Acrylic vs Celluloid vs Resin vs Plastic...

[aymr]

I was ordering polish from Tryphon today, and it appears that it's best to know what your pens are made of.

 

I'm mainly into modern pens, but I'm having trouble grasping the difference between all these terms:

Plastic

Acrylic

Celluloid

Resin

Thermoplastic

Lucite

Lacquer

and then Aurora has "auroroloid"

 

What the heck? Are these different things, or different names for essentially the same things?

 

Also, anyone know what modern Pelikans are made of, if there are differences between these different plastics?

 

Thanks!

Aym

 

PS - rubber and metal I think I got, and I've read an explanation of casein.

[Imzadi]

I have wondered the same thing. Thanks for asking.

[someonesdad]

Plastic

Acrylic

Celluloid

Resin

Thermoplastic

Lucite

Lacquer

and then Aurora has "auroroloid"

Hi, Amy:

 

Here's a shot at some of them:

 

Plastic is a general term for compounds usually made from hydrocarbons that tend to be soft and mechanically easily manipulated (you've probably heard the term "plastic deformation", which means moving and staying moved). Many are polymers (long-chained molecules). There are generally two types: thermoplastics which soften and melt at higher temperatures, allowing them to be molded and thermosets that cure, such as epoxy.

 

Acrylic is a term for methyl methacrylate, a gooey plastic I remember making it in freshman chemistry class in the 60's (but I don't remember the method!). In pure form it is clear and is commonly known under a variety of tradenames, such as Plexiglas, Lucite, Perspex, etc.

 

A resin is a liquid that can be transformed into a plastic -- for example, epoxy -- by the addition of another chemical.

 

Celluloid is a plastic that is made from nitrocellulose -- early films were made from it and were flammable.

 

Lacquer is a compound dissolved in a solvent which is then used as a coating. There are a variety of kinds, one such being urushiol, used on Japanese pens. There are also nitrocellulose lacquers and acrylic lacquers. Lacquer thinner is commonly available and contains a variety of aromatic organic solvents.

 

I haven't a clue what auroroloid is; no doubt it only exists in the mind of some marketing person.

 

Don

[tfwall]

What the heck? Are these different things, or different names for essentially the same things?

 

Also, anyone know what modern Pelikans are made of, if there are differences between these different plastics?

 

I haven't read a Tryphon label recently, but you're probably pretty safe using a plastic safe polish on any pens made from the compounds you list. I might be a little more cautious with celluloid though, if that wasn't specifically listed. Otherwise, they are just various names from related plastics.

 

Casein definitely requires different care, as does wood or metal pens.

 

HTH.

[thibaulthalpern]

The short answer is they're all forms of plastics.

 

The long answer is I don't know what the minute differences are

[aymr]

Thanks for all the input. It sounds like until I get into more vintage pens the polish is probably not dependent on the type of plastic my new pens are made of (does anyone still make casein? I certainly don't have any.)

 

Thank you!

Aym

[psfred]

Resin is the most generic term, referring to an organic material that is relatively soft and malleable. Most plastics can be called resins.

 

Plastic is most often used to refer to synthetic resins -- man-made long chain polymeric materials that are often thermo-plastic. These materials can be melted and molded into a variety of shapes, much easier than machining a pen barrel, for instance

 

Thermosetting plastics like Bakelite (and yes, there actually is such a thing, although it's quite rare as a fountain pen material) "set" from a liquid to a solid with heat, and once set cannot be melted and formed. Hard rubber is a similar material -- once manufactured, it's solid until it catches fire, it won't melt, nor, like Bakelite, isn't soluble in much of anything.

 

Celluloid is either nitrocellulose or cellulose acetate, both derived from natural products. You can usually tell the difference easily in fountain pens because the nitrocellulose used to make pens was cured with camphor, which is often still detectable by smell. It can be dissloved easily in many organic solvents, and is a thermo-plastic material. It is quite flammable, and softens usually around 160 F.

 

Acrylic plastics are much harder, and to the best of my knowledge, are not available in the lovely iridescent forms common in celluloid pens. Too bad. Anyway, the heat cured ones like those used by Parker for the "51" are fairly hard and wear resistant, and do not become brittle with age like the later polystyrene does. This is mostly due to the need to make Plexiglass UV resistant, I suspect, and the opaque fillers used to color it don't hurt at bit. "Lucite" is Du Pont's trade mane for acrylic. Acrylic can be injection molded, but this process was not available until the late 40's - all Parker "51"s and similar pens are made from heat cured rod stock.

 

Laquer is a resin dissolved in a solvent to form a paint or varnish that can be applied as a liquid that will dry (and usually chemically polymerize or "cure") into a hard, smooth surface. There are a number of natural lacquers, and a dizzying spectrum of synthetic ones, including nitrocellulose. These are all applied to some other material, even if that is only a paper backing.

 

As for polishing pens, any polishing compound that leaves a shiny finish will work, although to remove scratches you may need to start with a coarser material and finish with the normal fine one. Automotive paint polish will work just fine, as will Giovanni's polishes, Simichrome, and the stick stuff for buffing wheels at building supply stores. Use only the finer ones of those, though, unless you want a matte finish! I would NOT polish anything lacquered, though -- it's quite thin in comparison to a celluloid barrel and you may polish it right off.

 

Do not use a buffing wheel on pens, either, especially Celluloid pens. Even a low speed wheel can generate enough heat to soften celluloid and deform the pen or blister it. Ditto for Dremel tools and similar devices. Hand polish only. May take a bit longer, but you won't damage anything that way, and you will also avoid the "washboard" effect sometimes seen on Parker Vacumatics -- the opalescent plastic tends to be softer than clear rings (or vice versa), so gets ground off faster with a buffing wheel, leaving a rippled surface!

 

Peter

Edited December 14, 2008 by psfred

[aymr]

Wow! Fantastic information. Thanks, Peter! Now I really get it.

 

Thanks also for the places not to screw up - I'd rather not find those the hard way.

 

Amy