Polishing often eliminates microdefects on the surface of products and machine parts. In other words: imperfections are often not noticeable at first glance. Furthermore, sanding marks are removed and the parts are given a shiny surface at the same time.
There are different types of polishing, but in this article we will discuss steam polishing. Read on as we provide this information.
What is steam polishing?
In vapor polishing, a solvent is converted into vapor and sprayed directly onto the part or product to be processed using a stream of compressed air or circulated repeatedly in a chamber. The solvent melts the surface of the part when it reacts with it, making it smoother and more resistant to scratches.
Steam polishing is a special technique that improves the properties of material components such as acrylic (PMMA) or polycarbonate. It also improves the finish on interior and exterior surfaces and is particularly effective in polishing small parts. This method has the advantage of being able to polish delicate internal features such as threads, channels, openings and test areas for samples that are difficult to polish manually.
Steam polishing process: how does it work?
Steam polishing is a process for smoothing some plastic resin materials. More specifically, straightening is done using a Weld-On 4 solvent heated in a gaseous state. The use of this gas is mainly due to its reactivity with polycarbonates.
Before steam polishing, the part is sanded to reduce the frequency of deeper marks on the surface and to ensure that the steam reaches all parts of the surface. To do this, the surface of the part is processed with 1000 and 1500 grit sandpaper. It is then cleaned to ensure that it is free of dust and other contaminants that could interfere with the process.
Steam polishing process
Heating solvent : Weld-On 4 solvent is heated to its boiling point of approximately 1040°F or 400°C. This heating must take place in an environment with controlled parameters to ensure that the gas does not pose a danger to the environment or other people. It also helps prevent contamination.
Steam generation : Upon reaching the boiling point, the Weld-On 4 solvent produces steam that is used in the steam polishing process.
Spray : The steam generated is then applied by spraying onto the surface of the manufactured part or product. The heat from this steam quickly melts the plastic and fills in microscopic voids and scratches. When the gas is no longer present, the plastic quickly solidifies, providing a smoother, more perfect surface.
Which plastics can be steam polished?
Due to the different chemical structure, it is impossible to polish various plastics with steam polishing. Below are engineering plastic resins that you can steam polish.
Polycarbonate (PC)
Polycarbonates are a group of thermoplastic polymers that contain the carbonate group. Plastics in this group are strong, resistant and easy to process. In other words, polycarbonates can be easily thermoformed, molded or machined.
Furthermore, some types of this plastic are transparent. The chemical structure of polycarbonates makes steam polishing easy and beneficial.
To steam polish polycarbonate, a small amount of acetone or MEK (methyl ethyl ketone) should be added to a sealed container. The solvent condenses on the surface of the part and partially melts it. After condensation, evaporation occurs, giving the piece a smoother surface. Furthermore, this process is often repeated several times to achieve purity and a high level of smoothness.
Acrylic (PMMA)
Acrylic is an engineering thermoplastic with a translucent and transparent surface. Due to its non-crystalline nature, this material is often called acrylic glass. It is lightweight and shatterproof, making it ideal for producing clear optical prototypes.
Steam polishing acrylic components requires a small amount of solvent, such as dichloromethane or chloroform, placed in a sealed container along with the acrylic parts.
Condensation forms on the surface of the piece and then evaporates, leaving a smoother piece. Likewise, it is important to repeat this process several times to obtain the purity and smoothness required for these pieces.
Section
Acrylonitrile butadiene styrene, also called ABS, is a terpolymer. It is stronger than pure styrene and has a shiny, waterproof surface. It also has sufficient hardness and rigidity, which makes plastic production easier.
The surfaces of ABS parts can be polished to provide a perfect, shiny finish. Steam polishing causes the surface of the ABS part to melt and briefly reliquefy, after which it solidifies for a smoother finish. However, this requires the use of a vapor solvent such as acetone.
The time it takes to steam polish ABS depends on the size of the part, solvent concentration, and other factors.
nylon
Nylon plastics, also known as polyamides, have excellent mechanical properties that make them easier to manufacture on CNC machines.
Nylon parts are subjected to steam polishing with solvents such as methyl ethyl ketone (MEK), ethylene dichloride or acetone. The solvent evaporates and condenses on the surface of the part. What remains is a smoother surface finish.
Benefits of Steam Polishing
Steam polishing offers several advantages over traditional polishing. Some of these benefits are:
Improving light transmission
A major advantage of chemical vapor polishing is that it improves the light transmission of parts. Surface vapor polishing generally allows unobstructed passage of light, which is important in light-emitting applications.
Improves product aesthetics
Steam polishing improves the appearance of products and parts. Gives pieces excellent optical clarity, water clarity and a high gloss finish. As aesthetics improve, the value of the product also increases.
Surface finishing
Other subsequent surface treatments, such as: B. Grinding, leave deep and shallow marks on the surface of products. However, steam polishing does not produce these marks, as this process removes all irregularities and marks from the surface.
Ideal for use in the medical industry
This surface finishing process is widely used in the medical industry as it allows the production of smooth tools without tool marks. This is particularly important for the medical industry because tool brands often serve as pockets where dirt and contaminants accumulate.
Steam polishing versus manual polishing: how to make the right choice?
As there are steam and manual polishing, it is difficult to choose the right process for your needs. But don't worry, we'll discuss the pros and cons of these two polishing methods to help you make the right decision!
Manual polishing
Hand polishing is the traditional polishing method. Manufacturers often use this process to smooth the surface of wood, 3D printing plastics, CNC milled plastics, and metals. One of the advantages of this polishing method is easy access to the necessary equipment.
Furthermore, it has no negative effects on health. The only problem is the dust generated during polishing, which you can easily combat with a quality nose mask and other protective clothing.
However, this process is quite laborious and time-consuming. This is especially true if you want to produce parts with a high-quality mirror finish or excellent optical clarity. Another challenge you may face with this polishing method is the difficulty of achieving a consistent finish on parts with complex geometry.
Steam polishing
Steam polishing is an efficient and fast process for surface finishing. Furthermore, the manufactured parts have a consistently glossy finish and excellent optical clarity. The high surface consistency is due to the fact that the steam can reach even difficult-to-reach areas.
Additionally, steam polishing removes minimal material, which helps save on material costs. This polishing process is used on medical devices and equipment. It is also applied to features such as channels, recesses, openings, threads, and other features that require attention to detail.
The disadvantage of this process is that it is not suitable for all plastic materials. Another disadvantage is the setup costs, as expensive materials and equipment are often required for an ideal process. Furthermore, some materials that can be subjected to this process would still need to be annealed before polishing, which would consequently increase production costs.
Steam polished parts for various industries
Manufacturing industries that use steam polishing as their preferred method of surface finishing include medical device, food processing, and consumer products industries.
Medical apparatus
The medical device industry uses steam polishing to produce components that are aesthetically pleasing, visually clear, and have a glossy finish. This process also helps to smooth out entry areas, surface irregularities, and other marks on the surface of the medical instrument. Additionally, it helps remove debris on the surface of devices that pump blood.
food processing
Steam polishing improves the smoothness and shine of parts of the product that come into contact with food. In addition to the aesthetic benefits, it also improves the product's ease of cleaning and reduces the growth of harmful microorganisms.
consumer products
Steam polishing is also used in the consumer goods industry, as it allows the production of parts with a smoother surface. This reduces friction when in contact with skin and other products.
Get steam polishing services for your projects
Steam polishing offers several benefits, including a smoother, visually clearer surface with high transparency. However, there are accident risks and health risks that you should consider.
