MECHANICAL ROCKS

INTRODUCTION     The above figure shows the spray-up process.      It consists of fibre, chopper, mould etc...      Spray-up is an open moulding , composite fabrication process where resin and reinforcement are sprayed onto a reusable mould.   Working      First we cut the continuous fibres by help of chopper.      Then a mixture of fiber and resin along with catalyst is sprayed simultaneously onto a vertical mould.      The density of deposited laminate is later increased with the help of a roller by removing the entrapped air.      Multiple layers may be added to produce the desired thickness.      Curing is usually at room temperature but may be accelerated by the application of a moderate amount of heat.                   ...

  INTRODUCTION Pultrusion process is the type of closed mould processes. It is used for producing fiber reinforcement plastic of constant cross section such as I-beam, tube, pipes etc. The above figure shows that Pultrusion process. It consists of roller, tank which containing plastic resin, heated die and soon. WORKING Fibres are drawn from spools through uncured resin bath for impregnation. Then impregnated fibres are first fed into a pre-forming box which gives appropriate orientation to the fibres. These oriented fibres are then fed into a heated steel die, where polymerisation and curing takes place, and also determines the cross section of composite stock. After that pulling operation.(continuous length of consent cross-section can be drawn through die.  Reinforcement used in Pultrusion E-Glass, S-Glass /Carbon /Graphite/Aramid reinforcement are used.The forms either roving or mat or fibres...

INTRODUCTION ·        It is the method of production of  fiber -reinforcement plastics. ·        It is the open mould process. ·        It is the simple and oldest method. ·        There is virtually no limit to the size of the part that can be made. ·        The mould can be made of wood, sheet metal, plaster and FRP composite. ·     Working ·        In order to produce a composite by using glass fibres and polyester resin, a gel coat is first applied to the open mould. ·        Fibre glass reinforcement which is normally in the form of a cloth or mat is manually placed in the mould. ·        After pouring the plastic resin which are mixed with the catal...