ABSTRACT

This case study deals with the processing of raw material i.e., tin metal sheets through

various manufacturing stages.

The main manufacturing stages includes cutting of tin metal sheets as per desired

dimensions, edging of metal sheets, cornering of the metal sheets and then assembling of the

processed sheets by Seaming process.

The sealing of the assembled tin containers is one of the most important process ,since

any leakage may damage and reduce the quality of the finished product.

These finished containers are stored in a clean environment and thus supplied to

various industries as per their requirements.

Properties of Tin(Sn)

Tin is a malleable, silvery metallic element obtained chiefly from cassiterite. It’s atomic

number is 50 on the periodic table.

The physical properties of Tin are:

Color – Silver white

Malleability – Capable of being shaped or bent into extremely thin sheet

Ductility – Easily pulled or stretched into thin wire

Conductivity – Good transmission of heat or electricity

The chemical properties of Tin are:

Oxidation – Not easily oxidised

Reactivity with water – Stable in both cold and boiling water

Reactivity with acids – Does not react rapidly

Toxicity – Relatively low

Corrosion – Resist corrosion because it is protected by oxide film.

Based on above properties, Tin metal sheets are used as raw materials in the manufacturing of

the containers. Since Tin containers are non- toxic and non- corrosive, they are used in the

storage of food products like cashew nuts. Thus they can be stored in these containers for a

longer time and thus increasing the quality of the products.

Stages of manufacturing if Tin metal sheets

Stage 1: Cutting of metal sheets by metal sheet cutter

The tin metal sheets of dimension 36.5*28 are cut into two different sheets of dimensions

10*10 and 18.25*14. The sheets of 10*10 dimensions are then edged.

Stage 2 : Edging of metal sheets

The metal sheet of a 10*10 dimension is subjected to edging by using a device called sheet

edge cutter. The edge is filleted to a radius of 1.2 inch

Stage 3: Punching of edged metal sheets

The edged metal sheets are punched using a hand operated punching machine

Stage 4 : Punching the name of factory on the metal sheet

The metal sheets cut to a 18.25*14 dimension is filleted at the edges by 0.7 inch. The name of

the factory is punched on the edge filleted sheets. The punching is done by manually operated

punching press.

Stage 5 : Cornering of metal sheets

In this stage the edge filleted metal sheet is cornered to an angle of 90 by using manually

operated hydraulic press. It consists of a flywheel connected to the motor by a flat belt. Here

the rotary motion of the flywheel is converted into reciprocatory motion by the worm gear.

This results in the application of force in the perpendicular direction to the metal sheets.

Stage 6: Assembly of four corners of tin container

The metal sheets after cornering are subjected to assembly of the corners. In this process, the

four sheets are held at the corners and punching is performed.

Stage 7: Assembly of the container

The assembly of top and bottom sheets with the containers is done by Seaming machine. The

Seaming machine fits the top and bottom sheets to the corners of the container. The

containers after Seaming process, are passed through the conveyor

Stage 8: Sealing of Tin containers

Tin containers are sealed properly by soldering process. Copper is used as a solder. Zinc

Chloride(ZnCl2) acid is applied at the corners and then solder is applied followed by a red hot

iron sealer, which makes the solder to adhere at the corners and for a seal.

Stage 9: Storage of containers

The containers after sealing are cleaned properly and stored in a clean environment. The

containers are then supplied to the industries. Each container weighs 800 gms. These

containers can carry a load upto 10kg. About 500 containers are processed per day and the

production may exceed the given number based on the industrial demand.