Comil Tooling Select.. - Sawyer/Hanson Innovations

QUADRO ® COMIL ® Page 4 of 4
S CREEN S ELECTION C ONT’ D
“G” Grater Holed Screens: They have a cutting edge on the holes. Used for sizing products
that are harder or more ductile (with some elasticity). Applications include sizing tablets in the
Pharmaceutical and Nutraceutical industries, powderizing cream-filled cookies for reclaim,
grating cheese, chopping nuts, sizing compacted “ribbons” from roller compactors in dry tablet
manufacturing, sizing pre-compressed slugs in tablet manufacturing, sizing cereal flakes, sizing
bread loaves for crumbs. This screen is often used when a tighter particle size distribution
curve is desired. Sizes range rom 0.040” (1.00mm) to 1.25” (31.75mm) hole diameters.
A PPARENT H OLE S IZE
When selecting the proper screen hole size, the apparent
hole size must be considered. What is the apparent
hole size It is the size of the screen hole that is
"perceived" by a particle traveling by the screen hole.
At zero velocity, when a particle "looks" at a hole, it
sees the actual diameter of the hole. In this slide it is
labeled as D1.
However, if the particle was traveling at a certain velocity,
let's say "v", it will "see" the diameter of the hole as
D2.
“C” Condidur Holed Screens: They also have a cutting edge on the holes. It is available in
smaller holed sizes when compared to the “G” screen. This allows for finer milling with less
chance of screen blinding. Sizes range from 0.006” (0.15mm) to 0.039” (0.99mm) hole diameters.
Other specialty screens have not been covered here. Please consult Quadro for further details and also, the Application
Bulletins for more information.
D1 is always greater than D2. As the velocity goes up, the apparent hole size goes down.
For example, if you require a particle to be sized to 30 US Std mesh (or 0.0234"), then the screen selected should have a
hole diameter of approximately 18 or 20 US Std Mesh (0.0394" or 0.0331") or larger; of course, this depends on the impeller
rpm. Testing is generally recommended for proper tooling selection.
LOCAL REPRESENTATIVE
Quadro Engineering
613 Colby Drive
Waterloo, ON, CA N2V 1A1
T 519-884-9660
F 519-884-0253
sales@quadro.com
www.quadro.com
Quadro, Inc.
55 Bleeker Street
Millburn, NJ, USA 07041-1414
T 973-376-1266
F 973-376-3363
quadrosales@aol.com
www.quadro.com