Different Types of Surface Treatment Techniques

Jack Lie CNC machining expert

Specialize in CNC Milling, CNC Turning, 3D Printing, Urethane Casting, and Sheet Metal Fabrication Services.


Texture has an overwhelming impact on the product’s physical appearance; since different will be the texture, changed will be the appearance and feeling of that product. Along the same lines, let us have a look at fifteen texture implementation or surface treatment techniques.

Embossing

For making the metal surface concave or convex, metal embossing gets done using mechanical processing on the metal plate. A patterned work roller rolls the embossed sheet metal. The depth of each bump varies concerning the pattern on the work roller that usually ranges between 0.02 to 0.03mm.

For having a good and sustainable impression of the work roller on sheet metal, the process gets repeated multiple times unless the pattern is embossed on the sheet metal. Primarily, embossing metal plates are used in subway cars, decorating elevator cars, metal curtains, and architectural decoration on metal sheets.

At the same time, embossing has advantages over other techniques because it produces resistance against corrosion, pressure, and scratches. Also, it offers enduring and elegant looks.

Metal Wire Drawing

The process of metal wire drawing involves the repeated scraping of sand sheets. Typically, the metal wire drawing can show every small print or silk mark on the metal matte, which is the natural beauty of this process.

With the help of metal wire drawing, the drawings can get drawn into multiple patterns like chaotic lines, grooves, swirls, and straight lines.

Straight Lines: In wire drawing, the straight lines are drawn on the Aluminum plates by mechanical friction.

Rough Pattern: Rough pattern gets usually drawn with the back-and-forth movement of the aluminum plate under the high-speed operation of a copper wire brush.

Thread: A small motor is fixed on the table at 60 degrees, along with a circular felt on the shaft. Additionally, set a carriage with a fixed aluminum plate depression bar. After the setting gets done, a straight film of polyester is pasted on the edge of the carriage to control the thread’s width.

Corrugation: It generally uses a grain rub or brushing machine with the axial movement of the upper set of the rolls, and a wave pattern on the plate of aluminum gets drawn.

Paisley Pattern: A stone nylon wheel or cylindrical felt is used to obtain the silk mark on an aluminum or aluminum alloy plate. Most of the time, it gets used for purposes in the shape of decorative dials.

IML Technique

IML product comprises a hardened layer of transparent film with a printed pattern layer present in the mid. There is a plastic layer on the back. The ink remains in the middle to prevent the surface from being rubbed or scratched. That is how the color remains long lasted and non-faded.

Cutting: For molding and designing processes, the roll films get cut in square shape.

Graphics Printing: The characters and icons to get printed are pasted on already cut square-shaped films.

Drying and Fixing on the Ink: The printed films are placed in the oven at high temperatures. The reason behind this process is to dry the film.

Paste a Protective Film: During the punching process, the smearing of the printed surface should get avoided. For extra care, sometimes, single or double protective films need to be applied.

Punch Locating Holes: The thermoformed locating holes must get aligned for perfection. In the shearing process, locating holes are sometimes punched in advance that might cause a problem in alignment.

Material Injection: The film, precisely like the front mold, is placed on the front mold; the IML finished product gets passed through the injection molding.

Texture can get Realized: The outermost layer is of film material, so the surface remains non-tactile.

Product Features: The film production cycle is short, and it might include different colors, textures, and icons. It has excellent resistance against scratches. Meanwhile, the application of these products gets repeated in the 3D industry, mobile phone buttons, and logo.

IMR Technique

In this process, the film is printed with the pattern and bonded to the mold cavity using an extrusion or film feeding machine. After passing through the film feeding machine, the patterned ink gets separated from the film. The layer of the ink stays on the plastic to inflict required decorative patterns. Typically, the film is only a source to have the final print on the product. Other than that, and it has no use in the whole process.

Since it is a simple process, the defect rate can be brought down with little more care. Meanwhile, the product is durable, safe, and impregnable against damages, especially from edges.

Similarly, there might be bamboo, leather, and marble textures with a diverse range of surfaces. But the problem is that the texture is only a few microns thick, which can get scratched with a bit of stress. However, it is used on surface treatment parts of plastic, home appliance case, and mobile phone case.

Water Transfer Printing

The water transfer printing involves plastic films with a specific color pattern. It is subjected to macromolecular hydrolysis by water pressure. In recent years, water transfer printing has rapidly increased because it is a comparatively more manageable and efficient method of product printing.

Technically, there are two methods of water transfer printing: cubic transfer technology and watermark transfer technology. The first one gets the task done using the transfer of photo-pattern and texts. In contrast, the latter one belongs to the transfer of the entire surface of the product.

The plastic films are placed on the water surface, which usually gets tensed due to the barometric pressure of air. The film is settled on it. The product is instantly passed through the water with a minor stay in water unless the print is evident on the product’s surface.

