Category:

Description

INTRODUCTION:

AFCIMIX sand additives are prepared from specially selected materials. These additives are suitable for green sand moulding & are recommended for all synthetic, semi – synthetic and natural sand for iron, steel & copper base castings.

DESCRIPTION:

Following three types of AFCIMIX are manufactured to suit individual requirement.

  1. AFCIMIX: 11

Largely eliminates defects such as scab, rat tails and buckles, where there is strong localized heating e.g. in the vicinity of ingots or on horizontal mould surfaces exposed to radiant heat from metal, moisture is drawn away from the surface. This results in a wet weak underlying layer that can easily fracture resulting in the casting defects. AFCIMIX 11, without affecting permeability improves the wet strength of these underlying areas and eliminates the casting defects. It is recommended for iron & copper alloys.

APPLICATION:

AFCIMIX 11 is added early in the mulling cycle before other addition such as Bentonite, coal dust and Dextrin. For best results dry mulling is recommended.

Recommended procedure for additives:

  1. Add silica Sand in the muller.
  2. Add AFCIMIX 11 & dry mix with other dry sand additives.
  3. Add required quantity of water & mix well.

Recommended mixing proportions –

AFCIMIX 11 is added at the rate of 0.5 to 1% by weight. In exceptional cases 1 to 1.5% may be added in which case the addition of 0.5% extra water improves mould ability. When recycling previously treated sand, an addition of 0.05 to 1.0% of AFCIMIX 11 is usually sufficient.

ADVANTAGES AND BENEFITS:

  1. Non – irritant, non – toxic sand additive
  2. It improves anti scabbing properties of all types of green sand mixture.
  3. Improves sand mould ability.
  4. Promotes improved thermal stability of moulds resulting in better casting definition and dimensional accuracy.
  1. AFCIMIX 21:

AFCIMIX 21 is a complete additive for steel casting facing sands. This additive replaces Bentonite Cereals, Dextrin etc, which are added to synthetic sand used in steel foundries. When afcimix is added to sand & mulled with appropriate amount of water, it produces flowable green Sand and having excellent moulding characteristics and good air-drying properties. When exposure to air after moulding, yields a hard non – friable surface. Moulds produced have good resistance to erosion by metal.

APPLICATION:

Recommended procedure for additions:

  1. AFCIMIX 21 is added at early stage of dry mixing with other sand additives.
  2. Then add required percentage of water & mix well.

 

Recommended mixing Proportions:

  1. Add silica sand in the muller mixer.
  2. Add 5% AFCIMIX 21 for new sand & mix well.
  3. Add about 3% water by weight of new sand & mix well.
  4. Fine sand may require water unto 3.5 %.

 

The resulting mix is normally used as facing sand with a thickness of 25 – 75 mm, depending upon casting section. Reclaimed sand can be used but results are not as good as with all new mix. As a general guide, for every 25% reclaimed sand used, reduce the quantity of AFCIMIX 21 by 1% and increase the addition of water by 0.25 to 0.5%.

 

A rammed mould will begin to harden immediately on exposure to air and after about 30 minutes, will be noticeably harden than conventional green sand mix. Under normal conditions the mould will harden to a depth of approximately 35mm overnight and will continue, the longer the mould is exposed.

 

ADVANTAGES & BENEFITS.

  1. One shot addition reduces variables & inconsistency.
  2. Wide application range.
  3. Shake out problems are eliminated.
  4. Air hardening, hence reduces drying / baking cost.
  5. Non – toxic, non- irritant green sand additive.
  6. Very good green compression strength is achieved.
  7. Promotes improved thermal stability of moulds resulting in non – friable moulds, better castings definition & dimensional accuracy.
  8. Imparts excellent flow ability.

 

AFCIMIX – 24    (AIR SETTING TYPE)

Afcimix – 24 is red colour single shot additive of moulding sand in powder form to prepare mould.

Afcimix – 24 will replace 100 % use of Bentonite, Dextrin, and Iron oxide in foundries.

 

APPLICATION:

Recommended addition of Afcimix – 24 is as follows:

  1. For 100%silica sand:
Sr.

No.

 

 Ingredients

 
Dry New Sand

(for 100 % silica sand)

 Return sand Afcimix – 24 Addition Water To Substitute
1. 100 kg. NIL 10 % Max 3 – 4 % Max Bentonite ,Dextrin & Iron Oxide

 

  1. For 50%silica sand & 50 % Return sand:
Sr.

No.

 

 Ingredients

 
Dry New Sand

(for 50% silica sand & 50% Return sand)

 Return sand Afcimix- 24 Water To Substitute
1. 50 kg. 50 kg. 6 % Max.  3 – 4 % Max. Bentonite ,Dextrin & Iron Oxide

MIXING PROCEDURE:

For 100 % silica sand: -s

  1. Add dry silica sand 100 % in Muller or Mixer.
  2. For 1 minute.
  3. Add Afcimix – 24. Mix for 2 Minutes.
  4. Add water. Mix for 2 minutes.

 

For 50 % silica sand & 50 % return sand: –

  1. Add dry silica sand 50 % & return sand 50% in Muller or Mixer.
  2. Mix for 1 minute.
  3. Add Afcimix -24. Mix for 2 minutes.
  4. Add water. Mix for 2 minutes.

ADVANTAGES:

  1. Afcimix is a air setting type.
  2. Develop good strength after 1 hr.
  3. Avoids all headache of controlling addition of conventional 3 products

Started above.

  1. Green compression strength developed as follows:

 

SR. NO. PROPERTIES G. C. S. (Gm/cm2)
1 2 3
1. IMMEDIATE 150 140 140
2. AFTER 1 HOUR 170 180 170
3. AFTER 4 HOUR 720 680 700

PRECAUTIONS:

  1. Prolong mixing should be avoided.
  2. Close Afcimix bags tightly when not in use.
  3. Product is non – poisonous & safe to handle.

STANDARD PACKING: 50 Kg. HDPE Bag.