HK1181013B - Containers for fluids with composite agile walls - Google Patents

Description

Fluid container with composite flexible wall

Related application

The present patent application claims priority from united states provisional patent application No. 61/304,904, filed on 2/16/2010, in accordance with 35u.s.c. § 119, which is incorporated herein by reference in its entirety.

Technical Field

Embodiments of the present invention relate to fluid containers, and more particularly, to fluid containers including flexible walls. The flexible wall includes a shape memory component that tends to return the fluid container to an original shape. The sampling bag can be used for environmental sampling, such as in industrial hygiene applications.

Background

Conventional fluid containers may have rigid walls or flexible walls. A container with rigid walls has a defined permanent volume for containing a fluid, and a container with flexible walls has a variable or changeable volume. Conventional containers include, but are not limited to, bottles, cans, or bags. Such containers can be used for a variety of purposes, including obtaining and holding fluid samples as well as containing standard gas mixtures that can be used for calibration of analytical instruments. As used herein, the term "fluid" includes gases and/or liquids. There are many configurations of such containers that have been developed and specialized for particular uses.

The gas mixture under pressure is effective for preparing an industrial quantity of a standard fluid mixture and preferably has a relatively high concentration of one (or more) components in the carrier fluid. The gas mixture under high pressure is usually stored in a container with rigid walls. For laboratory use, such gas mixtures may be diluted with additional carrier fluids to the desired concentration of a particular component in order to prepare a standard mixture. Conventional containers for shipping, storing and using such standard mixtures may be containers with flexible walls comprising inert, low permeability materials. A material with a low adsorption on the walls for the contained components preferably increases the integrity of the mixture. Containers with flexible walls (also called sampling bags) are widely used for fluid sampling, air sampling and liquid sampling. Materials such as Kernel (Kynar) and Tedlar (Tedlar) are widely used to manufacture such containers.

In order to obtain a representative sample or to prepare an accurate standard, the container must be properly prepared prior to filling. Typically, the bag is flushed with a neutral gas and subjected to a high vacuum by a strong vacuum pump to remove all fluid from the container. The bag should be cleaned and flushed to cause desorption of any residue and its volume should be reduced to substantially zero. Any adsorbed residue or residual gas may contaminate any prepared fluid mixture or fluid sample placed in a poorly prepared bag.

Both rigid walled containers and flexible walled containers have their own advantages and disadvantages. The disadvantages of containers with rigid walls include their extremely high price and expensive maintenance; it is bulky and therefore expensive to store, transport and mail; it must be under overpressure when it is desired to deliver a gas vapor or mixture, and be completely evacuated before use for fluid sampling.

Another drawback of sampling through a container having rigid walls is that: after removing a portion of the sample from the container, the pressure in the tank may be reduced below atmospheric pressure, and additional carrier gas (e.g., noble gas) may be added to increase the pressure back to atmospheric pressure. This process dilutes the sample or standard and the analysis requires compensation for additional carrier gas.

One method of filling a container having rigid walls is to create a vacuum within the container. The driving force for the fluid to reach the container is provided by this vacuum. Small sampling vacuum pumps are unable to generate a sufficient vacuum within the container; therefore, a strong special vacuum pump is required.

An alternative to a container with rigid walls is a container with flexible walls or a bag. For containers with flexible walls, two filling methods are known and widely used: (OSHA technical Manual-Directive Number 08-05(TED01), effective on 6/34/2008)

A first method includes delivering a fluid or fluid sample (e.g., industrial ambient air) into a bag having an external pump. A schematic of this method is depicted in fig. 8. The sampling method includes a bag 40, a pump 50 powered by a battery 52, and tubing 44 connecting the pump 50 to the bag 40. A typical personal sampling pump is suitable for this sampling method.

The bag can be used for preparing standard fluid mixtures or for sampling. When preparing a standard fluid mixture, the bag is first filled with an appropriately measured volume of carrier fluid. The clean carrier gas is dosed by some fluid, typically added by a pump or syringe as shown in fig. 8. When used for sampling, a sample of the environment is delivered into the bag via a pump and tubing. The bag was then sealed and sent to a laboratory for analysis.

