Min Jia-Your Professional Tin Free Steel Supplier in China

Min Jia is professional enough to manufacture and supply you the best quality of tin free steel. We made it with many advantages and applications. The Min Jia tin free steel is capable of blank filmed laminated steel, polymer roller steel, and even laser laminated iron.

We have been supplying high-quality tin free steel for almost 10 years. We have excellent experiences when it comes to manufacturing effective tin free steel. We offer one-stop packaging solutions.

As your top manufacturer especially of tin free steel, we offer our products with a competitive price. We make sure you will find out beneficial when you choose Min Jia tin free steel for your growing business.

In Min Jia, your purchased products mainly of tin free steel are in wide applications. Our company manufactures million pieces of output by the support of 200 employees and 16 can lid production lines.

The tin free steel of Min Jia operates at an exact high temperature that doesn’t even cause discoloration and deterioration in steel surfaces. Because the tin free steel is formed with corrosion resistance, it is also useful in internal surfaces which are unpainted.

Compared with other types of tin plates the tin free steel has a higher quality of hardness that makes it more resistant in cutting. Therefore, while doing the cutting operation, lubricating the tin free steel is required.

Contact us now for more information and details about purchasing Min Jia tin free steel!

Tin Free Steel: The Ultimate FAQ Guide

If you have any question about tin free steel, you will find the answer right here.

Because this guide covers all information about tin free steel.

Let’s dive right in.

What is Tin Free Steel (TFS)?

Tin free steel

Tin free steel (TFS) is a black plate steel sheet covered with a layer of chromium and chromium oxide over the base of steel.

The layer gives it a delightful, glossy metallic completion on the two sides. It is also known as electrolytic chromium covered steel (ECCS).

What is Tin Free Steel used for?

Tin free steel is cost-effective and durable, with excellent package content protection abilities.

It also has excellent, allowing you to easily print logos, brand names, trademarks, advertisement, and promotional material on the packaging.

Uses of TFS range from making food packaging to construction materials.

The material is widely used in making food cans for fish, meats, beans and other types of canned foods.

It also used to make beverage cans for packaging coffee, tea, carbonated drinks, fruit juices and energy drinks. This is thanks to the material’s high resistance to corrosion.

TFS is also best for making crown cup-bottle tops and metal can lids.

What are the Main Features of Tin Free Steel?

The key features of steel include:

• Heat resistance -baking at high temperatures (around 400 degrees C) does not decolorize or harm the material characteristics of TFS steel.
• TFS has remarkable paintability properties. This material allows for easy painting of package surfaces to prevent rusting and corrosion.
• For its appearance, TFS steel gives an exceptional shiny surface finish, normal for metallic chromium.
• This material has excellent corrosion resistance when painted. The steel is usually painted on both sides. Depending on the contents, it can also be used with an unpainted internal wall.

Since TFS rusts easily in a humid setting, it should be used right away after unpacking.

• TFS’s metallic coating layer has a high electrical resistance, making it wieldable. However, it is essential to first remove the metallic coating layers in the area you intend to weld.
• Chrome is more rigid than tin- TFS is more resistant to cutting than electrolytic tinplate exposing the dies to more wear. Lubrication is needed during the cutting process to prevent wear.
• Cost-effective- Tin free sheet is cheap to produce, making it an affordable solution for many applications.

What are the Advantages of Tin Free Steel?

Tin free steel has numerous advantages, especially as a packaging material.

• TFS packaging increases the packaging contents while keeping up their wholesome quality.

Also, package spills present can be seen and sorted. This guarantees food safety and sanitation.

• The material is solid and challenging to crack, making it ideal for transporting food from one location to another.
• TFS’s better barrier properties hinder the development of pathogenic and food deteriorating microorganisms, preventing food contamination.

Again, no moisture vapor, odors, bacteria or gases can penetrate the packaging.

• Tin free steel has excellent thermal conductivity and high-temperature tolerance. The packaging can withstand high temperatures during processing and filling.
• Packaging containers made from Tin free steel come in a range of sizes, shapes, and types. They range from small elongated collapsible tubes to wide built-up containers.

An example of wide containers is steel drums, which has capacities of up to 110 gallons.

• The sheet offers an ideal decorative surface with its shiny surface finish.
• TFS packages are exceptionally recyclable.

