Puncture and Cut Gloves: Engineered Composite Materials

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In this post Knit and woven materials are reviewed and compared for protection and dexterity

In the Post“Safety Gloves: Cut and Puncture Resistant Fibers Explained”we covered the most common fibers used in cut and puncture gloves. While this review of fiber types is useful you cant select gloves based on fiber type alone. Most advanced protective materials are composite textiles and are made from multiple fiber types and combine other non-fiber materials.

Puncture and Cut Gloves Textile Options 

 Knits: The fastest growing textile for puncture and cut gloves is the knit. This is driven by automated glove knitting machines which allow us to manufacture the basic glove knit shell with low labor content.  Knits have some great advantages for gloves, jersey knit textile has 2 way stretch and stretch is a significant advantage for glove sizing, comfort and dexterity.  Like most things in life, knits and stretch come with a down side. The more open the knit and the more stretch the lower the protection will be for both cut and puncture.  Thin comfortable knits with stretch don’t have high fiber content per unit area. This fiber content per unit area is a simple idea for optimizing cut gloves.  the more of a given fiber type your have under the cutting edge the better the cut glove  performance will be.  With regard to puncture this is pretty clear, an open stretchy knit is not a very effective barrier to puncture.  Even large EN388 penetrators just push the knit fiber out of the way and slide right through the knit materials.  Smaller ASTM nail type penetrators and hypodermic needles penetrate knits with no resistance.

Wovens: Many puncture and cut gloves are sew from woven textiles,  however wovens don’t have much stretch so a glove made from all wovens has to be very carefully designed and sewn to fit well.  Wovens may not be as easy to use as knits but  they are standouts for cut and puncture performance. The weaving process can product a very dense textile like our TurtleSkin woven.   TurtleSkin  wovens have very high fiber density and deliver cut 5 performance in a very thin package.  Even better TurtleSkin weaves that have no sliding yarns so these weaves have high puncture resistance even to the smallest 28 gauge hypo needles. Puncture and Cut gloves made of TurtleSkin wovens preserve you tactile sense. You can really feel the shape of small object with these gloves because the wovens are so thin.

Coating-Knit-Woven Composites 

In the TurtleSkin line of Puncture and cut gloves we have found that the best marriage that is both comfortable and protective is to use a composite of both knits and wovens. We put the high protection wovens in the area where the risks are on the hand. Then in the areas that are not at risk  we use the stretch and openness of the knit to keep the glove comfortable.  This is an important concept in puncture and cut glove selection. Don’t over spec your protection area. If you ask for 100% protection when you don’t really need this much you will end up with a glove that is both more expensive and less comfortable. If you are not getting injuries on the back of the hand then don’t spec in high protection in this area.

The puncture and cut glove design process does not stop with the combination of multiple types of textiles, coatings play a large role. The mechanical strength for cut and puncture resistance is provided by the textile. Grip and abrasion resistance can be greatly improved with a well engineered coating. Soft polyurethane rubber coatings offer some of the best grip and wear performance around.  In addition to grip coatings provide an opportunity to improve cut and puncture resistance.  The coatings can include hard materials and can be engineered to increase the internal friction in the textile so the performance of puncture and cut gloves are improved. Just as in the case of the use of wovens, coatings reduce the stretch and dexterity in the glove so don’t over spec your coating area. Palm and finger tip coating is a great compromise. Full dipped puncture and cut gloves are not as comfortable as palm dipped gloves

Summary

  1. Knits are very important to comfortable puncture and cut gloves because of their stretch.
  2. Look for wovens for improved Cut and Puncture glove protection
  3. Look at the glove coating materials: Do they have enough grip and durability

 

© 2014 Warwick Mills Inc. All rights reserved.

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Glove Dexterity the Silent Factor in Specification of Cut Resistant Gloves

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Cut Resistant Gloves and Tactical Gloves Specification

We have EN388 and we have ANSI glove testing. The results from these Cut, Puncture, Abrasion and Tear tests certainly provide part of the picture on glove performance.   Some thing is missing however. With gloves the elephant in the room is dexterity. It makes no difference how cut resistant a glove is if it gets in your way of doing your job.  At TurtleSkin we have been making and selling needle and cut resistant glove for many years.  We have learned by customer purchasing patterns that dexterity is the key to glove acceptance.  Almost every day we hear much the same perspective from Safety Officers: “your gloves have the protection we need but will my team wear the gloves?” So no one says anything about Dexterity but all our customers want cut resistant gloves and tactical gloves that are just that— dexterous.

Glove Dexterity Testing for Safety and Tactical Gloves

The problem is that there are only a few tests for glove dexterity. There is the EN420 Pin Test, The ASTM 2010 pegboard test and there is the Minnesota Dexterity Test. So there are various methods  to choose from to make measurements and evaluate the performance of the gloves. Given that we have methods to test dexterity why don’t we use this data as part of a standard requirement for glove specification? The answer is two part.  Part of the problem is the data from these tests is not simple for customers and  Officers to relate to real work requirements. The second part of the problem is, these tests are based on using human subjects to run the Pin Pickup Test,  Pin Board Testing and the Minnesota Dexterity Tests. In our own program we have worked with these tests and it takes great deal of care to produce repeatable data that is reliable.  When you use human subjects the test subjects introduce variability into the test results.  Cut resistant glove testing does not have these subjective elements. However just because cut is easier to measure does not make dexterity un-important

What Are Our Options for Machine Based Glove Dexterity Testing for Cut Resistant Gloves?

At TurtleSkin we make a modest proposal. There are two pieces of data that can be used and that are simple to interpret.  The first test is a simple caliper measurement of  the thickness of the glove finger tips. The second test  is a machine based test to measure the stiffness of the glove material, ASTM D4032 for measurement of textile bending stiffness. The sensation and tactile performance of a glove is directly related to the thickness of material at the finger tips. It is obvious that the bending stiffness of the gloves is directly related to their dexterity.   These two tests can easily be related to glove performance and the results are easy to understand. To keep the playing field level this is a ASTM test run on a testing machine. The test results are very straight forward and easy to intemperate.

Thinner gloves with lower bending stiffness have higher dexterity.

We have demonstrated the the value of these the Thickness-Stiffness tests by correlating the results with human subject tests for glove dexterity and we get good agreement. So in the short term use the thickness stiffness criteria to help with selection of cut resistant gloves and tactical gloves for your users.

In the longer term the proposed Thickness/Stiffness tests have the advantage that they are easy for labs to run and thus the results can be compared even when performed by different labs. The best way to start your own dexterity specification program is to test gloves that you know your team have accepted as easy to work with. This established your baseline.  Send us 2 pairs of your gloves and we will test them for you and send you the results or test them in your own lab and you can use this data as a starting point for glove objective data driven purchasing. Over the long term we will be pushing to get ANSI/ISEA and NIJ to add these methods to the specs for safety and tactical gloves