Frequently Asked Questions

CO2 snow blasting is a cleaning and pretreatment process for solid surfaces. The supply media are liquid CO2 and compressed air. The blasting agent, the so-called CO2 snow particles formed from dry ice, are produced inside the snow blasting machine. Cleaning and surface preparation is dry, residue-free and environmentally friendly. CO2 snow blasting is often also called dry ice blasting or CO2 particle blasting.

Dry ice is solid CO2, i.e. carbon dioxide or carbonic acid in a solid state of aggregation. Under normal conditions, dry ice always has a temperature of -78.5 °C. The term "dry" refers to the ability to evaporate directly, i.e. to sublimate without becoming liquid or melting. The cooling capacity of dry ice when heated from -78.5 °C to 0 °C is approx. 640 kJ/kg. This corresponds to about 3 times the cooling capacity of conventional ice. The most important advantage, however, is that nothing remains after evaporation, which is not the case with water ice. When heat is added, for example by a rapid impact on a surface, the dry ice immediately changes to a gaseous state. Consequently, no liquid remains that could lead to renewed contamination of the surface. Dry ice is odourless and tasteless, bacteriostatic, non-toxic, non-flammable and inert.

Carbon dioxide (CO2) is a colourless, non-flammable and non-toxic gas. In its free state it is a natural component of air with a concentration of approx. 0.04 vol.% (fresh air 0.03 vol.%, urban air 0.07 vol.%). The maximum workplace concentration (daily average) is 5,000 ml/m3 (ppm) or 9,100 mg/m3. This corresponds to a concentration of 0.5 vol.%. The MAK short-term value for exposure peaks is 1.0 vol.%. Gaseous carbon dioxide is harmless up to 2.5 vol.% in air. Our exhaled breathing air has a concentration of approx. 4 vol.% CO2. High CO2 concentrations cause circulatory weakness, headaches, nausea and vomiting. Even concentrations of 8 to 10 vol.% can have an effect on the heart rhythm and respiratory rate, and can be fatal after 30 to 60 minutes. In its gaseous state, CO2 is heavier than air. For some years it has been clear that carbon dioxide is also a greenhouse gas, as the CO2 concentration rises at the same time as global warming. CO2 emissions are mainly caused by the combustion of fossil fuels. It is also produced in processes for the production of cement, lime or glass. From an environmental point of view, however, CO2 snow blasting is considered to be extremely environmentally friendly, as recycled - already produced - CO2 is reused. For CO2 cleaning, no additional CO2 is generated that influences global climate development. In liquid form it is offered in single gas bottles, bundles or for filling into tanks. Dry ice can be obtained in solid form in blocks, pellets or nuggets. The pre-produced dry ice can only be stored for a limited period because it permanently sublimates and absorbs moisture from the environment.

Compressed air and liquid CO2 are required for CO2 snow blasting. A power connection is not necessary, as our CO2 snow blasting machines have a maintenance-free pneumatic control system. Liquid CO2 can be supplied via a dip tube single cylinder (capacity up to 37.5 kg) or a dip tube bundle (capacity 450 kg) or, for stationary use, also via a tank supply.

Cleaning with CO2 snow blasting is based on several cleaning mechanisms, which are of varying importance depending on the application. The cleaning effect is based on thermal, mechanical and physical processes in the micro region of the surface. The thermal effects, due to different coefficients of thermal expansion between the impurity and the surface to be cleaned, lead to the removal of the impurity. The impurity is detached and transported away from the surface by the combined effects of sliding jet, oblique jet and impact jet processes acting on the impurity and the sublimation expansion of the CO2. In addition, oil and grease impurities are removed from the surface by the dissolving action of the carbon dioxide. The resultant cleaning is environmentally friendly and residue-free. Even sensitive and structured surfaces can be processed gently. CO2 snow blasting can achieve the highest cleaning qualities, so that completely particle- and germ-free surfaces are possible.

