This document discusses different types of core boxes used in foundry processes. It describes half core boxes, slab or dump core boxes, split core boxes, left and right hand core boxes, strickle core boxes, gang core boxes, and loose piece core boxes. Each type of core box is designed to produce a specific shape or type of core. The document also outlines common core materials like core sand, bentonite clay, pulverized coal, and water that are used to make cores within the core boxes. Core sand mixtures typically contain granular refractories, core binders, water, and special additives.

1. FOUNDRYFOUNDRY
TECHNOLOGYTECHNOLOGY
Module IIIModule III
ANOOP M S
Asst. Professor

2. CORE BOXESCORE BOXES
A Core box is basically a pattern for making core. Different
types of core boxes are
• HALF CORE BOX
• SLAB OR DUMP CORE BOX
• SPLIT CORE BOX
• LEFT AND RIGHT HAND CORE BOX
• STRICKLE CORE BOX
•GANG CORE BOX
•LOOSE PIECE CORE BOX

3. Half Core Box
• It can make cylindrical cores
• Half portion of the core is made in the core box at one time

4. Slab or Dump Core Box
• It resembles to half core box but it makes full core at a time.
• It is employed for making rectangular, square or trapezoidal
cores

5. Split Core Box
• It consist of two parts
•Two portions of the split core box is aligned and temporarily joined
together with the help of dowel.

6. Left and Right hand Core Box
•They are used to make cores for producing pipe bends
•Half of the pipe bend core is made in each core box
•Two halves of the pipe bend thus rammed are baked and then
connected together to make full core

7. Strickle Core Box
• Sand is rammed in a dump core box
•Top surface of the core in the core box is given desired shape or
contour with the help of a strickle board cut and finished to the
desired shape.

8. Gang Core Box
• It contains a number of core cavities so that more than one cores
can be rammed at one time.

9. Loose Piece Core Box
•Unlike half core box, loose piece core box can produce two halves
of a core, which may be neither identical in size nor shape.
•Asymmetric shape is obtained by inserting loose pieces in the core
boxes.

10. Core Materials
Materials required to make core are:
a)Core sand: It is a suitable sand mixture for making cores.
b)Bentonite clay: It is an aluminum pyllosilicate clay. The
types of bentonite are each named after the respective dominant
element such as pottassium,sodium,calcium and aluminium.
c)Pulverized coal: It is a fine powdered form of coal, which
created by the crushing, grinding or pulverization of coal.
d)Water

11. Core Sand
Ingredients of core sand are:
a) Granular Refractories
b) Core binders
c)Water
d)Special Additives

12. Core Sand
a) Granular Refractories
 Clean, pure and dry silica sand
 Coarse white silica sand of high refractoriness
 Finer lake or bank sands
a) Core binders
 Organic binders: They are core oils, cereal binders, water soluble
binders, wood product binder, wood flour, protein binder, synthetic
resins etc.
 Inorganic binders: Fire clay, bentonite, silica flour, iron oxides etc.
 Other binders: Portland cement and sodium silicate
a) Water
 In a core sand mixture, water content may vary between 2.5% to 7%
 Binders and additives are work only in the presence of moisture only.
a) Special Additives
 Coal dust, Asphalt, Graphite and Silica flour etc