Introduction to Degassing Chambers and Systems
A degassing chamber, often a vacuum chamber, is a sealed enclosure which enables the removal of air and other gases by creating a low-pressure environment. The general purpose of a degassing chamber is to eliminate trapped air or dissolved gases from materials (like liquids, resins, or compounds) so that these materials can set or be used without internal bubbles or voids. In simple terms, a vacuum pump removes the air out of the chamber, which causes any bubbles inside the material to expand and rise towards the surface. These bubbles then pop or collapse, effectively being pulled out of the material. As a result, the material is left in a bubble-free, degassed state.
A vacuum degassing chamber system typically consists of a strong container with a tightly sealed lid, connected to a vacuum pump via valves and hoses. The pump removes the air from inside while the vacuum is monitored via a gauge that shows the pressure drop. Under vacuum, many liquids or mixtures will expand, often 4 to 5 times in volume, as the trapped gas escapes, then they collapse back once the bubbles burst. For example, if you place mixed silicone or resin into a degassing chamber, you'll see it foam up as the entrapped air exits, and then settle down once degassing is complete. This process usually only takes a few minutes for most materials. However, for some materials, it can take longer. By the end, the material, be it resin, epoxy, or rubber, is generally free of internal air pockets and ready for use or curing without defects.
How and Why Degassing Works
Let’s start with the Ideal Gas Law which states that:
PV = nRT
Where:
P = pressure
V = Volume
n = number of moles
R = ideal Gas Constant
T = Temperature
Since the temperature, the Gas constant, and the number of gas molecules is the same, this can be shortened to:
P1*V1 = nRT = P2*V2
And further shortened to:
P1*V1 = P2*V2
According to the Ideal Gas Law, the Pressure is a function of Volume. When the air is trapped at atmospheric pressure (P1), it will have smaller Volume (V1). Let’s say that at 760 Torr (Ambient Pressure, P1), the gas bubble has a volume of 1milli Liter (V1). When vacuum is applied and lowered to say 5 Torr absolute pressure (P2) the volume of the bubble will increase to the proportion of the absolute pressure, which means that the gas bubble volume will be 152mL.
760Torr * 1mL = 5 Torr * 152 mL
This increase in volume will cause the bubble to float upwards because of buoyancy force. As soon as the bubble floats upwards, and reaches the surface of the liquid, it will pop and be pulled out by the vacuum pump (vacuum system).
Can degassing be done in Zero Gravity?
No, it cannot. As you can see, you need buoyancy for degasification, this means that in zero gravity, the expanded bubble will not float upwards and therefore, will not degasify the liquid. The only way to degasify in zero gravity is to use a centrifuge, in order to induce a centripetal force, so that the gas and liquid, which have two different densities, can be separated.
Applications Across Industries
Degassing chambers have a wide range of applications across different industries. Anywhere air bubbles or trapped gases are a problem, vacuum degassing can help. Below are some key areas where degassing chambers are commonly used.
Resin and Epoxy Degassing Work
In resin casting and epoxy applications, such as making jewelry, artworks, prototypes, or coatings, degassing vacuum systems are used to remove bubbles from the resin before it hardens. When you mix resin and hardener, you often introduce tiny air bubbles which can negatively affect the quality, clarity, and strength of the final product. Using a vacuum system to remove the air bubbles will result in a smooth, crystal-clear casting with improved structural integrity. Without degassing, the cured resin might contain voids or weak spots that not only look unsightly but also reduce the durability and quality of the product.
Vacuum degassing is especially important for epoxy resins used in high-performance applications, like composite materials or electronics potting, where trapped air will affect electrical insulation or bonding strength. By pulling a fairly strong vacuum, greater than 29 inHg, the resin de-airing process ensures a higher-quality outcome with minimal bubbles. In short, degassing chambers help resin artists and engineers alike achieve bubble-free, professional-grade results.
Silicone Mold Degassing
When creating silicone molds, using RTV silicone rubber to make a mold of a part or figurine, degassing is an essential step to ensure the mold comes out smooth and free of defects. Mixing silicone with its catalyst traps air bubbles in the liquid rubber. If those bubbles remain, the cured silicone mold can have tiny holes or voids on its surface, which then transfer as flaws onto the casted item. A degassing vacuum chamber solves this problem by degassing the mixed silicone before it cures.
Under vacuum, the silicone mixture dramatically expands into a foam as the internal air is drawn out. After sudden expansion and bursting of bubbles, the foam collapses back on itself once the bubbles burst. After this process, the silicone is visibly bubble-free and ready to be poured over the model. The result is a perfectly smooth mold that captures fine details without air pockets. Silicone degassing is considered standard practice in mold-making because it greatly improves the quality and lifespan of the mold. Even for low-viscosity silicones that trap less air, vacuum degassing ensures there are no hidden bubbles that could compromise the mold’s strength or the accuracy of the parts produced.
Industrial and Scientific Uses of Degasification Chambers
Beyond crafts and small-scale projects, degassing chambers play crucial roles in industrial and scientific contexts. In manufacturing, for example, vacuum degassing is used in metallurgy and materials production. A notable case is steelmaking: molten steel is often vacuum degassed to remove dissolved gases like hydrogen or oxygen. This is essential for producing high-quality alloy steels. In fact, certain high-strength steel grades used in automotive and aerospace sectors can only be made by vacuum degassing the molten metal. Removing these gases prevents internal flaws and improve performance, making the steel more ductile and reliable.
Vacuum Extrusion Chamber Production Technology
In the plastics or ceramic industry, vacuum degassing is used during processes like extrusion and molding. As plastic melts or liquid polymers are mixed, moisture and volatile gases can easily get trapped. A degassing chamber, often integrated into the production line, pulls out these vapors so the final plastic product has no voids or bubbles, resulting in higher strength, consistency, and quality. This is important for products ranging from high-end plastic components to delicate electronic encapsulations.