There are advantages and disadvantages of using this method with a sampling bag. Disadvantages include cost, inaccuracy and potential contamination of the use of external pumps to deliver and draw the fluid mixture. Contamination or inaccuracies may occur due to adsorption and desorption of some chemical or component of the gas mixture or sample on the tube walls, internal parts of the pump, filters, tubing and connectors. The adsorption of chemical components on the walls of the sampling bag causes the same problem. Even with clean walls, effective adsorption sites on the walls can reduce the concentration of certain chemicals when the sample gas is subsequently removed and analyzed. This adsorption can reduce the recovery of certain chemical compounds by as much as 15%. The recovery of this process can be improved by using expensive stationary pumps and connecting tubes, which are particularly useful for sampling trace components.

These methods may also be improved by using differently configured pumps and sampling bags. In this configuration shown in fig. 9, the flexible sampling bag 40 is hermetically sealed within an outer container 60 having rigid walls. Air from the outer container is evacuated by pump 50 via conduit 44. The pump may be powered by a battery 52. As the pressure in the outer container 60 decreases, and the bag 40 expands and air from the surrounding environment enters the bag 40. Thus, the vacuum outside the bag 40 and within the container 60 is the driving force for fluid sampling. In the embodiment shown in fig. 9, the inlet of the sampling bag is in direct connection with the surrounding fluid. This approach does not suffer from one of the major drawbacks from the configuration shown in fig. 8. The sample taken in the configuration of fig. 9 does not contact the pump 50 or tubing 44 and therefore there is no adsorption or cross-contamination due to the walls of tubing 44, connectors, filters or components of the sampling pump 50. However, other drawbacks of the configuration of fig. 8 are: the alternative configuration of fig. 9 is still adhered to, e.g., the components are bulky and heavy; the equipment is expensive; pumps require batteries and frequent maintenance; the adsorption on the walls of the bag is the same as described above.

Various embodiments of these methods are described in U.S. patents. For example, united states patent No. 3,866,474 to Hasselman describes a system for drawing a sample and an inert gas into a sample bag within a hermetically sealed container. U.S. patent No. 3,965,946 to deairo (D' Alo) describes an improvement in the construction of the outer container. United states patent No. 5,437,201 to Krueger describes a method of repeatedly washing a sampling bag within an outer container. A more complex device is disclosed in united states patent No. 5,714,696 to jemons (yeams). The device seeks to overcome the disadvantages of the system to obtain samples with a very low degree of contamination. United states patent No. 6,338,282 to Gilbert describes an apparatus for collecting liquids that demonstrates the versatility of this method. A more recent us patent 6,993,985 to sickerib (Srebro) describes the use of an apparatus combined with a single device still connected to an external vacuum source. Despite the cleanliness proposed by this method, the method uses rather heavy, bulky and expensive equipment that requires calibration and battery maintenance.

An attempt to avoid the use of a pump during sampling is disclosed in united states patent No. 4,546,659 to Gill et al. This patent discloses a small (10ml) enclosure for collecting a sample of atmospheric air for subsequent analysis. The envelope is formed by first and second opposing panels formed of a flexible, gas impermeable material that are peripherally sealed to define a collection chamber. The envelope contains an expandable member such as a coil spring or foam. The expandable member transfers force to the wall via the protective plate and the large diaphragm. These encapsulations have several disadvantages. For example, an expandable member in contact with the sampled fluid increases the likelihood of adsorption by internal elements (i.e., springs) or, particularly, any foam. In addition, the expandable member prevents complete evacuation of the enclosed contents. This large surface area for adsorption only allows high concentrations of chemical compounds to be sampled with acceptable recovery and accuracy. Furthermore, the envelope cannot be reused, since the sampling volume would need to be washed several times to clean the envelope, however, the encapsulated self-sealing septum does not allow for this procedure.

There is a need for a sampling bag that is capable of fluid delivery or fluid sampling without an external energy source, such as a pressure or vacuum pump, without an external container having rigid walls, without a tube and tube connector. In addition, there is a need for a sampling bag that generates its own driving force for sample collection. There is also a need for a sampling bag that reduces external contamination of standard mixtures or samples.

There is a further need for a container for standard mixtures that does not require the addition of additional carrier gas and any associated concentration calculations and volume compensation associated with the use of a container with rigid walls.

There is a further need for a sampling bag that allows for the use of substantially all of the sampling volume. There is a further need for such a device that is inexpensive, easy to manufacture, designed for multiple uses, available for use with both specially designed and conventional sampling bags, lightweight, small, manually or automatically operated, and easy to transport, and/or intrinsically safe in use.

