of glass sheets
    • B32B17/10036Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing characterized by the number, the constitution or treatment of glass sheets comprising two outer glass sheets
    • B32B17/10045Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing characterized by the number, the constitution or treatment of glass sheets comprising two outer glass sheets with at least one intermediate layer consisting of a glass sheet
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B17/00Layered products essentially comprising sheet glass, or glass, slag, or like fibres
    • B32B17/06Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material
    • B32B17/10Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin
    • B32B17/10005Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing
    • B32B17/10009Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing characterized by the number, the constitution or treatment of glass sheets
    • B32B17/10064Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing characterized by the number, the constitution or treatment of glass sheets comprising at least two glass sheets, only one of which being an outer layer
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B17/00Layered products essentially comprising sheet glass, or glass, slag, or like fibres
    • B32B17/06Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material
    • B32B17/10Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin
    • B32B17/10005Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing
    • B32B17/10009Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing characterized by the number, the constitution or treatment of glass sheets
    • B32B17/10082Properties of the bulk of a glass sheet
    • B32B17/10119Properties of the bulk of a glass sheet having a composition deviating from the basic composition of soda-lime glass, e.g. borosilicate
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B17/00Layered products essentially comprising sheet glass, or glass, slag, or like fibres
    • B32B17/06Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material
    • B32B17/10Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin
    • B32B17/10005Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing
    • B32B17/1055Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing characterized by the resin layer, i.e. interlayer
    • B32B17/1077Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing characterized by the resin layer, i.e. interlayer containing polyurethane
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B3/00Layered products comprising a layer with external or internal discontinuities or unevennesses, or a layer of non-planar shape; Layered products comprising a layer having particular features of form
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F41WEAPONS
    • F41HARMOUR; ARMOURED TURRETS; ARMOURED OR ARMED VEHICLES; MEANS OF ATTACK OR DEFENCE, e.g. CAMOUFLAGE, IN GENERAL
    • F41H5/00Armour; Armour plates
    • F41H5/02Plate construction
    • F41H5/04Plate construction composed of more than one layer
    • F41H5/0407Transparent bullet-proof laminatesinformative reference: layered products essentially comprising glass in general B32B17/06, e.g. B32B17/10009; manufacture or composition of glass, e.g. joining glass to glass C03; permanent multiple-glazing windows, e.g. with spacing therebetween, E06B3/66
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F41WEAPONS
    • F41HARMOUR; ARMOURED TURRETS; ARMOURED OR ARMED VEHICLES; MEANS OF ATTACK OR DEFENCE, e.g. CAMOUFLAGE, IN GENERAL
    • F41H5/00Armour; Armour plates
    • F41H5/02Plate construction
    • F41H5/04Plate construction composed of more than one layer
    • F41H5/0414Layered armour containing ceramic material
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2333/00Polymers of unsaturated acids or derivatives thereof
    • B32B2333/04Polymers of esters
    • B32B2333/12Polymers of methacrylic acid esters, e.g. PMMA, i.e. polymethylmethacrylate
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2369/00Polycarbonates

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Ceramic Engineering (AREA)
  • Aiming, Guidance, Guns With A Light Source, Armor, Camouflage, And Targets (AREA)
  • Laminated Bodies (AREA)
  • Joining Of Glass To Other Materials (AREA)

Abstract

La presente invención se refiere a un conjunto especial de materiales de una composición blindada transparente, para aplicaciones de transporte y arquitectura. Estas capas pueden estar hechas de diferentes materiales orgánicos o inorgánicos, incluyendo vidrio, vitrocerámica, materiales poliméricos, cerámica transparente, monocristal y pueden estar unidas entre sí por un material polimérico, en donde los puntos débiles están dibujados en la superficie o integrados dentro del volumen de cualquiera de las capas del laminado blindado, mejorando el comportamiento frente a los ataques de impactos múltiples. Este comportamiento se obtiene creando un patrón de debilidades ya sea en la superficie o integrado dentro del volumen de cualquiera de las capas del blindaje laminado. El patrón de debilidad puede obtenerse por diferentes procesos, incluyendo, pero sin limitarse a, intercambio iónico, templado térmico, rasgado / abrasión y por láser. La estructura laminada se beneficia de las capas heterogéneas ofreciendo una buena visibilidad antes y después, así como un mejor rendimiento contra la penetración de impactos múltiples.
CONC2017/0012225A 2017-08-23 2017-11-28 Blindaje transparente multi impacto CO2017012225A1 (es)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/IB2018/056404 WO2019038720A1 (en) 2017-08-23 2018-08-23 TRANSPARENT MULTI-CUT SHIELD

