September 2010

September 21, 2010

INSULATION

I have been selling insulation and/or insulated products for almost 50 years and I finally read the dictionary definition of insulation; “the action of insulating, the fact or condition of being insulated.” I believe these definitions are in complete. The definition does not say what exactly insulation is, i.e. that it actually is a material or a variety of different materials.

     Insulation as far as I am concerned is a physical entity; i.e. material and as such has certain qualities or attributes that allow it to function as insulation or better described as an insulating medium. In order for the insulation material to perform its function as an insulating medium it must be placed between two other materials. Think of the two window pane insulated windows. The claim is the air trapped between the two panes works as an insulator, to some degree it does, but if you placed polyester fiberfill as an example between the pains there will be an increase in the affect of the insulation derived from the two window panes. The insulator being the complete set of items, the glass and the fiberfill acting in concert as an insulating medium. The reason is simple the space that the fiber consumes reduces the ability of the air also trapped between the two panes of glass to move. Stagnant air like stagnant water increases in temperature. Without the fiber situated between the two panes of glass the air would as it is heated rise. The heated air would then via conduction pass its heat to the metal material the frame is constructed from. This action would not be any different than warm air going up a chimney of a fire place. When the fiber is placed between the window panes the ability of the air to rise is severely restricted. Any rising of heat must also be via conduction. That means the lower fibers are warm and the heat from the fibers moves up the fibers that are touching the lower fibers, a very slow process. The denser the fibers are packed into the space to a point the slower the process. However, if the fibers are to densely packed as to create a wall, most of the fibers touching each other, where the space between the fibers is almost non-existent the rate of conduction is increased. There is technically an optimum amount of fiber that could be used. To find that point would take significant testing so for practical purposes we must make a decision based upon some experience versus an actual calculation. Since we have been using glass as an example we could easily see that we do not pack in an excessive amount of fiber. It will be random to some degree because a uniform continuity over the entire surface would be impossible to accomplish. To the naked eye it could look uniform but in reality it would not be.

     A second example is the fiberglass insulation that is put in homes. Generally the amount of fiberglass used in the walls is less than what is used in the ceiling. The fiberglass used in the ceiling is generally 3 or 4 times thicker than what is used in the walls. The heat rises, it does not move sideways. Therefore less is needed in the walls. When the heat arrives at the ceiling it is stifled by the much thicker amount of insulation, heat loss is therefore greatly reduced.

     If we took the window panes and layed them down flat or we use the example of the ceiling they represent how a sleeping bags is positioned when put to use. For a sleeping bag we will change the material from glass exterior to woven nylon fabric. The one major difference between the two materials is the nylon fabrics vapor permeability. In the case of a sleeping bag the moisture the human body generates must be able to escape from the bag. An attribute of the fiberfill should be the fact that it does not absorb the moisture and that it does not inhibit the moistures ability to escape from the sleeping bag. There are basically two forms of fiberfill used as an insulating medium; continuous filament which I use and chopped staple fiberfill. Either can be used in a manner that does not incorporate the need for quilting. Each of the fiberfill’s can be layered so the appearance both outside and inside is smooth, there are no interruptions as is seen when either side or both sides are quilted. The quilting in my opinion is done simply for cosmetic reasons in almost all cases. When a company that makes very in expensive bags quilts them it is primarily to hold the fiberfill in place. However when these bags are laundered the fiberfill will bunch and go flat. The other instance happens to be an expensive bag. Here the manufacturer is using a stretchable sewing thread so the bag will stretch out as you move in the bag. My opinion of this product is that it is dumb, but the company has been making them for many years and there are obviously some consumers who think it is a good idea and buy them. I can not imagine they are particularly comfortable and I also believe they are probably not acceptable for temperatures below 35 degrees or so. These bags also have thin spots or cold spots just like any other quilted bag. In each case the insulating medium, i.e. the fiberfill is compromised.

