Electrolytic Tinplate£¨ETP£©

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