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pvhramani

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About pvhramani

  • Birthday 03/08/1949

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  • Website URL
    http://www.karmayog.org/nonprofits/profiles/profiledis.asp?r=240&id=17418

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  • Location
    India
  • Interests
    Indian Classical Music, Painting, Scenic Photography, Internet surfing
  • College Major/Degree
    BSc. Engg (mech)
  • Favorite Area of Science
    Materials and Energy
  • Biography
    A mechanical engineer by training, had experiences in Polymer Engineering, Plastics Processes, Mold Engineering, Adhesives and Coatings, Corrosion Technology and Product Developments; and currently involved in New Products Technology/ Developments
  • Occupation
    Tech. & Product Dev. Engineer

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  1. You need to understand this - a repetition from an earlier thread here: (1) Hybridized Wood/ Natural Fiber Polymer Composites (H-NFPC) could be in the sp.gr range of 0.75 to 1.15 (2) While the sp. tensile strength of steel is about 580 to 3, 000 (depending on mild steel, alloy steels, special steels etc), that of H-NFPC is about 1, 200 (the dimensional factors of sp.ten str are not mentioned here) (3) A derived property such as Equivalent Weight Rigidity (in Kgf-cm2) is still more interesting: all steels = 175, 000; cast Al alloys = 1, 495, 000; cast Mg alloy = 3, 700, 000; S-Glass Epoxy = 2, 730, 000; C-Epoxy = 13, 975, 000; H-NFPC = 7, 550, 000. If you are not able to understand these... please ask... I would help by giving a link for you to study these fundamental engineering properties of materials. Here you will find that NFPC/ H-NFPC based on wood/ natural fibers would be far superior to steel in RIGIDITY Modulus
  2. It is here that Engineering comes in. For example, cement has ZERO tensile strength; but in reinforced concrete (and more so in "pre-stressed concrete), it is one of the BEST building construction materials. And more over, as already noted, we are not using wood in its original form, but as NFPC and H-NFPC. The hybridized version would be a superior engineering material. And, based on certain study results, these composites could soon enter engineering structural systems in a big way:-)
  3. Hi 1. Let me begin with your last question: "Also, why is this thread the top Google result for H-NFPC?" In fact, as soon as I noted this observation from you, "googled" and saw the veracity of your statement! I too do not know how it reached there! 2. Your general statements about wood, its usage, its decay problems, and also about cellulose/ lignin have been noted. Without going deeper on the technicalities now itself, it is observed that almost all the "problem situations" of normal wood can be overcome in wood/ wood fiber based Composites. Also, about your apprehension of the "direct" use of wood: when wood is used without modification we tend to select only the so-called "best" wood materials, and that has been the cause of forest depletion and other "tree felling" related problems. More will come as this discussion progresses 3. The discussion here is on: wood/ wood fiber as a structural engineering material ... This suggests that wood/ wood fiber are to be considered in relation to other traditional Engineering structural materials such as: steel, aluminum, magnesium, plastics, ceramics, composites ... etc The following aspects are to be appreciated here: (i) When we say wood/ wood fiber, hereafter, it pertains to the different material systems in wood, modified for COMPOSITES development. And we shall not be looking at the "regular" wood usage - which has stood the test of time for thousands of years (some one had asked: "since when is wood construction not everywhere already?") (ii) As presented earlier, we shall discuss Natural Fiber Polymer Composites (NFPC), and Hybrid Natural Fiber Polymer Composites (H-NFPC), wherein the Wood/ Wood Fiber content shall take up to weight percentages of 40% to over 85% of the total composite weight (iii) It is assumed that every one has a general idea of what a Composite is. Here again, without going into the full technicalities, it would be briefly noted that a composite is homogeneous mechanical combination of two or more material systems, in which at least one material is normally a BINDER. Wood itself is a natural Composite; Concrete is an artificial composite ... 4. Now, coming back to NFPC and H-NFPC, the differences are as below: (i) NFPC has the main ingredient in the form of Wood fiber, and the binder ingredient is a Polymer that has affinity/ adhesion properties. The composite would also have certain special ingredients to impart decay resistance, fire-retardance, and so on (ii) H-NFPC is hybrid NFPC that would have as hybrid ingredient, superior strength engineering fibers such as Glass Fiber, Carbon Fiber , Kevlar* Fiber ... This hybridization dramatically changes the strength properties, although at the sacrifice of increased cost. (iii) We shall define Wood Fiber as wood elements having arbitrary length/ thickness ratio 100 or more; and the largest average thickness shall be arbitrarily restricted to 2.5 mm --------------------------------------- *Kevlar is a DuPont invented High strength Fiber ---------------------------------------------------------- It may be noted that Wood fiber Polymer Composites (which can also include various other fibrous materials such as Flax, Banana Fiber, Pineapple fiber, Corn cob fiber ...), termed NFPC or H-NFPC are not new, and various engineers and technologists are working on these. The main theme of this writer is to discuss its potential as ALTERNATE ENGINEERING STRUCTURAL materials in place of steel/ aluminum/ plastics in auto body systems, boat/ ship building systems, building construction, and various engineering structural needs where the temperature conditions lie within 120 deg C More to come later
