Electrolytic Tinplate£¨ETP£©
- Production Process
- Product Features
- Surface Inspection Items
ETP Structure
Most people believe that an ETP is composed of five layers, including base steel, iron-tin alloy, tin, passivation film and oil film. However, some people believe that it is made up of six layers; that is, there is a tin oxide film beneath the passivation film. Sometimes, the tin oxide film and the passivation film are collectively known as the oxidation film. See the following figure for the composition of an ETP.
Features of ETP Products
①Excellent Corrosion Resistance: By selection of a proper coating weight, appropriate corrosion resistance is obtained against container contents.
②Excellent Paintability & Printability: Printing is beautifully finished using various lacquers and inks for the purpose of enhancing protection and manufacturing different packages for different products;
③Excellent Solderability & Weldability: Tin plates are widely used for making various types of cans by hard soldering and sweat soldering. Now, electric resistance welding is applied for the can making industry, the common tinning amount of which can meet the application requirements;
④Excellent Formability & Strength: By selection of a proper temper grade, appropriate formability is obtained for various applications as well as the required strength after forming.
⑤Beautiful Appearance: Products with different kinds of surface roughness are produced by selecting substrate steel sheets of different surface finishes.
Specifications and Parameters
Black Plate | Nominal Thickness /mm | Nominal Width /mm | Nominal Length (Sheet) /mm |
---|---|---|---|
Single Reduce | 0.17¡«0.55 | 700¡«1200 | 500¡«1168 |
Double Reduce | 0.12¡«0.36 |
Categorization | Category | Code (s) | |
---|---|---|---|
Black Plate | £ | MR, L, D | |
Temper Grade | Single Reduce | T-1.5, T-2, T-2.5, T-3, T-3.5, T-4, T-5 | |
Double Reduce | DR-7M, DR-8, DR-8M, DR-9, DR-9M, DR-10 | ||
Annealing | Continuous Annealing | CA | |
Box Annealing | BA | ||
Differential Coating Marking | Marking for the side of lower coating weight | D | |
Marking for the side of higher coating weight | A | ||
Surface Finish | Single Reduce | Bright surface | B |
Stone surface | R | ||
Stone rough surface | R2 | ||
Silver surface | S | ||
Silver rough surface | S2 | ||
Matte surface | M | ||
Double Reduce | Stone surface | R | |
Matte surface | M | ||
Surface Treatment | Chemical passivation | CP | |
Electrochemical passivation | CE | ||
Low-chromate passivation | LCr | ||
Untreated | U | ||
Edge Shape | Straight line | SL |
Temper Grade Code | Hardness (HR30Tm) | |
---|---|---|
Target | Permissible Range | |
T-1.5 | 51 | 51±3 |
T-2 | 53 | 53±3 |
T-2.5 | 55 | 55±3 |
T-3 | 57 | 57±3 |
T-3.5 | 59 | 59±3 |
T-4 | 61 | 61±3 |
T-5 | 65 | 65±3 |
Hardness (a) is the average hardness of two test specimens, and one of the test
values is allowed to exceed the specified permissible range by one unit. |
Temper Grade Code | Hardness (HR30Tm) | |
---|---|---|
Target | Permissible Range | |
DR-7M | 71 | 71±5 |
DR-8/DR-8M | 73 | 73±5 |
DR-9 | 76 | 76±5 |
DR-9M | 77 | 77±5 |
DR-10 | 80 | 80±5 |
Hardness (a) is the average hardness of two test specimens, and one of the test values is allowed to exceed the specified permissible range by one unit. |
Classification | Coating Weight Code | Nominal Coating Weight (g/m2) | Minimum Average Coating Weight (g/m2) | ||
---|---|---|---|---|---|
Equally Coated (E) | 1.1/1.1 | 1.1/1.1 | 0.9/0.9 | ||
2.2/2.2 | 2.2/2.2 | 1.8/1.8 | |||
2.8/2.8 | 2.8/2.8 | 2.5/2.5 | |||
5.6/5.6 | 5.6/5.6 | 5.2/5.2 | |||
8.4/8.4 | 8.4/8.4 | 7.8/7.8 | |||
11.2/11.2 | 11.2/11.2 | 10.1/10.1 | |||
Differentially Coated (D or A) | 2.8/1.1 | 2.8/1.1 | 2.5/0.9 | ||
1.1/2.8 | 1.1/2.8 | 0.9/2.5 | |||
5.6/1.1 | 5.6/1.1 | 5.2/0.9 | |||
1.1/5.6 | 1.1/5.6 | 0.9/5.2 | |||
5.6/2.8 | 5.6/2.8 | 5.2/2.5 | |||
2.8/5.6 | 2.8/5.6 | 2.5/5.2 | |||
8.4/2.8 | 8.4/2.8 | 7.8/2.5 | |||
2.8/8.4 | 2.8/8.4 | 2.5/7.8 | |||
8.4/5.6 | 8.4/5.6 | 7.8/5.2 | |||
5.6/8.4 | 5.6/8.4 | 5.2/7.8 | |||
11.2/2.8 | 11.2/2.8 | 10.1/2.5 | |||
2.8/11.2 | 2.8/11.2 | 2.5/10.1 | |||
11.2/5.6 | 11.2/5.6 | 10.1/5.2 | |||
5.6/11.2 | 5.6/11.2 | 5.2/10.1 | |||
11.2/8.4 | 11.2/8.4 | 10.1/7.8 | |||
8.4/11.2 | 8.4/11.2 | 7.8/10.1 | |||
15.1/5.6 | 15.1/5.6 | 13.9/5.2 | |||
5.6/15.1 | 5.6/15.1 | 5.2/13.9 |