What is plasma?
What is plasma?
What is the plasma?
Plasma technology is based on a simple physical principle. Matter changes its state when energy is supplied to it: solids becomes liquid, and liquids becomes gaseous. If even more energy is supplied to a gas, it is ionized and goes into the energy-rich plasma state, the fourth state of matter.
Plasma was first discovered by Irving Langmuir in 1928. It is not rare; actually, quite the opposite is true. More than 99% of the visible matter in the universe is in the plasma state. It can be seen in its natural form on earth as lightning or as polar light in the Arctic and Antarctic, for example. During a solar eclipse, plasma can be observed as a bright circle of light (corona) around the sun.
With increasing
energy input, the state of matter changes from solid to liquid to gaseous. If
additional energy is then fed into a gas by means of electrical discharge, the
gas will turn into plasma.The term plasma
designates matter with a high, unstable energy level. When plasma comes into
contact with solid materials like plastics and metals, its energy acts on the
surfaces and changes important properties, such as the surface energy.In the manufacturing industry, this principle
is used for selective modification of
material characteristics. Treatment with Openair® plasma energy causes a
targeted and exactly adjustable increase in the adhesiveness and wettability of surfaces.
This makes it possible to use completely new (even non-polar) materials and
environmentally-friendly, solvent-free (VOC-free) paints andadhesives industrially.
Today, many chemical surface treatment processes can be replaced with Openair®
plasma treatment.
Plasma surface treatment
Atmospheric pressure plasma pretreatment is one of the most efficient surface treatment technologies for cleaning, activating, or coating materials like plastic, metal (such as aluminum), or glass.
Plasma cleaning
Openair® plasma surface pretreatment and plasma cleaning provide the optimal prerequisites for subsequent coating of plastic, metal, aluminum or glass.
Dry plasma cleaning with atmospheric plasma makes it possible to immediately continue processing the materials. The application allows a clean and cost-effective overall surface pretreatment process. Because of the high energy level of the plasma, it can selectively break open the structure of chemical or organic substances on the surface of the material. Using ultrafine cleaning, undesirable substances can be completely removed from even sensitive surfaces. This results in the optimal prerequisites for later coating.
Surface cleaning with plasma
Cleaning deep into the pores of a surface with Openair® plasma. No mechanical damage to the surface, no wet chemistry, environmentally-friendly process.
Safe, ultrafine cleaning of mold release agents, additives, softeners (plasticizers), and hydrocarbons
Micro-fine plasma cleaning removes even the smallest dust particles from plastics, which at first adhere firmly to the surface because of the additives. The plasma causes the particles to detach completely from the substrate. The reject rates valuable paintwork or coatings, such as in the automobile or mobile communication industries, are greatly reduced. By using the chemical-physical reaction in the nano range, high-quality, precisely defined surfaces are achieved.
Advantages of plasma cleaning with Openair® plasma:
Openair® plasma systems
Pretreatment with Openair® plasma is suitable for all applications where special surface qualities are critical for subsequent processing. Openair® atmospheric pressure plasma technology makes possible efficient, economical inline processes and customized design of overall production.
Effective plasma film pretreatment without changing mechanical properties
Openair® plasma technology is equally suitable for partial and large-area plasma pretreatment of aluminum foil and plastic films. Thanks to the targeted control of treatment parameters such as temperature, nozzle offset, nozzle width and speed, film materials are cleaned, activated or coated efficiently without the use of additives.
In contrast to other methods (such as the corona procedure), the mechanical property of the material is maintained with plasma treatment; the surface is not damaged.
Plasma systems for the coil coating process – efficient ultrafine cleaning without chemicals or wastewater
An example of the high efficiency of Openair® plasma activation is the manufacture of pre-coated sheet metal (coil coating). This material is needed in the industrial production of household appliances and in the automotive industry.
In the coil coating process, strip metal is provided with a surface coating or varnishing to achieve optimum protection against corrosion and to simplify subsequent production processes. For long-term layer and varnish adhesion, the aluminum strip must first be completely cleaned of rolling oils in an ultrafine cleaning process.
Openair® plasma removes all residues reliably and efficiently while activating the material surface for optimal adhesion and a flawless finish. The Openair® plasma treatment can be integrated inline directly upstream of the coating station in the rolling mill.