Disclosure of Invention

Embodiments of the container include flexible, flexible walls. The flexible, flexible wall tends to return the container to the initial configuration. The initial configuration may be a substantially fully expanded volume configuration, a substantially empty configuration, or a partially full volume configuration. The flexible wall may be deformed from an initial configuration by a force applied outside the sampling bag or a force inside the sampling bag. The force may be a hand or weight that presses on one or both sides of the container to deform the bag from an initial expanded volume configuration (partial or substantially full configuration) to a reduced volume configuration. When the force is removed, the container tends to return to the initial configuration due to the biasing force applied to the container by the flexible wall. In most cases, the flexible wall will return the container to the original configuration if the internal volume of the container is capable of equalizing the pressure between the interior and exterior of the container. The flexible wall may include one or more components having shape memory components that bias the sampling bag toward its initial configuration.

The walls of the container may comprise a plurality of layers or components. One layer may be a complete layer covering substantially the entire surface area of the bag wall or a partial layer covering only a portion of the bag.

In one embodiment, the container comprises a composite wall. The composite wall may comprise a plurality of layers. The layers may include an interior layer and a shape memory layer. The inner layer can be any layer suitable for the desired application, and for a sampling container, the inner layer can be flexible, low outgassing, have very low absorption, and/or impermeability. The inner layer may comprise at least one of a polyolefin (polypropylene, polyethylene), a polyfluoro plastic, PTFE, teflon, and other similar materials. Other layers of the composite wall may include materials to provide additional properties on all structures. For example, the second layer may have less permeability for compounds to enter the interior layer, thus increasing the impermeability of the composite wall. Another layer may include a shape memory component. The shape memory component may comprise at least one material selected from: polycarbonate, acrylic, polyester, metal or metal alloys, and other materials having shape memory. In some embodiments, the layer comprising the shape memory component may be relatively thick compared to other layers of the composite.

The other or inner layer may be a layer comprising a material with very low or zero permeability, such as stainless steel, nickel, aluminum, or other metal layers that are flexible and have sufficient permeability. In some embodiments, particularly embodiments in which this layer is an interior layer, the metal layer may comprise a thin surface sublayer or a chemically inert metal oxide coating. The metal oxide layer may also be silicided. The layers may be in any suitable order for the application in order to give the composite wall suitable characteristics.

Another optional layer may comprise an outer layer of the composite wall comprising a material having certain properties, such as static dissipation, good adhesion to a different material, low friction, and/or abrasion resistance. Such an outer layer may comprise, for example, at least one material selected from the group comprising: metallized polyester, polyurethane, nylon.

In certain embodiments, the shape memory component of the wall defines a primary shape of the container in its initial configuration, and the soft portion serves to conformally seal the container.

Embodiments of the container may have one of two typical initial configuration shapes, however, other shapes are possible:

a container comprising a shape memory component, the initial flat configuration of which results in the container having substantially zero volume between the walls in its initial configuration. The container having the flat initial configuration can be expanded by increasing the internal pressure, see fig. 1-a. The shape memory component can be in an initial flat configuration or in an arcuate initial configuration. If the shape memory components are in the initial arcuate configuration, a container having a flat initial configuration may be formed by placing the shape memory components having convex sides adjacent to each other, see a-1 of FIG. 1. The edges of the shape memory component are then fastened together by other layers of the container, see a-2 of fig. 1A. If a fluid is added to the interior volume of the container, the shape memory component will deform, as shown in a-3 of FIG. 1-A. In such an embodiment, the container will tend to deflate due to the tendency of the shape memory component to return to the initial flat configuration.

Another embodiment of a container comprising two arcuate shape-memory components with an inflated initial configuration is shown in fig. 1-B. In this embodiment, the arcuate shape memory elements are placed with the concave sides facing each other, see B-1 of FIG. 1-B. The force applied to the interior of the container may deflate the container as shown in B-2 of fig. 1-B. The container will have a tendency to expand and draw fluid into the container interior volume, see B-3 of fig. 1-B.

In embodiments of the container in which the walls have an initial flat configuration, the walls tend to return to the flat configuration after deformation, and the applied compressive force on the fluid within the interior volume can expel the fluid from the interior volume to zero volume. Such an embodiment may be used to provide a desired fluid flow or fluid sample within the volume for an external device-fig. 1-a, a-1, a-2, a-3.

