different types of celluloid

[davyr]

calling all materials science peeps:

 

what are the physical differences b/t cellulose acetate and cellulose nitrate? i know both are made of cellulose (wood pulp), and that cellulose nitrate requires camphor in the manufacturing process, requires aging for stability, is flammable (like film stock), and is what ping pong balls are made of.

 

can both be accurately called celluloid? which pens are made of cellulose acetate and of cellulose nitrate?

 

is cellulose nitrate inherently superior? apologies if this has been discussed previously (i searched the forum archives).

Edited November 14, 2005 by davyr

[wimg]

  davyr said:

calling all materials science peeps:

 

what are the physical differences b/t cellulose acetate and cellulose nitrate?  i know both are made of cellulose (wood pulp), and that cellulose nitrate requires camphor in the manufacturing process, requires aging for stability, is flammable (like film stock), and is what ping pong balls are made of. 

 

can both be accurately called  celluloid?  which pens are made of cellulose acetate and of cellulose nitrate?

 

is cellulose nitrate inherently superior?  apologies if this has been discussed previously (i searched the forum archives).

Hi Davy,

 

Generally, both materials are called celluloid, although that is not entirely correct. Cellulose nitrate is the stuff that was used for film in the past, which is why in cinemas they had fires every now and then, or broken films, if the film got too hot in one spot and burnt through or got weaker.

 

Cellulose acetate is the safe variant of this material, and I don't honestly know whether this was used in the film industry.

 

Celluloid, especially the marbled varieties used for pens, has an incredible depth to it, which I have never seen captured properly in pictures. Also, it is a little dangerous when turned: you shouldn't let it get too hot when making a pen out of it. It is also very tough material, very difficult to break, and usually has a faint camphor smell, as you indicated. Because it is so tough and difficult to break, shapes can be turned that are very thin walled, giving it an additional translucency.

Disadvantage is that it may get stained by ink, and that it doesn't like prolonged stays in or contact with water. This is why piston fillers made of this material generally have some kind of internal sleeve to protect it from ink, or have rubber sacs (like early/vintage celluloid pens).

 

Cellulose actetate, by some manufacturers called "Cellocride", is very similar to celluloid, but is not flammable. It is slightly more brittle, and thus breaks a little more easily, but it can stand heat and water a little better than celluloid. It has nearly the same depth that celluloid has, but not completely the same.

 

Oh, I think, but I may wel be wrong here, that it is only a fairly recent development that resin actually achieves similar transparant qualities, without it looking cheap, and without smelling strongly of glue or burnt plastic. Even so, the depth of celluloid is IMO second to none.

 

As you may know, I have a few Stipla Etrurias in my collection, and some of the models are made from true celluloid, and some from "Cellocride", and others from resin. I think the resin ones come fairly close to translucency and depth to the cellulose acetate variants (the non-black ones ), but I reckon the celluloid ones are in a class by itself. Of course, this is all in the eye of the beholder, in this case me .

 

Interesting in this regard is the Etruria Amber, which comes in a the new version nowadays, made in cellulose acetate, and with a big piston converter, and in an older version, if you can still get your hands on one, the Etruria Amber Grande, which is a piston filler made from real celluloid. IMO, it looks better. There is more depth to the red and amber marbling in the brown substrate of the pen. Oh, and it has a sleeve around its filling mechanism, to prevent ink coming into contact with the barrel.

 

HTH, warm regards, Wim

[TheNobleSavage]

Wimg

  Quote

Cellulose acetate

is used in film and motion picture film after the World War II era. Cellulose Acetate is a much safer, stable and suitable material. Especially due to the problems with Cellulose Nitrate being extremely volatile if it is not stored correctly. Cellulose Acetate is not volatile and is more forgiving than Cellulose acetate but not as strong as Cellulose Nitrate films. I do know that Acetate does not degrade as nitrate does and it is not as sensitive to heat and light as Nitrate is. But they recommend that you keep ALL CELLULOID out of excessive heat and excessive sunlight. As far as I know, Kodak (big yellow) still uses Cellulose Acetate on all of their film and they call it "celluloid side" this is the film surface. Kodak stopped using Cellulose Nitrate film in 1951-52. It is highly explosive if it is not stored correctly. How do I know this? I use motion picture film for my job, YES there is still a need for film, digital is still not up to par yet. There needs to be more improvements in the CCD technology for them to catch up with film especially high speed film!! I would hate to see the size of the CCD for a 70mm format high speed motion picture camera!!