Dry ice pellets have been used for cleaning for more than 30 years. Their acceptance in production and maintenance is quite unsatisfactory, due to the complex logistics involved and the high price of the dry ice pellets. In addition to the high investment and operating costs and the susceptibility of the blasting equipment to malfunctions, many sensitive components such as conveyor belts, switch cabinets, plastic parts and polished tools have also been damaged. Although dry ice blasting has many advantages over conventional cleaning methods, the disadvantages in terms of occupational safety and handling are of great importance for many companies. CO2 snow blasting is significantly more flexible and cost-effective. CO2 pellets and electric power supply are not required to operate the CO2 snow blasting machines. The power supply is provided by compressed air and liquid CO2 from single cylinders or bundles, each with a dip tube. A CO2 tank can also be installed for stationary applications. CO2 snow blasting is used in particular for sensitive surfaces and automated applications.

In CO2 snow blasting, the smallest compressed dry ice particles are generated in the machine, accelerated with the aid of high-performance nozzles and blasted onto the surface to be cleaned. The flow velocity of the CO2 particles in a free jet depends on the nozzle and setting parameters used. As a rule, the flow velocities range from 50 to 300 m/s. With special nozzles, we can also achieve flow velocities that are higher than the sound velocity of air at 330 m/s.

The dry ice particles in the CO2 snow jet have a diameter of 1 to 200 µm. The mean diameter depends on the nozzle and setting parameters used. Due to the small size of the CO2 snow particles, it is possible to clean finely structured surfaces and even small pores.

The CO2 snow jet is not electrically conductive. The prerequisite for this is that dry compressed air is used. If necessary, the compressed air must be prepared according to the specifications. When dry ice blasting with CO2 pellets, on the other hand, moisture from the ambient air is usually condensed in the pre-produced CO2 pellets due to the low temperature, so that the dry ice blasting itself can be electrically conductive.

The CO2 snow blasting unit is connected to compressed air and liquid CO2. No electrical power supply is required. Liquid CO2 can be supplied via a single cylinder (capacity up to 37.5 kg) or a bundle (capacity 450 kg), each with a dip tube, or, for stationary use, also via a tank supply. In the CO2 snow blasting machine, very small, compressed dry ice particles are produced, added to the compressed air as the blasting agent, accelerated with the aid of high-performance nozzles and blasted onto the surface to be cleaned. Flat nozzles, with jet widths of up to 125 mm, can be used to clean large surface areas. Even sensitive surfaces can be cleaned gently. Special round nozzles are used for stubborn impurities.

The control unit for CO2 snow blasting weighs 15 to 35 kg depending on the type (SJ-10/SJ-25). The SJ-25 trolley control unit has two large pneumatic tyres and a push handle. A special trolley is also available for the SJ-10 control unit. Both units can be easily moved by one person. The ergonomically designed blasting pistols are weight-optimized and fitted with hand grips. The nozzles are made of a special plastic and usually weigh only a few grams. Due to its low total weight and the ergonomic design, the handling, operation and transport of the CO2 snow blasting machine is very easy.

A CO2 snow blasting machine that is powered solely by compressed air is especially recommended for frequently changing cleaning locations with short cleaning times. Our trolley-mounted machines are ideal for these applications. In addition to the CO2 snow blasting machine, a trolley comprises one or more individual CO2 bottles with a dip tube. A typical application example is the cleaning of tools or moulds in production machines. CO2 cleaning can be carried out without dismantling, directly on the hot tools or moulds. Many customers use CO2 snow blasting for injection moulding, rubber and foam tools.

All CryoSnow products are "Made in Germany" and are subject to strict quality controls. Our CO2 snow blasting machines have a CE marking in accordance with the valid EU directives. Customers receive the corresponding CE Declaration of Conformity with delivery or, in the case of automated devices, a Declaration of Incorporation in accordance with 2006/42/EG.

The fluidic flow of all nozzles is optimized. In addition, all nozzles are made of an impact resistant, thermally insulated special synthetic material. Wear and tear of nozzles does not occur. In addition to powerful round nozzles, we also offer flat nozzles in different jet widths. The jet width of the flat nozzles can be more than 100 mm. In addition, we have a range of special and angled nozzles that are used for cleaning hard-to-reach areas.

The liquid CO2 supply of the manual CO2 snow blasting machines is mostly supplied using CO2 cylinders (content up to 37.5 kg) or CO2 bundles (content 450 kg), each with a dip tube. In automated operation, the liquid CO2 is extracted from a high-pressure tank with a branch line or a low-pressure tank with a pump or compressor and an insulated ring or branch line. The compressed air supply is provided either via the house network or via a screw-type compressor. Personal protective equipment in the form of hearing and eye protection as well as long working clothes and leather gloves are mandatory if the CO2 snow blasting machine is to be operated manually. In addition, sufficient fresh air or, if necessary, exhaust air extraction must be provided. The installation of a measurement and warning system for gaseous CO2 is mandatory for automated systems.