  4. Although in its natural form these materials are prone to certain attacks, with the great advances in Engineering Composites, this problem is surmounted. This writer has been working on certain Composites formulations, and on the basis of certain lab level tests, some very interesting observations have been made: (1) Hybridized Wood/ Natural Fiber Polymer Composites (H-NFPC) could be in the sp.gr range of 0.75 to 1.15 (2) While the sp. tensile strength of steel is about 580 to 3, 000 (depending on mild steel, alloy steels, special steels etc), that of H-NFPC is about 1, 200 (the dimensional factors of sp.ten str are not mentioned here) (3) A derived property such as Equivalent Weight Rigidity (in Kgf-cm2) is still more interesting: all steels = 175, 000; cast Al alloys = 1, 495, 000; cast Mg alloy = 3, 700, 000; S-Glass Epoxy = 2, 730, 000; C-Epoxy = 13, 975, 000; H-NFPC = 7, 550, 000. Without going into the detailed subject matter on Derived properties etc, it is noted that in many structural applications the equivalent rigidity section in H-NFPC would weigh as low as about 30% of the steel section. This is a great advantage from the point of view of weight, cost, energy and various other manufacturing and usage aspects. The idea of initiating this discussion is to create a forum of engineers who are interested in this, so that many more developments could be made, from the present infinitesimal level. This writer wishes to hear more on these from other engineers who have done works in Wood/ Natural Fiber engineered products/ systems.
  5. Hello I joined just today, and after I was really impressed at the superb quality of the web systems here, I also had a fast peep into some of the lively and knowledgeable discussions subjects. But am disappointed that here a subject that needs in depth understanding of materials engineering, Wood science, and knowledge about world materials scenario is being indulged in by relatively amateurish manner ... judging from the thread of discussions to my original presentation on wood fiber being considered as a specialty engineering material Having said that it is NOT my intention here to discourage any one in discussing on such subjects. But, here is a serious SCIENCE forum... and it is expected that one would indulge in "talking" on a subject only based on individual experience Thank you
  6. Technologically, we have developed various engineering structural materials that excel in strength properties; nano materials, whiskers, tungsten and boron fibers, super cermets, carbon fibers ... et.all. We boast of nano-materials and whiskers that could have tensile strengths and moduli of over a million and fifty million MPa respectively. But strangely, many of our day-to-day engineered materials needs are yet to be answered. The matter is further complicated in the present "globalized" economy - what is accepted in an advanced nation such as the US may have no meaning in countries such as Zaire, Chad, Afghanistan, Bangladesh ... etc. Yet, these under-developed nations, whose population account for more than half of the 7 billion men and women in the world, do not have even the rudimentary means of shelter, clothing and food - forget about owning even a bicycle! This writer has been wondering:Wood, which is a renewable resource could be a great general engineering structural material, if we could utilize the advantages of its renewable nature, low specific gravity, huge availability, and low cost. Let us consider, as an example - the COCONUT Tree. On the basis of the natural average life span of sixty years, the world would have annually renewable coconut tree resources to an extent of not less than 100 million tons! The significance here is that, even if we do not voluntarily cut the tree, its life span being sixty years, we have so much "tree resources" naturally made available. And, in a world beset with the problems of CO2 and GHG increases through over exploitation of resources and energy, this is a materials engineering opportunity to be "grabbed". From a technical angle, we may note that tree/ natural fibers such as those from coconut trees could even compete with some so-called super engineering structural materials - on the basis of "sp.strength", "equivalent weight rigidity", energy efficiency, availability and cost. NOTE: Coconut tree is just one example. There are hundreds of other species that are available as renewable natural tree resources What you think engineers. about this thought?
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