4 ATOMO Dental High Quality Dental Supplies -- General Features and Specifications of Nitrile Gloves

General Features and Specifications of Nitrile Gloves

1, Specification of Nitrile Gloves: 

Nitrile gloves can be separated into 2 categories: Medical use and Industry use.

FEATURES of medical use Nitrile gloves:

• Ultra Soft to minimize stress.
• 100% Latex Free.
• Powder Free. Non-sterile.
• Stronger. Meets/exceeds NFPA requirements.
• Tested using medical level standard ASTM D6319.
• Blue color.
• 100/box, 10 boxes/case.
• 2 thickness options: 3mil and 4mil, satisfy all situations.
• Length: 9.5"

A3 (3mil)

 A4 (4mil)

2, More information on Nitrile Gloves: 

Nitrile Gloves are made from Nitrile Rubber.  

Nitrile rubber, also known as Buna-N, Perbunan, acrylonitrile butadiene rubber, and NBR, is a synthetic rubber copolymer of acrylonitrile (ACN) and butadiene. Trade names include Nipol, Krynac and Europrene.

Nitrile butadiene rubber (NBR) is a family of unsaturated copolymers of 2-propenenitrile and various butadiene monomers (1,2-butadiene and 1,3-butadiene). Although its physical and chemical properties vary depending on the polymer’s composition of nitrile, this form of synthetic rubber is unusual in being generally resistant to oil, fuel, and other chemicals (the more nitrile within the polymer, the higher the resistance to oils but the lower the flexibility of the material).

It is used in the automotive and aeronautical industry to make fuel and oil handling hoses, seals, grommets, and self-sealing fuel tanks, since ordinary rubbers cannot be used.[1] It is used in the nuclear industry to make protective gloves. NBR's ability to withstand a range of temperatures from −40 to 108 °C (−40 to 226 °F) makes it an ideal material for aeronautical applications. Nitrile butadiene is also used to create moulded goods, footwear, adhesives, sealants, sponges, expanded foams, and floor mats.

Its resilience makes NBR a useful material for disposable lab, cleaning, and examination gloves. Nitrile rubber is more resistant than natural rubber to oils and acids, and has superior strength, but has inferior flexibility. Nitrile gloves are therefore more puncture-resistant than natural rubber gloves, especially if the latter are degraded by exposure to chemicals or ozone.[citation needed] Nitrile rubber is less likely to cause an allergic reaction than natural rubber.

Nitrile rubber is generally resistant to aliphatic hydrocarbons. Nitrile, like natural rubber, can be attacked by ozone, ketones, esters and aldehydes.


Production

Krynac 33110 F nitrile rubber bales
Emulsifier (soap), 2-propenenitrile, various butadiene monomers (including 1,3-butadiene, 1,2-butadiene), radical generating activators, and a catalyst are added to polymerization vessels in the production of hot NBR. Water serves as the reaction medium within the vessel. The tanks are heated to 30–40 °C to facilitate the polymerization reaction and to promote branch formation in the polymer. Because several monomers capable of propagating the reaction are involved in the production of nitrile rubber the composition of each polymer can vary (depending on the concentrations of each monomer added to the polymerization tank and the conditions within the tank). One repeating unit found throughout the entire polymer may not exist. For this reason there is also no IUPAC name for the general polymer. The reaction for one possible portion of the polymer is shown below:

1,3-butadiene + 1,3-butadiene + 2-propenenitrile + 1,3-butadiene + 1,2-butadiene → nitrile butadiene rubber
Monomers are usually permitted to react for 5 to 12 hours. Polymerization is allowed to proceed to ~70% conversion before a “shortstop” agent (such as dimethyldithiocarbamate and diethyl hydroxylamine) is added to react with the remaining free radicals. Once the resultant latex has “shortstopped”, the unreacted monomers are removed through a steam in a slurry stripper. Recovery of unreacted monomers is close to 100%. After monomer recovery, latex is sent through a series of filters to remove unwanted solids and then sent to the blending tanks where it is stabilized with an antioxidant. The yielded polymer latex is coagulated using calcium nitrate, aluminium sulfate, and other coagulating agents in an aluminium tank. The coagulated substance is then washed and dried into crumb rubber.

The process for the production of cold NBR is very similar to that of hot NBR. Polymerization tanks are heated to 5–15 °C instead of 30–40 °C. Under lower temperature conditions, less branching will form on polymers (the amount of branching distinguishes cold NBR from hot NBR).

Properties
The raw material is yellow in color, though it can be orange or red tinted, depending on the manufacturer. Its elongation after fracture is ≥ 300% and possesses a tensile strength of ≥ 10 N/mm2. NBR has good resistance to mineral oils, vegetable oils, benzene/petrol, ordinary diluted acids and alkalines.

