Duroplast- is it still used?

[catchfire]

I just watched (most of) a documentary on the Trabant and it was mentioned that the body was made of something called Duroplast. Apparently the cars did amazingly well in crash tests and lots of them are still around.

from Wikipedia:

Duroplast is light, flexible, and strong. It is made of recycled material, cotton waste and phenol resins. Because it can be made in a press similar to shaping steel, it is more suitable for volume car production than fibreglass.

Sounds too good to be true.

So is this material still used? If so, in what applications. If not, why not?

Thanks

[Dewey_Finn]

Well, your Wikipedia link mentions that the stuff can’t be recycled and that “burning it produces toxic fumes.” That’s not good in the event of a car fire.

[TriPolar]

Basically it’s a molded form of something like phenolic laminate. That is still used in specialized applications. Materials like fiberglass are more commonly used in structural applications. Molded plastic is also used for a lot of car parts.

[Stranger_On_A_Train]

Have you ever seen an actual Trabant? While they were considered highly desirable cars in the East Bloc (with wait lists of three or more years in East Germany, and even longer in other Warsaw Pact nations), they were about the only vehicle which could make a Yugo look safe and reliable. Post-Unification, before the former East Germans could afford to purchase Western European cars, “Trabis” were often seen sporting repairs literally affected with duct tape and dental cement. At the low speeds that Trabants could drive out the Micarta-like material might have provided more shock absorption than thin sheet metal (and was probably easier to patch), but a Trabant at actual highways speeds would have earned Ralph Nader’s true ire had they been imported into the US.

Stranger

[Melbourne]

Composite Thermoset Plastics are more difficult and more expensive to work with than simple Thermoset Plastics. And Thermoset Plastics are more difficult and more expensive to work with than thermoplastic plastics, or epoxies.

Historically, the main reason for working with CTP’s like Bakelite was that simpler, cheaper, easier plastics hadn’t been invented. There are still applications for composite materials – both Fibre Glass (epoxy) and metal-loaded thermoplastics are common for special uses – but composite thermoset plastics like “Laminex” are specialist materials for specialist applications.

I’m going outside my area of knowledge here, but I think that thermoset plastics have an advantage for hardness/scratch resistance.
It is an unfortunate fact of Physics that passengers of light cars suffer in collisions with heavy cars. The Trabant was a very light car because it was made out of composite materials (like the new Boeing jet).

[Kevbo]

Phenolic filled with various reinforcements still gets used for a few things where it is well suited. Populer reinforcements are paper, mica, and linen cloth. I stays stiff even up to very high temperatures…it doesn’t melt.A lot of electrical switch gear for example uses phenolic parts that serve both as mechanical supports and electrical insulators. There is a good chance that the circuit breakers in your house have mica-phenolic housings for example, though more modern plastics are gaining some ground. It is also a popular material for making handles on cooking pots.

[catchfire]

I’ve found this quote:

The Trabant’s production method, which was extremely labor-intensive, remained unchanged. …The inefficient, labor-intensive production line was kept open only because of government subsidies.

http://www.peasanttuning.com/?page_id=34

So it would seem Melbourne you were correct.

@Stranger_On_A_Train

At the low speeds that Trabants could drive out the Micarta-like material might have provided more shock absorption than thin sheet metal (and was probably easier to patch), but a Trabant at actual highways speeds would have earned Ralph Nader’s true ire had they been imported into the US.

Stranger

I’ve only heard positive things with regards to Trabant crash test results, but I get the impression it has quite a poor reputation. Do you have any source to back this up? Here’s what I’ve been able to find from a quick search.

From the link above:

The Trabant was a steel monocoque design with roof, bootlid, bonnet, fenders and doors in Duroplast, a form of plastic containing resin strengthened by wool or cotton. This helped the GDR to avoid expensive steel imports, but in theory did not provide much crash protection, although in crash tests it has actually proven to be superior to some modern small hatchbacks.

