Short Guide to Glove Puncture Testing

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Introduction:

In Europe and North America there is very close agreement in the in required puncture test requirements. There are some differences but more agreement. The most important factor to take away is that there are at least 3 types of puncture threats that glove specifiers need to consider. Large nail, small nail and hypodermic needle. Sadly good performance for one of these penetrators does not predict performance with the others. Gloves engineered for needle may not have high performance for the large nail and like wise large nail performance does not predict needle results. Users have to select glove and equipment designed for there puncture needs.

ANSI/ISEA Puncture Level for “Large Nail”

The ANSI test is best described as the large nail puncture test. The puncture probe is a 5mm diameter (3/16 Inch) with a dull conical tip.

There are 2 other puncture test that are important

  • NIJ 99-144 “Small Nail” ASTM F 1342 Puncture Resistance Levels

  • ASTM F3 2878-10 Hypodermic Needle Puncture 28 Gauge WMI

Of the 3 important puncture tests the “Large Nail” is the least informative about the material performance against sharp threats. The “small nail” and hypo test offer results relevant to sharp puncture threats

ASTM /ISEA 105 (EN388) Level Puncture (Newtons) Large nail

Level

Newtons

Grams force

lbf

0

< 10

0

1

≥ 10

1020

2.2

2

≥ 20

2039

4.5

3

≥ 60

6118

13.5

4

≥ 100

10197

22.5

5

≥ 150

15296

33.7

EN388 “Large Nail” Puncture Levels

The EN388 test is best described as the large nail puncture test. The puncture probe is a 5mm diameter (3/16 Inch) with a dull conical tip.

There are 2 other puncture test that are important

  • NIJ 99-144 “Small Nail” ASTM F 1342 Puncture Resistance Levels

  • ASTM F3 2878-10 Hypodermic Needle Puncture 28 Gauge WMI

Of the 3 important puncture tests the “Large Nail” is the least informative about the material performance against sharp threats. The “small nail” and hypo test offer results relevant to sharp puncture threats

The EN388 and ANSI 105 are off set by one level. EN388 level 4 is equal to ANSI 105 level 5.   

level

Newtons

grams force

lbf

1

20

2039

4.5

2

60

6118

13.5

3

100

10197

22.5

4

150

15296

33.7

NIJ 99-144 “Small Nail” ASTM F 1342 Puncture Resistance Levels

The NIJ-ASTM puncture test is based on a small 1.5mm diameter sharp penetrator. This is not a hypodermic needle but this test simulates a small sharp nail.

Like all penetration tests the “Small Nail” test uses a compression testing machine and a drum head clamp to hold the sample.

Level

Newtons

Grams force

lbf

Low

>20

2039

4.5

Moderate

>60

6118

13.5

High

>100

10197

22.5

ASTM F3 2878-10 Hypodermic Needle Puncture 28 Gauge WMI

We use the standard test for hypodermic puncture resistance. Base on Warwick’s 20 years of needle protection we have developed a set of levels that define a useful range of needle puncture resistance.

Like all puncture tests the needle puncture test is based on a compression testing machine. The sample is held in a drum head clamp.

 

Level

grams

Newtons

oz force

1 ≥

50

0.5

1.76

2 ≥

100

1.0

3.52

3 ≥

200

2.0

7.05

4 ≥

400

3.9

14.10

5 ≥

600

5.9

21.15

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Short Guide to Glove Cut Testing Methods

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Introduction:

Cut testing has 2 primary modes, knife edge only cutting and knife tip cutting. The standard evaluations for glove and safety gear use the knife edge only. The edge only cut data provides a good baseline for users on cut resistance. There is good agreement between the EN388, ANSI 105 an the NIJ cut criteria.  Users and glove specifiers should take note of the scalpel cut data for a better understanding of the actual resistance of the gloves and equipment in service. Real cut injuries generally include the knife tip.

ANSI/ISEA 105 Cut Level (ASTM F 1790-97 or -05)

The ANSI cut levels are based on the force required to cut through the protective material with a razor knife edge.

In this test the tip of the knife does not contact the material only the blade edge.

The most common cut testing method ASTM 1790-97 is based on a cutting distance for the knife of 25mm (1 inch). The force required to cut through the protective material in 25.4mm of knife travel is the test output.  

The levels are set as follows.

(25 mm of blade travel – ASTM F1790-97)
(20 mm of blade travel – ASTM F1790-05)
Level Grams force newtons lbf
1 ≥ 200 2.0 0.44
2 ≥ 500 4.9 1.10
3 ≥ 1000 9.8 2.20
4 ≥ 1500 14.7 3.30
5 ≥ 3500 34.3 7.71

Modified ASTM F 1342 Scalpel Cut Levels WMI

This Scalpel test is alternate to the straight knife cut tests.  This test measures the force required for the Scalpel blade to puncture and cut through the protective material.

Unlike the ANSI cut test the Scalpel test simulate cut events that involve the tip of sharp tools, sheet metal and glass shards.

The levels have been set to roughly correlate to the ASTM cut method, however because this is knife tip test there are differences in material performance.

The cutting force is measured on a compression testing machine with the sample held in a drum head clamp ring.

Level Grams force Newtons lbf
1 ≥ 75 0.7 0.17
2 ≥ 150 1.5 0.33
3 ≥ 300 2.9 0.66
4 ≥ 600 5.9 1.32
5 ≥ 1200 11.8 2.64

NIJ 99-114 cut rating (ASTM F 1790-97)

The NIJ  cut levels are based on the force required to cut through the protective material with a razor knife edge.

In this test the tip of the knife does not contact the material only the blade edge.

The most common cut testing method ASTM 1790-97 is used by NIJ for this rating. The test is based on a cutting distance for the knife of 25mm (1 inch). The force required to cut through the protective material in 25.4mm of knife travel is the output of this test.  

These levels are roughly the same as ANSI 105 levels 2, 3 and 4

The NIJ levels are set as follows.

Newtons Grams force lbf
Low < 5 509.9 1.12
Moderate ≥ 6 611.8 1.35
High ≥ 16 1631.5 3.59

EN388 Cut resistant levels Rotary Knife or ISO13997 Cut testing

The EN388 cut testing program has 2 tests. A test using a rotary knife machine that measure the rotations to cut through the sample. The calibration process for this machine make it unsuitable for some materials at the higher cut levels so a second test method ISO13997 is used. This is a straight razor knife force test. The ANSI 105 cut levels are similar at level 4 but are quite different for level 5. The ANSI 105 cut level 5 is a higher requirement.

Level Cut Index

(turns of knife)

EN388 rotary

ISO13997 testing

cut force Newtons

ISO13997

cut force grams

ISO13997

cut force lbf

1 >1.2
2 >2.5
3 >5
4 >10 13 1326 2.9
5 >20 22 2243 4.9
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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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