Central Excise Act (1 of 1944) , S.11A(1)— Show cause notice - Limitation - Willful Suppression of facts by appellants - Articles of plastic made from duty paid granules are exempted from duty since inception - Allegation in show cause notice that Petitioner have suppressed fact that goods produced fall under Chapters 84, 85 and 91 as parts of machinery depending upon end use and the goods do not fall under Chapter 39 - Further alleged that suppression, production and clearance of goods for extended period of limitation provided in proviso of section 11A(1) of Central Excise Act - Petitioner describing goods manufactured by it in declarations filed with Department as ? Articles of Plastic, Plastic articles reinforced by moulded components? - Declarations not mentioning that they were manufacturing as noted by Appellate Tribunal material used in batteries as battery parts - At no point of time, petitioner have disclosed to department that they were manufacturing battery parts such as vent plugs etc - Willful suppression of material facts with intention of evading duty on Battery parts - Additional Collector sustained notice on ground that it was within limitation five years - Issuance of notice on basis of investigation and visit of Preventive Section by Appellate tribunal, Proper .....