An important factor in the properties of NBR is the ratio of acrylonitrile groups to butadiene groups in the polymer backbone, referred to as the ACN content. The lower the ACN content, the lower the glass transition temperature; however, the higher the ACN content, the better resistance the polymer will have to nonpolar solvents as mentioned above. Most applications requiring both solvent resistance and low temperature flexibility require an ACN content of 33%.

Applications

A disposable nitrile rubber glove.
The uses of nitrile rubber include disposable non-latex gloves, automotive transmission belts, hoses, O rings, gaskets, oil seals, V belts, synthetic leather, printer's form rollers, and as cable jacketing; NBR latex can also be used in the preparation of adhesives and as a pigment binder.

Unlike polymers meant for ingestion, where small inconsistencies in chemical composition/structure can have a pronounced effect on the body, the general properties of NBR are not altered by minor structural/compositional differences. The production process itself is not overly complex; the polymerization, monomer recovery, and coagulation processes require some additives and equipment, but they are typical of the production of most rubbers. The necessary apparatus is simple and easy to obtain. For these reasons, the substance is widely produced in poorer countries where labor is relatively cheap. Among the highest producers of NBR are mainland China and Taiwan.

A hydrogenated version of nitrile rubber, HNBR, also known as HSN (highly saturated nitrile) is commonly used to manufacture o-rings for automotive air-conditioning systems.[3]

In January 2008 the European Commission imposed fines totaling €34,230,000 on the Bayer and Zeon groups for fixing prices for nitrile butadiene rubber, in violation of the EU ban on cartels and restrictive business practices (Article 81 of the EC Treaty and Article 53 of the EEA Agreement).[4]

Dangers
Use of these gloves when working with nitric acid or other strong oxidizers can be hazardous; the sample may spontaneously oxidize the gloves on contact, resulting in thermal and chemical burns from both the heat of oxidation and the caustic sample.[citation needed]

HNBR
Hydrogenated nitrile butadiene rubber (HNBR) is widely known for its physical strength and retention of properties after long-term exposure to heat, oil and chemicals. Trade names include Mill-Right ES (Garlock Klozure), Therban (Mobay) and Zetpol (Zeon Chemical).

Depending on filler selection and loading, HNBR compounds typically have tensile strengths of 20–31 MPa when measured at 23 °C. Compounding techniques allow for HNBR to be used over a broad temperature range, -40 °C to 165 °C, with minimal degradation over long periods of time. For low-temperature performance, low ACN grades should be used; high-temperature performance can be obtained by using highly saturated HNBR grades with white fillers. As a group, HNBR elastomers have excellent resistance to common automotive fluids (e.g., engine oil, coolant, fuel, etc.) and many industrial chemicals. Like NBR, fluid and chemical resistance improves as the ACN content is increased.[citation needed]

The unique properties and higher temperature rating attributed to HNBR when compared to NBR has resulted in wide adoption of HNBR in automotive, industrial, and assorted, performance-demanding applications. On a volume basis, the automotive market is the largest consumer, using HNBR for a host of dynamic and static seals, hoses, and belts. HNBR has also been widely employed in industrial sealing for oil field exploration and processing, as well as rolls for steel and paper mills.

XNBR
An improved version of nitrile butadiene rubber (NBR) is carboxylated nitrile butadiene rubber (XNBR). In this execution there are beside the sulfur bridges also carboxyl groups R-COO- on the double bond of the butadiene part. These groups will make ionic cross links with zinc (Zn2+) to give improved physical properties as compared to a non-carboxylated nitrile rubber. These ionic crosslinks are formed along with sulfur links. The carboxyl groups which are needed for these extra links are distributed randomly and are present at levels of 10% or less.

3, more detailed information for Medical gloves:

Medical gloves are disposable gloves used during medical examinations and procedures that help prevent contamination between caregivers and patients.[1] Medical gloves are made of different polymers including latex, nitrile rubber, vinyl and neoprene; they come unpowdered, or powdered with cornstarch to lubricate the gloves, making them easier to put on the hands.[2] Cornstarch replaced tissue-irritating Lycopodium powder and talc, but since even cornstarch can impede healing if it gets into tissues (as during surgery), unpowdered gloves are being used more often during surgery and other sensitive procedures. Special manufacturing processes are used to compensate for the lack of powder. There are two main types of gloves: exam and surgical. Surgical gloves have more precise sizing with a better precision and sensitivity and are made to a higher standard. Exam gloves are available as either sterile or non-sterile, while surgical gloves are generally sterile.

History
In 1890 William Stewart Halsted was the first to use sterilized medical gloves when he was at Johns Hopkins University.[4][5] With the publication of germ theory Halsted was using carbolic acid, introduced by Joseph Lister, to sterilize his hands and his nurse's hands. She was sensitive to the chemical, and it was damaging the skin on her hands; so he asked the Goodyear Tire and Rubber Company if they could make a glove of rubber that could be dipped in carbolic acid.

