Student Designs Cardboard Computer Case 329
SpaceGhost writes "The Houston Chronicle has a story on a Grad student at the University of Houston who has designed a cardboard case for a computer. This is not a new concept, but this one is meant to be used in manufacture. The idea is that it will be faster and easier to produce (no fasteners for example) and dramatically easier to recycle."
Better description and pictures (Score:5, Informative)
http://www.engadget.com/2009/02/05/recompute-a-closer-look-at-the-sustainable-cardboard-pc/ for a better description and better pictures
the case is the easy part (Score:4, Informative)
The case is either Al or steel sheet metal, easily recyclable. The toxic sludge and heavy metals in the PCB, capacitors and solder are the problem. Call me when they invent cardboard solder.
Re:grounding? (Score:4, Informative)
Grounding has always been via the power supply primarily, the power supply always has a ground plug for that reason. The case was just a handy secondary ground when working on the computers. I imagine that lame grounding strap will be more important for this case, but really grounding isn't a big risk unless you are in a very dry area and producing a large static buildup in your body.
Re:grounding? (Score:3, Informative)
What needs to be grounded? There are ground return paths in all component connections, and that is desirable over having random ground currents circulate in the case.
Having debugged a few interference problems on PCs myself, as far as RFI is concerned, radiation is primarily from external cables. The main problems with PCs are 1) Reradiation from the external power, peripheral, and network cables, 2) Pickup of stray radiation on cables inside the case itself.
Re:grounding? (Score:3, Informative)
Almost all of them do. In fact I am unaware of any case that doesn't.
devices(CD-Rom. hard dirve, etc) use their case for grounding, and you attach metal screws to old them onto the case, and most likely have other contact. You do not want to start having different 'ground points' in a case. That will casue drift and multiple different potentials.
This is why you should leave the computer plugged IN, but turned off at the power supply when working on them, also maintain contact with them usually via a strap.
That said, the risk of damage in normal conditions is real, but low.
Re:EMC Nightmere (Score:3, Informative)
Apparently you haven't opened one. There aren't many plastic cases around. There are aluminum cases with plastic molding on the outside.
Re:Better description and pictures (Score:3, Informative)
Unless your computer catches on fire it will never get hot enough for cardboard to burn. They put oven meals in cardboard, people reheat pizza in its box in the oven and cooking food in a oven is much hotter than a PC.
From this link: http://www.school-for-champions.com/science/feedback.cfm?next=10&topic=Thermodynamics&start=1#Science%20project%20boiling%20water%20in%20cardboard%20box [school-for-champions.com]
Paper must reach the temperature of 451 F (233 C) to burn. But the water in the box is less than 212 F (100 C) and any heat added to the paper will be absorbed into the water by conduction. The paper and water will be at the same temperature. In fact, any material you use that readily conducts heat will stay at about the temperature of the water.
Once all the water has turned to steam, the cardboard or paper will burn.
Not very recycleable. (Score:3, Informative)
a 100% aluminum or steel case is 100% recyclable. This "cardboard" thing is a gimmick. In fact most computer cases metal components are always recycled as the metal has the highest value.
Re:Seems like a cool idea... (Score:4, Informative)
But its probably not recyclable after it catches on fire from my overclocked processor
No worries. I think the melting point of solder is lower than ignition point of cardboard. So there's an automatic safety mechanism: solder melts, electric connections break, heating stops.
Re:the case is the easy part (Score:3, Informative)
Right. The RoHS is just a figment of our imagination; electronics companies actually decided to use crappier, more expensive solder in order to promote planned obsolescence.
Seriously, we've been hit twice in the solder department. First it was water-based fluxes (the problem wasn't the flux, but the flux remover, which had some truly nasty compounds in it). For quite a while they didn't work so well causing insufficient wetting of the components resulting in failure of the solder joint. Once that was ironed out, then the RoHS with the lead-free solder requirement came in. This time the solder goes on fine, only to later develop "whiskers" which short out the devices.
Re:Seems like a cool idea... (Score:3, Informative)