Liquid CO2 is available almost everywhere in the world. It is available from gas suppliers in different containers with standardized hook-ups. Typical containers are single CO2 bottles with dip tube, CO2 bundles with dip tube and CO2 mini tanks. Stationary high-pressure and low-pressure tanks can also be leased from gas suppliers. A tanker truck then fills these with liquid CO2 on a regular basis.

Liquid CO2 (carbon dioxide) is not classified as a hazardous substance. Care must be taken to ensure that gas bottles are secured against falling over. Containers must be protected from direct sunlight and stored at less than 50 °C. During transport, the driver must know the possible dangers of the load and what to do in the event of an accident. The bottle valve must be closed and tight during transport. The valve protection device must be fastened correctly. In case of doubt, the gas supplier should be consulted.

CO2 dip tube bottles have a dip tube inside which extends from the bottle valve to just above the bottom of the bottle. As long as a CO2 dip tube bottle is kept upright, CO2 is inevitably extracted from it in liquid form. CO2 dip tube bottles must not be equipped with a pressure reducer because the liquid carbon dioxide would block the pressure reducer and render it ineffective. The CO2 supply hose of the CO2 snow blasting machine is connected directly to the standardized bottle connection. CO2 dip tube bottles must stand upright during extraction so that the opening of the riser-tube remains below the level of the CO2 liquid.

The compressed air should be free of particles, water and oil. The required dew point depends on the application, i.e. in particular on the cycle and auxiliary process time as well as the climatic conditions at the cleaning location. The CO2 snow blasting machine itself makes no special demands on the compressed air. However, any impurities in the compressed air may be deposited on the surface to be cleaned during cleaning process. For manual applications, the compressed air quality should therefore meet class 1.4.1 of ISO 8573-1:2010. For automated operations that run continuously 24/7, class 1.2.1 of ISO 8573-1:2010 is usually required.

Our hoses are very light and can be installed with small bending radii. They do not contain silicone. The compressed air and liquid CO2 supply hoses are available in various lengths without power losses. The compressed air hose is available in standard lengths of 4 m / 10 m / 15 m / 20 m. Usually several compressed air hoses are connected together with the practical safety coupling disc. The CO2 supply hoses are also available from stock in any length. For reliable cleaning, however, the CO2 supply hose should be kept as short as possible.

The hose package between the control unit and the CO2 snow blasting pistol can be of any length without loss of performance. The standard lengths of the hose package for the manual CO2 snow blasting machines are 4 m / 6 m / 8 m. Any desired length can be manufactured. A later extension of the hose package is also possible. There is no process-related wea

You are welcome to send us sample components. We will test your application in our technical department and send you a short report with the most important setting and process parameters, together with your sample components for quality control.

Technical demonstrations are possible both at our premises and at yours, after the technical requirements have been agreed. Please contact us and make an appointment.

Our standard product range is available from stock. The delivery time is usually less than 1 week. Customer-specific products, such as automated CO2 snow blasting systems, usually have a delivery time of 4 to 8 weeks.

Every user of a CO2 snow blasting machine must read the operating instructions and should be fully instructed. In most cases, short instructions are given upon delivery of the products or a separate appointment is agreed with CryoSnow. In addition, we also offer comprehensive training for your employees.

CO2 snow blasting is used for manual and automated cleaning and pre-treatment of solid surfaces. Additionally, there are applications for cutting, deburring and cooling.

CO2 snow blasting can be used on a wide variety of solid surfaces. The process is used for the following materials: plastics, metals, composites, glass, ceramics, semiconductors, textiles, wood, etc. Powerful round and flat nozzles at blasting pressures of 7 to 10 bar are used for cleaning hard materials and stubborn impurities. For medium-hard materials or light impurities on hard materials, round and flat nozzles are used at blasting pressures of 5 to 7 bar. Sensitive materials are cleaned at blasting pressures of 2 to 5 bar. Surfaces can be processed gently with flat nozzles with a blasting width of more than 100 mm. With these nozzles it is possible to clean light impurities from several square meters per minute.