The aerospace industry relies on degassing to ensure materials will perform in the vacuum of space. Composites, adhesives, and potting materials for electronics are degassed so that they do not outgas or form bubbles at low pressure. This prevents failures in satellites or aircraft components due to trapped air expanding at altitude. Similarly, medical and pharmaceutical industries use degassing chambers for certain materials and preparations.
For instance, silicone used in medical prosthetics or implants is degassed to avoid any bubbles that could harbor bacteria or viruses, or reduce mechanical strength. Pharmaceutical labs might degas fluids, like ointments or solutions, to ensure accurate dosing and stability. Even electronics and optics industries use vacuum chambers to degas epoxy potting compounds or optical gels, preventing any cloudiness or electrical issues caused by trapped air.
In scientific research, degassing chambers help prepare samples free of dissolved gases (e.g., degassing liquids for sensitive experiments or extracting air from composites for material testing). In all these cases, the degassing chamber is a tool for enhancing material purity and performance by removing unwanted gases.
Food Processing and Packaging
Vacuum technology is widely used in food processing and packaging, and degassing chambers are a part of that. One common application is vacuum packaging for food preservation. In this process, food products (like meats, cheeses, coffee, etc.) are placed in packaging, and the air is pulled out before sealing. While this process, is not technically degassing, it is more like vacuum packaging (or vacuum sealing), removing oxygen and air prevents bacteria and mold growth, significantly extending the food’s shelf life. This kind of vacuum sealing keeps food fresh longer without relying on chemical preservatives. It also helps maintain flavor and texture, since the food isn’t exposed to air during storage.
Another food related use of degassing is in the beverage industry. For example, wineries and breweries sometimes use vacuum degassing to remove excess carbon dioxide or other fermentation gases from wine and beer. This eliminates unwanted flavors or aromas that can develop if those gases remain dissolved, resulting in a cleaner taste. Degassing in beverages also ensures consistent carbonation or flatness levels as desired by the producer. In addition, water treatment for food and drinks may involve vacuum degassing. Water used in beverage production is often degassed to remove oxygen that could cause oxidation or spoilage, and to get rid of any dissolved gases that might affect taste or cause corrosion in equipment.
Even some food products themselves are degassed. For instance, certain viscous food liquids (sauces, syrups, oils) may be degassed under vacuum to remove air bubbles, which improves their appearance and prevents oxidation. Overall, vacuum degassing in food processing helps in maintaining quality, safety, and flavor by removing air that would otherwise degrade the product.
Benefits of Degassing
Sanatron Degassing Chambers offers several key benefits across different applications. By removing trapped air and gases from materials, you can achieve improvements in both the quality and performance of products:
Improved Product Integrity and Durability:
Materials that have been degassed are free of internal voids, which means they are structurally robust. For example, a degassed resin casting or metal ingot has no hidden air pockets that could become weak points compromising quality. This leads to parts that are stronger and less prone to cracking or failure. In steel manufacturing, for instance, vacuum degassing produces cleaner, more ductile metal with higher integrity, which is crucial for safety-critical components.
Enhanced Aesthetic Quality:
Many products simply look better when degassed. Clear resins and epoxies cure without cloudiness or bubbles, yielding a professional-looking finish. Silicone molds come out smooth, so the cast items have perfect detail. Coatings and paints that are degassed will not have pinholes or blisters. Degassing removes the tiny flaws that can mar the appearance of finished goods, leading to a superior visual quality.
Consistent Material Performance:
Degassing helps ensure that materials behave predictably. With bubbles removed, the material’s properties (like density, strength, electrical insulation, etc.) are uniform throughout the volume. This consistency improves performance. For example, an electronic potting compound will insulate evenly without any air gaps, or a composite laminate will be solid without future de-laminations. It also means better batch-to-batch consistency in production. Products made with vacuum-degassed materials tend to show less variation and fewer defects between one batch and the next.
Reduction of Waste and Rework:
By catching and eliminating issues like air entrapment before a product cures or solidifies, degassing chambers help reduce the number of faulty items. Manufacturers and craftsmen see fewer rejects because the materials cure properly the first time. This not only saves time and materials but also increases confidence in the manufacturing process. In vacuum casting and molding, the use of a degassing chamber can dramatically improve yield and reduce the need for sanding, filling, or doing a project over due to bubbles.
Overall, a degassed material is easier to work with and results in a final product that has fewer defects and a higher quality finish. The investment in degassing pays off in the reliability and professionalism of the outcome, whether you’re producing a handmade epoxy tabletop or high-performance aerospace components.
Conclusion
Degassing chambers play a vital role across numerous industries and applications, from art studios to factory floors. By providing a controlled vacuum environment, these chambers effectively remove unwanted gases and bubbles from materials, thereby ensuring higher quality and reliability in the end products. Whether it’s creating a crystal-clear epoxy casting, molding flawless silicone parts, producing ultra-strong metal alloys, or preserving foods with minimal additives, vacuum degassing is often the key behind the scenes that makes it possible. The use of degassing chambers leads to products that are stronger, safer, and more aesthetically pleasing, with consistent performance that meets professional standards.
In summary, a degassing chamber is an indispensable tool whenever you need to eliminate air pockets and improve material quality. Its importance spans from improving small DIY projects (like removing bubbles in resin jewelry) to critical industrial processes (like preparing materials for aerospace or medical use). As we've seen, understanding its function and benefits – and knowing how to choose the right chamber for the job – empowers users to tackle projects with confidence. Degassing chambers will continue to be a cornerstone of quality assurance in manufacturing and craftsmanship, helping to deliver smooth, reliable, and high-performance results every time.