The role of vacuum in synthetic diamonds' production

Mention diamonds and most people will associate that with the jewelry sector. They will also have in mind that such gems are to be found in mines and sometimes won under severe conditions (“blood diamonds”). For such reasons, the industry already investigated in the 1950s how to produce synthetic diamonds.

Today, there are several processes available to create artificial diamonds. Not only for jewelry where even experts are challenged to differentiate a natural diamond from an artificial, but also for the much larger market for diamonds in the industrial sector. 

Four outstanding properties of synthetic diamonds

The key properties of synthetic diamonds that make them so interesting for the industrial sector are:

Some typical industrial application examples are machining and cutting tools, window material for transmitting infrared and microwave radiation, and heat sinks for lasers and transistors. Synthetic diamonds are also the base material for semiconductor wafers and Qubits for quantum computing. 

How are diamonds obtained?

Traditionally diamonds were naturally formed billions of years ago in the earth’s crust by carbon atoms being exposed to intense heat and pressure. However, due to technical advances, a new source of synthetically grown diamonds was created. This market can be divided into 2 main manufacturing methods:

  1. HPHT (High-Pressure High Temperature)– This method is based on how diamonds were naturally formed - compress carbon and add heat. The equipment footprint often has large and limited process control.
  2. CVD (Chemical Vapor Deposition)– This method is based on creating a vacuum environment and then introducing specific gasses to trigger a reaction. The equipment footprint often has a small and excellent process control.

MPCVD (Microwave Plasma CVD) growing process

Due to its small footprint and excellent process controls, the MPCVD growing process has gained in popularity. One important part of the MPCVD process is the creation of and maintaining optimal vacuum conditions inside a growth chamber. A typical growth chamber setup looks as below:

Synthetic diamond-making process. Source: NNE, 2019

The typical process steps are the following:  

  1. Layout diamond seed/substrate
  2. Close chamber and evacuate chamber for conditioning, heat up substrate
  3. Introduce hydrogen
  4. Turn on microwaves and generate plasma (~4000 °C) above the substrate
  5. Introduce process gases and start epitaxial growth
    • Methane – carbon source
    • Ethanol, Acetone, or Oxygen (optional) – helps improve the quality through oxygen plasma etching effect
    • Nitrogen (optional) – helps speed up the process (learned from experience and made MPCVD growing feasible economically)
  6. 1 to 4 weeks of growth period


Which are the vacuum pump requirements for the growth period?

  1. Initial pump down to about 2E-2 mbar base pressure
  2. Maintain pressure (100-300 mbar, typically in a range of 100-130 mbar) while process gasses flow
  3. Low-pressure cleanup of diamond color after production

Nowadays, oil-sealed rotary vane pumps are typically used in the MPCVD process. This is because these pumps are very well suited to achieve low conditioning pressure but also because they are mainly designed for continuous operation at fine vacuum. Additionally, these pumps face poor lubrication, overheating, or high oil loss when operating for days in the rough pressure phase required by this process.

 

Advantages of oil sealed pumps 

The oil lubrication of these vacuum pumps is secured by a built-in oil pump, which also enables a uniform oil distribution at rough pressure operation, whereas standard pumps without such oil pumps could fail.

Our range of rotary vane pumps is designed for operation at rough pressure and provides a perfect solution for the diverse pressure requirements of this growing process:


Browse Ash Air's range of vacuum pumps

View 3 Products

Claw Pumps

The Ash Air range of rotary claw vacuum pumps is the best alternative to rotary vane pumps. A vacuum claw pump is virtually zero maintenance and compared to rotary vane pumps can work at vacuum levels of 400 to 1000 mbar without overheating. Rotary claw vacuum pumps are the best choice for CNC guided wood routers.

Sub Categories

Fixed Speed Dry Claw Vacuum Pumps VSD+ Dry Claw Vacuum Pumps
View 4 Products

Liquid Ring Pumps

The Ash Air range of humble liquid ring pumps is still the most reliable form of large volume vacuum generation available today. These liquid ring pumps are simple to use and very reliable, and the best option when sucked air contains a large amount of saturated gas.

Sub Categories

Atlas Copco Liquid Ring Pumps
View 4 Products

Rotary Vane Pumps

Dry and oil-sealed vane vacuum pumps are robust, affordable and easy in maintenance. You can use DVP vane pumps for wide range of application, for skin packaging, holding, lifting, thermoforming.

Sub Categories

Dry Rotary Vane Pumps Oil-Sealed Rotary Vane Pumps
View 5 Products

Screw Vacuum Pumps

We have a quality range of oil-sealed screw pumps for sale that are energy efficient and have low life-cycle costs.

Sub Categories

Dry Screw Vacuum Pumps Oil Sealed Screw Vacuum Pumps
View 1 Products

Blowers

We have a great range of new and hire blowers from single stage ring blower through to large lobe blowers, and we also stock the service parts for common blowers across many brands.

