More than 1 million U.S. workers receive emergency treatment for acute hand injuries each year, and the U.S. Bureau of Labor Statistics estimates that 110,000 workers with hand and finger injuries lose days at work annually, which is second only to back problems as a cause of lost workdays.
With ever-greater strides in technology, jobs and their accompanying hand protection needs have become more specialized. At the same time, workers now demand task-specific personal protection equipment (PPE) that is comfortable to wear. In some cases, workers' hands must be protected from caustic chemicals or sharp objects. In other cases, it is the equipment — delicate electronics parts, for example — that needs to be protected from a worker's hands. As a result, research and development (R&D) has emerged as the lifeline of the glove industry; the group challenged to provide hand protection that works and is worn.
R&D at leading U.S. glove manufacturers is an exciting world where new discoveries are made every day. Typically, a company's team of six to 10 scientists may be working on dozens of “what if,” blue sky experimental concepts; 10 to 15 products that have the green-light for full investigation; and a half-dozen or so new products that are within 6 months of launch. Every glove concept starts with an idea, an idea that can emerge from anywhere from scientific research to the experience of an end user or even another industry's success. Before it comes to market, that glove concept goes through months or even years of development, internal testing, modifications and end user testing. Some concepts can be years in development and never make it to market.
Most of R&D's work takes place at the lab bench where samples are handmade, tested, retested, improved upon and then tested over and over again until the desired hand protection is achieved. However, because hand protection research is as much a matter of understanding work environments and worker needs as it is understanding chemistry and glove manufacturing capabilities, U.S.-based glove R&D teams spend a good amount of time away from the laboratory visiting end-user sites, evaluating hand protection challenges and gathering the insights that lead to new concepts. In addition, glove industry R&D departments contain libraries of trade journals and research papers across the spectrum of manufacturing, and include updates on everything from Federal Drug Administration requirements for medical devices and 510K approval to ASTM testing requirements.
A Multi-Faceted Pursuit
Glove industry R&D is multifaceted. Not only are R&D scientists (primarily chemists and chemical engineers) challenged to improve current hand protection products, they also are charged with coming up with new PPE concepts, assessing emerging hand protection needs in all industries and applying new materials and technologies from other industries — such as clothing and cosmetics — to hand protection. R&D involves every aspect of hand protection — from the threat to hand safety to glove material selection (including liners, coating and special fibers) to ergonomic design, fit and comfort and performance.
The disposable nitrile glove that provides barrier protection without the hazards of latex allergy, heat-resistant gloves that protect up to 500°F, chemical-resistant gloves designed to shield working hands from specific chemicals, cut-resistant gloves that use the same fibers that are used in bullet-proof vests and oil absorbent gloves that improve grip are all the result of R&D. Today, R&D is involved in incorporating everything from high visibility to nanotechnology into hand protection.
It's a process that has R&D scientists looking everywhere for new ideas. Thus, when the textile industry introduces a new fabric with stretch or stain resistance, or with properties that enable it to prohibit liquid entry from one surface yet facilitate wicking from the other, the glove industry takes note and tasks itself with applying this technology to hand protection. Similarly, cosmetic industry innovations in antimicrobials or skin softeners such as aloe that could make glove wearing more comfortable — and increase the amount of time workers wear gloves — are assessed as possible PPE enhancements. Even a new coating developed for a car's dashboard could be the starting point of a new glove coating.
When law enforcement and military applications required stealth along with barrier protection, glove industry R&D came up with black variations of the highly effective, nitrile disposable glove. When workers in the automotive industry needed a glove that would provide grip in oily conditions, R&D developed a sponge nitrile coating to fit the bill.
As scientists, glove R&D team members are always in search of the ideal product for the application. Along the way, they discover many offshoots with potential for full-fledged development. Even the slightest variation to an existing product undergoes comprehensive testing before it is incorporated as a new product. Thus, a change as small as altering the color of a disposable nitrile glove from white to black requires clinical verification that the extractables associated with the addition of different colorants will not be harmful to the wearer.
A Concept Morphs
Glove R&D is a matter of subtlety. Totally new glove concepts, like the introduction of the N-DEX disposable nitrile glove in the early 1990s, are the exception. More frequently, today's R&D deals with enhancing existing concepts to accommodate the requirements of a specific task. The sponge, nitrile-coated general purpose Zorb-IT glove family is a good example from my own company of how a concept evolves in different directions to meet different needs.
Four to 5 years ago, it became apparent that workers in industries such as the automotive industry needed a glove that would provide a secure grip in wet or oily conditions without requiring extraordinary grip force. That glove also needed to be washable without shrinking or delaminating and comfortable to wear.
The initial product to emerge from R&D and enter the market had a nylon liner flat-dipped in a sponge nitrile coating. From this initial concept, R&D went on to create a cut-resistant version of the glove to meet workplace PPE needs where cuts to the hand are a risk. This glove, again flat-dipped, employs a shell of aramid fibers (DuPont's Kevlar) spun with stretchable, breathable Lycra. The glove concept continued to evolve with the option of a three-quarter dipped model to provide over-the-knuckle protection and a hi-visibility model for added visibility on the job site.
