atv223
06-02-2011, 02:59 PM
Hello everyone, I am a brand new owner of a Kahr PM9 and very excited to have been turned onto this site from some members over at PAFOA.com! I have learned a ton already and glad I got here before I took my shiny new PM9 to the range for the first time.
In reading lots and lots of the site here, I see people talking a about spray cleaners and their impact on “polymers”. Since I have some experience in this area, I thought I would jump in here and clear up a couple of things.
First, people seem to be refereeing to polymers as if they are a single material and are all affected the same way by the same chemicals. As an analogy, it would be like referring to “Metal”, and thinking titanium, tin and steel all react the same way to chemicals and the environment.
Polymers are a very broad class of materials with extremely different physical and chemical properties. Everything from latex gloves, to car tires to Kevlar, to Teflon to plastic milk jugs to paint to epoxy resin would be classified in as a “polymer”. Obviously, they all have very different properties.
From what I can tell, virtually all Polymer Guns are made from either Nylon 6 or Nylon 6/6, which are both engineering grades of a thermoplastic polymer (I am assuming Kahrs are made of this but I don’t know for certain). I am guessing, but not 100% certain, that they actually are glass or carbon fiber reinforced versions for added strength, stability and impact resistance. Both neat and fiber reinforced versions of these 2 Nylon’s are used extensively in “under hood” automotive applications due to their strength, relatively high temperature stability and generally good resistance to automotive fuels and oils. They are also used in lots of other industrial applications due to their relatively low costs related to their physical properties. At the moment, in bulk pelleted form, 33% Glass Reinforced Nylon 6/6 sells for about $1.50/pound.
Here are a couple of links to chemical resistance of Nylon 6 and 6/6. http://www.unitika.co.jp/plastics/E/nylon/nylon6/07a.html (http://www.unitika.co.jp/plastics/E/nylon/nylon6/07a.html)
http://www.cable-ties.com/catalog/pdfs/nylon66_chem_resist.pdf (http://www.cable-ties.com/catalog/pdfs/nylon66_chem_resist.pdf)
Interesting to note from the charts is that Acetone appears to have no effect on Nylon, but as many of you know, acetone is very good at striping paint and lacquers.
Another interesting thing I have personally witnessed about Nylon is how it reacts with water. Nylon is hydrophilic, meaning it absorbs water and it will absorb water out of the air (humidity). The water actually acts as a plasticizer for Nylon (making it softer and more flexible). Conversely, in extremely dry environments, Nylon can become brittle. Mind you, much of the practical implications of this property are negated by fiber reinforcements.
Anyway, this is probably more than anyone really wanted to know, but I hope this helps at least clear up some questions in people’s minds. The real take away is that all “polymer” aren’t the same.
In reading lots and lots of the site here, I see people talking a about spray cleaners and their impact on “polymers”. Since I have some experience in this area, I thought I would jump in here and clear up a couple of things.
First, people seem to be refereeing to polymers as if they are a single material and are all affected the same way by the same chemicals. As an analogy, it would be like referring to “Metal”, and thinking titanium, tin and steel all react the same way to chemicals and the environment.
Polymers are a very broad class of materials with extremely different physical and chemical properties. Everything from latex gloves, to car tires to Kevlar, to Teflon to plastic milk jugs to paint to epoxy resin would be classified in as a “polymer”. Obviously, they all have very different properties.
From what I can tell, virtually all Polymer Guns are made from either Nylon 6 or Nylon 6/6, which are both engineering grades of a thermoplastic polymer (I am assuming Kahrs are made of this but I don’t know for certain). I am guessing, but not 100% certain, that they actually are glass or carbon fiber reinforced versions for added strength, stability and impact resistance. Both neat and fiber reinforced versions of these 2 Nylon’s are used extensively in “under hood” automotive applications due to their strength, relatively high temperature stability and generally good resistance to automotive fuels and oils. They are also used in lots of other industrial applications due to their relatively low costs related to their physical properties. At the moment, in bulk pelleted form, 33% Glass Reinforced Nylon 6/6 sells for about $1.50/pound.
Here are a couple of links to chemical resistance of Nylon 6 and 6/6. http://www.unitika.co.jp/plastics/E/nylon/nylon6/07a.html (http://www.unitika.co.jp/plastics/E/nylon/nylon6/07a.html)
http://www.cable-ties.com/catalog/pdfs/nylon66_chem_resist.pdf (http://www.cable-ties.com/catalog/pdfs/nylon66_chem_resist.pdf)
Interesting to note from the charts is that Acetone appears to have no effect on Nylon, but as many of you know, acetone is very good at striping paint and lacquers.
Another interesting thing I have personally witnessed about Nylon is how it reacts with water. Nylon is hydrophilic, meaning it absorbs water and it will absorb water out of the air (humidity). The water actually acts as a plasticizer for Nylon (making it softer and more flexible). Conversely, in extremely dry environments, Nylon can become brittle. Mind you, much of the practical implications of this property are negated by fiber reinforcements.
Anyway, this is probably more than anyone really wanted to know, but I hope this helps at least clear up some questions in people’s minds. The real take away is that all “polymer” aren’t the same.