Are car bumpers thermoplastic?

[sandsnakes]

Ok I know this is a weird question, but are car bumpers made of a thermo plastic?

Reason is, I want to have a go at making a sheath for a tactical knife and I can get an endless supply of car bumpers. Now rather then spending money on Kydex I want to perfect the design and just develop the technique before I spend out lots of dosh.
The sheath does not have to be pretty just tough and functional.

So someone here is bound to know if it can be done! BCUK is that kind of place.

Sandsnakes

 

[sapper1]

Not much help but some are.Generally the ones on cheaper models.For fiestas and KA's are.

 

[Tadpole]

Ok I know this is a weird question, but are car bumpers made of a thermo plastic?

Reason is, I want to have a go at making a sheath for a tactical knife and I can get an endless supply of car bumpers. Now rather then spending money on Kydex I want to perfect the design and just develop the technique before I spend out lots of dosh.
The sheath does not have to be pretty just tough and functional.

So someone here is bound to know if it can be done! BCUK is that kind of place.

Sandsnakes

Have a butchers at the back of the bumper. Somewhere there should be a stamp
PP polypropylene
PPO polyphenylene oxide
TPE thermoplastic elastomer
PUR polyurethane plastic rigid
TPUR thermoplastic polyurethane elastomer

 

[sandsnakes]

Thanks guys. I assume I am looking for these three?

TPE thermoplastic elastomer
PUR polyurethane plastic rigid
TPUR thermoplastic polyurethane elastomer

Sandsnakes

 

[gregorach]

If they're plastic, they're unlikely to be thermosetting...

For prototyping, it might be worth looking at Polymorph - a low-temperature thermoplastic. Never used it, but I keep looking at it whenever I'm in Maplin and thinking "That's gotta be handy for something...."

 

[FGYT]

all plasitcs are Thermo but i fink i knows what you means

Thermoform so can be heated and re shaped or even remelted if it bends generally its a thermoforming plastic

Thermoset generally is brittle etc so wont bend when heated or melt just turns to ash bakalite being the old stuff most peeps know

warm it up n see

ATB

Duncan

 

[Draven]

all plasitcs are Thermo but i fink i knows what you means

Thermoform so can be heated and re shaped or even remelted if it bends generally its a thermoforming plastic

Thermoset generally is brittle etc so wont bend when heated or melt just turns to ash bakalite being the old stuff most peeps know

warm it up n see

ATB

Duncan

Thermoplastics is a generally accepted category to cover thermoforming plastics :swordfigh

What he said though, thermosetting plastics are usually pretty brittle and therefore I find it highly unlikely that a car bumper would be made of one - they would likely turn into shards in a crash, whereas a thermoplastic, while you would get cracks and sharp points, it would most likely stay in mostly one piece. Thermosetting stuff you're more likely to find only when there's a risk of it getting hot - electrical sockets, for example. In fact, I think it's law that plugs and sockets must be thermosetting - that doesn't mean much though, my Chemistry teacher tried to demonstrate this and the plug melted quick as y'like. This is, though, why old lightbulb sockets become exceptionally brittle, like a prawn cracker - brittle to start with, and the heat makes them more so!

Just being thermoforming doesn't make it suitable for sheaths though, unfortunately. Ideally want a low temperature to make the plastic formable, but as high a melting point as possible so it doesn't get gooey - have fun getting a blade out of molten plastic goo

Pete

 

[Shewie]

Don't get too close to the fire with your prototypes SS, you might not be able to get your knife out again

 

[Mesquite]

Isn't Kydex used to make car dashboards and the like?

 

[sandsnakes]

it will be going to a place that gets very hot in the summer, so not sure about the 60 degree bit.

So kids, you know what I am trying to do, any suggestions as to a cheep way to achive it? Its for a tactical knife, the idea is so that the sheath will be hard, flat can hang upside down at funny angles and the blade not fall out also can be laced to equipment. Hence I want to play with a hot mouldable plastic, its an intresting thing about car dashboards Mesquite, can anybody confirm this. Are they made of kydex?

Sandsnakes

 

[helixpteron]

Did you hear about the plastic surgeon that fell asleep in front of the fire........ He melted!

 

[BOD]

Sandsnakes,

First, let me say this is the smartest question I have seen on BCUK for a while.

Human ingenuity has a chance in the post industrial decline. Like some of the former headhunters of Sarawak who live closer to towns we will be scrounging in junkyards for car springs and bumpers to make our tools and weapons.

Second, it seems you and a couple of others are correct. Some are not only thermoplastic but Kydex itself


http://en.wikipedia.org/wiki/Kydex

http://www.kydex.com/applications/transit

http://www.kydex.com/articles/Optare_Bus.pdf

Well done.

Maybe there will be a new wave of crime - stolen bumpers from some makes of car The BB and BCUK forums will be monitered by the police

 

[bandel4]

While I was out paddling at a nearby lake, I found this piece of (whatever is left) of a plastic bin. These bins are widely used in Malaysia, they stand about 1.5meters high with wheels and a lid.

I decided to bring it back to make a sheath for one of my parangs.
Tools I used includes a hacksaw, an electric drill and rivets.
The outcomes are as below:

Well, they work pretty well.
The black 'strap' around the sheath are actually push bike inner tubes. They help hold the sheath together and doubles as emergency fire starters as well.

A bit on the heavy side though but overall I am pleased

Will try to post more pics when I find the time to write about it on me blog.

Regards,

 

[sandsnakes]

Thanks Bod,

i will keep you all posted about what works. Expect a mysterious amont of Volvo bumper recycling to be reported in the press.



Hey Bandel, if you have any of it left see if its thermoplastic and can be heat moulded at home with simple tools. Lets start a resource list!


Sandsnakes