Finishing services are applied at the final stage of components to ensure that the final effect is consistent and perfect, especially for some prototypes that require a cosmetic apperance. Some desingers want the prototypes have a same effect as the design, so the post-treatment finishing is necessary to satisfy customer.
NICE Rapid is specialist in rapid prototyping and rapid tooling services, we are pleased to provide finishing services for your products, like anodization, plating, vapor polishing, pad printing, painting etc…Warmly welcome to contact us if you need.
Anodization is an electrochemical surface treatment for aluminum components that got a film anodizaed coating, which has protective, decorative and other function properties. By applying electricity to aluminum, the parts become an anode to cathode in a completed circuit, while immersed in an electrolyte acid bath. The electricity and acid batch work together to open up the surface of texture and crystal structure, which build the thickness of natural oxide layer.
Also, the thickness of coating can be divided into three types according to the anodization type
|
Anodized type |
Thickness |
|
Chromic Acid Anodize Type I |
0.00005”-0.0001” |
|
Sulfuric Acid Anodize Type II |
0.0001”-0.0008” |
|
Hard Coat Anodize Type III |
0.0008”-0.003” |
Anodizing is widey used in aluminum alloys, which improves corrosion and wear resistance.
Moreover, it provides better adhesion for paint primers and glues than does
bare or untreated metal. Here, we see some advantages of anodizing:
Aluminum is ideally suited to anodising and many colors are available. Due to the changes in surface and crystal structure, the anodized surface becomes ideal for absorbing dyes in color applications. Anodized aluminum surfaces provide color stability under ultraviolet light and a chip-free painted surface. See below picture that show the work process of color anodization.
For the color selection, there are two kinds of standard color code for reference: Pantone Code & RAL Code.
Sometimes there will be color aberration when we match color according to the code.
No, they are two different process. Plating is a process where a coating is applied to the surface while anodizing is a process that modifies the surface. Electroplating is a process that to add a metal protective layer on the surface, but aluminum is generally not suitable for electroplating.
Yes, anodizing will affect the dimension because there is a coating on surface of aluminum parts. In general, 50% of an anodized coating will penetrate the surface of material, and 50% of the coating will be formed on surface. Therefore, the change in final dimensions is determined by the thickness of coating.
We need to control the thickness of coating with exceptional accuracy by using advanced technology. Sure, we are also committed to provide the high-quality products and keep close contact with our customers.
There are some popular methods of plastic polishing in our daily lives, like Flame polishing, vapor polishing, mechanical plastic polishing, direct machining, and buffing.
Vapor polishing is a method that utiliese vapor to polish plastics, which reducing the surface roughness or improve clarity. This method of polishing is used to get an optical quality finish effect from non-transparent plastic. Such as lens or windows that require an lightweight optical quality, vapor polishing is the fast and best way to achieve optimal transparency.
Some plastics are repsond well to vapor polishing:
Before polishing, the parts need sanding up in order to
remove some burr. Then the part or
surface of parts need to be polished is exposed to strong Weldon gas vapors.
The solvent vapor melts the plastic on a molecular level. And the vapor is
allowed to evaporate after completion of the process. Then the surface of parts
becomes clear, smooth and get optical quality finish.
Meanwhile, vapor polishing is a special process that requires exceptional skill with chemical applications and specialized machinery. It requires a clean and dust-free environment as well. Therefore, this process requires special training of technicians to operate.
Pad printing also called tampography, it is a process of transfering a 2D image onto a 3D part.
Before to understand how pad printing work, we need to know the compnents of pad pritning machine seperately. The pad printing machines consitont of an etched plate ( also name as cliché) and pad two parts, usually the type of range depending upon the number of colors and size.
|
Item |
Description |
|
Pad |
1.Pads are made from silicone material, it is a ink transfer systerm during pad printing process. 2.Different type and hardness depending on the application. Common pads are round and retngular shape but any other shape are avalibable as well. 3.The shape and size also depending on the application and artwork that required. |
|
Ink cup |
1.The ink cup is a housing mechanish that used for the ink printed on a part. When ink cup slides over the etched plate, it leaves a small amount of ink in the etch. This process named doctoring. 2.The ink cup consitont of a ring and cup two main components. The ring can be used for doctoring the plate, to ensure the ink is only left in the etched postion of plate. 3.The material of ring can be metal, plasti and ceramic. Usually the ceramic is the preferrable due to ceramic is gentle enugh and strong, it will not scratch the plate. |
|
Plate |
1.A pad printing plate (also called cliche) is etched with the image, which can hold the image to be printed. 2.It includs two types of etch process: Laser Plate-making and Photolymer Plate-making. |
1. Laser plate-making is a very fast process of
etching a plate with a CO2 or fiber laser, it uses computer
technlogy to etch plate, which has complete repeatability. Usually etching a plate needs 5-7 minues.
