EP0700577A4 - Method and apparatus for glow discharge plasma treatment of polymer materials at atmospheric pressure - Google Patents
Method and apparatus for glow discharge plasma treatment of polymer materials at atmospheric pressureInfo
- Publication number
- EP0700577A4 EP0700577A4 EP94918192A EP94918192A EP0700577A4 EP 0700577 A4 EP0700577 A4 EP 0700577A4 EP 94918192 A EP94918192 A EP 94918192A EP 94918192 A EP94918192 A EP 94918192A EP 0700577 A4 EP0700577 A4 EP 0700577A4
- Authority
- EP
- European Patent Office
- Prior art keywords
- electrodes
- plasma
- glow discharge
- gas
- web
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Ceased
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J7/00—Details not provided for in the preceding groups and common to two or more basic types of discharge tubes or lamps
- H01J7/24—Cooling arrangements; Heating arrangements; Means for circulating gas or vapour within the discharge space
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
- H01J37/32—Gas-filled discharge tubes
- H01J37/32009—Arrangements for generation of plasma specially adapted for examination or treatment of objects, e.g. plasma sources
- H01J37/32082—Radio frequency generated discharge
- H01J37/32174—Circuits specially adapted for controlling the RF discharge
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C59/00—Surface shaping of articles, e.g. embossing; Apparatus therefor
- B29C59/14—Surface shaping of articles, e.g. embossing; Apparatus therefor by plasma treatment
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64C—AEROPLANES; HELICOPTERS
- B64C23/00—Influencing air flow over aircraft surfaces, not otherwise provided for
- B64C23/005—Influencing air flow over aircraft surfaces, not otherwise provided for by other means not covered by groups B64C23/02 - B64C23/08, e.g. by electric charges, magnetic panels, piezoelectric elements, static charges or ultrasounds
-
- D—TEXTILES; PAPER
- D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
- D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
- D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
- D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
- D04H1/54—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties by welding together the fibres, e.g. by partially melting or dissolving
- D04H1/56—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties by welding together the fibres, e.g. by partially melting or dissolving in association with fibre formation, e.g. immediately following extrusion of staple fibres
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
- H01J37/32—Gas-filled discharge tubes
- H01J37/32009—Arrangements for generation of plasma specially adapted for examination or treatment of objects, e.g. plasma sources
- H01J37/32082—Radio frequency generated discharge
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
- H01J37/32—Gas-filled discharge tubes
- H01J37/32431—Constructional details of the reactor
- H01J37/32733—Means for moving the material to be treated
- H01J37/32752—Means for moving the material to be treated for moving the material across the discharge
- H01J37/32761—Continuous moving
- H01J37/3277—Continuous moving of continuous material
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B7/00—Heating by electric discharge
- H05B7/16—Heating by glow discharge
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C59/00—Surface shaping of articles, e.g. embossing; Apparatus therefor
- B29C59/14—Surface shaping of articles, e.g. embossing; Apparatus therefor by plasma treatment
- B29C2059/145—Atmospheric plasma
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29K2023/00—Use of polyalkenes or derivatives thereof as moulding material
- B29K2023/10—Polymers of propylene
- B29K2023/12—PP, i.e. polypropylene
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J2237/00—Discharge tubes exposing object to beam, e.g. for analysis treatment, etching, imaging
- H01J2237/32—Processing objects by plasma generation
- H01J2237/33—Processing objects by plasma generation characterised by the type of processing
- H01J2237/336—Changing physical properties of treated surfaces
Definitions
- the present invention relates to a method and apparatus for modifying the surface properties of organic and inorganic polymer materials such as film and fabric, woven and non-woven.
- meltblown polymer web is as a wet cell battery plate separator.
- the base polymer compound is impervious to the electrolyte.
- the meltblown, non-woven fabric structure is ion permeable if the surface thereof is thoroughly wetted by the electrolyte.
- this latter requirement of wettability is not an inherent characteristic of most commercial polymers such as nylon, polypropylene, polyethylene and poly(ethylene terephthalate) .
