I have to design a sleeping bag for a science project....?

Question

Alright, so for science I have to design a lightweight sleeping bag that can insulate heat very well. What types of fabrics are light and warm? In this design I also have to have a conductor fabric... something that can conduct heat well. Please, give me some examples of fabrics I can use in this design. Thanks!

Answer 1

Most fabrics are insulators, not conductors. I'm puzzled why "conducting" would be part of the design since the intention of a sleeping bag is to hold body heat, NOT release or transfer it.

You might consider utilizing aluminized material (like those silver "space blankets"). Aluminum is a "conductor" technically but those blankets are really used to reflect and retain heat, rather than "conduct." Acrylic or polypropylene "polar pile" fabrics are good lightweight insulators, as are closed-cell foam, down, wool and fluffy polyester, especially the type with hollow fibers. Silk is an excellent and very light insulator also.

Sounds like a fun project. Good luck!

Answer 2

ineresting question. Without the exact wording of the criteria it will be tough to come up with the correct answer.

a fabric that is a GODD conductor of heat will mean that you will LOSE heat and thus be cold. What you want for a sleeping bag is a fabric that is a POOR conductor of heat.

If there is no durability criteria or comfort criteria, you can make a very cheap, EXTREMELY GOOD sleeping bag by starting with the liner and working your way out.

Begin with a thin reflective mylar film liner. Such "blankets" are handed out at marathons and included in camping emergency first aid kits. A simple plastic film with a mirrored coating will help the body retain a great amount of heat. These were called "space blankets" in the 1970s i suppose due to their discovery and development from the U.S. space program.

Next I would bond a layer of CLOSED CELL foam. Closed cell does not compact very well, but has great insulating capability. This is particularly important when sleeping on the ground. The conduction of heat from the body to the ground it the greatest heat loss, and even 1/8" of closed cell foam will prevent hypothermia from this. 1/4" is more than enough, and is used as a "sleeping pad" below most standard sleeping bags. by incorporating it into the bag, you make a complete system that greatly exceeds the capabilities of a standard bag. Last I would include a outer covering of rip-stop nylon for some durability and by which things such as a zipper, loops, a hood, and baffles or gussets could be attached. What you choose to attach is the custom part of your design.

The down sides of this scheme are:
1) it will not be very comfortable. The plastic against the body will be sharp on the corners and folds. It will not breathe so you will be in a plastic bag and all your body moisture will condense and you will wake up soaking wet.

2) it will not be durable. the reflective coating on the mylar film flakes off and thet film gets gray and dull within a few hours of minor movement. This means that it will lose it's reflective quality rapidly after only a few uses.

3) it could potentially be lethal. like a plastc bag, if you were to be trapped inside, you would run out of oxygen rapidly. you would need to be sure to fashion a hood that was completely breathable. Both wool and polyester/polypropolene are great fabrics for outdoor use. they breathe well and do not hold moisture very well so they stay warm when damp.

The UP side of this design is:
1) low cost. A bag capable of sustaining life to -40F degrees could be manufactured for about $15 US.

2) light. You could keep the weight to under 2 lbs. particularly if you used a thicker closed cell foam for the bottom, and a thin foam for the top.

You could optionally include a polypropolene inner liner to wick the moisture away, mitigating the plastic bag effect somewhat.

the shape should be "Mummy" so that it follows the contours of the body. less fabric = less weight = less air inside to keep warm=less surface area by which to lose heat.

regarding actual fabrics and materials, Cotton is the worst fabric for outdoor use. It loses all insulating qualities when even slightly damp, and is worse than being naked when wet. Wool is a miracle fiber. It wears well, has outstanding heat retaining properties when wet, and is very workable. Polypropolene is a great lightweight substitute for wool, but retains odors badly. a few nights and the stink will never be removed from the bag.

For fillers, down is the best, lightest, compactable filler when DRY. Once wet, it has very very poor insulating value and gets heavy and will take days to dry out and become useful again without artificial means. If your life depends upon it, avoid down.

Synthetic fiblers such as Thinsulate and Hollowfill are heavier than down, do not compact as well, but will retain a high percentage of their heat when wet. even a wet bag of hollowfill will keep you alive below freezing.

Answer 3

Goose down is an excellent insulator for sleeping bags and compacts well. Use with an inner liner with cotton flannel to wick away any sweat . Use with a gortex or nylon shell on the outside to keep out rain and wind or melted snow below you.. A closed foam mattress is also normally used to insulate from the cold ground , This could be separate or attached to the bottom of the bag.The bag should conform to the shape of your body for warmth and to save on material and weight.Add on hoods are also used sometimes.
The layering system is very effective for sleeping bags and can be good to adjust what is necessary to survive in very harsh cold environments or in warmer weather.In very cold environments
You don`t have to worry about the bag getting wet except from melting snow under the bag or sweating profusely inside the sleeping bag . So the bag must have an inner liner with wicking capability and outer shell that is water proof and breathable like gortex. A bag like this can keep you alive in - 40 degrees Celsius or - 45 degrees Fahrenheit. Good luck!

Answer 4

The best sleeping bags in the world are filled with lightweight fillers/fibers such as hollofill or goose down; good external shell material is nylon - it's light and very durable. The interior materials need to be slightly absorbant; some companies use a thin cotton flannel. A good resource to see different kinds of sleeping bags would be Backpacker Magazine's annual gear guide - you should be able to find a copy in a local library.

Answer 5

Use a delicate impartial colour to look any photos you're posting. you may make a geometrical structure border showing top and left perspectives of an identical structure by technique of folding different shapes and then reducing them out an putting them at the same time.

Answer 6

I found a wonderful site for you. This guy is a backpacker and makes a $250 sleeping bag for around $90. He tells you exactly what you'll need. What material you'll need and how to put it together for a summer one or a winter one. I think you'll like this site.

Answer 7

i nsay make the insed lining wool then a layer of cotton then a layer of polyester or lycra

Answer 8

cant beat thinsulate

Answer 9

probably cotton?