Our roots blowers, side channel blowers are built to last, and are backed up by our promise of excellent customer service to keep your business performing well day in and day out.

Sub Categories

Side Channel Blowers
Show More



Ash Air: Your one stop shop partner

With hundreds of years of combined experience and a broad product range, Ash Air is a great partner for your vacuum pump operations. From rotary vane pumps to screw pumps and accessories, we have a large variety of products. We also have a dedicated applications team ready to calculate the ideal pump configuration. With a global support organization, we can support your manufacturing operations wherever they may be located in New Zealand.

 

Do you have an idea for our #expertcorner? Let us know!

Useful links:

Book Your Compressor Service



Who we are and how Ash Air can help your business!

Ash Air has been around in New Zealand since 1979, and we’ve grown into a nationwide company with international support and a reputation for quality and reliability.We look after all things compressed air for your business!

  • Reciprocating, Screw, air compressors
  • Vacuum pumps
  • Nitrogen
  • An extensive line of air treatment components

Ash Air's range of Chicago Pneumatic, Alup, Pneumatech, and Quincy compressors are used extensively around the world in industries ranging from oil and gas to food, automotive and farming, and we bring you these world class compressors here in the land of the long white cloud.Our technicians are compressed air equipment experts and are dedicated to addressing customer needs. Supported by a 13 locations nationwide, Ash Air offers one of the widest selections of compressed air equipment and parts available today in New Zealand.

Reliability and Efficiency

With Ash Air compressors, you can count on reliability and high performance for even the most demanding applications. We focus our efforts on the following:

  • Increasing uptime
  • Reducing unexpected repairs
  • Reducing energy consumption
  • Improving the cleanliness of compressed air


Talk to the team today:  CONTACT US CONTACT US

Read more from our #expertcorner


Lighting tower reminds night, but also refers to diesel engine. In turn, night reminds us of silence, which is not exactly what we associate with an engine... With urban centers becoming increasingly dense and legislation increasingly strict about noise pollution in construction sites, keeping decibels to acceptable levels has been the great challenge of the main construction equipment manufacturers. …


In today’s world of increasing environmental awareness and the drive for sustainable practices, industries are actively seeking innovative solutions to reduce energy consumption and minimize their carbon footprint. If your business uses air compressors, focusing on energy recovery in air compressors is one area to pay attention too.  …


Did you know that 70% of the total cost of compressor installation consists of energy costs?

There are many reasons why saving energy is important for your business as it helps you in many ways to make your business more efficient as well as providing you with many different forms of value. Ash Air's range of Alup products can help you become more energy efficient to help reduce energy bills, reduce your costs and comply with all environmental legislation. …


Exactly what is compressed air? Where does it come from? What is it for? When we compress—or squeeze—air into a small space, we call it compressed air. When humans discovered the ability to compress air, civilisation made a huge leap forward. The reason? Compressed air opened the door to all kinds of new production methods.  …


Compressed air system leaks are indeed a big source of energy waste. Leakage in piping systems have been shown to exhibit leaks of up to 25 percent of the total energy costs. Addressing leaks is one of the first maintenance steps a facility can take to reduce energy costs. …


Think about efficiency for a minute. Every year with constant innovation, things are becoming even more efficient. Everything from electronics to industrial machinery are being developed to get more done faster while using less power. …


The air surrounding us is a mixture of fry air and water vapor. The amount of water in the air depends on the temperature and volume of the gas. The higher the air temperature, the higher the air's ability to absorb more moisture. Find out about compressed air humidity here. …


Investing in an on-site industrial gas generator is a great way to reduce your environmental footprint and your operating costs. Once you have taken this important step, there are some other things you can do to maximize your gas generation energy savings. Here are seven of them. …


For many businesses, preserving energy and becoming more sustainable have become top priorities. That not only saves them money but also makes them more competitive in the future, when demand for “green” products and services will only increase. Not just because governments mandate greater sustainability but also because customers expect it. …


While you relax and read this, do you see an electronic appliance around you? Wondering how could you relate to the current read? We got you! Compressed air is all around, in the electronic appliances you use right now. …


There are many contaminants that can threaten your compressed air system, but moisture is among the most prevalent. You may be thinking, but it’s just water, but water can have a devastating impact on your compressed air system, your production equipment, and your end product. The best way to prevent moisture from contaminating your compressed air is with a dryer. …


Compressed air can be one of the most expensive forms of energy for manufacturing plants, often using more energy than other equipment. One horsepower of compressed air requires eight horsepower of electricity. With many air compressors running at efficiencies as low as 10%, there’s often plenty of room for improvement. Fortunately, 50% of compressed air systems at small- to medium-sized industrial facilities have opportunities for low-cost energy conservation. …


As easy as it would make all of our lives, vacuum pumps are far from being “one size fits all”. Not only do you have the size to consider when choosing a vacuum pump, but more importantly type. I will briefly touch on some of the advantages and disadvantages associated with each vacuum technology we deal with. This should give you a better understanding of where to begin your search... …