- meltblown webs of these polymers are currently used as battery plate separators, wettability is achieved chemically by means of surfactants. This process not only generates hazardous industrial waste but produces a product of limited utility life.
- Wettability is also a desirable property for tissue and cloth used to wipe or clean the body, for surgical sponges, wound dressings, feminine hygiene products and reusable woven knit fabrics. Similarly, wettability is an important material surface property for printing and laminating.
- plasma usually describes a partially ionized gas composed of ions, electrons and neutral species. This state of matter may be produced by the action of either very high temperatures, or strong direct current (DC) or radio frequency (RF) electric fields. High temperature or “hot” plasmas are represented by celestial light bodies, nuclear explosions and electric arcs. Glow discharge plasmas are produced by free electrons which are energized by an imposed DC or RF electric field and then collide with neutral molecules.
- DC direct current
- RF radio frequency
- These neutral molecule collisions transfer energy to the molecules and form a variety of active species which may include photons, metastables, individual atoms, free radicals, molecular fragments, monomers, electrons and ions.
- active species are chemically active and/or capable of physically modifying the surface and may therefore serve as the basis of new surface properties of chemical compounds and property modifications of existing compounds.
- Low power plasmas known as dark discharge coronas have been widely used in the surface treatment of thermally sensitive materials such as paper, wool and synthetic polymers such as polyethylene, polypropylene, polyolefin, nylon and poly(ethylene terephthalate) . Because of their relatively low energy content, corona discharge plasmas can alter the properties of a material surface without damaging the surface.
- Glow discharge plasmas represent another type of relatively low power density plasma useful for non-destructive material surface modification. These glow discharge plasmas can produce useful amounts of visible ultraviolet radiation. Glow discharge plasmas have the additional advantage therefore of producing visible and UV radiation in the simultaneous presence of active species.
- glow discharge plasmas have heretofore been successfully generated typically in low pressure or partial vacuum environments below 10 torr which may necessitate batch processing and the use of expensive vacuum systems.
- polymer species exposed to low pressure glow discharge plasmas respond with enhanced surface wettability characteristics. However, the chemical/physical mechanisms are not understood and the characteristic is lost upon drying. Rewettability remains elusive.
- Another object of the invention is to teach a glow discharge plasma process for treating polymer web or film that provides a stable, rewettable product.
- Another object of the invention is to provide a method and apparatus for continuously processing a polymer web or film of indefinite length through a glow discharge plasma at atmospheric pressure and standard temperature.
- a still further object of the present invention to teach the construction and operating parameters of a glow discharge plasma having operability in an environmental pressure of about one atmosphere or slightly greater.
- the present invention provides as a product an improved web, preferably a meltblown polymer web, having a surface enhanced by exposure to a sustained atmospheric, glow discharge plasma.
- the invention also includes a process specially adapted for the manufacture of said web product, and apparatus specifically designed for carrying out said process.
- the above and other objects of the invention to be subsequently explained or made apparent are accomplished with an apparatus based upon a pair of electrically insulated metallic plate electrodes which may or may not have a median plate or screen between them. These plates are mounted in face-to-face parallel or uniformly spaced alignment with means for reciprocatory position adjustment up to about 5 cm of separation.
- the plates are water cooled and covered with a dielectric insulation.
- an impedance matching network is added to the circuit for charging the electrodes.
- the parameters of such a matching network are adjusted for the most stable, uniform operation of the glow discharge. This condition can occur when the reactive power of the plasma reactor is minimized.
- a radio frequency power amplifier connected to both plates delivers at least 180 watts of reactive and plasma power at a working voltage of 1 to at least 5 kV rms and at 1 to 100 kHz.
- the electrical discharge from a standard commercial Tesla coil may be briefly applied to the volume between the R.F. energized plates.
- An electric field established between the metallic plate electrodes must be strong enough to electrically break down the gas used, and is much lower for helium and argon than for atmospheric air.
- the RF frequency must be in the right range, discussed below, since if it is too low, the discharge will not initiate, and if it is too high, the plasma forms filamentary discharges between the plates. Only in a relatively limited frequency band will the atmospheric glow discharge plasma reactor form a uniform plasma without filamentary discharges.
