The present disclosure generally relates to atomizers for consumer spray products, and more particularly, relates to high volume atomizers which vibrate a perforated substrate in contact with a liquid product supply to dispense the liquid product.
Dispensers for releasing liquid products into the ambient air are well known in the art. These devices may deodorize, humidify, disinfect, emit a fragrance, deliver a medical or cosmetic spray, or distribute toxins into the air to kill and or repel unwanted pests, such as insects. Consequently, each application may require a different type of spray or spray property. For instance, some applications may require smaller droplets with a shorter plume length while others may require larger droplets with a longer plume length. Similar considerations may be made with respect to other attributes such as spray orientation, direction, discharge rate, or the like. Therefore, continuous efforts are directed toward new techniques of dispensing liquid products that may adapt to any and all spray requirements.
Several techniques have been employed to dispense liquid products into the air. One of the more common dispensers includes aerosol dispensers which release pressurized liquid products from gas-filled containers. Common alternatives to aerosol dispensers include atomizers which reduce a liquid product into tiny droplets and or particles to be released into the air as a fine spray. While the dispensers noted above may be useful in releasing liquid products into the ambient air, they have their drawbacks.
Aerosol dispensers have been commonly used to dispense liquid products and are well known in the art. Moreover, aerosol dispensers provide a low cost method of dispensing liquid products in any orientation and direction. In an aerosol dispenser, the liquid product to be dispensed is typically mixed in a solvent and a propellant. The propellant provides a force to expel the liquid when a user actuates the aerosol container. The two main types of propellants used in aerosol containers today are liquefied propellant gases (LPGs), such as hydrocarbon or hydrofluorocarbon (HFC) gas, and compressed gas propellants, such as compressed carbon dioxide or nitrogen gas. To a lesser extent, chlorofluorocarbon propellants (CFCs) are also used.
Propellants that use LPGs share several disadvantageous traits. While the use of CFCs is being phased out due to the harmful effects of CFCs on the environment, many aerosol dispensers still use hydrocarbon propellants. Hydrocarbon propellants contain Volatile Organic Compounds (VOCs) which may have detrimental effects on the environment. The content of VOCs in aerosol dispensers is an unwanted byproduct and is consequently regulated by various federal and state regulatory agencies, such as the Environmental Protection Agency (EPA) and California Air Resource Board (CARB).
Compressed gas propellants also possess disadvantages. Dispensers that use compressed gas propellants exhibit spray attributes that are inconsistent throughout the life of the dispenser. Specifically, their spray performance relies solely on pressure provided by the gas remaining in a container. As the gas is depleted, the spray properties of various dispensers have shown an increase in droplet size and or shorter plume lengths due to the decrease in propellant pressure. In many cases, the lack of propellant pressure leaves excessive amounts of the unused liquid product in the container.
The concept of atomizers that dispense liquids into the ambient air is also well known in the art. In general these devices supply the liquid product to a vibrating perforated plate which, due to its vibrations, consistently breaks up the liquid into fine droplets and ejects them in the form of a mist or a cloud. As the droplets travel, the liquid evaporates from the droplets and disperses into the atmosphere.
One disadvantage to atomizers pertains to the inability to spray in any direction and or orientation. Many of the atomizers do not allow transport of a liquid to the vibrating plate for atomization unless the device is upright. For instance, the capillary in a capillary-based atomizer may not be in fluid communication with the liquid product unless it is situated in the upright position. Additionally, many atomizers are not substantially sealed to prevent leaks or spills when the device is not upright.
Additional drawbacks relate to relatively large discharged particles, low discharge rates and short spray lengths. Dispensing large particles creates situations in which the droplets are too large to effectively evaporate into the ambient air. Subsequently, the droplets may eventually settle on surrounding surfaces to cause more problems than it attempts to solve. Low discharge rates and short spray lengths further limit the atomizer to only certain products and applications. For instance, an atomizer would not be able to spray a fragrance high enough to reach the center of a large room.
Nonetheless, a few advances have shown an atomizer to release smaller droplets of approximately 30 microns. While the droplet size is consistently smaller, the atomizer discharges at rates of only microliters per hour and ejects plume of less than one foot in length. Other advances have shown an atomizer outputting at increased rates of microliters per second and extending plumes to 15 centimeters. However, the reach of these sprays are still relatively short and the atomizers are still unable to spray in any direction and or orientation.
Therefore, multiple needs exist for an improved atomizer for common consumer products that is capable of spraying in any orientation, increases plume lengths, increases the delivery rate, and does not release harmful pollutants into the environment. Additional needs exist for improved atomizing techniques that may be easily adapted for use with a wide variety of applications.
