Esterbrook J Plastic

[acornham]

What is the Esterbrook J made out of? Is it acrylic, celluloid, or some other plastic?

[pajaro]

Looks like old dinner plates made of Melamine.

[gweimer1]

I think it's Pyralin. I need to check my book, but that's what I recall reading.

[amberleadavis]

Hmm... that's a Dupont Product. I thought Esterbrook was making their own material, but I am NO expert in this field. I look forward to your reply!

[alanshutko]

I thought I saw somewhere it was cellulose acetate, but when I last tried finding out, I couldn't find anything authoritative.

[Joe T]

Does anyone know how to repair the hairline cracks in the lip below ring on a cap Esterbrook Pastel Purse pen. 

[FarmBoy]

They can be solvent welded but it often doesn’t go well. Ink stains cause them stand out. 
 

You could remove the cap lip, make a new one from a donor cap and hide the joint under the cap band 

[gweimer1]

As noted above, it really depends on how bad (and how many) they are.  I've been able to use Easy-Solv for some decent solvent welds, but it's the ink stain that is the real problem.  The pastel CH pens are notorious for cap lip cracks....and usually in the multiple range.