There is no proven tin free sheet toxicity of life on the planet. This makes TFS environmental friendly.

• The material is resistant to stains caused by Sulphur which helps maintain its beautiful appearance on display shelves.

What is the difference between Tinplate and Tin Free Steel?

Tinplate is made through the electrotinning process, which thinly coats steel sheets with pure tin (Sn). The tin coating is most often applied to enhance the rust and corrosion resistance properties of steel.

The steel sheet to which tin coating is applied is known as Black plate.

If chromium (Cr) and chromium oxides are used to cover the steel instead of tin, the resulting material is tin-free steel.

Below are some notable differences between Tinplate and Tin free steel.

Surface Appearance

When the same surface finish is applied to both steel surfaces, TFS offers a unique surface luster characteristic of metallic chromium.

Chromium coating is extremely thin, so any defect on the TFS surface is visible to the naked eye.

Variance in Cost

Tin free sheets are cheaper to produce than tinplate sheets. Because of the cost reduction, TFS is commonly used for general packaging.

 Corrosion Resistance

TFS has outstanding corrosion resistance after painting, which is much better than tinplate.

Soldering

Soldering is not consistent with TFS. As a result, it can’t be used for applications requiring tin bonding. Tinplate sheet, on the other hand, has high solderability properties.

Weldability

TFS can be welded after the metallic coating layers are removed, but it is less wieldable than tinplate sheets.

Also, Tin free steel cannot manufacture three-piece cans because electric resistance welding is required.

In non-welding market segments, including metal closures and ends, cemented seam cans and DRD cans, tin free sheets may replace tinplate.

Coating

Tinplate has various coating weights to satisfy the needs of various applications, while TFS usually has only one coating weight.

Also, TFS, unlike tinplate, does not have scratch protection. After TFS has been molded into cans and painted, care should be taken to avoid scratching the surface.

What is the Production Process of Tin Free Steel?

Tin free steel is manufactured under stringent quality control to ensure properties appropriate for different uses.

The following process is used to produce tin free steel

Step 1: Charging of the Coil

The black plate coil is mounted on a buckle and is fed to the steel plating portion.

The head end of the new belt is then soldered to the tail end of the preceding belt to run the system continuously.

Loop towers collect different material lengths so that two coils can be welded without stopping operation in the processing area.

Step 2: Side Trimming

The strip of the black sheet is cut to the last width. In the steel melting unit, the scrap is automatically balanced, stripped and recycled.

Step 3: Cleaning and Pickling

The strip is then electrolytically washed, pickled, and rinsed through several tanks to ensure that the black strip surface is clean.

Step 4: Electrolytic Deposition

The deposit is made of chromium and chromium oxide. On each surface added, the metallic chromium cover is around 55.0 milligram per square meter.

The film of oxides varies between 7 and 22.0 milligrams per square meter, but it’s usually in a lower range.

Step 5: Oiling

Before it exits the coating line, a very thin oil film is applied electrostatically.

Butyl stearate (BSO) oil is applied to prevent scratching of the tin free steel surface. In some instances, acetyl tributyl citrate (ATBC) oil is more compliant with some lacquering and painting systems.

Step 6: Recoiling

The finished TFS bands recoil on a mandrel with a standard diameter.

Step 7: Quality Inspection

Finished tin free steel batches are visually and physically tested to ensure that they meet the required quality standards.

Is Electrolytic Deposition Process better than Hot Dip coating Process in Tin Free Steel Manufacturing?

Yes.

The hot dipping process was the first modern method of tin free steel production.

It involves dipping single sheets of steel in molten chromium/chromium oxide for a short period.

Tin free steel is now commonly produced by continuously electroplating chromium/chromium oxide onto a steel substrate.

In an electrolytic coating line, the sequence of operations occurs at speeds of up to 10 meters per second.

The process is better than hot-dip coating for the following reasons:

• Hot-dip coating is a low-speed sheet-by-sheet process, while the high-speed continuous coating is a high-speed continuous sheet production process.

With electronic deposition, it is possible to make the sheets with different coating masses on each side.

Coating each side satisfy the various corrosion conditions found within and outside the TFS can or container.

The electronic coating offers a simple and precise thickness of the coat throughout the sheet. The Hot dip process gives minimum coating thickness, which is difficult to control.

