Adhesives And Glues Project Report

Adhesives, Glues and Gums Project Report

Fevicol type adhesives come  under the category of synthetic resins and latex adhesives and are made from polyvinyl acetate is a  thermoplastic, odourless, tasteless, non-toxic, essentially clear and   colourless  resin.  It has a non-crystalline and relatively  branched   rather  than linear  structure. Most   grades  of  resin  have  a  somewhat    broad molecular  weight  distribution. They do not  melt,  but  soften over a temperature  range. The  resin  is  unaffected   by sunlight,   ultraviolet   light  and air,  furthermore it will absorb a small  amount of water. Polyvinyl acetate  is  neutral  and   non-corrosive.   The  various  grades   have good heat stability below 100oC, show slight discoloration  at  approximately 150oC and decompose  at 50oC but brittle at 10  to 15oC.    

Because of their  relatively  low cost, ready  availability,  wide  compatibility and excellent adhesive characteristics,  many polyvinyl   acetate resins,  solutions and emulsions are  treated  as  commodity  items  by the adhesives  industry.  Most   of  the differences in physical properties among polyvinyl acetate grades are  primarily a function   of molecular  weight.   Low molecular  weight   grades are soft  and  deformable at  room   temperature,  whereas   the high molecular weight grades are hard  and   tough.   All grades have  outstanding  adhesive  to many surfaces,  porous and   non-porous.  The excellent adhesion is due  in part to  the highly polar  acetate groups in the polymer and partially to  the unique  combination  of viscosity,  tack,  tensile  strength  and  other  properties that exist  during application of the  adhesive  and during a formation and ageing of the bond.
Few Project reports on Adhesives