…

In 1997, the Trabant was celebrated for passing the “Elchtest” (”moose test”), a 60†km/h (37†mph) swerve manoeuvre slalom, without toppling over like the Mercedes-Benz A-Class infamously did. A newspaper from Thuringia had a headline saying “Come and get us, moose! Trabi passes A-Class killer test”

As for uses, I found this:

This Duroplast material on phenolic resin basis with organic filler has the following properties:
high stiffness and hardness, low tendency to creep, high heat forming resistance, low thermal linear expansion, high surface slip resilience, low flammability.
Phenolic resins are available only in dark colored shades. They are not suitable for use with food.
Typical applications include thermally insulating operating elements.

http://www.jwwinco.com/technical/characteristics-plastics.htm

Thanks for the responses.

[jz78817]

I’ve only heard positive things with regards to Trabant crash test results, but I get the impression it has quite a poor reputation. Do you have any source to back this up? Here’s what I’ve been able to find from a quick search.

your “cite” isn’t relevant. the moose test is about a vehicle’s ability to carry out an emergency lane change maneuver (avoiding a moose standing in the road) at speed without rolling over. what that has to do with the material of the exterior body panels is beyond me.

as for actual crash tests, I doubt the Trabant would fare very well. occupant protection in a collision is all about energy dissipation outside of the occupant cage, and preventing the colliding object from intruding into the occupant zone. exterior body panels contribute fairly little to this* so the material they’re made from isn’t all that important. the main energy dissipation in a collision comes from the structure itself. with modern cars the “subframe” is specifically designed to collapse in a controlled manner (like an accordion) and being made from metal it undergoes plastic deformation (i.e. it bends) and gets very hot thereby dissipating some energy from the collision. even on a steel bodied car the exterior panels contribute a fairly small amount.

in other words, the people who claim the trabant did well in crash tests because some of the body was made from duroplast don’t have a frickin’ clue what they’re talking about.

• an exception would be the newer “small overlap” offset crash test cooked up by IIHS; the shape of the exterior body panels can promote deflection away from a colliding object which is just as valid as absorption as far as occupant protection is concerned.

[naita]

“but in theory did not provide much crash protection, although in crash tests it has actually proven to be superior to some modern small hatchbacks”

If you want to equate “It doesn’t do as badly as you’d think and it isn’t the worst around” with “amazingly well” you’re free to do so and I’ll even admit it’s grammatically justified, but if someone had used that in a car ad I’d call them weasels.

[GreasyJack]

The claim that the Trabant “has actually proven to be superior to some modern small hatchbacks” is more a testament to how incredibly poorly a lot of 80’s economy cars performed in crash tests. The early McPherson strut-equipped FWD “modern” small cars were superior in terms of cost, weight and interior space, but they left the passengers more exposed than earlier small car designs. For example, somewhat famously the 1st generation Golf/Rabbit was a major step backwards from the old VW Beetle in terms of crash performance. At the time of the fall of the Berlin Wall, the Trabant may well have performed better than comparable western cars* simply by virtue of being an obsolete design.

*“comparable” meaning the flimsiest of economy cars

[catchfire]

Personally I’ve never even heard of this car until just recently, until I saw this german documentary.

http://www.autos.ca/car-history-and-auto-shows/feature-a-car-for-a-dollar-the-trabant/

The lack of a reliable and consistent supply of quality steel and a shortage of operating funds required the engineers to develop new materials with which they could build body panels. After some failed experimentation with cardboard, a young mechanical engineer by the name of Dr. Wolfgang Barthel developed Duroplast, a unique material created by applying a resin to readily available recycled cotton that would be heated and pressed into body panels in place of traditional steel. The use of a synthetic body made the car light and proved very durable. When Trabants began flooding out of East Germany after the fall of the Berlin Wall, the German Automobile Association tried to have the cars deemed unworthy by conducting crash tests on them. However, it was discovered that their results were based on the damage sustained to a 30-year old car that had crashed at a speed 14% faster than the norm. Re-tests on more recent examples proved the Trabant out-performed many of the more modern rival brands. Duro-plast panels were indeed roadworthy, and gave the Trabant the distinction of being the first production car to utilize significant amounts of recycled materials for the structure of the body.