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US201762549028P 2017-08-23 2017-08-23

Publications (1)

Publication Number Publication Date
CO2017012225A1 true CO2017012225A1 (es) 2018-02-20

Family

ID=62596754

Family Applications (1)

Application Number Title Priority Date Filing Date
CONC2017/0012225A CO2017012225A1 (es) 2017-08-23 2017-11-28 Blindaje transparente multi impacto

Country Status (2)

Country Link
CO (1) CO2017012225A1 (es)
WO (1) WO2019038720A1 (es)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115923264B (zh) * 2022-10-17 2024-06-04 杭州乾智坤达新材料科技有限公司 一种冲击后保持高能见度的防弹防爆玻璃
US20250146796A1 (en) * 2023-11-07 2025-05-08 Timo Olavi Tervola Ballistic shield with a transparent window
CN117799251A (zh) * 2024-01-03 2024-04-02 中国科学技术大学 一种具有仿生混合结构的安全玻璃及其制备方法
CN117818171B (zh) * 2024-01-03 2025-12-26 中国科学技术大学 一种具有仿贝壳结构的夹层玻璃及其制备方法
CN119178363B (zh) * 2024-11-22 2025-04-11 武汉理工大学 一种抗冲击高强韧层状梯度结构及其制备方法

Family Cites Families (60)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3573150A (en) 1968-07-24 1971-03-30 Us Army Transparent armor
GB1359166A (en) * 1971-05-21 1974-07-10 Glaverbel Panels incorporating a glass or vitrocrystalline sheet and the manufacture thereof
US5686689A (en) 1985-05-17 1997-11-11 Aeronautical Research Associates Of Princeton, Inc. Lightweight composite armor
FR2605267B1 (fr) 1986-10-15 1989-06-30 Goeury Walter Panneau de protection et notamment ecran balistique
FR2642419A1 (fr) 1988-12-19 1990-08-03 Europ Propulsion Materiau de protection a structure ceramique multi-couches
US5326606A (en) 1992-08-12 1994-07-05 Armorvision Plastics & Glass Bullet proof panel
US5637244A (en) 1993-05-13 1997-06-10 Podarok International, Inc. Method and apparatus for creating an image by a pulsed laser beam inside a transparent material
DE4336321A1 (de) 1993-10-25 1995-04-27 Ver Glaswerke Gmbh Beschußhemmende Panzerglasscheibe für Kraftfahrzeuge
US5506051A (en) 1994-01-27 1996-04-09 Nicolectronix Ltd. Laboratories Transparent sheet composites for use as bullet-proof windows
US5705765A (en) 1996-05-30 1998-01-06 United Defense, L.P. Passive roof armor
US6009789A (en) 1997-05-01 2000-01-04 Simula Inc. Ceramic tile armor with enhanced joint and edge protection
US5970843A (en) 1997-05-12 1999-10-26 Northtrop Grumman Corporation Fiber reinforced ceramic matrix composite armor
GB2336807A (en) * 1998-04-27 1999-11-03 David Adie Ceramic sandwich material for ballistic protection
FR2795365B1 (fr) 1999-06-25 2002-07-12 Saint Gobain Vitrage Vitrage feuillete blinde, en particulier pour vehicules automobiles
US6333486B1 (en) 2000-04-25 2001-12-25 Igor Troitski Method and laser system for creation of laser-induced damages to produce high quality images
US6532857B1 (en) 2000-05-12 2003-03-18 Ceradyne, Inc. Ceramic array armor
GB2368383A (en) 2000-10-26 2002-05-01 Secr Defence An armour tile with angled edges
US6601497B2 (en) 2001-04-24 2003-08-05 The United States Of America As Represented By The Secretary Of The Army Armor with in-plane confinement of ceramic tiles
US7562612B2 (en) 2001-07-25 2009-07-21 Aceram Materials & Technologies, Inc. Ceramic components, ceramic component systems, and ceramic armour systems
US6818268B2 (en) 2002-04-03 2004-11-16 The United States Of America As Represented By The Secretary Of The Army Transparent armor structure
US7311790B2 (en) 2003-04-25 2007-12-25 Siemens Power Generation, Inc. Hybrid structure using ceramic tiles and method of manufacture
US7318956B2 (en) 2003-12-23 2008-01-15 Labock Technologies Inc. One way bullet-resistant transparent panel
WO2007058665A2 (en) 2004-12-03 2007-05-24 Cccip, Llc Optically transmissive armor composite
GB0506360D0 (en) 2005-03-30 2005-05-04 Secr Defence A ceramic element for use in armour
CA2604287C (en) 2005-04-12 2016-01-05 Arkema France Transparent bullet-resistant acrylic sheet
US7617757B2 (en) 2005-05-26 2009-11-17 Composix Co. Ceramic multi-hit armor
EP2287557A1 (en) 2005-06-10 2011-02-23 Saint-Gobain Ceramics and Plastics, Inc. Transparent Ceramic Composite