But R&D did not stop there. Interestingly, there was a call in the field for a version of the glove with “some, but less” oil absorbency. This led to the introduction of a “lite” version of the glove in an aesthetically appealing black color that effectively conceals oil stains.
Thus, one glove concept — the need for a glove that would provide grip despite oily conditions — has led to a growing family of five glove models. And this is the case in dozens of instances. Task requirements have led to disposable gloves in various thicknesses and colorations. Chemical hazards have been the impetus to variations in chemical-resistant gloves. Varying degrees of flexibility are afforded in very similar general-purpose glove models, each designed to help the worker perform the specific task safely and comfortably.
It's a Science
Despite all the emotional and practical issues that lead to development of a glove concept, glove industry R&D is a science, not an art. Most R&D takes place within the categories in which PPE gloves are produced: cut-resistant gloves, chemical-resistant gloves, disposable gloves, general-purpose gloves and thermal gloves.
The type of testing involved in the development of each glove is dependent upon the task for which it will be used. The equipment used is state-of-the-art, and the testing is rigorous. Here is a brief look at some of what is involved in ensuring that concept gloves in each of these areas come to market fully-capable of living up to the promise their name and category offer.
Disposable gloves: During the development stage, disposable gloves are tested for everything from barrier protection and durability and strength to elasticity, fit and comfort, tactile sensitivity and allergenicity. In the laboratory, the MTS Insight and Q-Test machines are used to test tensile strength, relaxation and puncture resistance. In the early stages of development, laboratory scientists hand dip the same gloves forms as will eventually be used on the manufacturing floor to test various glove thicknesses and to calibrate the ideal temperature for the form in manufacturing gloves. Before the glove is finally introduced, as many as 2,000 to 3,000 dozen pairs of gloves may have been trialed and field-tested.
Disposable gloves for the health care industry: These disposable gloves undergo even more testing and scrutiny before they are introduced. Once a medical glove has been thoroughly tested by the manufacturer's laboratory and, in many cases, outside laboratories with credentials in testing products that must provide a barrier against blood-borne pathogens, a 510K is filed with the Federal Drug Administration and the product is reviewed by the FDA for approval for use in the United States. Similar procedures are followed with other countries in which the product will be offered.
Cut-resistant gloves: Workers in industries such as meat cutting and packing, glass cutting, metal stamping, construction, carpentry, forestry and fishery require cut-resistant PPE every day on the job. Cut-resistant gloves are rated on a scale of 1 to 5 using American Standard Testing Methods (ASTM), with 5 being the highest level of cut resistance. The rating is in terms of grams of resistance.
In the laboratory, the TDM-100 is the equipment most frequently used to determine cut resistance. Importantly, after a specific cut-resistant glove model has been introduced, every week samples are tested for cut resistance by quality assurance. (It is essential to note that although 5 is the highest rating for heavy-duty applications, no cut-resistant glove provides protection against serrated blades.)
Chemical-resistant gloves: Most chemical-resistant gloves are coated gloves. The R&D team continually is working to create gloves that stand up to chemical permeation and degradation for longer and longer periods of time. The gas chromatograph equipment is used in the laboratory to determine the chemical breakthrough time (chemical permeation) for coatings/gloves per ASTM F-739 Method for Heavy Exposure. Gloves also are measured per ASTM F1383 Method for Intermittent Contact with Chemicals.
General purpose gloves: The new age replacement for the leather or cotton work gloves that were worn a century ago, general purpose gloves come in many forms. Depending upon the application, laboratory testing involves everything from testing grip to testing launderability, abrasion resistance, shrinkage, wicking capability and dexterity. The Friction/Peel Tester is used for grip testing. It is used to determine the C.O.F. for gloves on different substrates (sheet metal, glass, etc.) The Taber Machine is used to measure abrasion resistance.
Thermal gloves: Heat and cold are hazards on many worksites. In the laboratory, the Thermal Conductivity Tester documents how much heat is conducted from a known source (a plate heated to a specific temperature) through the glove material to the person wearing the glove. Designed per ASTM F1060, this conductivity tester indicates at what temperatures heat will be felt by the wearer and at what temperatures pain and injury might occur.
A Broad-Base Effort
Not all glove industry R&D occurs in the company-based laboratory. The laboratory is where concepts come to life and new standards are established. After that, end-users provide valuable input as to how the concept prototype performs. This input, some of it subjective, can lead to additional products, enhancements to the concept product or in some cases entirely new concepts.
In addition, because many aspects of hand protection are so specialized, concept products frequently are evaluated by outside testing laboratories and, in some cases, educational institution teams to validate performance. At the end of the cycle, the successful testing and introduction of a new PPE glove is as exciting for the R&D team as winning top marks in any Insurance Institute for Highway Safety car crash test.
Eric Goddard is the R&D supervisor for Best Glove. Before joining Best, he worked for Ansell Healthcare as a product development chemist. He has 9 years of experience in research and development of PPE for hand and arm protection.