Stainless steel is a strong, sleek, and durable alloy used all around the world. However, did you know you could change its characteristic silver look to personalize it per your style? Let’s discuss how.
In this article, we’ll take you through all the types of stainless steel printing you can use to customize your steel products’ surfaces and finishes.
What Is Stainless Steel Printing?
Stainless steel printing is the process of creating designs on the surface of stainless steel. This can be achieved through inks, laser engravings, chemical solutions, and electrochemical reactions.
Printing on stainless steel has become a fairly standard industrial practice to customize steel products for brands, identification labels, data, or art usage.
Let’s discuss your options if you want to print on your stainless steel.
Types of Stainless Steel Printing Techniques
Here are some common printing techniques used for stainless steel industrially.
1. Screen Printing
This is a fairly common technique used to print on stainless steel. You take a mesh screen, create a stencil on it, and then apply ink to it. Note that every color in your design needs a separate screen.
Here’s how the process goes:
- First, you coat your mesh screen with a photosensitive emulsion and expose it to UV light through the artwork. This will harden the emulsion in selective areas, creating a stencil.
- Then, you force ink through the stencil onto the surface.
- You cure your ink at a high temperature to ensure it adheres to the surface and dries swiftly.
- You repeat the process for every color in the design, applying ink of one color at a time.
Screen-printed stainless steel gives you durable results that are strong against environmental degradation. This is why it’s common in signage, nameplates, etc. However, we’ll advise you not to print intricate designs this way, as the ink can sometimes bleed or smudge.
2. Pad Printing
Pad printing works much like stamping a pad on paper: You prepare your inks, press the pad onto them, and then press the pad onto the surface of the steel. Let’s look at the details.
- First, you need to print your artwork on a film or a plate. It needs to be of accurate dimensions – the same as the intended size on the surface.
- Then, you prepare a pad by shaping and molding a silicon or rubber sheet as per your artwork.
- You take your ink and paint it over the artwork on the plate. Then, you press the pad onto the plate to soak up the ink.
- Finally, you press the soaked pad onto the surface of your stainless steel, depositing the picture onto it. You may have to do this multiple times or in different layers to achieve a high-quality print.
- You cure your printed object for a while to let the ink settle.
Pad printing can produce intricate, high-quality designs depending on the skill of your designer and manufacturer. Note that its wear resistance depends on the quality of the inks you’re using for your steel.
3. Flexographic Printing
Flexographic printing utilizes flexible printing plates to deposit ink on the stainless steel’s surface. Here’s how it works:
- You prepare a printing plate by etching it with the design that’s to be deposited on the steel. The etched areas are the only ones to come into contact with the steel later.
- Then, you mount your printing plate into a printing press to apply ink to it.
- You then press the plate onto the steel’s surface to transfer the ink.
- Finally, you cure the inks to ensure they stick to the steel’s surface well.
This form of printing is ideal for flat stainless steel surfaces. It’s especially useful for labels and tags, as it’s a fast process.
4. Dye Sublimation
In this printing technique, you use a sublimation ink to transfer a dye to your stainless steel surface. Here’s how the process goes:
- You print your dimensionally accurate artwork on transfer paper using sublimation inks.
- You prepare your stainless steel surface by appropriately cleaning it.
- Then, you put the transfer paper with the printed side down on your metallic surface and use a pre-heated press to apply heat and pressure. The temperature and contact time will vary per your ink.
- You then remove the transfer paper and apply a protective coating if necessary.
This printing method can yield high-quality, durable results. Although, they depend majorly on the quality of your inks and your adherence to the printing guidelines.
5. Inkjet Printing
This is a type of Direct-to-Metal (DTM) printing, where you don’t need pre-treatments or coatings to print on the surface of a metal.
In inkjet stainless steel printing, you use a printer that sprays ink droplets onto the steel’s surface to print the image digitally. Here’s how the process goes:
- You prepare your artwork in the correct dimensions and save it in a format compatible with the printer.
- Then, you prepare your substrate by cleaning it and, if necessary, priming it with a primer that’s compatible with the ink.
- Afterward, you simply put your stainless steel substrate into the printer and let it do its job.
- You cure and dry your project to let the ink properly settle and adhere to the surface.
The inkjet printing process is almost purely automatic, so you can get your high-quality prints swiftly. You may have to pass your substrate through the printer more than once to achieve sufficiently opaque colors and get the detailing right.
Note that this technique is also suitable for flatter or slightly curved surfaces.
Other types of DTM printing on stainless steel include UV printing and laser marking. The former uses UV-curable inks and cures them with UV light. And the latter uses a laser beam to alter the metal’s surface properties and leave a mark.