Here’s the scene that prompted me to wonder about all this. At about 7 mins there is a graph comparing the crash test results of the trabant and some other similar cars. I don’t know what the graph is showing but it seems to imply the Trabant has out performed other cars. (Sorry this video is in german I couldn’t find an english version online)
http://www.youtube.com/watch?v=udaQaiKVOe0&list=PLB226707156E48B8A

So I’ve seen this pro-Trabant view from Germany.

Then I get this anti-Trabant view from England/Top Gear, where a British Trabi collector basically derides the car as having no interesting technology and a representation of everything bad with East Germany. A car so unsafe it would never be approved in the West, that would simply disintegrate in a collision.

http://www.youtube.com/watch?v=cqWqF56aZtc

Now I understand Top Gear can be guilty of being a tad hyperbolic at times, but in this case this seems to be the general opinion I’ve found from most Westerners.

Capitalists aren’t the only people who sometimes make bad cars.

Edmunds.com calls the 1957 Trabant, a two-cylinder, two-stroke engine compact from East Germany, “one more reason why communism is evil.”

The car was common in its home country, given the lack of competition, and was sometimes exported. It was East Germany’s answer to the Volkswagen Beetle, and in some ways it was comparable, with the major difference being that the Beetle was a worldwide success and the Trabant was a spectacular failure.

“Over the years, the Trabant has become an underground poster child for bad global cars,” Oldham says. “It was produced for a long time, but never got better, never [embraced] any technology improvements” despite 30 years in production.

http://www.thestreet.com/story/11381094/3/10-worst-cars-of-all-time.html

Also confusing the issue is that the documentary mentions the Trabant won several rally races in it’s day.

Honestly I don’t care one way or the other, it just seems to me that someone is wrong here and there are a lot of political and nationalistic factors coloring people’s opinions.

[GameHat]

@Melbourne

And Thermoset Plastics are more difficult and more expensive to work with than thermoplastic plastics, or epoxies.

What thermoset plastics are you referring to? Because in my industry (unsaturated polyesters and vinyl esters) this simply isn’t true.

Epoxies are two-component systems - typically a resin and a hardener - that need to be mixed to initiate curing. Moreover most mid to large size epoxy parts need to be baked to get full cure.

Unsat polyester and vinyl ester resins are cheaper by the pound, they are one-component systems, and they don’t need to be baked to fully cure.

My last two big projects were in replacing epoxies at large scale manufacturers. One was using an epoxy to make large (~30m) wind blades, the other was a manufacturer making machinable flotation blocks. In both cases the epoxy was the expensive, difficult to work with option. The UPR or VE was cheaper and easier to process.

[naita]

@catchfire

Here’s the scene that prompted me to wonder about all this. At about 7 mins there is a graph comparing the crash test results of the trabant and some other similar cars. I don’t know what the graph is showing but it seems to imply the Trabant has out performed other cars. (Sorry this video is in german I couldn’t find an english version online)

This is a wag, but the comparisons are between the Trabant and somewhat contemporary small cars in head on collisions with immovable objects.

Compared to today all those small cars were death traps, but while the rest of the world did a lot of development into making cars safer, the Trabant stayed pretty much the same.

A head on collision is the most favourable test for a light car, which has lesser mass to stop. And, a wag on a wag, they’re comparing the most favourable of the results, which is probably low speed impacts.

[GreasyJack]

@catchfire

Also confusing the issue is that the documentary mentions the Trabant won several rally races in it’s day.

It’s very light construction, FWD drivetrain and high power-to-weight ratio 2-stroke engine made it a halfway decent rallying platform. That doesn’t mean it was a particularly good or reliable car for daily transportation.

Come to think of it, that applies to most cars that have historically done well at rallying! I’m looking at you 70’s and 80’s era Lancia, Peugeot and Audi!

@naita

Compared to today all those small cars were death traps, but while the rest of the world did a lot of development into making cars safer, the Trabant stayed pretty much the same.

Well, but like I was mentioning up thread, western car makers didn’t really get serious about small car safety until the 90’s sometime, by which time the Trabant had already ceased production.