ROllER MILL.pptx

ROllER MILL

1. TOPIC: Mechanism of SIZE Reduction & Roller Mill PHARMACEUTICAL ENGINEERING Prepared by kashish Wilson Assistant Professor, MM College of Pharmacy, MM(DU), Mullana Ambala

2. SIZE REDUCTION: INTRODUCTION : Size reduction is a process of reducing large solid unit masses into small unit masses, coarse particles or fine particles. Size reduction process also termed as comminution or diminution or pulverisation. Size reduction may be achieved by TWO methods Precipitation process Mechanical process

3. OBJECTIVE OF SIZE REDUCTION : It improves appearance. It increases surface area. It facilitate absorption and bioavailability. It improves the stability. It facilitate extraction. It facilitate mixing. In aerosol and inhalation preparation. Parental suspension. It facilitate drying. Ophthalmic suspension. Increase in viscosity.

4. Modes of size reduction : Cutting : The material is cut by means of a sharp blades Eg : cutter mill Compression : In this mode material is crushed between roller by the application of pressure Eg : roller mill Impact: This involve the operation of hammer/bars at high speeds. When a lump of material strikes the rotating hammers, the material splits apart. Eg : fluid energy mill Attrition : breaking down by the rubbing action between two surfaces. Eg : fluid energy mill, ball mill

5. Roller mill : Principle: stress&attrition(rubbing action) Construction : it consists of two cylindrical rollers made of stone or metal Rollers are capable of rotating on their longitudinal axes. One roller is driven directly using a motor, while second one runs freely. The gap between the rollers can be controlled to obtain the desired particle size. Uses : used for crushing and cracking of seeds before extraction of fixed oils.

6. Thank you