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

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ROllER MILL.pptx

  • 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.