Originally Posted by mtbakerskier
Im going to have to call bull shit on this.
First off there isnt really much benifit in vertically laminated glass in skis, unless the laminate is a full 360 degree woven mesh.
(errrr...that's why i never MENTIONED vert lam glass...)
Secondly constructing vertical laminates inst rocket sciene, and the tooling isnt that different. In fact the only diffenrece is that a ski with a true 360 degree glass wrap usses a bradded "sock" that wraps the core of the ski. So the only major difference in the tooling required is a fiarly inexpensive bradding machine. All lamiantes skis still use the exact same presses.
(what are you talking about, horizontal vs. vert lam., or 360 glass wrap?it appears you have no clue what you're talking about, at all.all skis do NOT use the same lam machines,a horizontally laminated ski or board is essentially plywood, constructed in a flat, wide press.vert lam is when the ski is made of narrowstrips of wood, setup side by side.i've seen them both, extensively)
I am completely at loss(you could stop right there and hit the nail on the head)
trying to figure out where you are going with adhesions issues. As there is NO ski that has evere been made with a laminate consisting of Wood to Polyethylene (wrong again, braniac. "P-TEX" *IS* polyethylene, which is what most bases are constructed of.many wood-core skis and snowboards have direct adhesion of the wood to the p-tex, by way of an adhesive or by heat process. there are very few adhesives which actually adhere to polyethylene, and those which do, do not adhere well to wood, hence one of the manifold issues with regard to polyethylene x wood adhesion.you see, MOST skis are made with wood being laminated to p-tex, in direct contrast to the nonsense you posted)
or Polyurethane to Polyethelene. All Skis have a glass lamainte that seperates the Base from the skis core. (absolutely false. in fact, the "glass" laminate is usually [drum roll] "polyester-based and, further, many wood-core skiis use no laminate between the base and the 'lumber'.)
The issue with bonding the base material has NEVER had anything to do with the core, but a LOT to do with how the base material is treated inorder to bond to the matrix. I.E. Intregrated fiber layer, Corona treatment, or a Flame treatment. Polyurethanes are actually quite easy to bond to and are not that muc different than a wood core inthe actual laminate
Before you start disscusssing Laminate anlysis of ski construction, Please do usall a favor and at least get the basic laminate principles right.(ummmm.... keep up, genius )[/
gottalove some of the 'experts' here.....
"bull shit" my ass
Ohhh this is going to be a fun one........ Apareantly ?I gave you too much credit, and should have dumbed it down another level. I dont know where you learned the abouve, but if you want to sit back and read for a few minutes I'll fill you in a bit on ski construction. I actually have a B.S. in Plastics Engineering with a heavy emphasis on Composits. Hell My senior project was devloping and enitrely new method of ski construction, utilizing manufactoring methods that have yeet to be devloped in the ski industry.
First off lets get the whole laminate thing right.
99% ofall wood core skis on the market presently use thin strips of wood vertically laminated into a Core. Only a few mom and pop operations use plywood cores, infact try to name one popular ski that uses a plywood core. I have cut apart several k2 skis from the "Mahre days" that had V. or (Thin wood strips) laminated wood cares. Laminating several thin strips off wood togehter than maching the reslutant beem into a core is quite easy, infact you can easily do it in a garage with a few clamps and a planer. Most of the big guys do this in house, the rest get it from a supplier such as Core Competence in Qubec.
I gave you the benifit of the doubt that you where talking about using vertical strips of glass along the sides of the ski. This serves abosultly no function unless the glass fibers complely wrap the ski in an unbroken 360 degrees.
Every ski manufatured uses essentially the EXACT same PRESS, with a few variaitons. I.E. Heated and cooled, heated, no heat, Airbag vs. hydrolic.
Ussing a vertical or a horizontal wood laminated core makes no diffenrece at all. As the cores are all lmainated in a completly seperate process than lamination of the entire ski. The core is bassically treated as a solid piece when it is laminated into the ski. All that determins the needed width of the press platens, is the width of the ski, the mold width, and weather or not you are pressing a pair of skis together or a singe ski at a time. Hell the newest generation of presses can do over four pair of skis at once.
Now the fun stuff. P-tex is just a trade name (The US supplier calls there stuff Dura Surf I.E. Crown Plastics), the varying degrees and quality levels of p-tex are determined by wether or not High Density Polyethlyene or Ultra High Molecular Weight Polyethylene is used. While it is true that in its rare form Polyethylene is very dificult to bond to, all of the Polyethylene used in ski construction is treated so that it will bond to either Polyester resins or various expoxies, both of wich last time I checked bond to wood with no issues at all. In fact both polyester and expoxies have been used with wood in boat and plane construction long before they where ever used in skis. As I said early the base material used in skis is always treated on one side so that it will bond with wichever resin system is used. This can be done by embeding small fibers in one side of it, Mechanically increasing the surface area of one side (Sanded) and with either a Corona or a Flame treatment.
Now back to laminates, and how they work in compostis. Laminated composits get all of there strenght, stiffness and most other properties from seperating two strucutal skins consisting of a fiber embeded in a matrix, and seperating these skis by some distance with some sort of a core, be it wood, polyurathne foam, honeycomb, etc.
Bonding the the base material directly to the core of the ski would completly negate the enitre reason that the core is there in the first place, wich is why I stated that Polyethylene is NEVER EVER bonded directly to Wood or to Polyurathane in a ski. There is always at least one glass or other fiber layer between the base material and the skis core. Other wise you would not have a strutual laminate, and the skis would instantly snap if flexed in the wrong direction, wich we all know is not true.
I really dont have a clue what your talking about when you say a "glass" laminate is polyester based. By defintion, fiberglass is made from glass fibers and only refers to the actual glass cloth or matte that is used. This can be in either a polyester or a expoxy matrix. By the way Matrix is the "glue" that holds laminates and composits together.
That should prety much sum up 90% of the "laminated" skis out there and btw most cap skis are really laminates with a one piece top sheet and side wall. However there are several variations on how the matrix is applied to the fibers (glass, carbon, etc). The only other process used to make skis is Reaction injection molding wich is an entirely diferrent topic, unless you want to get into some more modern processes that are not currently used in the ski industry, and wich I would rather not talk about as they are part of an ongoing project that I am involved with.
So instead of learing from the various how to make your own ski or board at home websites, you might want to check out The Hand Book of Composits, second edtion, or Plastics materials and processes.