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A Glove Box Lesson from A to Z

April 03, 2017 at 12:12 PM

Glove Box

In its simplest of forms, the term “glove box” probably brings about an image of a glass case with some black gloves, but glove boxes are as varied as the applications in which they are used. With so many variables to consider, this month’s glossary-like blog is intended to help you not only understand different parts and functions, but also appreciate the potential of the latest in glove box technology and glove box design.

What is a glove box? 
Also known as a glovebox or glove box system, a glove box is a hermetically sealed enclosure (airtight) built for the purpose of sensitive applications. As we learned in an earlier blog update, a glove box can be designed with negative pressure or positive pressure, to protect the person or the process. If the purpose is to contain contamination, thereby protecting the operator, negative pressure is used. If it is the process that needs protecting, positive pressure in the form of inert gas is used to prevent a reaction with oxygen and moisture, and contamination entering the enclosure. How you can best achieve that non-reactive state depends on your application, your glove box engineer, and the investment you are willing to make.

A to Z
Acrylic Glove Box: This phrasing is common for lower-end, bench-top glove box models with a purge-style release that do not typically include a gas management system. Rather, inert gas is constantly pumped into and purged from the enclosure to maintain low O2 and H2O levels. These are more common among less sensitive applications.

Additive Manufacturing: Also known as “3D Printing,” this term encompasses a variety of 3D printing techniques, selective laser sintering and electron beam sintering being two examples. These processes can use titanium powder which quickly reacts to oxygen, nitrogen, and moisture, resulting in a poor product or even explosions. To offset those risks, an argon gas management system can displace the oxygen and moisture within the hermetic enclosure that is housing the 3D-printing equipment, and surround it with argon which will not react with the titanium. (See “Understanding Potential Reactions in a 3D Printing Enclosure” for a fuller explanation.)

Aftermarket: Think of this like giving a second life to something outdated. Since glove boxes can be designed to last for many years, and technologies can change over time, it’s common to need some kind of add-on, usually to upgrade control of the inner atmosphere. Older glove boxes often benefit from modern controls and a superior gas purification system that simply wasn’t available during initial production. At Inert, we welcome these opportunities to elevate our customers’ working potential. Our gas management systems, sensors, and other glove box parts can be outfitted to older glove box models, whether manufactured by us or not.

Application Glove Box: This phrasing is generally used for a glove box that has been customized for a specific purpose, such as powder handling, 3D printing, or atomic layer deposition (a method of producing conforming thin films, common in semiconductor device fabrication). We also hear the phrases “glove box isolator” or “hermetic enclosure” used when referencing any number of application-specific glove box needs.

Antechamber: “Ante” is Latin for “before,” so this is the space that must be crossed prior to entering the glove box. Glove box antechambers are equipped with an air lock, so when objects are passed into and out of the glove box the inside atmosphere can remain controlled. The possibilities for antechamber design and use are endless. Round is the most common for ease of gas management, but rectangular and other types are also used. T and L shaped chambers facilitate movement of objects between glove boxes with an interlocking system to prevent contamination of either enclosure.

Custom Glove Box: Similar to an application glove box, this is a standard glove box that has been customized to fit a specific need, such as to integrate with original equipment manufacturer (OEM) tools.

Dry Glove Box: This is an enclosure with a moisture-free environment for applications that specifically require no water be present. A gas management system is used to achieve and maintain the lowest-possible concentration of water in the atmosphere. At Inert, our systems are designed to accomplish H2O, considered the industry ideal.

Gas Management System (aka Gas Purification System): This is our specialty. Inert gas management systems allow total control and the ultimate in automation of glove box conditions. In a nutshell, a gas purifier removes oxygen, moisture, and solvent vapors, while a blower recirculates the gas through the enclosure, and integrated sensors constantly analyze the gas for impurities. We often get requests for gas management systems to replace prior purging techniques, resulting in cash and gas savings. We explain the benefits of recirculating versus purging more fully in a previous blog. When referring to the specific gas used, you might hear these called “Argon Management Systems” or “Nitrogen Management Systems.”

Glove Box Gloves (aka Dry Box Gloves): Gloves are the human interface to the enclosure. The gloves allow someone to work inside the glove box from the other side of the glass, keeping both the process and person safe. Gloves are made in different sizes, and configured for ambidextrousness or a left/right-hand fit. To ensure process integrity and safety, different glove materials are used in design. High-performance butyl gloves, like those standard on Inert glove boxes, are anti-static and resistant to chemicals, ultra-violet light, and ozone, as well as impervious to gas and liquids of most any kind. Butyl gloves are most common in microelectronics, wet chemistry, pharmaceutical production and medical device manufacturing. CSM (aka Hypalon) gloves are commonly used in the presence of high heat or oxidizing chemicals, used in some pharmaceutical and medical industries.

Glove Box Manufacturer: This is Inert. As it implies, a glove box manufacturer is a company who designs and engineers glove boxes to be used in laboratories, research facilities, and manufacturing processes around the world. As opposed to companies that build a huge variety of equipment, glove box manufacturers like us specialize in achieving controlled atmospheres for customer-specific conditions. There is no one-size-fits-all mentality with a glove box engineering partner.

