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Life Sciences: Glove Box Technology Applications and Advancements

Fri, 08/01/2003 - 12:00am
Rich Renehan

Will medical device manufacturers, biological research, and food processing embrace and deploy dryboxes, isolators, and mini-environments much like the electronics and pharmaceutical industries have? Will yield improvements and reduced operating expenses drive the manufacturers to invest in gloveboxes and isolators for cost-effective controlled environments? What effect will this have on the cleanroom indusby? Today's manufacturing processes are more frequently being analyzed and reduced to precise time and motion studies to improve quality control, yields, and to track and contain costs Advances in Statistical Process Control (SPC) progqms, fltra tion technologies, air locks, and microscopes with external monitors, have enabled more complete control over temperature, humidity, pariiculate, and process monitoring in gloveboxes Larger port diameters, new sleeve and glove designs, and thinner, more durablepolymers have improved ergonomics and tactile sensitivity for glovebox operators.

Glovebox History

Glovebox use began in the 1940s to contain radioactive materials and to protect scientists and researchers who were experimenting with hazardous materials. The diameter of the ports were small to limit the potential exposure to users. The department of energy, NASA, and many military produdion and research facilities began using gloveboxes for handling every thing from plutonium to the first rocks retrieved from the moon.

Pharmaceutical manufacturers have been wholeheartedly embracing isolator and containment technologies in recent years. European and American manufacturers have continued to deploy glovebox (isolator)technologies for various processes including; sterility testing, sterile processing, liquid filling, and bulk powder processing. Packaging, research and radiological isotope processing are other applications utilizing isolation and containment technology. Japan, Israel, New Zealand, Australia, Singapore and Taiwan have also been showing increased interest in glovebox technology.

The electronics industry has embraced glovebox and mini- environments for controlling particulate and static contamination. Today's newest 300mm wafer-fabs are incorporating robot- ic mini-environments to eliminate the largest single source of contamination, the human worker. Processes that would once be done in a cleanroom environment can now maintain greater environmental control at lower costs in a glovebox. Product can be kept up to lo00 times cleaner in a glovebox than more standard cleanrooms.

Health care, food processing, aerospace and education markets also seem to be embracing glovebox technologies further accelerating the growth in this market. The trend to protect product, people, and processes will likely continue rapid growth, offering benefits of greater control, safer workplaces, improved production yields, improved product shelf-life and a considerable reduction in expenses for operations, consumables and waste disposal.

One of the reasons for acceptance of gloveboxes and mini-environments is that the operating expense differential between controlling a modest-sized, lo00 square foot IS0 class 7 cleanroom with associated garments and supplies,versus a glovebox, isolator or mini-environments significant. While the initial capital expense of a glovebox is greater than a cleanroom, over time the glovebox or isolator will prove a more economical investment. Perhaps more importantly, the contamination control improvements resulting from keeping the people out of the environment completely is clear and is certainly documented in various studies.

Material Options

Preferred gloves for electronics and research applications tend to be butyl for controlling gas permeation and moisture. Anti-static Nitrile sleeves and gloves have also proven quite popular for seam-sealing microchips and for production and research with other static-sensitive devices. Some cleaning processes and research applications demand even greater chemical resistance and require the use of Viton gloves. Neoprene and Hypalon gloves and sleeves can be combined with any size and polymer hand portions to offer optimal ergonomics and suit- ability for a myriad of tasks.

The glove of choice for many of these applications has been Hypalon or Nitrile as they have proven to be resistant to sterilants including Vaporized Hydrogen Peroxide and this has made them a preferred altemative to the more expensive Viton. Layered glove manufacturing processes enables production of lead-loaded gloves for protection from radioactive materials as well as combinations providing chemical compatibility and structural integrity.

Drybox gloves are available in various polymers including: natural rubber, Nitrile, Neoprene, Hypalon, Butyl, and Viton. New advances in dipping technology have enabled such advanced gloves as Polyurethane for improved abrasion and chemical resistance and multiple polymer gloves like PolyurethaneNiton and Polyurethane/Hypalon to offer chemical and punctured abrasion resistance.

Design styles range from one-piece fully dipped to two-piece straight sleeve or don/bellows styles. The sleev/glove combinations offer GOS (Glove Over Sleeve) for sterile applications and GUS (Glove Under Sleeve)for containment. Glove system lengths range from 20" to 37" while maximum reach can be achieved with the proper selection and alignment of the gloveports.

Sleeve/glove combinations also enable wider varieties of sizing and polymer choice and the replacement costs are more economical than replacing fully dipped gloves. Both styles have options for polymer thickness generally .015"and .030" (15and 30 mil), but two piece sleeve/glove combinations and advanced manufacturing and processing techniques have brought thinner gloves to the market. Thicker gauge gloves are used when dexterityand tactile sense are not as critical and when durability and abrasion resistance is a primary concern.

Gloveboxes and isolators are most frequently constructed of stainless steel with lexan or laminated safety glass windows (sometimes leaded) with circular or oval entry and egress ports/rings for product as well as for glove mounting for human access. There are a wide variety of other materials used in the construction of these chambers including: aluminum, glass, sheet metal and many advanced plastics. It is highly recommended by industry specialists to build mock-up units of wood for consideration of all logistical and ergonomic factors. Soft-Wall gloveboxes are often constructed of PVC or high quality clear plastic and are used in Space or other situations when weight is an extreme concern or when disposability is desired.

Future Growth

Glovebox technology is well suited for adaptation to robotics and some of the manipulator arms on the market that are already electronically and mechanically controlled. The hardware requires custom fittings and covers to protect the moving parts and the products inside these chambers. Many of these "mini-environments'' are widely used in advanced electronics and semi-conductor factories. In the Pharmaceutical realm there are over 200 aseptic filling lines using isolators and industry leaders and manufacturing engineers continue to embrace enclosures.

Cost savings realized from glovebox use helps level the international playing field in manufacturing technologies requiring controlled environments. Companies from countries that may have lesser developed infrastructures might now be able to research, develop and manufacture products requiring controlled environment processes. All this, at a fraction of the cost of clean-mom controlled processes. This bend will ultimately improve quality control and increase yields and profitability industry wide. In addition, cost savings can be ultimately passed on to consumers allowing wider access to medical devices and medicines world-wide.

Cleanrooms require expensive power just to regulate and change the air on a continuous basis. Supplies including gloves, garments, booties, and wipers are also quite expensive to purchase and maintain. Disposal of these items is both environmentally and fiscally costly.

Prognosticators envision long assembly lines of IS0 Class 3 controlled environments functioning perfectly well on a dirt floor with comfortable operators wearing lab coats rather than costly cleanroom "bunny- suits". While the dirt floor may seem to be an extreme example, it could become a reality and guidelines for containment, isolation and glovebox technology need to include such concerns.

It seems highly likely that Medical Devices will continue to increase the demand for isolators, dryboxes and mini-environments. Glovebox/Isolator manufacturers are very busy keeping up with demand and many of their systems are fully validated to comply with regulatory agencies. Glove supply and offerings are improving rapidly and will continue to meet the custom needs of manual and robotic isolators. It seems wise for production engineers and managers to consult with drybox and isolator manufacturers before embarking on what could be a far more costly process environment.

It is hardly likely that glovebox technology will replace cleanroom manufacturing, especially with some many thousand clean- room projects implemented worldwide since 2000. It is more likely that isolators and gloveboxes will be used in conjunction with cleanroom technology to W e r control the variables in critical and/or hazardous manufacturing processes.

Note: Hypalon and Viton are registered trademarks of DuPont

 

 

 

 

 

 

 

 

 

 

 

 

 

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