Embodiments of the container having an initial configuration with a substantially fully expanded volume configuration or a partially fully expanded configuration may be forced to a flat shape with substantially zero internal volume. The flexible wall with the shape memory component will then exert a pressure difference between the surrounding environment and the inner space, thereby providing a certain driving force to cause the fluid to fill the permanently expanded volume of the container-fig. 1-B, B-1, B-2, B-3.

Embodiments of the present invention provide sampling bags that permit sampling without any additional devices and permit the design of sampling bags that allow self-sampling. As used herein, self-sampling means sampling that will continue once started without further assistance from the person taking the sampling.

Other aspects and features of embodiments of the sampling bag including the flexible wall will become apparent to those skilled in the art upon review of the following detailed description, exemplary embodiments of the invention, taken in conjunction with the accompanying drawings. Although various features may be discussed with respect to certain embodiments and figures, all embodiments may include one or more of the features discussed herein. Although one or more particular embodiments may be discussed herein as having certain advantageous features, each of such features may also be integrated into various other embodiments of the invention discussed herein (except where such integration is incompatible with other features thereof). In a similar manner, although exemplary embodiments may be discussed below as system or method embodiments, it should be understood that such exemplary embodiments may be implemented in a variety of systems and methods. Additionally, U.S. patent application entitled "DEVICE FOR FLUID SAMPLING" (DEVICE FOR FLUID SAMPLING), filed on 16/2/2011 in the name of the same inventor, is hereby incorporated by reference in its entirety.

Drawings

FIG. 1 is a schematic view of a composite flexible wall and its general shape remembered before and after assembly and the forces exerted by the flexible wall

FIG. 1-A positions a-1, a-2, a-3; position a-1 wall before assembly; a-2 position of the wall after assembly and a-3 position of the wall after ejection

FIG. 1-B positions B-1, B-2, B-3; position b-1 of the wall before assembly, position b-2 of the wall after assembly; by flexible walls to a permanent volume b-3

FIG. 2 Container with composite wall

Figure 2-a container with composite walls-showing a permanent tendency to remain in a flat position, thereby creating an overpressure in the chamber

FIG. 2-B Container with composite walls-showing the permanent tendency to remain inflated at a location defining an interior space, creating an under-pressure in the chamber

FIG. 2C depicts a shape memory component comprising two straight sides and two curved sides

FIG. 2D depicts a sampling bag including the shape memory component of FIG. 2C, the sampling bag shown in a flattened state

FIG. 2E depicts a perspective view of the sampling bag shown in FIG. 2D in an expanded or filled state, the design of the shape memory component resulting in a "pillow" shaped sampling bag with taut and less wrinkling on the sidewalls

Fig. 3 cross-section of a multi-layer flexible wall comprising a material with shape memory-cross-section of a seam: 3 a-side wall; 3 b-a flexible wall pivotally connected; 3 c-flexible walls with thinner sections as flexible hinges; 3 d-flexible wall with edge rotating in the profiled sleeve; 3 e-flexible walls with edges connected by rings

FIG. 4A container with a sampling tube and flow restrictor connected in series

FIG. 5 container connected in series with colorimetric cylinder

FIG. 6 Container connected in series with Collision device

Fig. 7 a sampling device hanging on a container-lapel on a belt for personal sampling in the respiratory area

FIG. 8 schematic of direct sampling with pump and sampling bag

FIG. 9 schematic of indirect sampling with pump and sampling bag

FIG. 10 schematic of indirect sampling with a large hand-driven syringe-type pump and internal sampling bag

Fig. 11 hard-walled container-canister for vacuum sampling: a is 0.4L; b-15.00L

Fig. 12 a sampling pouch with internal moving parts.

Detailed Description

An embodiment of a sampling bag is shown in fig. 1A and 1B. The embodiment of the sampling bag includes a flexible wall. The flexible wall may be mounted in different configurations in different embodiments to provide different forces. The flexible wall includes means for imparting motive force to the wall of the sampling bag. In an embodiment, the flexible wall may include at least one shape memory component. The shape memory component may be a component that provides a biasing force towards the initial configuration, such as a panel or leaf spring. In certain embodiments, the shape memory component is incorporated into the wall of the container. In some embodiments, the shape memory component may be incorporated into the container wall such that the shape memory component will not come into contact with the fluid within the container. In other embodiments, the shape memory component may be incorporated into the container such that the shape memory component does not prevent deflation of the container such that the container has substantially zero internal volume. As used herein, "substantially zero internal volume" means that the internal volume can be compressed to less than 5% of the total volume of the substantially fully expanded volume of the container.