- An electric field established between the metallic plate electrodes must be strong enough to electrically break down the gas used, and is much lower for helium and argon than for atmospheric air.
- the RF frequency must be in the right range, discussed below, since if it is too low, the discharge will not initiate, and if it is too high, the plasma forms filamentary discharges between the plates. Only in a relatively limited frequency band will the atmospheric glow discharge plasma reactor form a uniform plasma without filamentary discharges.
- a one atmosphere charge of air, helium or argon is established and maintained for processing material such as polymer film and web to produce desired surface characteristics such as wettability and re-wettability.
- Figure 1 is a schematic of the present invention component assembly.
- Figure 2 is an impedance matching network distinctively suitable for powering the present invention.
- Figures 3, 4 and 5 are representative alternative power supply output stage circuits.
- Figure 6 schematically represents an alternative embodiment of the invention.
- Figure 7 schematically represents the upper chamber of a one atmosphere glow discharge plasma reactor having a median grid plate.
- Figure 8 represents a graph of voltage, current and power waveforms for a uniform glow discharge plasma.
- Figure 9 represents a graph of voltage, current and power waveforms for a filamentary discharge plasma.
- Figure 10 is a log-log graph of total and plasma power density in milliwatts per cubic centimeter, as functions of RMS voltage applied to the electrodes.
- Figure 11 is a log-log graph of total and plasma power density in milliwatts per cubic centimeter, as functions of R.F. frequency.
- Figure 12 is a graph of amplifier frequency and corresponding breakdown current phase angles respective to a particular operating example of the invention.
- Figure 13 is a graph of amplifier frequency and corresponding power consumption respective to a particular operating example of the invention.
- the electrodes 10 are fabricated of copper plate having a representative square plan dimension of 21.6 cm x 21.6 cm. Silver soldered to the plates 10 are closed loops 11 of 0.95 cm copper tubing having hose nipples 12 and 13 connected therewith on opposite sides of the closed tubing loop. The edges of the electrode plates should have a radius of curvature comparable to the separation between the electrode plates and median plate to discourage electrical breakdown at the edge of the electrodes. Not shown are fluid flow conduits connected to the inlet nipples 12 for delivering coolant fluid to the loop 11 and to the outlet nipples 13 for recovering such coolant fluid.
- the integral metallic units comprising plates 10 and tubing 11 are covered with a high dielectric insulation material 14 on all sides to discourage electrical arcing from the edges or back side of the electrode plates.
- some mechanism should be provided for adjusting the distance s between plates 10 up to about 5 cm separation while maintaining relative parallelism.
- Such a mechanism is represented schematically in Figure 1 by the rod adjusters 15 secured to the upper and lower plates 10. This arrangement anticipates a positionally fixed median plate 30.
- parallelism is used in the context of parallel planes, it should be understood that the terms also comprises non-planar surfaces that are substantially equidistant. Also included are the geometry characteristics of a cylinder having an axis parallel to another cylinder or to a plate.
- Energizing the plates 10 is a low impedance, high voltage, R.F. power amplifier 20 having independently variable voltage and frequency capacities over the respective ranges of 1 to at least 5 kV and 1 to 100 kHz. Between the RF power supply 20 and the plates 10 may be an impedance matching network 31, described in greater detail relative to Figure 2. ⁇
- an environmental isolation barrier 21 such as a structural enclosure suitable for maintaining a controlled gas atmosphere in the projected plan volume between the plates 10.
- Inlet port 22 is provided to receive an appropriate gas such as air, helium or argon, mixtures of helium or argon with oxygen or air or a mixture of argon with helium.
- gas pressure within the isolation barrier 21 is substantially ambient thereby obviating or reducing the need for gas tight seals. Normally, it is sufficient to maintain a low flow rate of the modified atmospheric pressure gas through the inlet port 22 that is sufficient to equal the leakage rate. Since the pressure within the isolation barrier 21 is essentially the same as that outside the barrier, no great pressure differential drives the leakage rate.
- a vent conduit 28 controlled by valve 29 is provided as an air escape channel during initial flushing of the enclosure. Thereafter, the valve 29 may be closed for normal operation.