Product quality is achieved in functionality and appearance when an electronic deposition is applied to the sheet.

 Typical Electronic Deposition line

What are the Quality Control items in the Tin Free Steel Manufacturing Process?

Tin free steel production process is consistently monitored to ensure the end product meets both regulatory and client’s requirements.

Monitoring, in this case, is done both manually and automatically, with the focus being on the following aspects:

• Mechanical properties – the end product must meet the requisite hardness, yield strength and tensile strength specifications.

Necessary tests such as the Rockwell hardness and tensile strength tests may be conducted to ensure this.

• Sizing – Dimensional accuracy must be achieved for tin free steel.

Plate thickness, length tolerance, diagonal difference, stacking and burrs are things that QC experts check concerning the size.

• Shape parameters – Bowness (C warp, L warp), camber, askewness, edge waviness etc., are some of the things checked during quality control. TFS shape must conform to the initial design specifications.
• Corrosion resistance – This is a significant aspect of tin free steel. Thus, it must be ensured by strictly regulating the metallic chromium and chromium oxide deposit amounts.
• Printability and paintability – These two are critical QC items during tin free steel production.

With this, specific monitoring items include the type of oil used and film thickness.

The passivation method, passivation process and passivation film thickness are also monitored.

You also need to ensure surface cleanliness by minimizing/avoiding smudge and surface stains.

How do you Specify Tin Free Steel?

Tin free sheet specification depends on the black plate used, tempering, annealing process, coating weight and space finish.

The black plate is continually cast, which kills the aluminum content present.

TFS steel bases are available in the following types:

• Type MR – These base steels have low residual element content and excellent corrosion resistance. MR steels are quite versatile and thus preferred for use in general purpose applications.
• Type L – The residual elements in type L steel are minimal (Cu, Ni, Co and Mo). This type of steel has excellent corrosion resistance, which makes it suitable for food packaging applications.
• Type D – For these, Aluminum killed base steel is used. These types of steel are used in applications that require deep drawing. They are also suitable for extreme formations that produce Lueder’s lines.

For metallic chromium layers, TFS is made with minimum weights of 50 mg/Sq m and maximum average coating and 150 mg/Sq m.

The minimum and maximum average coating weights for chromium oxide layers is 5 mg/Sq m and 35 mg/Sq m, respectively.

As for form, TFS is available in two forms: coils and sheets.

TFS coils come with thicknesses ranging from 0.15 to 0.60 mm and widths ranging from 700 to 970 mm. likewise, TFS sheets are also available in different sizes ranging from 508 mm to 1050 mm.

What is Tin Free Steel Structure?

 Tin free steel structure

Tin free steel comprises four layers:

Base layer: Steel Foundation

The steel base in TFS ensures formability and machining, as well as providing strength to finished products.

Inner middle layer: Metallic Chromium Layer

The metallic chromium layer has good passivation and corrosion resistance. It can only protect the steel base mechanically since it is a cathodic coating.

An extremely thin layer of chromium oxide is simple to manufacture because of the high passivation capability of metallic chromium.

Outer, Middle Layer: Chromium Oxide Layer

The electrode potential of the chromium oxide film is higher than iron, and it has relatively high chemical stability.

TFS is cathodic when surrounded by ordinary corrosive products, requiring coating to protect the contents.

This layer closes pores in the metallic chromium layer and provides excellent coating adhesion as an amorphous layer.

Surface layer: Oil Film Layer

The oil film layer acts as lubrication for TFS. Tin free sheets lubrication is superior to that of ETP. Tin as a soft metal reduces friction and provides a lubrication effect to the steel sheet.

What are the available Surface Finish Options for Tin Free Steel?

There are various surface finish options available for TFS:

• Bright finish—the surface roughness is targeted at 0.25 Ra in this form of finish. Bright finishes are used in making packaging cans.
• Matte Finish–This finish aims for surface roughness of 1.00 Ra. Matte is a rusty finish that is mainly used for crowns caps.
• Silver Finish–This finish is also known as a satin finish. It is a rough, dull finish that is commonly used to manufacture artistic cans.
• Stone Finish–Stone finish aims for surface roughness of 0.40 Ra. Printing is easier with this finish, and scratches are less noticeable.