     You can use as I have said the chopped staple fiberfill in the non-quilted method but its efficiency as an insulting medium very quickly gets compromised. Several companies over the years have manufactured their sleeping bags in this manner. The main problem has to do with the collapsing of the fiberfill. To begin with to the best of my knowledge the manufacturers of the fiberfill have made then as low melt fiberfill products. They blend two fiberfill’s, one that is heat set at 475 C and the second has a sheath (coating) of a material that melts when it is subjected to temperature of 300 degrees F (in the USA). The sheath liquefies and becomes the glue that holds the fibers together. Years ago when resin bonded fiberfill’s were made they were much loftier than the low melt fiberfill’s on a weight for weight basis. However in a short period of time they would lose their loft and resilience. The low melt products start out with less loft so loft loss isn’t as apparent but it is happening. When bags with this construction of fiberfill are stuffed and un-stuffed the loss of loft becomes even more apparent. Generally speaking the bags made with this fiberfill are temperature rated from 0 degrees F and higher but they almost always end up as 40 degree bags no matter where they start. Remember the spaces between the fibers that trap the air is reduced virtually to nothing so conductive heat loss is increased dramatically and moisture retention is enhanced because a wall of fiber has been created. The fibers are packed into themselves. Even though the bags were made without quilting which are cold spots, the fact that the loft has been lost means the bags ability to perform is not any better than the quilted bag. The insulation, the combination of the two layers of nylon and the layer or layers of fiberfill have been compromised and are rendered in my opinion almost useless. Also when these bags are laundered the fiber does deteriorate even more.    

     The continuous filament fiber is in my opinion the best of the available materials for the making of an insulation. There are however two problems that exist with it in the way it is used; one, the manufacturers who do use it with the exception of myself do not use enough weight on a per square yard basis and then they quilt it. Of course the quilting reduces the loft where it is quilted to zero. Then the fact that the weights are so light the amount of fiber that would stifle the flow of air is of little value. So the package so to speak making up the insulation is not much better than the chopped staple product. In addition the fiber will collapse in a short period of time making for a warm weather sleeping bag again just like the chopped staple bag! Quilting continuous filament fiber restricts it so it gives up and dies versus my method of layering it in a bag with out restriction so the fiber will separate slightly causing an increase in loft.

     The insulation that I use is a combination of the same three components two layers of nylon and continuous filament fiberfill. This is what I call and have trade named Lamilite. This insulation incorporates the best of the components that are currently available. I also believe that these components will not be replaced in years to come. The nylon quality that I use has demonstrated that it heats to source (body) temperature very quickly and retains the heat, has exceptional vapor permeable capacity and for its weight extreme strength. The fiberfill “continuous filament” has demonstrated when used in appropriate weights will keep the nylon materials apart easily. The fact that the nylon fabrics are kept apart over the overall length of the sleeping bag means there is complete uniformity. Like the window panes being kept uniformly apart means greater heat retention and like the widow panes having the fiber added means that the movement of heated air is stifled. How much fiberfill is necessary for a specific temperature would take significant testing, and would it be adequate for all people in general, probably not. To satisfy the greatest number of people using a greater amount of fiberfill insulation becomes necessary. I am sure there are some people who could use my +20 degree bag when the temperature is 0 degrees. I prefer to use a greater amount of insulation for each temperature range so those who find the bags to be “over kill” exercise the use of the zipper to cool down. The fiberfill should also have the capacity not to retain moisture either by stifling its movement while it is in a vapor state or via absorption. The continuous filament fiber the is used in the manufacture of Wiggy’s bags has demonstrated on a continuous basis that it retains enough heat that as moist vapor is actually driven out of the bag; this is an exceptional characteristic for an insulating medium to have.

     Simply put there is no other material used as an insulating medium that has these positive characteristics.

     The one material I have not mentioned until now is down. Using down requires material that does not have much of a vapor permeable capability. The amount of moisture that does get through the lining fabric is absorbed quickly by the down. Two things now happen; one the bag gets heavier from the moisture it is retaining and two the loft deteriorates; loss of loft. Once the cycle starts it can not be reversed and the insulating capabilities are compromised. Therefore, down is not a good choice for use as an insulator.