HEPA Filter: This offers filtration without electricity. It collects particles like dust, powders, particles, and other contaminants from the glove box atmosphere as it is recirculating. HEPA filters are used in glove boxes and much larger enclosures, like clean rooms, and need to be replaced periodically to ensure that they are working at maximum efficiency.

HMI Panel: This is a screen for human-machine interface (HMI). It is where automation commands are given to the glove box and where data is displayed, such as pressure, oxygen levels, and functions currently in use. HMI panels are also designed to quickly alarm the operator, should anything ever go wrong. Inert uses color touch screen HMI panels with a programmable logic controller (PLC) by Siemens to provide easy glove box interaction.

Inert Atmosphere: This is a controlled environment inside an airtight (hermetically-sealed) enclosure, comprised of a non-reactive gas with O2 and H2O. It is suitable for experiments or actions that require the absence of water, oxygen, or other gases that interfere chemically on a molecular level. Glove boxes and other enclosures are manufactured with gas management systems to achieve an inert atmosphere. Our company was named Inert because we specialize in creating inert atmospheres for any process.

Inert Gas: This is a gas that does not react or form bonds with chemicals or molecules under normal conditions. Nitrogen is non-reactive enough that it is the most commonly used gas in glove boxes, although it is not suitable for all glove box applications. The noble gas family, which includes argon and helium, are the least reactive gases and are what are typically meant by the term “inert gas.”

Laboratory Glove Box: When a laboratory needs a glove box, this phrasing is usual. These are typically standard gloveboxes like Inert’s PureLab or I-Lab systems, and can be used for chemistry and pharmaceutical research in universities or industrial laboratories

Moisture Sensor: Also known as a moisture analyzer or H2O analyzer, this device measures water content inside a hermetic enclosure, usually in tandem with a gas management system. As a blower recirculates gas through the system, it passes by the sensor where it is analyzed down to the parts per million (ppm). Ideally, a reading of

Negative Pressure Glove Box: This is a glove box with a pressure of gas lower than the outside atmosphere, usually to protect the operator from contamination of some kind. Negative pressure glove box gloves are sunk inward rather than being pushed out, like those of a positive pressure glove box.

OLED: Short for organic light-emitting diode, these are manufactured in inert atmospheres and are used in cell phones and lighting, among other things. They are comprised of thin organic films deposited between two conducting sheets of glass or plastic, which emit light and create shapes when electricity is directed to certain parts. Creating OLEDs under inert conditions protects against defects.

Oxygen Sensor: As it sounds, this measures the oxygen level in a glove box. Inert’s line of sensors are labeled EOS (enhanced oxygen sensor) and are tailored to different conditions. When solvents are used in the process, we recommend our EOS-2 electrochemical oxygen sensor to alleviate any safety risks as solvent vapors can interfere with the reading and decay the sensing ability. Otherwise, our EOS-1 zirconia sensor will do the job of measuring oxygen.

PLC: This is the Programmable Logic Controller integrated to a gas management system, where inputs and outputs are sent through the system to signal various processes, like turning valves on or off. Inert uses Siemens SIMATIC S7-1200 PLC controllers on our glove boxes after careful evaluation of all options.

Purge Box: This is a glove box that constantly pumps gas inside to achieve low oxygen and moisture levels. There is no gas management system or automations. Purge boxes can only achieve at best the low ppm levels of the gas source, which may be higher than 1 ppm, sufficient for less sensitive work.

Purifier Column: This is a piece of glove box equipment that holds materials (copper catalyst and molecular sieve) capable of removing oxygen and moisture from the inert gas. The larger the volume of gas, the larger the purifier column usually integrated with the system. Columns require periodic regeneration to retain their absorbing capabilities, using a gas mix of argon or nitrogen with 3-7% hydrogen. Regeneration in Inert glove boxes can be done easily from the PLC without removing the columns from the system.

Recirculation System: This usually refers to the blower part of the gas management system that moves the gas around the enclosure, over the analyzers, and through the purifying columns. Recirculating the inert atmosphere inside the glove box gives accurate sensor reading while ensuring that all the gas is being purified in the columns.

Regenerable Solvent Vapor Removal: To protect the main purifying column in a glove box that uses solvents, this is a column that uses molecular sieve to remove harmful vapors. As implied by the name, this column also requires regeneration in order to remove the collected solvent vapors and to allow the column to continue working effectively.

Traceability: A feature of quality gas management systems, this is trending data useful to glove box operators. This data includes box pressure, levels of oxygen and moisture, and gas consumption (among other things) and is stored for a matter of time, as required by industry or company standards. 

Vacuum Pump: This removes pressure, which is necessary for pulling down antechambers when introducing an item into the glove box. It also pulls suction off purifying columns when regenerating.

Welding Glove Box: This glove box is designed to protect welding processes, using a gas management system. The glove box provides a controlled inert atmosphere for TIG (tungsten inert gas) and resistance welding for industries like electronic packaging, lamp manufacturing, and solar cell production.

If you have any questions about subject matter covered here, or how to achieve an inert atmosphere for your particular process, please don’t hesitate to call us at 978.462.4415.