- Narrow material flow slits 23 are provided in the isolation barrier 21 to accommodate passage of a material web W between the plates 10 as drawn from a supply reel 24 onto a rewind reel 25. Drive for the reels 24 and 25 is controlled to provide a predetermined residence time between the plates 10 and within the plasma for any given web element.
- an impedance matching network is added to the power circuit for charging the electrodes 10.
- the parameters of this matching network are adjusted for the most stable, uniform operation of the glow discharge. This condition can occur when the reactive power of the plasma reactor is minimized.
- Figures 3 through 5 represent alternative power supply options having respective attractions.
- Figures 3 corresponds to a configuration wherein the bottom electrode terminal x is connected to ground potential and the top terminal T 2 is charged at the full working potential.
- Figures 4 and 5 are electrical equivalents wherein the T ⁇ and T 2 voltages are 180° out of phase but at only half the maximum potential.
- Figure 4 represents a grounded center tap transformer whereas Figure 5 represents a solid state power circuit embodiment.
- Shown in Figure 6 are two optional embodiments, the functions of which are to drive a reciprocating gas flow containing active species from the plasma back and forth through the web W. This can be accomplished either by a bellows 35 actuated by a reciprocating shaft 33, or by a piston 36 activated by a reciprocating shaft 32.
- the change in volume of the upper chamber will give rise to a periodic reversal of the pressure differential across the web W, hence, a periodic reversal of the gas flow.
- a passageway from behind the piston can be connected to the lower chamber as shown in the dashed line piping 34.
- the Figure 6 embodiment of the invention provides an electrically grounded screen 30 to support the web W as it is drawn between the opposite material flow slits 23.
- This configuration attenuates an accumulated electrical charge on the web and also structurally supports the traveling fabric web as a pressure differential membrane between an upper, gas inlet chamber and a lower, vent chamber. This swept flow differential assures an internal saturation of the web W by the gas containing active species from the plasma.
- Electric fields employed in a one atmosphere, uniform glow discharge plasma reactor are only a few kilovolts per centimeter, values which, if D.C., would usually be too low to electrically break down the background gas. Gases such as helium and air will break down under such low electric fields, however, if the positive ion population is trapped between the two parallel or uniformly spaced electrodes, this greatly increasing their lifetime in the plasma, while at the same time the electrons are free to travel to the insulated electrode plates where they recombine or build up a surface charge.
- the most desirable uniform one atmosphere glow discharge plasma is therefore created when the applied frequency of the RF electric field is high enough to trap the ions between the median screen and an electrode plate, but not so high that the electrons are also trapped during a half cycle of the R.F. voltage.
- the electrons may be trapped by bipolar electrostatic forces.
- the RF frequency is so low that both the ions and the electrons can reach the boundaries and recombine, the particle lifetimes will be short and the plasma will either not initiate or form a few coarse filamentary discharges between the plates. If the applied frequency is in a narrow band in which the ions oscillate between the median screen and an electrode plate, they do not have time to reach either boundary during a half period of oscillation and be carried for long times. If the more mobile electrons are still able to leave the plasma volume and impinge on the boundary surfaces, then the desirable uniform plasma is produced. If the applied RF frequency is still higher so that both electrons and ions are trapped in the discharge, then the discharge forms a filamentary plasma.
- FIG. 7 is a schematic of the upper chamber of the one atmosphere glow discharge plasma reactor. The lower boundary of this space is the midplane screen or base, the floating potential of which should remain near ground if the RF power supply output is connected as a push-pull circuit to the two electrodes with a grounded center tap. In the data reported herein, the median screen was grounded through an inductive current choke. In the configuration of Figure 7, a Cartesian coordinate system is applied as shown, with the applied electric field in the x-direction.
- the maximum amplitude of the electric field between the grounded median screen and the upper electrode is E Q , and the separation of the screen from the electrodes is the distance d.
- the median screen, with an exposed sample on it, is assumed not to allow ions through the median plane from the upper chamber to the lower, or vice-versa.