What are the Temper Grades of Tin Free Steel?

HR 30 T is the unit of hardness (temper) measurement for Tin free steel. When TFS made from a continuous annealed material, the temper grade is given a CA mark, such as T-5 CA.

The standard temper grades for TFS are classified into two:

Single reduced TFS Temper Classes

• T-1–Temper grade – T-1 has a hardness of 49 +/- 3 on the scale of hardness. It’s used in applications that need a lot of versatility, such as deep drawing applications.
• T-2 temper grade – T-2 has a hardness of 53 +/- 3 on the scale of hardness. It’s used in applications that need some stiffness and mild drawability.
• T-2.5 temper grade – It has a hardness of 55 +/-3 on the scale. It’s used in applications that need T-2 temper grade drawability combined with T-3 temper grade stiffness.
• T-3 temper grade – Its hardness value is 57 +/-3. It’s used in applications where stiffness is needed to prevent buckling.
• T-4 temper grade – Hardness for T-4 is 61 +/-3 on the hardness scale. It’s used in applications that demand a lot of rigidity, including can end and crowns.
• T-5 – Temper grade T-5 has a hardness of 65 +/-3 on the scale. It’s used in applications that cause a high level of buckling resistance.

Double Reduced (DR) Temper Classes

These are high-strength thin steel materials. DR tin free steel is formed by cold reducing the steel material after annealing.

Temper grades for this are as follows:

• DR -8 – The hardness of this temper grade is 73 +/-3. It’s used in applications where stiffness and strength are needed.
• DR-9 temper grade – It has a hardness of 76 +/-3 on the hardness scale. It’s also used in applications where stiffness and strength are required.
• DR -9 M – DR -9 M temper grade has a hardness of 77 +/-3 on the scale. It works similarly to DR- 9.
• DR-10 – Temper grade 10 has an 80 +/-3 hardness rating. It’s used in applications that need a lot of stability.

What is the difference between Continuous Annealing and Batch Annealing for Tin Free Steel?

Continuous annealing vs batch annealing

Annealing is an integral part of the tin free steel making process. It is basically where the steel base is heated to make it soft to be manipulated and worked with.

Specifically, annealing changes the microstructure of the steel. It minimizes its hardness, improves steel ductility, and reduces its stress for easy coating and fabrication.

In TFS production, a box (or batch) annealing (BA) or continuous annealing (CA) may be used.

Continuous annealing is a sustained and unchanging phase. It creates a material with a fine grain size compared to box annealing (BA), thanks to shorter annealing periods. The mechanical characteristics, therefore, differ for the same temper number.

Tight wound coils are stacked three or four high on convector-spaced bases between coils when batch-annealing. The cover of the stack is lowered and sealed at the foundation.

The mechanical features in continuous annealing are best suited to high-speed automated lines. This is because they provide greater consistency of physical properties.

CA annealed temper (hardness) compared to batch annealed usually is on the higher side of the ordered tolerance parameters.

Batch annealing softness enhances its drawing capabilities and is often preferred for slower lines and components.

In BA, TFS properties will vary from coil to coil as it is not possible to achieve the same heat treatment in the entire batch ordered.

The batch annealing is on the lower parameter of the Rockwell tolerance compared to continuous annealing.

What are the required Quality Standards for Tin Free Steel?

Some of the quality standards that tin free steel should conform to include:

• ASTM A630: it specifies the quality standard tests for TFS. These include the methods to determine tin coating weights for Electrolytic Tin Plate.
• ISO 9001: this is a global standard that lays out the specifications for quality management. TFS manufacture must follow the guidelines of ISO 9001 in their quality control practices for tin free steel.
• FDA: the food and drugs administration regulates all materials that are to be used in food contact applications. In this case, Tin free steel for food and beverage packaging must be FDA approved.
• RoHS: this standard prohibits the use of dangerous substances in tin free steel. Such substances include Cadmium (CD) and its compounds, lead (PB) and its compounds, and forbidden flame retardants polybrominates biphenyl (PBBs).

Tin free steel with RoHS approval guarantee that the use of safe materials in their manufacturing.

• DIN 8580: it defines the terms and definitions of processes of manufacturing for tin free steel.
• JIS G 3315: This standard specifies the recommended standards for Tempering and surface finish (Surface roughness Target value µmRa) for TFS.

