personal protective equipment
Personal protective equipment (PPE) is protective clothing, helmets, goggles, or other garments or equipment designed to protect the wearer's body from injury or infection. The hazards addressed by protective equipment include physical, elect ...
, aims to protect the wearer's entire
face
The face is the front of the head that features the eyes, nose and mouth, and through which animals express many of their emotions. The face is crucial for human identity, and damage such as scarring or developmental deformities may affect th ...
(or part of it) from
hazard
A hazard is a potential source of harm. Substances, events, or circumstances can constitute hazards when their nature would potentially allow them to cause damage to health, life, property, or any other interest of value. The probability of that ...
road debris
Road debris, a form of road hazard, is debris that accumulates on or off a road. Road debris includes substances, materials, and objects that are foreign to the normal roadway environment. Debris may be produced by vehicular or non-vehicular sour ...
, chemical splashes (in
laboratories
A laboratory (; ; colloquially lab) is a facility that provides controlled conditions in which science, scientific or technological research, experiments, and measurement may be performed. Laboratories are found in a variety of settings such as s ...
or in
industry
Industry may refer to:
Economics
* Industry (economics), a generally categorized branch of economic activity
* Industry (manufacturing), a specific branch of economic activity, typically in factories with machinery
* The wider industrial sector ...
medical
Medicine is the science and Praxis (process), practice of caring for patients, managing the Medical diagnosis, diagnosis, prognosis, Preventive medicine, prevention, therapy, treatment, Palliative care, palliation of their injury or disease, ...
and laboratory environments).
Applications
Medical
In
medical
Medicine is the science and Praxis (process), practice of caring for patients, managing the Medical diagnosis, diagnosis, prognosis, Preventive medicine, prevention, therapy, treatment, Palliative care, palliation of their injury or disease, ...
applications the device is used to protect a medical professional during a procedure that might expose them to
blood
Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells.
Blood is com ...
or other potentially infectious fluids or aerosols. An example is the use of a CPR mask while performing rescue breathing or CPR. Another example is the use of face shields to reduce the likelihood of inhaling potentially infectious bioaerosols.
Police and military
File:AssaultTraining2016-18.jpg, Russian combat engineer with a 6B47 helmet and ballistic face shield, alt=
File:US Navy 060127-N-9641C-002 Chief Damage Controlman, John Brooks, removes the face shield from a Sailor's MCU-2-P gas mask.jpg, alt=text, Removing a face shield from a Sailor's MCU-2/P gas mask after washing it with decontamination solution during a General Quarters Drill aboard an aircraft carrier
In
military
A military, also known collectively as armed forces, is a heavily armed, highly organized force primarily intended for warfare. Militaries are typically authorized and maintained by a sovereign state, with their members identifiable by a d ...
or
law enforcement
Law enforcement is the activity of some members of the government or other social institutions who act in an organized manner to enforce the law by investigating, deterring, rehabilitating, or punishing people who violate the rules and norms gove ...
environments, a face shield may be designed for ballistic or non-ballistic protection. The non-ballistic shield will provide no protection from projectiles shot from firearms, but is usually designed to withstand low velocity impacts, like caused by punches or thrown objects.
A ballistic face shield is designed to stop or deflect blast and fragments from operators wearing
bomb suit
A bomb suit, Explosive Ordnance Disposal (EOD) suit or a blast suit is a heavy suit of body armor designed to withstand the pressure generated by a bomb and any fragments the bomb may produce. It is usually worn by trained personnel attempting bo ...
s To protect the wearers eyes and face from ballistic threats in combat is envisioned in the PEO Soldier program for the United States Department of Defence.
Construction
A face shield is intended to protect the wearer's partial or entire face and the eyes from hazards. Face shields should be used with
spectacles
Glasses, also known as eyeglasses (American English), spectacles (Commonwealth English), or colloquially as specs, are Visual perception, vision eyewear with clear or tinted lens (optics), lenses mounted in a frame that holds them in front ...
and/or
goggles
Goggles, or safety glasses, are forms of protective eyewear that usually enclose or protect the area surrounding the eye in order to prevent particulates, water or chemicals from striking the eyes. They are used in chemistry laboratories and ...
. On many
construction sites
Construction are processes involved in delivering buildings, infrastructure, industrial facilities, and associated activities through to the end of their life. It typically starts with planning, financing, and design that continues until the a ...
many workers use face shields to protect them from debris or sparks. Many tools for cutting and working with metal recommend the use of a face shield. Examples include welding equipment or metal chop saws.
Manufacturing
Two methods are used to manufacture face shields:
extrusion
Extrusion is a process used to create objects of a fixed cross section (geometry), cross-sectional profile by pushing material through a Die (manufacturing), die of the desired cross-section. Its two main advantages over other manufacturing pro ...
and
injection molding
Injection moulding (U.S. spelling: injection molding) is a manufacturing process for producing parts by injecting molten material into a mould, or mold. Injection moulding can be performed with a host of materials mainly including metals (for ...