In accordance with one aspect of the disclosure, a high volume atomizer for dispensing a liquid product is provided which comprises an actuator; a substrate to which the actuator is operatively associated, the substrate comprising a plurality of perforations; a supply of the liquid product in contact with the perforations; and a control circuit in electrical communication with the actuator; wherein the actuator is capable of vibrating the substrate at a velocity no less than 500 mm/s and is selected from the group consisting of a piezoelectric ceramic, a piezoelectric crystal, a flextensional transducer, an oscillating magnetic couple, a high speed motor, and a servo motor.
In accordance with another aspect of the disclosure, a high volume piezoelectric atomizer for dispensing a liquid product is provided which comprises a first piezoelectric actuator; a substrate to which the piezoelectric actuator is operatively associated, the substrate comprising a plurality of perforations; a supply of the liquid product in contact with the perforations; and a control circuit in electrical communication with the piezoelectric actuator.
In accordance with another aspect of the disclosure, a high volume piezoelectric atomizer for dispensing a liquid product is provided which comprises a substantially sealed liquid chamber; an electronics chamber; a piezoelectric actuator; a substrate comprising a plurality of tapered perforations; a supply of the liquid product in contact with the tapered perforations; and a control circuit disposed within the electronics chamber, the control circuit in electrical communication with the piezoelectric actuator.
In accordance with another aspect of the disclosure, a high volume atomizer for dispensing a liquid product having a Valpey factor of at least 51.0 is provided which comprises an actuator; a substrate to which the actuator is operatively associated, the substrate comprising a plurality of perforations; a supply of the liquid product in contact with the perforations; and a control circuit in electrical communication with the actuator.
These and other aspects of this disclosure will become more readily apparent upon reading the following detailed description when taken in conjunction with the accompanying drawings.
While the present disclosure is susceptible to various modifications and alternative constructions, certain illustrative embodiments thereof have been shown in the drawings and will be described below in detail. It should be understood, however, that there is no intention to limit the present invention to the specific forms disclosed, but on the contrary, the intention is to cover all modifications, alternative constructions, and equivalents falling with the spirit and scope of the present invention.
Referring now to the drawings and with particular reference to
As shown in
Wicks, as described herein, have a plurality of non-capillary fibers and are adapted to the polarity and or non-polarity of a particular liquid product. Such wick compositions serve to promote the ability to spray in any orientation and or direction, and to minimize inconsistencies caused by gravity. More specifically, gravity may significantly impede fluid flow if a wick is longer than a few millimeters and transports fluid against the force of gravity. In order to overcome gravity at delivery rates exceeding microliters per minute, the composition and properties of a wick may be modified. Some important properties affecting the performance of a wick may include the pore size, pore volume and hydrophilicity. Of these properties, hydrophilicity has the greatest impact on the performance of a wick. Furthermore, the hydrophilicity of a wick composition may be one that is compatible with the polarity of a particular liquid product to be dispensed.
The majority of liquid products that may be used with the embodiments disclosed herein may include aqueous mixtures of actives and other ingredients, for example, air fresheners, insecticides, repellents, cleaners, or the like. For such liquids, a typical hydrophilic wick, for example polyester, may be used for optimal compatibility and uninterrupted performance. In contrast, cotton may be too hydrophilic while polyethylene may be too hydrophobic. Alternatively, for applications involving non-polar liquid products, a hydrophobic wick such as polyethylene may provide better performance than cotton, nylon, polyester, or the like.
Still referring to
As shown in the particular embodiment of
A piezoelectric actuator 12 may include a piezoelectric material that converts mechanical energy into electrical energy, and vice versa. More specifically, providing pulsed electrical current to a piezoelectric actuator 12 may mechanically vibrate the actuator 12 and its associated substrate 14. A control circuit for providing such current may be provided in electrical communication with the piezoelectric actuator 12 via wires or other conductors. Upon actuation, the control circuit may vibrate the substrate 14 and its tapered perforations 16 against a liquid product supply or a wick 18 at velocities of 500 mm/s or more. Subsequently, the atomized liquid product may be dispensed from the perforations 16 to provide plumes of approximately 2 feet (610 mm) or more in length.