Moreover, the dry plasma process is particularly environmentally friendly. The large amounts of chemicals that would otherwise be required for ultrafine cleaning are omitted entirely.
Also, the time- and energy-intensive drying processes necessary in wet chemical treatment are no longer required.
Advantages of Openair® plasma systems for coil coating:
Openair® plasma activation: high-efficiency surface activation, targeted, selective, environmentally friendly and with long-term stability
Wherever components will be coated, painted or glued in subsequent steps, selective surface activation of the starting materials is indispensable. Many materials require surface modifications, such as for printing with water-based inks, for bonding with long-term stability with VOC-free adhesives, or producing material composites.
Openair® plasma activation ensures especially efficient surface modification of plastic, metal, textiles, glass, recycled and composite materials. Surface energy is targeted by the plasma activation and achieved selectively, exactly where it is needed. The result is clearlybetter wetting capability of the surfaces.
Activate surfaces with plasma
Determination of surface tension with test inks shows that, with low surface tension, wetting is impossible. After activation with Openair® plasma, the surface is fully wettable.
Determination of the surface tension with test inks shows:
With low surface tension, wetting is impossible. After surface modification using Openair® plasma activation, the material surface has significantly better wetting capability.
What does surface activation with atmospheric pressure plasma achieve?
Surface activation with Openair® plasma is especially effective when nonpolar materials have to be treated, such as plastics that consist of long-chain polymers. Such nonpolar surfaces are difficult to bond and coat. Because plasma energy selectively modifies the surface tension, these materials can be processed easily and new material combinations can be produced, as in the adhesive bonding process.
Advantages of Openair® plasma activation:
What is plasma?
What is the plasma?
Plasma technology is based on a simple physical principle. Matter changes its state when energy is supplied to it: solids becomes liquid, and liquids becomes gaseous. If even more energy is supplied to a gas, it is ionized and goes into the energy-rich plasma state, the fourth state of matter.
Plasma was first discovered by Irving Langmuir in 1928. It is not rare; actually, quite the opposite is true. More than 99% of the visible matter in the universe is in the plasma state. It can be seen in its natural form on earth as lightning or as polar light in the Arctic and Antarctic, for example. During a solar eclipse, plasma can be observed as a bright circle of light (corona) around the sun.
With increasing
energy input, the state of matter changes from solid to liquid to gaseous. If
additional energy is then fed into a gas by means of electrical discharge, the
gas will turn into plasma.The term plasma
designates matter with a high, unstable energy level. When plasma comes into
contact with solid materials like plastics and metals, its energy acts on the
surfaces and changes important properties, such as the surface energy.In the manufacturing industry, this principle
is used for selective modification of
material characteristics. Treatment with Openair® plasma energy causes a
targeted and exactly adjustable increase in the adhesiveness and wettability of surfaces.
This makes it possible to use completely new (even non-polar) materials and
environmentally-friendly, solvent-free (VOC-free) paints andadhesives industrially.
Today, many chemical surface treatment processes can be replaced with Openair®
plasma treatment.
The measuring variables that particularly characterize plasma are electron temperature and emission of various species excited in the ultraviolet and visible range.
The only way to pretreat even very thermally sensitive plastics under atmospheric pressure without damage is by using high electron temperature and low ion temperature.
The luminous phenomena (optical emissions) of a relaxing* plasma can be detected with the use of optical emission spectroscopy (OES). To do this, characteristic emission bands of the species excited in the plasma in the visible, and especially in the ultraviolet, range of the spectrum are transmitted by an optical fiber to the evaluation electronics and then further processed with special software. The process monitoring components of the Plasmatreat systems operate according to this principle of optical monitoring. This allows for uniform quality over the entire plasma process.
* Relaxing: The transition of plasma into its basic state. In this process, the excitation energy that was previously supplied is released into the environment in the form of light.
Optical emission spectrum of the plasma in the visible and ultraviolet range
Atmospheric pressure plasma pretreatment is one of the most efficient surface treatment technologies for cleaning, activating, or coating materials like plastic, metal (such as aluminum), or glass.
Plasma cleaning
Openair® plasma surface pretreatment and plasma cleaning provide the optimal prerequisites for subsequent coating of plastic, metal, aluminum or glass.