. Face shields cut from extrusion sheets provide better
impact resistance
In materials science and metallurgy, toughness is the ability of a material to absorb energy and plastically deform without fracturing.molecular weight
A molecule is a group of two or more atoms that are held together by Force, attractive forces known as chemical bonds; depending on context, the term may or may not include ions that satisfy this criterion. In quantum physics, organic chemi ...
plastic
Plastics are a wide range of synthetic polymers, synthetic or Semisynthesis, semisynthetic materials composed primarily of Polymer, polymers. Their defining characteristic, Plasticity (physics), plasticity, allows them to be Injection moulding ...
pellets while injection molding must use lower molecular weight plastic pellets, which provide better melt flowing property needed by injection molding.
Face shields can be made of
polycarbonate
Polycarbonates (PC) are a group of thermoplastic polymers containing carbonate ester, carbonate groups in their chemical structures. Polycarbonates used in engineering are strong, toughness, tough materials, and some grades are optically transp ...
cellulose acetate
In biochemistry, cellulose acetate refers to any acetate ester of cellulose, usually cellulose diacetate. It was first prepared in 1865. A bioplastic, cellulose acetate is used as a film base in photography, as a component in some coatings, and ...
which provides normal impact resistance, optical quality, heat resistance and good chemical resistance.
Face shields thick made of extrusion
polycarbonate
Polycarbonates (PC) are a group of thermoplastic polymers containing carbonate ester, carbonate groups in their chemical structures. Polycarbonates used in engineering are strong, toughness, tough materials, and some grades are optically transp ...
sheets can withstand the impact of a nominal diameter steel ball traveling at the speed (European standard, protection against high-speed particles – medium energy impact), while injection molding face shields must have at least thickness to withstand the same impact. But injection molding can provide more complicated shape than extrusion.
During the
COVID-19 pandemic
The COVID-19 pandemic (also known as the coronavirus pandemic and COVID pandemic), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), began with an disease outbreak, outbreak of COVID-19 in Wuhan, China, in December ...
, people from 86 countries engaged in the voluntary production of PPE to supplement traditional supply chains - many of which had been interrupted. They collectively produced a total of 25 million face shields with techniques including
3D printing
3D printing, or additive manufacturing, is the construction of a three-dimensional object from a CAD model or a digital 3D model. It can be done in a variety of processes in which material is deposited, joined or solidified under computer ...
&
Laser cutting
Laser cutting is a technology that uses a laser to vaporize materials, resulting in a cut edge. While typically used for industrial manufacturing applications, it is now used by schools, small businesses, architecture, and hobbyists. Laser cutt ...
, in addition to injection molding.
File:3D printing of face shields.jpg, 3D printing of face shields during COVID-19 pandemic
File:Headpiece.stl, 3D file for printing a face shield
File:Buckle.stl, Buckle for the face shield
File:FaceShield3D20.jpg, Final shield
Standards
;
ANSI
The American National Standards Institute (ANSI ) is a private nonprofit organization that oversees the development of voluntary consensus standards for products, services, processes, systems, and personnel in the United States. The organiz ...
(American Standard)
* Mark Z87: Basic impact: Faceshields shall be capable of resisting impact from a 25.4 mm (1 in) diameter steel ball dropped from a height of 127 cm (50 in).
* Mark Z87+: High impact: Faceshields shall be capable of resisting impact from a 6.35 mm (0.25 in) diameter steel ball traveling at a velocity of 91.4 m/s (300 ft/s).
; EN 166 (European Standard)
These shields are for protection against high-speed particles, and must withstand the impact of a 6 mm nominal diameter steel ball, striking the oculars and the lateral protection at the speed stated.
* Mark A:
* Mark B: .
* Mark F: .
** ref. EN166
; CSA (Canadian Standard)
Z94.3-15 ''Eye and Face Protectors'' Class 6 relates to face shields, and is divided into 3 sub-classes
*6A – Impact, piercing, splash, head, and glare protection.
*6B – Radiation protection. Also for low heat, splash, glare, and light non-piercing impact protection.
*6C – High-heat applications and light non-piercing impact protection only.
**ref. CSA Z94.3-15
Helmet
A helmet is a form of protective gear worn to protect the head. More specifically, a helmet complements the skull in protecting the human brain. Ceremonial or symbolic helmets (e.g., a policeman's helmet in the United Kingdom) without protecti ...
*
Visor
A visor (also spelled vizor) is a surface that protects the eyes, such as shading them from the sun or other bright light or protecting them from objects.
Nowadays many visors are transparent, but before strong transparent substances such a ...
*
Windshield
The windshield (American English and Canadian English) or windscreen (Commonwealth English) of an aircraft, car, bus, motorbike, truck, train, boat or streetcar is the front window, which provides visibility while protecting occupants from t ...
Face masks during the COVID-19 pandemic
During the COVID-19 pandemic, face masks or coverings, including N95 respirator, N95, FFP standards#FFP2 mask, FFP2, surgical mask, surgical, and Cloth face mask, cloth masks, have been employed as public and personal health control measures ag ...