Best and Worst Materials for Vacuum Service

Choosing the best material for your vacuum system is an important decision. Not only does it affect the cost of the machine, but also its efficiency, durability, and capacity. Though not all materials are suitable for every system, some standouts can save you money in the long run. Here’s a list of what to watch out for.

Best Materials To Consider

Steel

This is an excellent material because it’s inexpensive and easy to work with. It’s affordable and easy to get your hands on, but it has a few setbacks that make it an undesirable option.

While tubing can be ready to use with minimal preparation, components like valves and fittings cannot be used without undergoing a hardening process. This process is costly and can take weeks or even months to complete. Once hardened, steel will be robust enough for almost all applications, but if the machine needs heavy-duty work or needs a lot of abuse, you may have trouble with the material cracking under pressure.

Aluminum

It is as strong and durable as steel but has several advantages. It’s less expensive than steel, more readily available than steel, and can easily be welded to produce high vacuum systems that are stronger, more durable, and easier to work with. There are two types of aluminum: cast and wrought.

Cast aluminum is made into machine parts by melting aluminum in a mold and then releasing it. It’s cheap to produce, but the surface finish is uneven and cannot be easily machined once hardened. Wrought aluminum is more expensive than cast, but it can be machined after welding and has a better surface finish. The more you work with it, the stronger it gets making it more durable than steel.

Plastic

It is not as strong and durable as steel or aluminum, but it is still an excellent material for vacuum system construction. It’s more flexible than steel, making it cheaper to produce and easier to use, but the downside is that it cannot tolerate very high pressures. It is not a problem for most applications, but if you are trying to run a machine under high pressure, you will have no other option but to use metal.

Polymer

This material is more resistant to extreme temperatures and pressure than other materials and is very lightweight. Its short cycle life makes it less desirable than steel or aluminum, but the advantages offset this. The most crucial benefit of polymer is that it is very light, which makes it easy to move around and allows you to install machines in tighter spaces. Unfortunately, the high cost of materials also offsets this.

Silicone

It is a high-quality, long-lasting material for vacuum system construction. It has similar advantages to polymer and is an excellent option if you need to run your machine in high pressure or extreme temperatures. You will, however, have to use particular tools when working with silicone. The material has a higher content of silicone oils that can catch fire and cause burns if not handled properly.

Polyester

This is a lightweight, solid, durable material used to produce lawn equipment and clothing. While it’s strong enough for vacuum system construction, it’s not as cheap or easy to work with as plastic or aluminum. It also requires a unique maintenance process to keep it from breaking down too quickly under normal conditions.

Materials To Avoid

Paper

While the paper is excellent for producing documents, it’s not suitable for making vacuum systems. The material tends to fall apart under pressure, and most components will require hardening and other expensive and time-consuming treatments.

Wood

It will not hold well under high pressure or extreme temperatures. It will also require a lot of maintenance because it deteriorates quickly in normal conditions, and you won’t be able to work with it when it breaks down.

Steel wool

It is cheap and available but not particularly strong. The problem with steel wool is that once it cracks, it will weaken the rest of the components built around it. If a part breaks down, you won’t be able to work with other members because they’ll also become weak and break down.

Cadmium

It is a semi-conductive material classified as a metal. It’s pretty expensive and has a shallow melting point. The problem with cadmium is that it will eventually burn up if exposed to high temperatures. Therefore, if you’re making a vacuum system that needs to operate under high pressure or in extreme temperatures, you’ll have to use something else.

Lead and antimony

These materials are classified as non-conductive metals. They conduct electricity but will still not be able to maintain a high vacuum due to the stringent maintenance requirements.

Polyvinyl chloride

It is a non-conductive plastic that melts at a low temperature. The biggest problem with this material is that the components will become weak and unreliable once it melts. It’s also not as easy to work with polyester or polymers because it requires more specialized tools, and you’ll have to apply certain conditions to keep the material from breaking down.

Teflon

It is a non-conductive plastic with many of the same problems as PVC, but it does not have anywhere near the same level of durability. Teflon will also melt at higher temperatures and can become brittle if exposed to extreme heat over long periods.

Oxidized materials

They have a higher than usual level of oxygen in their composition. The most common examples of this are copper and steel. These metals will burn up if exposed to high temperatures and cannot tolerate extreme pressure.

Sulfur

It is used in high vacuum system construction for special applications. Still, it’s unsuitable for main applications because it breaks down under heat, makes the parts brittle, and becomes less durable over time.

While there are many materials and combinations of materials you can use for a high vacuum system, they also have many disadvantages. The only way to choose the best material for your application is by weighing each material’s advantages and disadvantages and matching them against the needs of your application. You can always contact the experts at High Vac Depot for any questions you may have.