The motive force or shape memory component may bias the walls away from or toward each other, depending on the desired initial or "as is" configuration of the shape memory component incorporated into the container. The shape memory component can be any component that can be deformed by a force and will return substantially to its original shape when the force is removed. The shape memory element may be used to increase or decrease the volume of the pouch when the shape memory element returns substantially to its original shape and the container returns to the original configuration.

An embodiment of a sampling bag is shown in fig. 1A. The shape memory component 15 has an original curved shape and is arranged with the convex sides adjacent to each other. Although not shown, the shape memory element can have any shape, including rectangular, square, triangular, circular, oval, or other shape. In addition, the shape memory element can be bowl-shaped such that a force can be applied to flatten the center of the bowl and upon removal of the force, the shape memory element returns substantially to its original bowl shape. For example, the embodiment of the sampling bag 8 shown in FIG. 2 includes two generally rectangular shape memory elements 15. In the embodiment of fig. 2, the shape memory component occupies a substantial portion of the wall of the sampling bag 8. Alternatively, the shape memory component may comprise apertures, slats or ribs.

Returning to fig. 1A, the shape memory component 10 may be incorporated into the wall of a container having flexible walls such that the shape memory components are compressed flat against each other, as shown in fig. 1A-a 2. The container is configured to hold the shape memory components pressed flat against each other. If the container shown in fig. 1-a is filled with a fluid, the flexible composite wall with shape memory will distort.

Another embodiment of a container or sampling bag is shown in fig. 1-B. In this embodiment, the two shape memory elements in the flexible wall are arranged with their convex sides adjacent to each other. In such an embodiment, the flexible wall exerts a flexible force that tends to open the container, thus creating a moderate under-pressure within the container or sampling bag. This moderate under-pressure generates the driving force to cause the fluid to fill the container or sampling bag and complete the sampling without the need for an external energy source. The direction of the fluid moving by the force expressed by the flexible wall is shown with an arrow. The embodiment depicted in fig. 1 demonstrates the versatility and variety of containers and sampling bags that can be designed with flexible walls with their unique properties to displace fluids instead of more complex systems. The shape of the shape memory component and the movement constraints of the shape memory component due to the flexible wall design create a sampling bag or container with a consistent full fill volume.

FIG. 2-A shows a perspective view of an embodiment of a sampling bag having a shape memory component similar to that shown in FIG. 1-B. The embodiment with the flexible wall is in a flat position, whereby a force can act on the flexible wall. The flexible wall 10 of the sampling bag comprises a shape memory component. In the embodiment of fig. 2-a, the shape memory component fits inside the composite material of the flexible wall and does not overlap the entire area of the flat wall. In the drawings, two sides of this part are bounded by dotted lines, and the other two sides have a common seam 12 with the other parts of the composite wall. In some embodiments, the shape memory component will be sandwiched between other layers of the multilayer flexible wall.

Further on fig. 3, the type of seam with or without shape memory elements is illustrated in more detail. The shape memory component 15 of the flexible wall 10 of the embodiment shown in fig. 2 is shown in cross-section. In this embodiment, the shape memory element 15 is substantially rectangular or has a similar shape. The two opposite side edges of the wall 10, which contain the component 15 inside, are hinged or in a movable sealing connection by means of a seam 12. The end of the memory member 15 partially contained in the wall 10 is shown in phantom on fig. 2A. Thus, when the inlet/outlet 20 of the device is opened, fluid can enter and fill the negative pressure space inside the device by the movement of the shape memory component. In such an embodiment, the device substantially takes a cylindrical shape, as shown in fig. 2-B. The sidewall 11, without the shape memory element 15, forms the other two sides of the substantially cylindrical sampling volume. The flexible force of the walls 10 helps to tension those side walls, thereby defining substantially the same reproducible volume each time the device is filled with fluid.

The embodiment of the flexible-walled container of fig. 2-B is shown in an open state with the shape memory component in a "relaxed" or original shape. In one embodiment of the sampling method, the sampling method includes applying a force to the flexible wall. When a force is applied to the flexible wall, the sample bag is flattened and the volume inside the sample bag is reduced. Upon application of sufficient force, the volume in the sample bag may be reduced to almost zero and the fluid in the sample bag is substantially emptied. Upon release of the force, the flexible wall will return to its original shape. The repeated application and removal of force to the flexible wall allows the sample bag to be substantially completely flattened and then expanded, thereby purging any contamination from the previous fluid contents.