2. Photopolymer plate-making utilise the photosensitive plate material and a UV exposure unit to let the plate exposed to UV light numberus times. Photopolymer plate-making takess about 30 minutes process time, but it is the most cost-effect method to etch plate.
The pad printing machines consitont of three components (the plate, the ink cup and pad) that can delivery a print to a substrate. Firstly, the plate is etched with an image; Secondly, the ink will be stored in a cup, when the cup slides over the etched plate and leaves a minuscules amount of ink in the etch. The printing pad is a delivery system that presses a somewhat soft silicone material on the etching filled with ink to obtain an image, and moves it to the substrate, finally presses it again to transfer the image.
Pad printing is a very popular printing process to transfer the logo. It is used in a variety of printing appliances.
Sandblasting (also called abrasive blasting ) is a generic term for the process of smoothing, shaping and cleaning a hard surface by forcing solid sandy particles across that surface at high speeds. Some raw sandy particles inclduing copper ore, quartz sand, emery sand, iron sand and Hainan sand. See our sandblasting machine.
There are two representative international standards for the grade of sand blasting, namely cleanliness. One is the "SSPC-" formulated by the United States in 1985. The second is "SA-" formulated by Sweden in 1976. Let’s see below chart to know the grade.
|
Grade |
Standard |
|
Sa1 (SSPC-SP7) |
Using the easy manual methods to polish parts, it is the lowest class. |
|
Sa2 (SSPC-SP6) |
Using sandblasting machine to polish parts, it requires the oil, rust, corrosion and others can not be exited on surface of parts. |
|
Sa2.5 |
A level commonly used in industry and used as an acceptance of technical requirements and standards. It requires near white cleaning. |
|
Sa3 (SSPC-SP5) |
It is the highest treatment level in the industry, also known as white cleaning level (or white level), defects, rust and so on must not exist. |
There are some reasons to tell you why general parts need to do sandblasting, expecially for some aluminum parts need anodization treatment.
Reason 1: The surface of product is flat and the burr is removed, which avoid the harm of burr to human.
Reason 2: Polishing the surface of part to improve smoothness, which makes parts keep uniorm metal color. The appearance of product looks more beautiful.
Reason 3: Sandblasting can make a small round angle at the edge of part, which makes the appears more beautiful, more precise.
Reason 4: The mechanical parts can produce even fine concave surface after sandblasted, it will have a nice quality surface after have being anodized.
Also, sometimes customers will require not to do sandblasting before anodization, because the parts may get deformation after sandblasting, especially for some parts has thin thickness. In this suitation, we should keep in touch with customer and follow customer’s requiremnts.
There are lots of types in sandblasting, such as wet sandblasting, vapor blasting, bead blasting, wheel blasting, vacuum blasting and so on.
The common type we can offer is bead blasting. Bead blasting is used to clean calcium deposits from pool tiles or any other surfaces, remove embedded fungus, and brighten grout color. Usually, the parts can get a nice appearance after bead blasting.
Paint is a kind of surface coating process for industries products, it includes plastic painting, silk screen and pad painting process. The layer of coating is a liquid paint through natural air or baking.
Liquid paints are ideal for situations where a specific color is needed, where the coating needs to be smooth, or there is a lot of color variation. According to different requirement of glossiness, we can provide gloss, semi-matt and matt painted surface.
|
Type |
Description |
Picture |
|
Gloss Painted |
Good reflective effect, high anti - luminosity, clean andclear surface bright
|
|
|
Semi-matte Painted |
Between gloss and matt painte |
|
|
Matte Painted |
Low reflection rate, color and lustre is softer |
|
The liquid paint is easy to absorb dust particles, it will affect the surface of products.
Too high temperature, paint is easy to melt, forming flow marks, The temperature is too low, the paint will not dry easily.
In order to remove some burr and make the surface become more flat, the liquid paint coating is easy to dry.