Glove materials

Latex

Neoprene
The first disposable latex medical gloves were manufactured in 1964 by Ansell. They based the production on the technique for making condoms.[6] These gloves have a range of clinical uses ranging from dealing with human excrement to dental applications.

Criminals have also been known to wear these gloves during the commission of their crimes. These gloves are often chosen because their thinness and tight fit allow for dexterity. However because of the thinness of these gloves, fingerprints may actually pass through the material as glove prints, thus transferring the wearer's prints onto whatever surface is touched or handled.[7][better source needed][8]

The participants of the Watergate burglaries infamously did so wearing rubber surgical gloves in an effort to hide their fingerprints.

Alternatives to latex
Main article: Latex allergy

Nitrile powder free gloves
Due to the increasing rate of latex allergy among health professionals, and in the general population, gloves made of non-latex materials such as vinyl, nitrile rubber, or neoprene have become widely used. Chemical processes may be employed to reduce the amount of antigenic protein in Hevea latex, resulting in alternative natural-rubber-based materials such Vytex Natural Rubber Latex. However, non-latex gloves have not yet replaced latex gloves in surgical procedures, as gloves made of alternative materials generally do not fully match the fine control or greater sensitivity to touch available with latex surgical gloves. (High-grade isoprene gloves are the only exception to this rule, as they have the same chemical structure as natural latex rubber. However, fully artificial polyisoprene—rather than "hypoallergenic" cleaned natural latex rubber[10]—is also the most expensive natural latex substitute available.[11]) Other high-grade non-latex gloves, such as nitrile gloves, can cost over twice the price of their latex counterparts, a fact that has often prevented switching to these alternative materials in cost-sensitive environments, such as many hospitals.[12] Nitrile gloves are made up of synthetic rubber. It has no latex protein content and more resisted to tear. Also it is very resistant to many chemicals and is very safe for people who allergic to latex protein.[13] We can say that nitrile glove is the most durable type of disposable gloves.[14] Although nitrile gloves are known for its durability, extra care should be taken while handling with tarnish silver and high reactive metals because those substances can react with sulfur, an accelerant in nitrile gloves.[13]

Powder-free medical gloves are used in medical cleanroom environments, where the need for cleanliness is often similar to that in a sensitive medical environment.[citation needed]

Double gloving
Double gloving is the practice of wearing two layers of medical gloves to reduce the danger of infection from glove failure or penetration of the gloves by sharp objects during medical procedures. A systematic review of the literature has shown double gloving to offer significantly more protection against inner glove perforation in surgical procedures compared to the use of a single glove layer.

4, A summary of important facts on Nitrile gloves 

Wearing Nitrile Gloves

Nitrile gloves are durable and can be worn for long periods of time before they start to break down. This can be a problem because your hands will become sweaty and any dirt particles that were on your hand before you put the glove on will start to irritate your skin after extended periods of wear. So change your nitrile gloves frequently during your work day to avoid this. 

Of course, it goes without saying, doctors, nurses, paramedics, dentists, tattoo artists and others who work in situations where blood or other bodily fluids are likely to be encountered, should change their gloves between clients. This applies to all types of gloves, not just nitrile gloves.

Nitrile Glove Ordering

Nitrile rubber is not quite as elastic as latex rubber. Because of this, it is really important to get the size right. If you are ordering for several people, order a case of each size. 

Keep your gloves fresh. If your gloves have been stored unopened in a cool, dry, dark environment, they should be good for up to two years after you have purchased them from ATOMO Dental If you have kept them longer than this, you should consider replacing your stock with fresh gloves. All gloves deteriorate over time and nitrile gloves are no exception. 

If you are confused about whether to order powdered or powder-free nitrile gloves, allow us to suggest that you try powder-free nitrile gloves first. Nitrile rubber is not as "sticky" as latex and many people do not have any trouble getting their nitrile gloves on and off. 

Nitrile gloves are powdered with two different types of powder:

• USP Cornstarch
• Calcium Carbonate

If you think there might be any issues with either of these substances within your working environment, then you will definitely need to order the powder-free variety. ATOMO Dental gloves are powdered only with the highest possible grade of cornstarch: 100% pure, USP edible cornstarch. If you are using your nitrile gloves in a medical environment where open wounds are frequently encountered, you should know that cornstarch has been recently found to occasionally inhibit healthy healing. 

Nitrile Glove Storage

Nitrile butadiene rubber gloves are the best type of gloves for use in high temperature environments. But do not let this confuse you about how nitrile gloves should be stored: Nitrile gloves should be stored in a cool, dry, dark environment in order to extend their shelf life. Nitrile synthetic rubber deteriorates over time in the presence of light, moisture and heat. 

Please contact ATOMO Dental for more detailed information on medical gloves and Nitrile Gloves: 

1241 Quarry Lane #125
Pleasanton, CA 94566
Phone: 925-484-1686
Toll free: 866-980-0988
Fax: 866-980-0988
Email: support@atomodental.com