6. Laser Marking
In this technique, you use a high-powered laser to create designs on the surface of your metal. The exact nature of the designs will depend on the marking method you’re utilizing:
1.Laser Engraving
As you glide the laser beam on the stainless steel, it will selectively carve a permanent deep, and precise mark. The engraving process is physical, and there is no color change involved.
2.Laser Annealing
Here, the laser beam oxidizes the parts of the metal it touches, leaving a high-contrast marking on the steel. The process is chemical, and there is no material removal involved.
3.Laser Etching
Here, the laser beam vaporizes the metal on coming in contact with it, leaving a mark that’s not only deep but also in a contrasting color. Although etching leaves a less deep mark than engraving, it is more visible due to the color change.
4.Laser Foaming
In this technique, the laser beam heats the steel and leaves a raised texture wherever it comes into contact.
Your choice of technique depends on the power of your laser. You can alter the width and depth of your markings by adjusting the laser’s focus or choosing an adequately rated laser.
This technique gives durable ink-free text and designs. Intricate applications, like stainless steel jewelry printing, often use lasers.
7. Chemical and Electrochemical Etching
In chemical etching, you selectively remove material from the steel to create a design. This is mostly an ink-free process, much like laser engraving and embossing.
- First, you prepare your design and print it on your steel substrate.
- Then, you apply a ‘resist’ to the areas that you don’t want etched. This material protects them against the etching fluid.
- You immerse the substrate into the etching liquid to carve a design on the steel. The longer you leave your steel, the deeper the grooves will be.
- You then use a stripping solution to dissolve and clean the resist off of your steel.
- Finally, you clean your etched steel and, if necessary, apply a protective coat on it.
Electrochemical etching works on the same principles. However, instead of using chemical means only, you use a mixture of an electrolyte and an acid. And you apply a low voltage to the steel’s surface for the reaction to proceed.
Both these etching processes can give you long-term, durable results that can stand wear, tear, and corrosive forces.
Inks Used in Stainless Steel Printing
Printing on a stainless steel surface requires specialized inks that can adhere to the metal despite its smoothness and low surface energy. Common inks include:
1. Epoxy Inks
Epoxy inks are durable, strongly adhesive, and available in a range of colors and finishes, making them a common choice for printing on metals. They are also stable against corrosive forces, abrasion, chemical agents, and UV light, making them suitable for indoor and outdoor use alike.
They are pricey, however.
2. UV-Curable Inks
UV inks are popular in metal printing as they adhere well, dry fast, and are resistant to fading and smudging.
You cure these inks by exposing them to UV light. These scratch-resistant inks come in various colors and finishes, making them desirable for high-end applications.
Although you must note that you need the proper equipment to print and cure using UV-curable inks. This can make them an expensive option.
3. Solvent-Based Inks
In these inks, the pigment is carried by a solvent that penetrates the surface of stainless steel to help the pigment stick to it. This results in a strong, abrasion-resistant print.
A major drawback of these inks is that they use Volatile Organic Compounds (VOCs) as solvents, which pose environmental and health issues.
4. Water-Based Inks
These inks are swiftly emerging as eco-friendly options to use in stainless steel printing, and many inkjet printers use them.
As the name implies, water-based inks use water as their solvent. You can add additives to improve these inks’ qualities, like UV resistance and longevity. These inks come with excellent color saturation, good surface adhesion, and fast drying times.
However, water-based inks are less durable compared to their alternatives, so they require more care and maintenance. This makes them unsuitable for harsher applications, like industrial use.
5. Ceramic Inks
You can utilize ceramic inks to print on stainless steel. These also come in various colors and finishes and offer superior adhesion and durability. They can be useful in high-traffic and harsh environments.
After you’re done depositing your ceramic inks, you have to fire the printed steel at a high temperature to cause fusion between the pigment and the steel. This may warp the steel, depending on the substrate’s shape and properties. The firing process can be expensive and time-consuming compared to other alternatives.
Pre-Treatment and Post-Treatment in Stainless Steel Printing and Their Importance
If your stainless steel surface isn’t prepared adequately before printing, your inks won’t adhere well to the surface. And if you do not protect your design after printing, the inks will corrode or get damaged. Here’s what these treatments entail:
Pre-treating Stainless Steel for Printing
No matter what printing technique you opt for, you’ll have to clean your metal’s surface appropriately to prevent texture or loosely bound ink. You may also have to take additional measures to ensure the print sticks well.
Although the exact nature of pre-treatment depends on your technique, the following steps are common:
- Cleaning: You need to clean your stainless steel surface with a solvent or a detergent to remove dust and dirt.
- Degreasing: Then, you’ll have to use a degreasing agent, like alcohol or acetone, to ensure no oils are left on the steel.
- Etching: Metals often have smooth surfaces that do not hold inks. You may have to etch the steel using an acidic solution to create a rough surface that holds the ink better.