The best part of this technique is that it exactly prints what you have on the film irrespective of its 2D or 3D view. After considering the efficiency of this method, it gets widely used in the automotive industry, control panels, and household appliances.

OMD Technique

Mainly, the OMD technique utilizes the coexistence of temperature and pressure. The coating to be printed is heated and put under pressure to strengthen the products. This process hugely betters the surface finishing, hardness of the product, and graphics design.

However, the OMD technique has two types:

The first one is known as high-pressure transfer or Extend IMR Technology (OMR). Once the pattern gets printed on the film, the high-pressure vacuum can cover the plastic surface directly. After the print is shifted from the film to the product, the film should be torn, and the outer surface of the printed product should not be covered. The applications of this technique are found for fiberglass, plastic products, miscellaneous metals, etc.

The second type is Extend IMF Technology (OMF). The outer layer of the workpiece gets covered using the protective product. The applications of the process are found in medical equipment, transportation, and decoration of aviation-based products.

Hot Press Forming

The process is much like the injection molding process; however, it is not useable for plastic products. The molten material gets injected into the die and cavity after heating it to its melting temperature. Then it is left to be cooled. The applications of this process are overwhelming in different industries like the cookware industry.

Texturing

Typically, it is the process of chemical osmosis that involves the printing of different textures on desired products. It also includes a sandblast technique that sprays the glass sand directly on the surface of the desired metal at the sanding time. Once the process gets completed, the final product experiences feature like the improved appearance of plastic parts, better surface strength, non-slip and anti-rotation feeling, and easy wear of the prints. Texturing has vast examples in the leather industry, automotive industry, plastic industry, etc.

Hot Stamping

Hot stamping is also famous with the name of gold stamping. With the action of heat and pressure, the pattern of the stamp gets transferred to the substrate. The force of the mold creates excessive stress on the stamping pattern to inflict a clear impression on the substrate. Moreover, hot stamping and foil are two fundamental parts of the hot stamping process. The process of hot stamping foil comprises of the following steps:

The substrate is brought into contact with hot stamping foil.
Using heat and pressure, the impression of the hot stamp gets transferred onto the substrate.
Reducing the pressure and peeling of the polyester’s film.
Replacing the hot stamping foil with the printing stamp that will be stamped.
Recently, the use of hot stamping has widely increased in different industries. The leading industries that use hot stamping are the textile and leather industry. Likewise, it is a durable and reasonable option to have printed any of the products.

Laser Engraving (Ray Engraving)

This technology is based on the CNC laser processing medium. Under laser irradiation, the physical degeneration of molten material and vaporization of the metal material is conducted to achieve processing. The laser engraving technology helps print the images on the substrate. The technical advantages of laser engraving include precision, which can withstand any deformation and high efficiency, leading to a shorter lead time and more production. At the same time, it is an environment-friendly and energy-saving approach to getting the substrate printed.

Metal Etching

Metal etching is also known as photochemical etching. A protective film on the etching region is placed, which is removed after the etching gets completed. When the metal is etched, it meets the chemical solution to develop resistance against corrosion and dissolving. Most probably, the applications of metal etching are found in consumers’ products and making different patterns on the aluminum plates. Furthermore, a metal horn net is a typical example of etching.

VCM Plate

The VCM plate is a process of coating a finished metal sheet using printed films. With the method of sticking, the printed film product is laminated to the sheet of steel metal, which results in the formation of desired patterns on the surface of the steel sheet. Usually, the VCM board presents diverse colors, beautiful prints, and smooth effects. Therefore, VCM is hugely adopted for plating purposes. Typically, it is based on steel plates. A metal color laminated steel sheet gets coated with vinyl chloride on its surface. Ultimately, the desired patterns appear on the product.

CNC Machining

CNC machining involves the use of CNC machining tools. To physically process the substrate, the CNC machine is fed with the feed rate and spindle speed. The tool keeps on moving according to the provided design. CNC machining has many advantages over the conventional or manual machines since CNC machine is much more precise and prompter than traditional machines.

Metal Stamping

It involves the transfer of hot stamping foil on the surface of the material to be printed. For metal substrate hot stamping, the hot stamping film gets applied on the surface of the substrate. The hot stamping foil comprises versatile patterns and colors. Thus, it provides printed products with alluring and excellent visuals and icons.

Silk-Screen Printing

Silk-screen printing is a cost-effective approach for having attractive designs and patterns on the surface of desired products. The film or the screen possesses the image of the icon or pattern to get printed on the product. Usually, the screen is made up of nylon, silk, polyester, and metal mesh. For making the print on the product, it is directly put under the film with the stencil. Then the ink from the screen shifts on the product under the squeeze of the doctor blade. The stencil on the screen seals its central part to avoid the passing of pigment through the screen.