CO2- snow blasting machines have a huge potential and maximum flexibility. In general, the machines can be used to remove the following surface impurities: particles, dust, grease, oil, finger prints, releasing agents, black wash, manufacturing residues, glue and adhesive deposits, polishing residues, anti-corrosive agents, cooling lubricants, asphalt, wax, varnishes and thin coats of paints, smoke residue, fluxing agent deposits, soot and limescale, as well as germs and fungi.

The dry and solvent-free process ensures that no residues are left on the surface. The surface is dry after cleaning. No post-cleaning treatment or drying is needed.

An automated use of CO2 snow blasters can easily be implemented. The equipment can be configured either to operate in synchronization or continuously. The use of flat nozzles makes surface processing very effective. When pre-treating plastic surfaces, a CO2 snow blasting nozzle can even clean several square metres per minute. Any number of nozzles can be integrated into an automated CO2 snow blasting system. Depending on the process control, the nozzles are controlled either together or separately.

The manual CO2 snow blasting machines are already fully operational in the standard scope of delivery. The investment costs amount to 8,000 to 10,000 euros. In most cases, however, our customers want additional accessories due to the planned application, so that the acquisition costs are usually between 9,000 and 13,000 euros. These are net list prices, ex works in 13599 Berlin.

Please contact a financial services provider or your bank with our product information and purchase offer. Such institutions will almost certainly be able to provide you with suitable proposals for different contract models, with regard to term, partial or full amortization, residual value and method of payment. A financial purchase, for example with a term of 12 months, is also possible. With this type of financing, the purchased object is added to your assets for tax purposes right from the start.

You are welcome to send us samples to test a new application. After this, we can also arrange an appointment for a demonstration at your company or at our premises. If you still need a trial period, please contact us. We will examine the possibility of a hire agreement and send you a hire offer.

Our smallest automated CO2 snow blasting machine is the SJ-10 auto, which can be delivered from stock. The control unit can control one or two JP-10 CO2 snow blasting pistols. Small round nozzles for selective cleaning as well as flat nozzles up to approx. 50 mm blasting width are available. With a nozzle system, the purchase costs start at approx. 12,000 euros. However, process monitoring is not yet included in this scope of delivery. Depending on the exact requirements, additional components and sensors can be selected. The liquid CO2 supply for the SJ-10 auto can usually be achieved with a CO2 bundle fitted with a dip tube. All automated CO2 snow blasting systems are designed to customer specifications. Automation for large-area applications or with several nozzles requires one or more control cabinets as well as CO2 snow blasting modules with the required nozzles. The acquisition costs depend on the process monitoring and are usually above 40,000 euros, without peripherals. Further investments for compressed air and liquid CO2 supply, soundproof cabin, robot, exhaust air system and gas warning system can also be supplied at customer request

The operating costs are the costs of compressed air and liquid CO2. The compressed air costs depend on your compressor or compressed air system. As a rule, these amount to 0.01 to 0.03 euro/m3 in German industry. The liquid CO2 costs depend on your supply contract with a gas supplier. You have to agree the conditions. For example, the liquid CO2 costs can be around 0.50 euro/kg for a liquid CO2 supply with bundles. Consequently, the operating costs are dependent on the exact consumption values of the media. Usually, there are no additional operating costs. In a typical application with the CO2 snow blasting machine SJ-10 with a compressed air volume flow of 1 m3/min at a blasting pressure of 6 bar and a liquid CO2 consumption of 0.2 to 0.3 kg/min, the operating costs amount to 5 to 10 euro/h. With the manual CO2 snow blasting machine SJ-25, the operating costs for compressed air and liquid CO2 are in the range of 20 to 40 euro/h, depending on the application, when used with a CO2 bottle or CO2 bundle, each fitted with a dip tube.

As a rule, the liquid CO2 costs for automation with supply via a stationary tank are 20 %, compared to manual application. Usually, operating costs of less than 5 euro/h per nozzle can be achieved.

The maintenance costs are negligibly low as the CO2 snow blasting machines do not have any maintenance parts. The working parts which need to be replaced are kept to a minimum. We have automated systems in operation that have already been running more than 10,000 operating hours without failure. There is no wear on nozzles and hoses. We do recommend, as far as possible, to have every CO2 snow blasting machine checked by us once a year. For cost accounting purposes, generally accepted annual maintenance costs of, for example, 1 % of the investment costs should be accounted for.