 

As for Cellulose Nitrate, we have a lot of this film in our vault from previous missile launches and technical footage from the 40s and 50s. We keep the vault in a humidity and tempature controlled environment.

 

I hope that helps

 

TNS

Edited November 15, 2005 by The Noble Savage

[antoniosz]

I just finished grading another 300 midterm exams and I am not in good shape for serious discussion. However there is a good article that you can read about celluloid.

 

CELLULOID OBJECTS: THEIR CHEMISTRY AND PRESERVATION by JULIE A. REILLY

JAIC 1991, Volume 30, Number 2, Article 3 (pp. 145 to 162)

 

Enjoy

 

Also here is a primer on polymers/plastics etc that I posted few days ago on PT

 

One of the most difficult things to understand about all plastics is that when the name (e.g., celluloid) does NOT define unique the material.

 

Celluloid = Celluloid Nitrate + Residual Camphor + Colors/stabilizers/antiflamants

Plastic = Polymer + Solvent + additives

 

Even within one "class of material" (e.g., cellulose nitrate) a cellulose nitrate may different from the other not only in the proportions of the parts but also by the type of solvents and additives. This means that properties may vary significantly from celluloid to celluloid. For example some additives may improve stability but may be detrimental to machinability.

 

Actually even Celluloid Nitrate is not "uniquely" defined. The repeat unit of the polymer is unique but the length of the chains defines properties. Strength, ductility and machinability vary with chain length and not necessarily with a monotonic relationship. The sizes of the polymer chains differ from one celluloid to the one due to small (or large) differences in the manufacturing process.

 

Polymer = a material whose molecules consist of a "chain" of a repeated group of atoms (repeat unit).

Plastic = a polymer with additives.

Additives = other materials added into a polymer in small amount to modify properties, stability, color, processing etc.

Solvent = a material that desolves the plastic

 

http://aic.stanford.edu/jaic/img/jaic30-02-003-fig001.jpg

[davyr]

wow, thank you all for the detailed info!

 

i wonder if c-nitrate is considered the superior material c/w c-acetate. i.e. would you rather have a pen made of c-nitrate vs c-acetate?

[TheNobleSavage]

I have a few pens made out of Nitrate. Both of them are made by Platinum and they are somewhat modern. You can really smell the Camphor when you open the cap

 

TNS

[davyr]

  Quote

I have a few pens made out of Nitrate. Both of them are made by Platinum and they are somewhat modern. You can really smell the Camphor when you open the cap

yeah, i sniff my nitrate pens too... sorta like when as kids we used to sniff mimiographed handouts at school

[jar]

  On 11/16/2005 at 9:25 PM, davyr said:

yeah, i sniff my nitrate pens too... sorta like when as kids we used to sniff mimiographed handouts at school

Those were more likely from a Spirit Duplicator than mimeograph, if in the US from a Ditto Machine. Mimeograph was a different process.

[Aelfattrum]

  On 4/17/2017 at 2:55 PM, jar said:

Those were more likely from a Spirit Duplicator than mimeograph, if in the US from a Ditto Machine. Mimeograph was a different process.

Expand  

 

Spirit Duplicator sounds like something out of Ghostbusters (even wikipedia says "Spirit duplicators were used mainly by schools, churches, clubs, and other small organizations", which still sounds like it could be along Ghostbusters/Ouija board lines).

 

I suppose it's an appropriate topic for necro'ing an 11-year old discussion (and, for my part, a thread who's latest post was 4 years ago).