MANUFACTURING AND FEATURES OF TINPLATE

 

The different stages of the process of tinplate manufacturing will be detailed thoughout this paper: from the base steel production and its different varieties to the several consecutive sequences of tinning.

 

TABLE OF CONTENTS

0.-Introduction

1.-What is tinplate and for what is it used?

2.-Steelmaking

3.-Base Steel manufacturing

4.-Manufactuing sequence

5.-Base Steel composition

6.-Types of base steel

7.-Tinning process

8.-Tin

9.-Electrolytic tinning

10.-Tin Free Steel (TFS)

 

0.- INTRODUCTION

In spite of being invented in ancient times, tinplate is a material which reached a huge development over the 20th century. The United States bet high on this industry. As a consequence, it achieved its greatest degree of activity in that country in the seventies decade. Afterwards, the huge deployment of beverage containers, the use of aluminium as raw material by North America, the alternative containers and the obsolescence of the American steelmaking industry, caused the decline of that market.

It did not happen the same in other areas of the world. Europe was able to update their steelmaking industry in time so as to maintain its competitiveness and, consequently, to make possible that the European tinplate was able to resist in its fight against aluminium. That fact did not avoid that a wide variety of canning had a negative effect somehow. However, the mentioned sector overcomed that situation by means of the merge of several metallurgical companies which allowed themselves to keep their technological excellence.

In the same way, the tinplate market and other similar products continued well positioned in that market in other geographical areas, such as South America, The Far East and Asia.

Nowadays, although this sector still has to survive in a competitive market, it continues being transcendental all over the world. For this reason, it is recommendable to get know a little bit more about how this material is made. 

 

1.- WHAT IS TINPLATE? FOR WHAT IS IT USED?

Tinplate is a material which is made through a mix of steel sheets and catalytic covering or by a process of passivation of the tin sheet in both sides of this component.

This material is widely used in the food industry to protect and increase the life cycle of the canned products, for instance sardines, peppers, tomatoes, grains, condensed milk, chocolate, spices, coffee, among others.

In the same line, its use has spread to household items, such as household appliance, cleaning products, insecticide and many more. It could be also found in car parts, decoration materials or sealing caps.

 

2.- HOW IS TINPLATE MADE?

Tinplate contains a 99%, or even more, of steel, that is to say, it is a product which is made up basically with steel. The manufacturing process really begins in the blast furnace and in the tin foundry, but, in practice, it is considered to start from the steel manufacturing process. In fact, this is the moment when the composition and type of steel ingot will be selected in order to define its future use as rolled product. As a result, the basic raw materials required to manufacture tinplate are steel and refined tin.