US7626138B2 (en) 2005-09-08 2009-12-01 Imra America, Inc. Transparent material processing with an ultrashort pulse laser
US7875565B1 (en) 2006-05-31 2011-01-25 Corning Incorporated Transparent glass-ceramic armor
US7861638B1 (en) 2006-06-15 2011-01-04 Defbar Systems Llc Transparent blast and ballistic projectile resistant barrier
US7703375B1 (en) 2006-08-15 2010-04-27 Lawrence Technological University Composite armor with a cellular structure
DE102006047110A1 (de) * 2006-09-27 2008-04-03 Deutsches Zentrum für Luft- und Raumfahrt e.V. Keramische Panzerung und Verfahren zur Herstellung einer keramischen Panzerung
US7681485B2 (en) 2006-11-16 2010-03-23 American Development Group International, Llc Transparent ballistic resistant armor
WO2008140480A1 (en) * 2006-11-30 2008-11-20 Corning Incorporated Crack-arresting transparent armor
EP2087194B1 (en) 2006-12-05 2013-01-09 Oran Safety Glass Ltd Blast and impact resistant window pane systems
US8161862B1 (en) 2007-01-08 2012-04-24 Corning Incorporated Hybrid laminated transparent armor
US8176828B2 (en) 2007-03-21 2012-05-15 Schott Corporation Glass-ceramic with laminates
US20080236378A1 (en) 2007-03-30 2008-10-02 Intellectual Property Holdings, Llc Affixable armor tiles
US20090320675A1 (en) 2007-04-23 2009-12-31 Landingham Richard L Mosaic Transparent Armor
US20100275767A1 (en) 2007-08-31 2010-11-04 Linda Ruth Pinckney Multi-hit capable transparent, multi-stack armor system
US8603616B1 (en) 2007-09-27 2013-12-10 Schott Corporation Lightweight transparent armor window
US7641965B1 (en) 2008-06-30 2010-01-05 E.I. Du Pont De Nemours And Company Transparent light-weight safety glazings
US20150132560A9 (en) 2008-11-13 2015-05-14 Thilo Zachau Highly transparent impact-resistant plate laminate and armored or bulletproof glass and articles made with same
US20110072961A1 (en) 2008-11-20 2011-03-31 GKN Aerospace Transparency Systems, Inc. Environmental seal technology for spaced transparent armor
US8281550B1 (en) 2009-08-11 2012-10-09 Agp Plastics, Inc. Impact and fire resistant windows
US8932510B2 (en) 2009-08-28 2015-01-13 Corning Incorporated Methods for laser cutting glass substrates
US20110127242A1 (en) 2009-11-30 2011-06-02 Xinghua Li Methods for laser scribing and separating glass substrates
WO2012039803A1 (en) 2010-06-22 2012-03-29 Standard Bent Glass Corporation Armor
US8640591B2 (en) 2010-06-30 2014-02-04 Corning Incorporated Transparent armor with improved multi-hit performance by use of a thin cover glass
DE202011001371U1 (de) 2011-01-12 2011-04-14 Isoclima Gmbh Panzerglasscheibe und zugehörige, durchschusshemmende Vorrichtung
US8652281B2 (en) 2011-01-31 2014-02-18 The United States Of America, As Represented By The Secretary Of The Navy Spinel ceramics via edge bonding
US9157703B2 (en) 2011-04-01 2015-10-13 Am General Llc Transparent Armor Structure
US10046540B2 (en) 2011-04-22 2018-08-14 Oran Safety Glass Inc. Light weight temperature resistant transparent laminate structure
CO6790239A1 (es) * 2012-05-09 2013-11-14 Agp America Sa Vidrios blindados curvos con vidrios, vitro- cerámicos o cerámicos curvados mecánicamente en la capa externa
US9938180B2 (en) 2012-06-05 2018-04-10 Corning Incorporated Methods of cutting glass using a laser
CN105246850B (zh) * 2012-11-29 2018-01-30 康宁股份有限公司 通过激光损坏和蚀刻制造玻璃制品的方法
US9383173B2 (en) 2013-07-22 2016-07-05 The United States Of America As Represented By The Secretary Of The Army Transparent armor construction
US20150034613A1 (en) 2013-08-02 2015-02-05 Rofin-Sinar Technologies Inc. System for performing laser filamentation within transparent materials
CA2883427A1 (en) * 2014-02-28 2015-08-28 The Royal Institution For The Advancement Of Learning / Mcgill University Methods and systems relating to enhancing material toughness
US20170197873A1 (en) * 2014-06-06 2017-07-13 The Royal Institution For The Advancement Of Learning/Mcgill University Methods and systems relating to enhancing material toughness

