alright so i have a few broken racquets and they were sitting around and i needed to make some room but wanted to keep something from them for sentimental reasons. so i cut the shafts off so that ill have those. now when i was doing that one of the racquets was my old forza Ti-24 N-forze (the handle broke and couldnt replace/get it fixed) and when i cut the shaft off well it had this piece of plastic in it and i was wondering what on earth could that be for. here are some pictures of it, i was wondering if anybody knew what the relevence of having it in there was. it was a piece of plastic not ridged at all it was really soft and just rolled up into a tube shape and put in there.
I've seen this in almost all the rackets where I've broken the shafts out of curiosity. The following is my based on my experience with carbon fibre bike frame construction. I'm fairly sure the same applies for badminton rackets. There's a couple of ways of forming a tube or hollow shape from sheets of the carbon. One method is to use an internal "balloon" (the tube) to wrap the sheets around. The other method uses expanding foam which is also wrapped with the carbon. The "balloon" or foam forces the sheets outward as the material is cured. Some manufacturers may try to pull some of these "internal" molds out or dissolve them but some leave it inside. For bike frames, the foam can have a small effect of vibration damping.
It may be a plastic tube or bladder, which is a necessary component in molding a racquet. To understand how racquets are made, think about sandwiches. Sandwiches have different layers just like racquet materials. You choose the designed composite layers of graphites and other matrerials and stack the layers one on top of each other. Say you want materials that are extra stiff for very high young's modulus plus materials that are very strong plus say titanium. For this you get one layer of the highest grade ultra high modulus graphite, stack another layer of high strength high modulus graphite on top but with a slightly different orientation, then add another layer of titanium. Now you have a 3-layer sandwich. Cut this sandwich into strips, each strip long enough for one racquet. Take one strip of this sandwich and roll or wrap it around a tube or bladder. Put this strip into a mold. Heat the mold, connect a pump into the tube or bladder and pump air into the tube or bladder. The pressure of the air in the tube, along with the heat, will bond the 3-layer sandwich strip. The end product is a racquet, nice and clean on the outside, but look inside you will see a tube or bladder. The tube or bladder has the role of bonding your sandwich.
hum alright thanks for answering my question, i ask cause i also had a broken Yonex AT-800 OF and an Forza Kevler 7 N-forze which i also cut up (they both broke on the head) and they didnt have this bladder in them at all so i was just wondering about that. well thanks for giving me some insight into that.
Sometimes the bladder doesn't look like a plastic tube. More often it looks like a collapsed and wringled clingwrap which you may mistake it as part of the graphite.