Dry plasma cleaning with atmospheric plasma makes it possible to immediately continue processing the materials. The application allows a clean and cost-effective overall surface pretreatment process. Because of the high energy level of the plasma, it can selectively break open the structure of chemical or organic substances on the surface of the material. Using ultrafine cleaning, undesirable substances can be completely removed from even sensitive surfaces. This results in the optimal prerequisites for later coating.
Cleaning deep into the pores of a surface with Openair® plasma. No mechanical damage to the surface, no wet chemistry, environmentally-friendly process.
Safe, ultrafine cleaning of mold release agents, additives, softeners (plasticizers), and hydrocarbons
Micro-fine plasma cleaning removes even the smallest dust particles from plastics, which at first adhere firmly to the surface because of the additives. The plasma causes the particles to detach completely from the substrate. The reject rates valuable paintwork or coatings, such as in the automobile or mobile communication industries, are greatly reduced. By using the chemical-physical reaction in the nano range, high-quality, precisely defined surfaces are achieved.
Advantages of plasma cleaning with Openair® plasma:
- 100% cleaning
- No dilution effect (compare to aqueous cleaning)
- No need for additional consumables (compare to CO2-beam cleaning)
- Cleaning of the complete material structure surface topography, instead of just peaks (compare to sand blasting)
- No additional space required – inline integration in the manufacturing line
- Economical and ecologically efficient surface pretreatment
Openair® plasma systems
Pretreatment with Openair® plasma is suitable for all applications where special surface qualities are critical for subsequent processing. Openair® atmospheric pressure plasma technology makes possible efficient, economical inline processes and customized design of overall production.
Effective plasma film pretreatment without changing mechanical properties
Openair® plasma technology is equally suitable for partial and large-area plasma pretreatment of aluminum foil and plastic films. Thanks to the targeted control of treatment parameters such as temperature, nozzle offset, nozzle width and speed, film materials are cleaned, activated or coated efficiently without the use of additives.
In contrast to other methods (such as the corona procedure), the mechanical property of the material is maintained with plasma treatment; the surface is not damaged.
An example of the high efficiency of Openair® plasma activation is the manufacture of pre-coated sheet metal (coil coating). This material is needed in the industrial production of household appliances and in the automotive industry.
In the coil coating process, strip metal is provided with a surface coating or varnishing to achieve optimum protection against corrosion and to simplify subsequent production processes. For long-term layer and varnish adhesion, the aluminum strip must first be completely cleaned of rolling oils in an ultrafine cleaning process.
Openair® plasma removes all residues reliably and efficiently while activating the material surface for optimal adhesion and a flawless finish. The Openair® plasma treatment can be integrated inline directly upstream of the coating station in the rolling mill.
Moreover, the dry plasma process is particularly environmentally friendly. The large amounts of chemicals that would otherwise be required for ultrafine cleaning are omitted entirely.
Also, the time- and energy-intensive drying processes necessary in wet chemical treatment are no longer required.
Advantages of Openair® plasma systems for coil coating:
- High efficiency in the cleaning of aluminum coils
- Surface activation prior to corrosion protection coating and varnishing
- Saving water, chemicals and wastewater
- Possibility of one-sided or two-sided pretreatment
- Variable nozzle configuration depending on the degree of contamination
- Cost-efficient inline integration
Openair® plasma activation: high-efficiency surface activation, targeted, selective, environmentally friendly and with long-term stability
Wherever components will be coated, painted or glued in subsequent steps, selective surface activation of the starting materials is indispensable. Many materials require surface modifications, such as for printing with water-based inks, for bonding with long-term stability with VOC-free adhesives, or producing material composites.
Openair® plasma activation ensures especially efficient surface modification of plastic, metal, textiles, glass, recycled and composite materials. Surface energy is targeted by the plasma activation and achieved selectively, exactly where it is needed. The result is clearlybetter wetting capability of the surfaces.
Activate surfaces with plasma
Determination of surface tension with test inks shows that, with low surface tension, wetting is impossible. After activation with Openair® plasma, the surface is fully wettable.
Determination of the surface tension with test inks shows:
With low surface tension, wetting is impossible. After surface modification using Openair® plasma activation, the material surface has significantly better wetting capability.