Also Published As

Publication number Publication date
WO2019038720A1 (en) 2019-02-28

Similar Documents

Publication Publication Date Title
CO2017012225A1 (es) Blindaje transparente multi impacto
ES2596903T3 (es) Artículos que incluyen revestimientos anticondensación y/o de baja emisividad y/o métodos para la fabricación de los mismos
CN104377223B (zh) 柔性显示器
BR112014013200A2 (pt) dispositivo para visualizar uma imagem em um substrato laminado
KR102369633B1 (ko) 유기발광다이오드표시장치 및 이의 제조방법
PE20141856A1 (es) Metodo para formar una imagen laser a color con alta fluencia reflectante y documento en el cual se produce de este modo una imagen laser a color
ES2621941T3 (es) Estructura laminada que incluye en ella un revestimiento de imprimación
BR112018011957A2 (pt) para-brisa laminado veicular com sinalização luminosa interna
ECSP19032104A (es) Documento de seguridad con un elemento de seguridad, un método para producirlo y un elemento de seguridad
MX2015002193A (es) Cristal compuesto con propiedades opticas conmutables electricamente.
US20150036299A1 (en) Flexible display device
BR112018011956A2 (pt) para-brisa laminado veicular com sinalização luminosa interna
MX2015015030A (es) Impresion de color aditivo.
BR112018074285A2 (pt) teto de vidro laminado luminoso de veículo, veículo incorporando o mesmo e fabricação
MX2018006131A (es) Guante con deteccion de interrupciones con un alto contraste entre el color en el lado de colocacion y el lado de sujecion del guante.
MX2018007324A (es) Vidrio delgado de color quimicamente reforzado.
MX2017000005A (es) Ensamble de acristalamiento luminoso.
BR112018074286A2 (pt) teto de vidro laminado luminoso de veículo, veículo incorporando o mesmo e fabricação
EA201791307A1 (ru) Многослойное стекло
JP2016103395A5 (es)
BR112018011958A2 (pt) para-brisa laminado veicular com sinalização luminosa interna
MX2015012924A (es) Escudo balístico.
BR112018074289A2 (pt) teto de vidro laminado luminoso de veículo, veículo incorporando o mesmo e fabricação
MX2013011600A (es) Metodo y aparato para ventana de iluminacion en estado solido mediante un diodo organico emisor de luz con emision de un lado, por lo menos parcialmente transparente.
CO2018009498A2 (es) Un panel sándwich