Description

Crsut leather is a semi-finnished stage of leather, which is processed until it becomes white or cream white in colour, full in substance and smooth texture. Crust leather has an advantage in that it has relatively lighter shipping weight. It is a product of higher added value than the wet-blue leather. The distinct feature of this product from the wet-blue leather is that it has a visible physical property such as size, thickness, fullness, looseness of grain and grain damages together with other properties of physical and chemical nature. It is rather a product of better tensile and tear strength, chrome and fat contant etc. then wetblue leather.

Crust leather is used as an input to garment and upper shoe production. It is also used as indispensable input for finished leather production.

TECHNOLOGY AND ENGINEERING
TECHNOLOGY
•  PRODUCTION PROCESS
The processes that follow from the Wet-blue leather stage to produce crust leather are mentioned below
A. TRIMMING
Rough edges of leather are trimmed to remove uneven and ragged edges.
B. SPLITTING
Thick hides will be split by splitting machine. The top layer is called the grain part and the bottom layer, flesh part.
C. SHAVING
Thickness of splitting is adjusted in a machine fitted with shaving blades which reduce the substance of the leather according to the desired thickness
D. RETAINING, FAT LIQUORING AND DYEING
This is a combined process in which the semi-finished leather will get a final tanning and some further treatment.
E. SETTING OUT
As in sammying thin process involves the removal of moisture content. Creases are also removed at this stage.
F. DRYING
The damp leather is dried. In hot weather natural drying is preferred.  
G. CONDITIONING
After drying, leather becomes stiff. For further operations, a certain degree of conditioning, i.e. moistening the leather to *8 to *0 per cent moisture content, is essential. Then, staking and sorting unit operations follow. In the production of the crust leather substantial effluent is generated. Full or partial treatment of effluent is essential to avert its adverse impact on environment.
•  PRODUCTION PROGRAM
The plant will start its operation at *5% of its full capacity in the first year with a *0% build-up of capacity reaching full capacity in the fourth year and then after, considering skill development & market penetration problem.  
•  MATERIALS INPUT
A. RAW & AUXILIARY MATERIALS
The main raw material for production of crust leather is wet-blue leather. In addition to the major raw material (i.e., wet-blue leather ), crust leather production requires the following auxiliary materials: oils, synthetic tannins, vegetable tannins, aniline dyes, sodium bicarbonate, sodium acetate and formic acid. Annual consumption and of raw & auxiliary materials with cost.  
Crust Semi-finished Leather
Crust / Semi-leather furnished lamb skins can be offered from the following selections.
RGULAR/ RUN
Grade: RUN (I+II)
Size: Minimum 7 sqft. per pelt.
SUPER
Grade: SUPER (I+II)
Size: Minimum 8.5 sqft. per pelt.
THIRD
Grade: THRID (III)
No Less Than 3 sqft. Of usable material