What does surface activation with atmospheric pressure plasma achieve?
Surface activation with Openair® plasma is especially effective when nonpolar materials have to be treated, such as plastics that consist of long-chain polymers. Such nonpolar surfaces are difficult to bond and coat. Because plasma energy selectively modifies the surface tension, these materials can be processed easily and new material combinations can be produced, as in the adhesive bonding process.
Advantages of Openair® plasma activation:
- High process speed and safety
- Large process window due to homogeneous plasma jet
- Cost-effective, environmentally-friendly surface modification
- Pretreatment without corona effect, no material contact with high voltage
- Robot-controlled inline integration in the manufacturing line
PlasmaPlus®: selective plasma coating in all different types of application
All different types of materials like plastic, glass, metal, aluminum, PET film, textiles, etc. can be coated with PlasmaPlus®. Plasma polymerization with the PlasmaPlus® process is already being used successfully for surface coating in a large number of different industrial applications.
Principle of surface coating with Openair® plasma
Surface treatment and plasma coating with the laboratory system Plasmatreater AS400.
Examples of successful PlasmaPlus® applications:
- Improvement of barrier characteristics of plastics for packaging using plasma polymer nanocoating
- Paintability with long-term stability and resulting high flexibility in manufacturing thanks to nanocoating with PlasmaPlus®
- PT Release coatings, for injection molding tools, allow a high number of process cycles without the components having to be stressed with release agents that contain silicone.
- PT Bond coatings assure long-term adhesion in the adhesive joint.
- Because of their good barrier effect, corrosion protection coatings with PlasmaPlus® offer extremely high corrosion protection with long term resistance to corrosive electrolytes – especially for aluminum alloys.
The extensive potential of atmospheric pressure plasma technology
Openair® Plasma technology makes it possible for industry to respond to continuously increasing demands on raw materials and materials efficiency, energy savings, and to avoid use of pollutants and chemicals. According to demea (source: Deutsche Materialeffizenz Agentur [German Materials Efficiency Agency]), material costs represent the greatest share of costs by far, at approx. 45.4%, even ahead of personnel costs.
New functionalities with nanocoating
Depending on the application, PlasmaPlus® nanocoating deposits a specific functional coating down into the microstructures of the material surface. This results in high efficiency layers that give the materials completely new properties. The creation of selectively functionalized surfaces means completely new performance for the products of tomorrow. These applications extend from electrically-conductive coatings,
New environmentally-friendly processes and end products
Using dry Openair® Plasma technology, many wet chemistry processes can be eliminated. Ultrafine cleaning with plasma already replaces entire washing processes, which makes drying that uses a lot of energy unnecessary. High efficiency plasma activation makes the use of environmentally hazardous and health damaging bonding agents and primers unnecessary. The significant improvement in adhesion enables
Innovation with plasma technology: new applications for all areas of industry
The potential range of applications using Openair® Plasma technology is inexhaustible. In many areas of industry, treatment with atmospheric pressure plasma is already firmly established. In other areas – say, in life sciences and new forms of energy, but also in aviation and aerospace – intensive research is being conducted on new application solutions. Today, there are already groundbreaking successes in protective coating of solar cells, the development of fuel cells, and innovative lightweight construction with carbon fiber materials. Initial tests in the treatment of human skin further demonstrate the extensive potential of plasma technology in future breakthroughs.
Innovative solutions for medical technology and the life sciences with Openair® and Aurora Plasma
Sterilizing microcleaning with Openair® Plasma, facilitating new material combinations for implants, functional coating of instruments, clothing and equipment, pretreatment of microfluidics or balloon catheters with Aurora Plasma – all of these open up new options in medical technology and the life sciences.
Clinically safe, sterile, reproducible – wide spectrum of applications for Plasma in medical technology
Manufacturing processes in medical technology demand the highest possible standards that far exceed the demands in most other industries. Surfaces must be not just clean but absolutely flawless or sterile. Beyond that, pre-treatment processes in medical technology must be very reliable and precisely reproducible.
Plasma pre-treatment to improve adhesion of printing inks has been widely used in medical technology for some time. With Openair® Plasma, Plasmatreat has taken it a big step further.