- the electric field between the electrodes shown on Figure 7 is given by
- the equation of motion for the ions or electrons between the two plates is given by a Lorentzian model, in which the electrons and ions collide only with the neutral background gas and, on each collision, give up all the energy they acquired from the RF electric field since the last collision to the neutral gas.
- the equation of motion for .the ions or electrons in the Lorentzian model is given by
- Equation 13 states that the RMS displacement of the particle has to be less than half the clear spacing in order to have a buildup of charge between the plates.
- the distance d is identified with the distance between the grounded median screen and the energized electrode.
- the collision frequency v c is approximately given by Eqs. 7a or 7b for ions or electrons, respectively, at one atmosphere, and the RMS voltage is that which bounds the upper and lower limit of the uniform discharge regime.
- the range of parameters over which we have operated a one atmosphere, uniform glow discharge plasma reactor is given in Table 1.
- the nominal pressure at which this discharge has been operated is one atmosphere.
- the variation of several torr shown in Table 1 is not intended to represent the day-to-day fluctuations of barometric pressure, but the pressure differential across the midplane screen which is intended to drive active species from the upper plasma through the fabric being exposed.
- the RMS power shown in Table 1 is the net power delivered to the plasma, less the reactive power which does not appear in the plasma.
- d is the separation of a plate from the median screen in centimeters.
- the power densities shown in Table 1 are far below those of electrical arcs or plasma torches, but also are several orders of magnitude higher than the power densities associated with some other forms of plasma treatment such as corona discharges.
- the power densities of the one atmosphere glow discharge plasma are generally low enough not to damage exposed fabrics, but are also enough higher than coronal plasmas used for surface treatment that they should provide far more active species than the latter.
- the plasma parameters, such as electron kinetic temperature and number density are somewhat speculative at this early stage in the development of our invention. A few results from probing the plasma midplane with a floating Langmuir probe indicates that the plasma, without grounding the midplane screen, will float to positive potentials of several hundred volts.
- the ion kinetic temperatures are very likely close to that of the room temperature atoms with which they frequently collide at these high pressures; the electrons apparently remain numerous and energetic enough to excite the neutral background atoms, hence making this a glow discharge.
- the existence of excited states which emit visible photons implies that the electron population has a kinetic temperature of at least an electron volt.
- the diagnostic difficulties of measuring plasma parameters at this high pressure are very severe, since ordinary Langmuir probing technique cannot be applied due to the short mean free paths of the electrons compared to a Debye distance. Electron number densities, however, may be measured by microwave interferometric techniques.
- Figures 8 and 9 are shown two waveforms of voltage and current taken in helium at the same electrode separation and gas flow conditions, but at two different frequencies.
- Figure 8 was taken in the uniform glow discharge regime at a frequency of 2.0 kHz
- Figure 9 was taken in the filamentary discharge regime at a frequency above the uniform plasma operating band at 8.0 kHz.
- the high output impedance of our RF power supply results in a voltage waveform (trace B) that is very close to sinusoidal.
- the reactive current waveform (trace C) is interrupted by a breakdown of the plasma twice each cycle, once when the voltage is positive, and once when the voltage is negative.
- Trace A shows the reactive current waveform at the same voltage and operating conditions, but in air, rather than helium.
- the plasma power is of interest because it is proportional to the production rate of active species in the plasma; the reactive power is significant because it determines the required power handling rating of the plasma power supply and associated equipment.
- the total power is the sum of plasma and reactive power.
- FIG 10 is shown a log-log plot of the plasma and total power density in milliwatts per cubic centimeter, as functions of the RMS voltage applied to the parallel plates.
- On Figure 11 is a similar presentation of the power density plotted on log-log coordinates as a function of the frequency. The approximate bound of the uniform plasma discharge regime is shown by the arrow.
- the Figure 1 described physical apparatus sustained a glow discharge plasma in one atmosphere of helium at standard temperature with a separation distance s of 3.0 cm between plates 10.
- the plates were energized with a 4.4 kV rms working potential. Holding these parameters constant, R.F. frequency was increased as an independent variable.
- Figure 12 charts the corresponding breakdown current phase angle as determined relative to the voltage waveform node.