Referring now to
Turning to
Turning now to
Turning to
Turning to
Referring back to the particular embodiment of
Turning now to
Still referring to the particular arrangement 40 of
The schematic of
Several factors may contribute to the size of the droplets released by an atomizer. The greatest known contributors may include the size of the perforations in a substrate, or a plate, and the velocity at which the plate vibrates. Moreover, at a constant plate velocity, the droplet size may increase with increasing perforation size, and at a constant perforation size, the droplet size may increase with increasing plate velocity. During the course of experimentation, however, tests provided unexpected results with respect to the particle size of droplets dispensed. It has been determined that a plate with larger perforations may produce a spray with significantly smaller droplets or particles. More specifically, at constant drive voltage and resonant frequency, higher plate velocities in combination with smaller perforations produced larger particles than lower plate velocities and larger perforations.
Turning to the table of
Turning now to
Turning now to
Referring now to
The results provided in
In general, the performance of an atomizer may be measured by examining the properties of its spray. More relevant spray properties may include the size of the droplets, plume length and the rate of discharge. A simplified approach to measuring atomizer performance may combine these traits into one index, for example, a Valpey factor. The Valpey factor may be defined by the equation
Vf=100rd+0.1lp−xd
where rd is the discharge rate in g/s, lp is the observed plume length in mm, and xd is the droplet size in microns. The Valpey factor summarizes atomizer performance, by combining the droplet size, plume length and the discharge rate of an atomizer into one index.
Based on the foregoing, it can be seen that the present disclosure provides a high volume atomizer with features that improves efficiency and performance. Using the embodiments and the relationships disclosed herein, it is possible to atomize a liquid product into smaller droplets, longer plumes and greater discharge rates. More specifically, an atomizer constructed in accordance with the teachings of the disclosure is capable of providing plume lengths of approximately 2 ft (610 mm) or more and discharge rates of approximately 0.20 g/s or more. Accordingly, the performance of the present disclosure may be summarized to exhibit a Valpey factor of 51.0 or more. Atomizers currently existing in the art exhibit only a fraction of this value.
Furthermore, the present disclosure is capable of atomizing in any orientation without leaking and without significantly affecting performance. The atomizer includes a liquid chamber with a cap and a gasket, and a novel plate arrangement that is in direct contact with a supply of a liquid product to substantially seal in a liquid product. Moreover, the supply of a liquid product is not provided by capillary action but by using the polarity or non-polarity of a liquid product. The technology allows the device to atomize consistently while it is upright, upside down, sideways, or in any other orientation. This is a significant improvement over atomizers currently existing in the art which may leak, spill or not work at all in such orientations. While a few atomizers may be able to spray in these positions without leaking, their performance is inconsistent and gradually decreases in quality.
While only certain embodiments have been set forth, alternatives and modifications will be apparent from the above description to those skilled in the art. These and other alternatives are considered equivalents and within the spirit and scope of this disclosure.
Number | Name | Date | Kind |
---|---|---|---|
4119096 | Drews | Oct 1978 | A |
4753579 | Murphy | Jun 1988 | A |
4877989 | Drews et al. | Oct 1989 | A |
5511726 | Greenspan et al. | Apr 1996 | A |
5518179 | Humberstone et al. | May 1996 | A |
5685485 | Mock et al. | Nov 1997 | A |
5823428 | Humberstone et al. | Oct 1998 | A |
6293474 | Helf et al. | Sep 2001 | B1 |
6296196 | Denen et al. | Oct 2001 | B1 |
6339897 | Hayes et al. | Jan 2002 | B1 |
6378780 | Martens, III et al. | Apr 2002 | B1 |
6382522 | Tomkins et al. | May 2002 | B2 |
6439474 | Denen | Aug 2002 | B2 |
6450417 | Gipson et al. | Sep 2002 | B1 |
6450419 | Martens, III et al. | Sep 2002 | B1 |
6540153 | Ivri | Apr 2003 | B1 |
6706988 | Helf et al. | Mar 2004 | B1 |
6843430 | Boticki et al. | Jan 2005 | B2 |
6854662 | Chen | Feb 2005 | B2 |
6857580 | Walter et al. | Feb 2005 | B2 |
6921020 | Ivri | Jul 2005 | B2 |
6969008 | Helf et al. | Nov 2005 | B2 |
7017829 | Martens, III et al. | Mar 2006 | B2 |
7108197 | Ivri | Sep 2006 | B2 |
7281811 | Thuot Rann et al. | Oct 2007 | B2 |
20050023368 | Valpey, III et al. | Feb 2005 | A1 |
20050271371 | Wefler | Dec 2005 | A1 |
20060011737 | Amenos et al. | Jan 2006 | A1 |
20060026817 | Valpey, III et al. | Feb 2006 | A1 |
Number | Date | Country | |
---|---|---|---|
20090272818 A1 | Nov 2009 | US |