What are the available Sizes for Tin Free Steel?

The temper, thickness and width determine tin free sheet size.

TFS is available in the following dimensions:

• TFS Sheets – these are produced in thickness ranges of 0.15mm to 0.50mm with a length of 510mm to 1,070mm.

Custom sizes can be made from 0.13mm to 0.60mm thickness and Length 460mm to 1,110mm. The width of the sheet is 670mm to 1,060mm.

• TFS Coils – possible thickness for this starts from 0.15mm to 0.60mm. Customized order production measurement ranges from thickness 0.07mm to 0.80mm. The width of the sheet is 670mm to 1,060mm.
• TFS Hoop – tin free steel hoops can be 0.15mm to 0.50mm thick. The width can range from 30mm to 500mm. Custom sizes allowable ranges between 0.13mm and 0.60mm for thickness and 10mm to 500mm for width.

Always communicate your specifications to the manufacturer so they can produce the right tin free steel for you.

What are Packaging, Marking and Transportation Requirements for Tin Free Steel?

 Tin free steel

Tin free steel can be transported in sheet or coil packaging.

Sheet Packaging

Here, the TFS is placed on a wooden skid. Angles are placed at each of the four corners to cushion the sheets.

The sheets are then wrapped with cardboard, followed by rustproof paper and then fastened with metal band strapping.

Steel cover and metal cap wrap the outer packaging. The package is fastened with outer metal band strapping.

Then seal and label are glued on the outer packaging.

Coil Packaging

The TFS coil is wrapped with waterproof cardboard; inside corner, angles are fixed to cushion sheets.

The package is then wrapped with rustproof paper and outside corner angles out.

A metal band is used for strapping, after which a seal and label are pasted on the package.

Shipping laws require that the exterior of the packaging also be labelled with the manufacturing history.

A service card is put in the package too.

The specification, weight, size, sheet number, inspection number, grade, coil number, and date of manufacture are included on the label and service card.

Which is the best Coating Option for Tin Free Steel?

Chromium and chromium oxide coatings have superior lacquer adhesion and storage properties on tin free steel.

These coatings comprise chromium metal and chromium oxides in different proportions.

Unlike tinplate, which has various coating weights, tin free steel coating is made in single uniform sizes.

The same manufacturing sequence is used in the production of tin free steel in the production of electrolytic tinplate. Mechanically, the coating lines are identical.

Chromium and chromium oxide are deposited during the electrolytic deposition process.

The amount of metallic chromium coating added to each surface is approximately 55.0 milligrams per square meter.

What are the Usage Precautions of Tin Free Steel?

Keep the following things in mind when using/working with tin free steel:

• Soldering and D1 formation are not compatible with tin free steel. It can, however, be used in almost any application where tin free steel is used after it has been painted.
• To avoid rust, paint TFS cans on the outside. Avoid painting cans meant for packaging engine oil or cooking oil.
• TFS’s metallic coating has a high electrical resistance. As such, you should strip the metallic coating layers in the welded region before welding.
• Unlike tinplate, TFS does not have sacrificial protection. After TFS is produced into cans and painted, extreme care should be taken to avoid scratching the surface.
• In a humid setting, TFS can rust. Therefore, you use it immediately after unpacking.

What is the Sustainability record for Tin Free Steel Packaging?

Firstly, food insecurity is a prominent concern around the globe. Fish and other food produce easily go bad when they are fresh; many people discard excess food after a few weeks.

Tin free steel packaging preserves food well. It protects perishable items from moisture, odor, and light, giving them a long shelf life, often up to three years.

This helps combat the food insecurity threat.

Secondly, the high temperatures of retort cooking effectively sterilize food cans.

This is critical in maintaining the safety of packed content without preservatives, refrigeration or freezing.

Thirdly, canned products last longer than those packed for refrigeration or freezing.

TFS canning extends the product’s shelf life and saves energy resources that could otherwise be used in refrigeration and freezing.

Last but not least, tin free steel offers a stable shield between the products packed and steel.

Because of their unbreakable and portable qualities, products are easy to store and ship even to remote areas.

With this information, you can certainly choose a suitable tin free steel for your unique applications.

However, in case you have any question about tin free steel, feel free to contact us.