- Figure 13 charts the total power, including reactive and plasma input power required to sustain the plasma at the respective R.F. frequencies.
- the Figure 1 described physical apparatus is used to sustain a glow discharge plasma in one atmosphere of helium at standard temperature with a separation distance s of 1.0 cm between plates 10.
- the R.F. frequency was held constant at 30 kHz while plate potential was manipulated as the independent variable and current breakdown phase angle, ⁇ , (Table 2) and total power, P, (Table 3) measured as dependent variables.
- a third operational example of the invention included a one atmosphere environment of helium between a 1 cm separation distance s between plate electrodes 10 charged at 1.5 kV rms potential.
- the R.F. frequency was manipulated as the independent variable.
- Table 4 reports the corresponding phase angle ⁇ of breakdown current.
- the measured dependent variable of Table 5 reports the corresponding total power consumption data.
- the largest volume helium plasma of 3.1 liters was achieved with the above described apparatus at a 3.2 cm plate separation having a 5 kV rms potential at an R.F. frequency of 4 kHz.
- Meltblown webs formed from nylon, poly(ethylene terephthalate) , polypropylene and polyethylene have been processed by exposure to the glow discharge plasma described herein to produce desired material characteristics, increased wettability and re-wettability.
- Wettability of a material is objectively measured by either or both of two tests including (a) the angle of a water bead supported on the material surface and (b) the time required to wick along a predetermined material length.
- a poly(ethylene terephthalate) web after 2.5 minutes of glow discharge plasma exposure to a 5kV, 4kHz across a 4.5 cm plate separation, experienced a 0° surface bead angle and a 37.37 second wicking rate determined by the INDA standard absorption test. Prior to plasma exposure, the web had a large surface bead angle and no wicking capacity. Similarly, after only 60 seconds of exposure to the same plasma, a nylon web, having a high surface bead angle and no wicking capacity enjoyed a 0° surface bead angle and a 16.61 second wicking rate (INDA standard test) upon wetting and re-wetting.
- meltblown webs poly(ethylene terephthalate) and polypropylene (PET and PP), were treated by the one atmosphere glow discharge plasma with helium or helium plus active gases as the working gas for a treating time period of from one-half minute to two minutes.
- the power supply voltage was from 1,000 V rms to 4,000 V rms and the frequency was from 1 kHz to 100 kHz.
- the webs had a fiber size of 2 to 2.5 microns, a pore size of 20-25 microns, and a porosity of 90%. Table 6 lists some initial results from these treatments.
- Wettability was justified by contact angle, wickability, and wetout of the liquid through web thickness and on the web surface.
- Wickability was measured according to INDA standard (1st 10.1-92), in which time was measured for the liquid (double D's water) to rise 2.4 cm high.
- Physical fiber surface change was analyzed by photomicrographs taken using the ETEC Auto Scan electron microscope for a magnification of 2,000x to 4,000x.