Post-Treatment of Printed Stainless Steel
It’s important to ensure your prints settle well. Common post-treatment steps include:
- Drying: You must thoroughly air-dry or heat-dry your printed stainless steel to let the chemicals and ink set.
- Curing: You may have to cure certain inks and printing materials with heat or UV light, depending on the nature of your supplies.
- Finishing: If necessary for your application, add polish or a protective finish for high shine and better protection.
Characteristics of Printed Stainless Steel
Here are some important things to know about printed stainless steel:
1. Durability
If you choose high-quality inks and follow pre-treatment, treatment, and post-treatment plans properly, you’ll get durable prints on your stainless steel. You can increase these prints’ longevity by applying a clear protective coating on top of them.
The environment you keep your printed stainless steel will also determine the lifespan of your designs. If you want labels and tags for industrial environments, use laser, dot peening, etching, stamping, or embossing to ensure your mark is visible even if the inks fade away. Although the inks used on steel have a very low chance of fading away if applied correctly.
2. Toxicity
Your stainless steel’s food safety and toxicity depend on the printing process and inks used. Some steel inks or protective coatings can contain cadmium and lead, which may leach into food if used in processing or storage.
It’s always best to contact a trusted steel fabricator and ensure they’re transparent about their practices.
3. Cost-Effectiveness
The cost-effectiveness of printed stainless steel depends on the complexity of your design, your technique, and the number of projects printed.
Traditional, manual printing methods, like screen printing, require more time and effort, so they cost more than digital prints. Techniques like laser marking are also expensive due to the cost of equipment and skilled workers.
In comparison, pad printing, flexographic printing, and digital methods are more budget-friendly, especially for small to medium-sized runs. However, in the end, it all depends on how complex your projects are.
The Uses of Stainless Steel Printing
You’ll find printed stainless steel in many fields to enhance visual appeal, functionality, and safety.
- Automotive and Aerospace: The stainless steel parts in cars and planes often have to be printed for identification and branding purposes.
- Medical Industry: It’s critical to have identification data printed on items like implants and diagnostic tools. As these are often made with stainless steel, this information is printed on them.
- Identification of Equipment: Industrial machinery needs durable labeling to ensure that it is safe for its intended use. Stainless steel printing is often utilized here for equipment identification.
- Art and Jewelry: Given the enhanced personalization options and aesthetic appeal of printed stainless steel, it’s common in consumer-facing goods like jewelry.
- Branding and Business Use: Businesses get their logos printed on their metallic objects for branding purposes.
Challenges of Stainless Steel Printing
Stainless steel has low surface energy, so printing materials and inks have trouble adhering to it properly. Its oxide layer is resistant to bonds as well. As a result, you can face problems when printing on stainless steel. For example:
1. Material Compatibility Issues
Material compatibility issues can appear on various fronts when printing on stainless steel surfaces. For instance, if your ink is not specifically formulated for stainless steel, it can wear, peel, flake, or fade off.
Similarly, the chemical you use for pre-treating must be compatible with your ink, or you won’t be able to create your prints. Post-treatment chemicals must work well with the inks as well, or their durability will get affected.
2. Difficulty in Printing Fine Details
Given the problems with ink adhesion, printing finer details on stainless steel’s surface can be challenging. This is especially true if you use traditional methods, like screen printing. Although techniques like laser marking can solve this problem, they are expensive and may not fit everyone’s budget.
Also, as stainless steel is a reflective material, seeing fine details and thin lines on it is tricky and can render such designs useless.
3. Limited Color Options
Traditional printing methods for stainless steel offer fewer colors as they have to keep the adhesion of inks in mind: inks of different colors do not stick similarly. Similarly, techniques like laser marking and chemical and electrochemical etching also pose a challenge when it comes to offering colors, as there is no ink involved in the processes, to begin with.
Even though newer digital techniques offer more colors, many smaller manufacturers can not afford them.
Endnote
In this modern age, you can customize almost anything, and stainless steel is no exception. from using lasers to screen printing by hand or using a digital printer, there are multiple techniques you can use to print on stainless steel. Make sure to use high-quality material and follow the preparation, main steps, and post-treatment techniques closely.
If you’re looking for a reliable company for your stainless steel printing needs, you can contact us here.
FAQs
1. How to maintain printed stainless steel?
The maintenance of printed stainless steel products is straightforward:
- Clean using mild soap, a soft cloth, and warm water. Avoid abrasive cleaners at all costs.
- Avoid scratching the paint.
- Make sure you store your products in a dry place, away from sunlight.
2. Can stainless steel printed products be recycled?
Printing on stainless steel does not affect its fundamental properties. So, printed steel products can be recycled by melting them down.
However, some types of inks used in printing can leave residues and may have to be cleaned and treated before they’re melted.
If you want to prioritize sustainability, choose inks that minimize residue whenever you can.