     There are several companies that have thus far continued to manufacture sleeping bags using chopped staple fiberfill as there insulating medium even though they have had the continuous filament fiber available to them for years. Why they have shied away is a mystery to me. Since its inception in 1968 the entire better priced sleeping bag manufacturers at the time and for the most part to this day started using it versus the chopped staple fiberfill since only the lower priced manufacturers used chopped staple fiberfill. The retailers became well educated about continuous filament fiber; it was originally called Polarguard. Each time some companies that have made a chopped staple product for use in sleeping bags the manufacturers who have tried it have gotten burned and the retailers ultimately reject it. It is relegated to being used by low priced sleeping bag makers.

     What would be in the best interest of those companies that make higher priced sleeping bags is if they had people educated in what insulation is and how it works on staff. Once they did get the education they so sorely need I would expect them to contact me so they too could be using LAMILITE. I would gladly sell it to them, I am a capitalist.

     In conclusion; I have said many times to buy any sleeping bag other than a Wiggy’s bag would be a complete waste of money. The reason; simple LAMILITE stands alone as the finest most efficient insulating medium in the world and I expect that to be the case for many, many, many years to come.

ADDITIONAL INFORMATION ABOUT CHOPPED STAPLE FIBER                       

When the DuPont Company started selling polyester fiber they made fiber for specific end items; as an example they made a coarse 15 denier (basically the thickness of the fiber with a crimp) fiber for use as a carpet fiber. The crimp gave the fiber the necessary resilience because carpet is walked upon. They made 2 and 3 denier fiber for use in spinning with cotton or wool for yarn that eventually was woven into fabric. You know them as cotton poly blend or wool poly blend fabrics. When it came to fiber for fill purposes they made a fiber with a spiral crimp like a spring so it also had resilience. This was a specific fiberfill fiber. Other fiber manufacturers such as Eastman Chemical produced a very resilient fiberfill fiber with a different type of crimp, but it was fiberfill specific. When other fiber companies entered into the business of offering fiber for fiberfill it was not fiberfill specific but rather waste fiber they couldn’t use for blends. They generally did not have any crimp or very little at best. When put through the garneting equipment they would not generate much loft so they were blended with the fiberfill specific fiber. The only benefit was to the garnetters who paid $0.10 per pound versus the fiberfill specific fibers that cost $0.60 per pound. The end product lost loft very quickly.

     In 1968 when Celanese Company introduced the continuous filament fiber trade named Polarguard it was fiberfill specific. Over the years since many companies DuPont included and to this day have tried to duplicate what Celanese was selling only to fail. One guess I have is that these other companies were using fiber that may have been intended for use in the blends area of fiber manufacturing. The company that purchased the Celanese technology has for all intents and purposes a lock on the market. They have over the years made some improvements so what I purchase for Lamilite is better now than it was 10 years ago.

     Today DuPont does not make any polyester fiber, to the best of my knowledge neither does Eastman Chemical. Actually to the best of my knowledge there are no fiber producers in Asia that make fiberfill specific fibers so any of the chopped staple fiberfill’s being incorporated into sleeping bags or outerwear garments world wide are probably waste fibers. The resin bonding of these fibers or low melt bonding of these fibers will only last so long, generally one or two uses as sleeping bag insulation and maybe a season as jacket insulation.

     Any manufacturer using these fiberfills is counting on planned obsolescence to hopefully get new business for the following season. Here is one more reason to consider Wiggy’s bags since they are guaranteed for a life time of use. A former friend told me my bags were to good, they would last to long. I told him if they proved to be as good as I claimed those who bought them would tell their friends who were looking to buy a sleeping bag about Wiggy’s and I am very please to say that my customers have become my best salesman for which I am very grateful, THANK YOU. 

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