AIRnet offers moisture-eliminating drop fittings called Quick Drops! Quick Drops make “drop-tees” obsolete, removing the need for extra parts and pipe, while saving time and money. …


Proper compressor installation and commissioning helps ensure trouble-free startup and long-term reliability. Thorough inspection and critical review during each phase of the installation process eliminates “built-in” deficiencies or problems which c... …


Price is an important consideration when choosing a tool for metalworking applications, but it alone should not be the deciding factor. Other things also contribute to the total cost of ownership, performance, and, ultimately, the overall productivit... …


Are you faced with the decision of whether to switch from purchasing bottled nitrogen or oxygen to on site gas generation? In that case, the decision is easy. You should! Lower costs, the right purity, less transportation emissions, improved safety, no logistics headaches. In all of these areas, on site gas generation is the superior solution. And making the switch is easy. All you need is a gas generator and a supply of compressed air. …


Did you know that one of the largest costs for industrial manufacturers is compressed air? That’s right – anywhere from 12% to 40% of a facility’s total energy costs come from its compressed air installation. This means that finding innovative ways (no matter how small) to increase compressed air efficiency can amount to big savings over the long run! Items like leak elimination, air audits, reduced pressure bands, and reducing unloaded running hours are some of the most popular ways to decrease energy usage – but there are many other actions that you can take. Read on to discover additional ways to reduce your costs and make sure your compressor system is running as efficiently as possible! …


A properly sized and designed piping system is a necessary component of any distribution compressed air system. Without this key component in place, the delivery of air from the compressor to the specific points of use will be inefficient and costly, both in the short term as well as in the long term. Let’s look more closely at how to size your compressed air piping system to ensure minimal pressure loss while maintaining maximum efficiency. …


Potential for growth of micro-organisms in a compressed air system is tied to the moisture level (dew point) of the compressed air. In simple terms, if there is moisture in your compressed air, microorganisms such as mold and bacteria have the environment they need to grow and thrive. While it’s true that as air is compressed, much of the moisture present in the intake air will condense, enough moisture remains to allow micro-organisms to proliferate. …


Your compressor installation is a workhorse that requires regular service and maintenance to help it achieve maximum efficiency and longevity. This is where compressor monitoring and data gathering technologies come in, as these provide meaningful information on your system that can be visualized, tracked over extended time periods, and used to make insightful decisions regarding compressor performance.  …


A variable speed compressor is not for every application. VSD rotary screw compressors need to be ran in a location that is in need of 24/7 compressed air and has a changing demand on the amount of air needed. If your compressed air needs are constan... …


Compressed air purification equipment must have a very low pressure drop, long service life and be strong enough to withstand the most strenuous operating conditions. Protection from oil slugs or compressor air/oil separator failure is essential. …


Intelligent Connectivity System (ICONS) is the eyes into your compressed air system. Ditch the logbooks, the regular visits to the compressor room and dealing with surprises with your compressor. • Most maintenance organizations operate between 10% to 40% efficiency • Most spend more than 50% of time on emergency work • Reactive maintenance costs 3-5 times more than preventive maintenance. …


Compressed air is used in many different industries. From refrigerator manufacturers to toy makers, companies around the world depend on compressed air to produce products. It's so important that many consider it a utility as significant as electricity, water or natural gas. …


Compressed air is always contaminated. Contaminants include, • Liquid oil - oil aerosols - oil vapor, Dirt - microorganisms - pipescale, Trace gases: carbon monoxide, sulfur dioxide, nitrous oxide. Learn more about why you need to filter compressed air...  …


As part of a concerted effort worldwide to reduce energy consumption, CO2 emissions and the impact of industrial operations on the environment, regulatory authorities in many countries have introduced legislation to encourage the manufacture and use ... …


Air is always contaminated with solid particles such as dust, sand, soot, salt crystals and water as it leaves the compressor. An effective compressed air treatment system lowers the dew point of the air and takes out the elements that may harm equipment downstream of the compressor and dryer …


Dewpoint spikes immediately after desiccant switchover (line C) indicate that the desiccant was not sufficiently cooled before being brought on-line. Hot desiccant will not adsorb moisture well until it cools down, after which the dewpoint should dro... …


Don’t be alarmed if you find oil in your air compressor tank. Actually, all rotary screw compressors pass trace amounts of oil in the compressed air. The question is how much is the normal amount of oil in my compressor tank? …


As you know, compressed air filters protect your machine from dirt, dust, oil and water. These contaminants are extremely common in the areas you would find a compressed air system and will wear down your machine if not properly filtered out. …

Show More

Quick Links
Get in touch

0800 808 486

  help@ashair.co.nz

  Nationwide coverage, all regions



Keep up to date with news, promotions and more

Full URL


© 2026 Ash Air • Website design by Fuel