PVC v.s. ABS material for Prop making?

[Kilryth]

Who has had experience with both PVC and ABS materials for Prop making? I'll tell you what I know, in hopes that someone can tell me what I don't know.

They're both vacuum-formable, both can be flexible and durable, and both are lightweight. ABS is generally treated with a UV protectant to keep it from degrading in UV rays, but the protectant causes it to yellow in time with too much sun exposure. Obviously not a problem, if you paint it.

My questions are: Given the same thickness plastic, which one is more durable? Which one is more flexible? Which one is more likely to chip, dent, crack, or break when dropped on concrete? Has anyone done stress testing with them?

I'd like this post to be about general prop building materials and their specifications, rather than focusing on their applications.

This link was also helpful in comparing their properties: http://www.diffen.com/difference/ABS_vs_PVC
ABS is more impact-resistant than PVC.

Edit: Through some additional research on PVC roofing, I've found:

PVC becomes soft/flexible from the increased use of Plasticizers. Plasticizers tend to evaporate with exposure to heat, rain, and UV rays. This leaves the PVC less flexible, more brittle, and more prone to damage from impact. In essence, PVC is a brittle resin that is filled with liquid plasticizers, which improves flexibility and durability.

 

[Altoidian]

There are UV resistant PVC- it's found in the electrical dept at Home Depot- it is light gray in color and you can bend it same as white. ABS is a very tough type of plastic a combination of polybutadine and styrene. I like to compare the two plastics to acrylic and Lexan plastics- One will shatter or fracture, the other is almost bullet proof. ABS can be heated to bend- but, it's extreemly tough. I have never been able to shatter it- it can crush, but, will not break (not that I have ever seen). You can assemble the plastics in a similar fashion, but use the corresponding adhesive. Essentially, the adhesives for both are "melt" or "dissolve" types of glues- the two pieces to be adhered are basically welded through chemical melting. The adhereiing surfaces must be fairly smooth. White PVC is very susceptible to UV destruction over time. sunlight will destroy the molecular bonds and since it is basically translucent, iover time, the entire structure will be penetrated and degraded. UV affected PVC is very brittle and becomes weak to impact force. It also is less resistant to sheer forces. For longer lasting structures of these material, use the ABS first then the gray electrical grade of PVX as next choice. The cost factors: ABS is slightly more expensive than PVC and the gray PVC is slightly more expensive than the white. The fittings are also more expensive in both the ABS and gray PVC. The gray tends to be stronger than the white due to it's extra thick walls. ABS is stronger than both types of PVC, but, the fittings can be hard to get in smaller diameters. Hope this answered your questions.

 

[Kilryth]

There are UV resistant PVC- it's found in the electrical dept at Home Depot- it is light gray in color and you can bend it same as white. ABS is a very tough type of plastic a combination of polybutadine and styrene. I like to compare the two plastics to acrylic and Lexan plastics- One will shatter or fracture, the other is almost bullet proof. ABS can be heated to bend- but, it's extreemly tough. I have never been able to shatter it- it can crush, but, will not break (not that I have ever seen). You can assemble the plastics in a similar fashion, but use the corresponding adhesive. Essentially, the adhesives for both are "melt" or "dissolve" types of glues- the two pieces to be adhered are basically welded through chemical melting. The adhereiing surfaces must be fairly smooth. White PVC is very susceptible to UV destruction over time. sunlight will destroy the molecular bonds and since it is basically translucent, iover time, the entire structure will be penetrated and degraded. UV affected PVC is very brittle and becomes weak to impact force. It also is less resistant to sheer forces. For longer lasting structures of these material, use the ABS first then the gray electrical grade of PVX as next choice. The cost factors: ABS is slightly more expensive than PVC and the gray PVC is slightly more expensive than the white. The fittings are also more expensive in both the ABS and gray PVC. The gray tends to be stronger than the white due to it's extra thick walls. ABS is stronger than both types of PVC, but, the fittings can be hard to get in smaller diameters. Hope this answered your questions.

Holy cow, this answered my question down to a T, lol. Sounds like PVC is more likely to break than ABS is to deform then.

 

[Altoidian]

ABS is not going to deform easily. And i kind of doubt the "deformation' forces are significantly different between these three materials. It is not steel, of course. But using proper engineering thought too a design, it's not deforming very easily. I was not able to actually find any info on stress testing of either material. But, ABS is exceptionally tough.

The problem is, finding it in smaller diameter than 2". I don't think I have ever found it readily available in anything less than 2". You may find a resource on the web, but the shipping costs might be interesting. The softer plastic is Polypropylene . Very pliable. But hard to find plastic glue-up fittings.

Glad I could help.

edit: An excellent information resource is McMaster Carr company. Their web catalogue is absolutely loaded with techincal test information on every kind of plastic you can imagine. they aslo show all the examples, fittings, adhesives, etc. You may have to register to use it, but it is free. If they ask you for a "company name" make one up- like "RDC Fabrication"" or "Professional Resources & Consulting"- they never check. They don't like "pogs' or jerks inundating them with questions. If you get registered, they are an absolutely amazing resource for just about everything you can imagine. They have a branch in L.A. and their shipping is awesome.