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- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Plasma & Fusion (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Textile Engineering (AREA)
- Aviation & Aerospace Engineering (AREA)
- Physical Or Chemical Processes And Apparatus (AREA)
- Treatment Of Fiber Materials (AREA)
- Plasma Technology (AREA)
- Treatments Of Macromolecular Shaped Articles (AREA)
- Chemical Or Physical Treatment Of Fibers (AREA)
Abstract
Description
Claims
Applications Claiming Priority (9)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US08/068,508 US5387842A (en) | 1993-05-28 | 1993-05-28 | Steady-state, glow discharge plasma |
US68508 | 1993-05-28 | ||
US68739 | 1993-05-28 | ||
US08/068,739 US5456972A (en) | 1993-05-28 | 1993-05-28 | Method and apparatus for glow discharge plasma treatment of polymer materials at atmospheric pressure |
US08/145,349 US5403453A (en) | 1993-05-28 | 1993-10-29 | Method and apparatus for glow discharge plasma treatment of polymer materials at atmospheric pressure |
US145786 | 1993-10-29 | ||
US145349 | 1993-10-29 | ||
US08/145,786 US5414324A (en) | 1993-05-28 | 1993-10-29 | One atmosphere, uniform glow discharge plasma |
PCT/US1994/006151 WO1994028568A1 (en) | 1993-05-28 | 1994-05-26 | Method and apparatus for glow discharge plasma treatment of polymer materials at atmospheric pressure |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0700577A1 EP0700577A1 (en) | 1996-03-13 |
EP0700577A4 true EP0700577A4 (en) | 1996-12-27 |
Family
ID=27490710
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP94918192A Ceased EP0700577A4 (en) | 1993-05-28 | 1994-05-26 | Method and apparatus for glow discharge plasma treatment of polymer materials at atmospheric pressure |
Country Status (6)
Country | Link |
---|---|
EP (1) | EP0700577A4 (en) |
JP (1) | JPH08511898A (en) |
KR (1) | KR960702844A (en) |
AU (1) | AU679237B2 (en) |
CA (1) | CA2163967C (en) |
WO (1) | WO1994028568A1 (en) |
Families Citing this family (19)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5714308A (en) * | 1996-02-13 | 1998-02-03 | Eastman Kodak Company | Atmospheric pressure glow discharge treatment of polymeric supports to promote adhesion for photographic applications |
US5789145A (en) * | 1996-07-23 | 1998-08-04 | Eastman Kodak Company | Atmospheric pressure glow discharge treatment of base material for photographic applications |
US6879103B1 (en) | 1997-03-18 | 2005-04-12 | The Trustees Of The Stevens Institute Of Technology | Glow plasma discharge device |
US6900592B2 (en) | 1997-03-18 | 2005-05-31 | The Trustees Of The Stevens Institute Of Technology | Method and apparatus for stabilizing of the glow plasma discharges |
US5872426A (en) * | 1997-03-18 | 1999-02-16 | Stevens Institute Of Technology | Glow plasma discharge device having electrode covered with perforated dielectric |
DE19713127C1 (en) * | 1997-03-27 | 1998-11-12 | Brueckner Maschbau | Corona electrode arrangement |
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JP3016821B2 (en) * | 1990-06-15 | 2000-03-06 | 東京エレクトロン株式会社 | Plasma processing method |
JPH0582114A (en) * | 1991-09-18 | 1993-04-02 | Fuji Photo Film Co Ltd | Secondary battery |
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- 1994-05-26 JP JP7501055A patent/JPH08511898A/en active Pending
- 1994-05-26 EP EP94918192A patent/EP0700577A4/en not_active Ceased
- 1994-05-26 AU AU69623/94A patent/AU679237B2/en not_active Ceased
- 1994-05-26 KR KR1019950705310A patent/KR960702844A/en not_active Application Discontinuation
- 1994-05-26 WO PCT/US1994/006151 patent/WO1994028568A1/en not_active Application Discontinuation
- 1994-05-26 CA CA002163967A patent/CA2163967C/en not_active Expired - Fee Related
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GB891469A (en) * | 1957-05-27 | 1962-03-14 | Minnesota Mining & Mfg | Improvements in polymers |
US4316791A (en) * | 1979-08-22 | 1982-02-23 | Office Nationale D'etudes Et De Recherches Aerospatiales | Device for chemical dry etching of integrated circuits |
JPS5747873A (en) * | 1980-09-03 | 1982-03-18 | Toshiba Corp | Plasma etching method |
JPS6344965A (en) * | 1986-04-22 | 1988-02-25 | Nippon Paint Co Ltd | Formation of multilayer film |
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PATENT ABSTRACTS OF JAPAN vol. 012, no. 258 (C - 513) 20 July 1988 (1988-07-20) * |
See also references of WO9428568A1 * |
Also Published As
Publication number | Publication date |
---|---|
CA2163967C (en) | 2008-11-04 |
EP0700577A1 (en) | 1996-03-13 |
AU679237B2 (en) | 1997-06-26 |
AU6962394A (en) | 1994-12-20 |
WO1994028568A1 (en) | 1994-12-08 |
KR960702844A (en) | 1996-05-23 |
CA2163967A1 (en) | 1994-12-08 |
JPH08511898A (en) | 1996-12-10 |
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