The Openair® plasma process allows for effective adhesion of hard/soft material combinations, applying finishes to membranes (filter media), and plasma functionalization of plastic surfaces. And all that is guaranteed to be aseptic thanks to plasma sterilization.
Advantages:
- Simple processes with dry, physical plasma treatment
- Reliable reproducibility of the pre-treatment parameters
- 100% process monitoring using PES (plasma emissions spectroscopy)
Plasmatreat has more than 20 years’ experience of using low-pressure plasma and atmospheric plasma to pretreat polymer surfaces, including treatment steps such as cleaning, adhesion promotion and deposition of functional coatings or layers. In our laboratories in Silicon Valley, we work with partners in industry to develop groundbreaking solutions.
Plasma chemistry with Openair® Plasma – ideal initiator for new reactions
Chemical compounds are still manufactured today almost exclusively in batch processes according to the appropriate formulations. But when highly customized compositions must be created, such as in pharmacology, this traditional approach is very elaborate and difficult to automate.
A continuous reaction technology is required that is characterized by very precisely measured flow and mixing processes. If, for example, the application of energy is needed for targeted initiation of reactions, only conventional heating or an open flame are available. Since any flame causes spontaneous oxidation, direct contact with the chemicals is not possible.
This is not the case with plasma initiation. The function principle of Openair® plasma is such that it will ionize almost any specific process gas at a high level and is therefore ideally suited as an initiator of reactions in chemistry and biochemistry.
More in-depth research into reaction chemistry is currently underway at Hannover University, Germany, where the synthesis of organic compounds using plasma technology is being investigated.
Plasma medicine – can the direct application of Openair® plasma heal wounds?
The term plasma medicine refers to the direct treatment of human cells with plasma. For almost 15 years, the research group under Prof. Gary Friedman at Drexel University (Philadelphia, PA) has pioneered work on the use of atmospheric plasma systems to treat the skin. He was the first to examine the impact of the most varied direct and indirect applications of plasma to human skin. In the process, he discovered a synergetic relationship between bacteria reduction through the application of plasma (plasma disinfection) and wound healing.
Today this work is being pursued intensively at many research institutions internationally. The "Campus PlasmaMed" research program (Leibniz-Institut for Plasma research and technology e.V. ), Düsseldorf University, Bochum University, and the Max Planck Institute in Munich, all in Germany, deserve special mention in this connection.
Plasmatreat has a wealth of experience in the area of disinfection of technical surfaces in medicine, known as plasma sterilization. Openair® plasma jets are extremely effective in treating surfaces in continuous operation. Because of the potential-free nature of plasma energy, it is in principle suitable for the treatment of human skin as well.
Extensive verifications and further development of jet technology are required to get to the point of using it in human medical applications. The development of systems for controlled medical plasma treatments presents tremendous opportunities for the future.
Plasmatreat is engaged in intensive exchanges with universities and institutes with a view to finding more partners to collaborate with in its exploration of the exciting field of plasma medicine.
Plasma disinfection – new methods to disinfect surfaces using atmospheric plasma
Naturally occurring microorganisms such as fungi and bacteria are critically important for the natural recycling of matter and the survival of ecosystems. Microorganisms are even used in the pharmaceutical and food industries to produce specific active ingredients.
On the other hand, bacteria and fungi can cause illness and a toxic reaction can ensue. Even the smallest contamination in industrial production can cause major problems, up to and including product spoilage or even the destruction of entire systems.
Microbial growth without plasma treatment after exposure
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Germs are killed by plasma treatment
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Plasmatreat works together with leading institutions to implement Openair® plasma technology as a highly effective method of surface disinfection (plasma disinfection). The Openair® plasma process is especially suited for use in safely disinfecting surfaces when combined with pulsed plasma triggering and special process gases. Because plasma is potential free, the inline process is simple to control and its process parameters are 100% reproducible.
Biocompatible implant coating: biofunctionalization with PlasmaPlus® in medical technology
Plasmatreat is a pioneer in the use of atmospheric plasma coating for implants, both as wear protection and as a biocompatible coating that promotes ease of integration with tissue.
Use of Openair® plasma and PlasmaPlus® to manufacture medical plasma polymer coatings, as wear protection or implant coatings, is an extremely promising area of application. The first plasma-coated implants are already in trials.
