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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Puncture and Cut Glove

Cut Glove Optimization: Knit Needs to Work with the Dip

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Knit Basics for Cut Gloves

Knit gloves are made on knitting machines with a limited range of needle density. Thick gloves made from large yarns are generally knit on machines of 8-10 gauge (8-10 needles per inch). These yarns are the same size you find in winter coats. The larger yarns require the larger needle spacing.  Many high cut level gloves  (level 4-5)  use these large yarns and 8-10 gauge knits. For finer and thinner knit gloves the most common knitting style is 13 needles per inch. The 13-gauge knits often use small yarns such as 210 denier nylon. This is about the size of the yarn you use in an oxford shirt. Larger yarns contain more fiber and offer more cut resistance for a cut glove.

Openness in Knit Fabric

The knitting machine gauge and the yarn size controls how open the glove textile will be. As an example,  for 13-gauge knits using our 210 denier yarn there is perhaps 30-40% open area in the textile. The % openness in the knit affects how the glove feels and how much stretch it will have. Most users would agree that more open knits result in cooler more comfortable and dexterous gloves.  The down side of more open knits is that it is much harder to create high level cut glove with small yarns with open space. (More on this in another post.)

The Knit Needs to Work with the Dip for Best Cut Glove Dexterity and Cut

Most users like the grip and durability that palm coated knit gloves offer.   Knit gloves with high levels of openness have an additional benefit for dipping and coating.  With high open area the dip coating can penetrate the textile and encapsulate the yarn on the palm of the glove.  The dip can by nitrile,  polyurethane or NR latex. When the dip can penetrate the knit the coating has the best possible attachment to the textile.  We all want our gloves to be durable and comfortable.  For comfortable gloves with good dexterity the coating and the knit must be thin, no more than 2-4mm in thickness total.  For this type of thin coating layer to be durable it must be well supported by the textile. The rubber in the coating does not have good tear strength. The yarn in the glove provides the reinforcement to prevent premature failure of the coating layer.  A special kind of glove coating uses dots or pads of coating that are thicker than a full dip layer. This dotted coating provides the option to increase the coating thickness and wear resistance without making a cut glove stiff.

For optimal cut glove design the knit density and the coating work together to give you good dexterity and good cut performance.

When the knit works with the dip you can build a thin comfortable durable cut glove.

© 2014 Warwick Mills Inc. All rights reserved.

 

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