Film and gelatin

<p>I was just wondering the other day (and today as well) - is there any film on the market, whose gelatin emulsion is not made from animal fat?</p>

<p>As far as I know none is made from the fat it is made from the hoofs and hide.</p>

Nearby Peabody, MA - http://eastmangelatine.com/ - used to be a shoe manufacturing area, is film made from old shoes?

<p>http://www.gelatin-gmia.com/html/qanda.html</p>

<p>As far as I know, all gelatin is made using the method described here.</p>

<p>- Randy</p>

<p>my mistake - i meant animal products. I know that there is also a kind of gelatin that is made fom non-animal products - liek in food you can have a normal gelatin in it, or a substitue that's not made form animal products</p>

<p>All gelatin comes from animal sources. Most gelatin used in film comes from cattle bones. Unless they have changed in the past few years, the bones come largely from US slaughter houses that handle high grade beef. They avoid bones from uncontrolled sources that might have questionable feed. Some layers in some products use gelatin from pig skin. I'm aware of experiments with fish gel, but I don't know if it was ever used in products. Thre were numerous attempts over the decades to create an artificial gelatin substitute. None could duplicate all of the functions of gelatin:</p>

 

<ul>

<li>must have mechanical strength in dry film</li>

<li>must swell and allow processing solutions to permiate</li>

<li>must allow uniform coating</li>

<li>must allow uniform setting (via chilling)</li>

<li>must allow removal of water (drying)</li>

<li>must keep silver halide crystals separate during precipitation</li>

</ul>

<p>I'm probably missing several functions</p>

<p>The commonest plant-derived gelatin substitute is agar. This is the stuff that's used in labs for bacterial culture media, as well as lots of other purposes. It's also used in food products like vegetarian yogurt, which is what Irenej's talking about. I've never heard of it being used in photographic emulsions, but I bet someone has tried it over the last century or so.</p>

<p>I would imagine a few other functions would be clarity, resistance to air entrapment, longevity, and cost effectiveness.<br /> Oh, and the ability to tolerate all kinds of fruit being mixed in. 8^D</p>

<p>I guess the most sure way would be to ask the makers like Ilford, Kodak or Fuji about the possible use of these substitutes in films and how they turned out. Actually I'll probably email them or something, to be sure. I would be pretty excited if somebody actually produces film with that kind of gelatin used for emulsion</p>

<p>Just to clarify, "gelatin" is not the same as "gel" -- "gelatin" refers to a specific substance (derived from collagen). Agar gives a hydrogel with similar properties to gelatin, but agar is mostly polysaccharide while gelatin is a protein (thus the chemistry is very different).</p>

<p>Interestingly, most inkjet printing paper uses a considerable amount of gelatin as "sizing".</p>

<p>My recollection is that Kodak tried making emulsions with various gelatin substitutes, but found them all wanting in some way. There is a strong chemical interaction between the gelatin and the growing silver halide grains during the preparation of the emulsion, and film makers are careful about the grade and source of the gelatin they use.</p>

DuPont is said to have worked on polyvinyl alcohol or the like as substitute for gelatin. But as gelatin is a "by-product" from animal husbandry, there is no real technical need to replace it. I was surprised that it is also used in high-gloss offset printing, as gelatin manufacturers state, but paper in general may be susceptible to microbial decay by the animal-derived glue used. Poor gelatin quality can however severely impact the properties of photographic products, as it occured in former East Germany.

<p>"I was just wondering the other day (and today as well) - is there any film on the market, whose gelatin emulsion is not made from animal fat?"<br>

======================================<br>

My brother use to work for Kodak as an intern years ago. He told me that Kodak use to get their animal fat from pig farms in North Carolina and to a lesser extent other parts of the country. The pig fat use to come in on large vats and transported throughout the company on rail-road tracks. Then they were dumbed into a Huge Pot where it was cooked and mixed with other chemicals. I could imagine the smell ! </p>

Note: Ron Andrews above is a retired Kodak engineer who "managed the formula for Kodachrome and some Ektachrome films, and helped design several new color negative films. " I suspect he may know what he is taking about.

<p>Ron Andrews has captured the essence of the situation.<br>

There are a number of polymers that could be used, but they do not 'gel' or chill up to a solid like gelatin (think JELLO). Fish gelatin also does not chill set. One polymer was found at Kodak that would allow good emulsions to be made, but it had a lot of other drawbacks.<br>

The only polymeric (non gelatin) photographic material I know of is the thermally developed silver halide system based on silver behenate. Even it may contain a small amount of gelatin.<br>

Ron Mowrey</p>