Repeated washing of the contents permits dynamic equilibrium to be reached between the fluid mixture sampled on the inner sidewall and the removal of any chemical compounds adsorbed on the inner wall of the sample bag. Such a balance cannot be achieved with any conventional sampling system or method used with conventional sampling bags. Conventional sampling bags can only be filled once by any known grab sampling method.

The embodiment of the device of fig. 2 is shown with a universal inlet/outlet 20, but one of ordinary skill in the art can appreciate that any alternative to inlet/outlet 20 can be used. The inlet/outlet of embodiments of the container or sampling bag may have any desired design. Embodiments of the container or sampling bag may have multiple inlets/outlets. The inlet/outlet may be a dedicated valve 22 or 24 as shown, which may be used, for example, when specifically needed.

Embodiments of containers or sampling bags such as the embodiments shown in fig. 1A, 1B, 2A and 2B are extremely simple and reliable when a direct grab sampling of a fluid such as air is required. The ability to flush the device several times with the fluid being sampled has numerous advantages over existing methods and devices. The original walls from the low sorption material used in any known device have a small number of active sites that can be sorbed, but the sites are important when the target substance (contaminant) is relatively low (e.g., in the Parts Per Million (PPM) or Parts Per Billion (PPB) range). Even in a freshly filled sampling bag assuming no diffusion through the wall, the recovery rate for the first filling of the sampling bag can be 85-90% due to adsorption on the wall. Recovery is defined as the percentage of the amount of compound as indicated by the analysis compared to the actual amount of compound in the sample environment. Thus, when using a design according to the invention and completing several flushes with the sample fluid, for a given concentration, even a low concentration, this will result in a high recovery close to 100%. In FIG. 2E, an embodiment of a shape memory component is depicted. The part expressing flexibility 15 (fig. 2-C) has a shape similar to a "pillow" shape, with two parallel opposite sides. This shape of the pouch 40 when fully inflated helps to provide good pull-up of the flexible side wall 11 without wrinkling, thus defining a highly reproducible volume. When the bag is intended to act as a driving force for a moderate negative pressure, a bag with a reproducible volume is required. This shape may be advantageous and is incorporated into the embodiments shown in fig. 4,5, 6 and 7.

As already mentioned, the device is shown with a simple inlet/outlet 20, which may be replaced by a suitable valve 22 or 24 and/or a connector or connecting line 44, as shown in fig. 4 to 7. Replacing the inlet/outlet port 20 with an appropriate valve 22 or 24 (not discussed herein and below in construction) having preset flow properties or capable of flow regulation and adjustment can provide important features such as long term sampling-15, 30, 60 minutes or 8 hours, and the ability to take samples through a septum fitted directly into the valve or its cap. It is contemplated that such valves have open/close functionality and/or components to regulate fluid flow. Such valves may be integral to the valve, or may be interchangeable to achieve different flow rates.

Different embodiments of portions of the flexible wall 10 are shown in fig. 3. The cross-section of the flexible wall in fig. 3-a of the flexible wall according to the invention comprises a flat shape-memory component 15 and a side seam 12 between two opposite sides of the opposite wall 10 containing the component 15. The other sides may have the same type of seam or may involve a direct connection between the shape memory elements 15. The embodiments of the portions of the flexible wall shown in fig. 3b and 3c have a direct connection between the shape memory components. Such a direct connection may comprise a thinner portion of the same flexible material as shown in fig. 3-c, a pivoting connection that may provide edge of material with shape memory as shown in fig. 3-b, another connecting member, or a combination of connecting members. In these embodiments, the shape memory component 15 is sandwiched between the other components of the composite flexible wall 10. However, the shape memory component may also be an inner or outer layer of the composite flexible wall, or the flexible wall may be composed entirely of shape memory components.

Embodiments of the container or specimen bag may be used for taking samples over an extended period of time. Embodiments of the container, such as, but not limited to, the embodiments shown in fig. 1-B and 2, may provide a moderate under-pressure source in combination with other sampling devices. Some sampling devices require particularly small pressure differentials for extended periods of time. Thus, various long-term sampling devices are given here and hereafter as examples. The embodiments depicted in fig. 4,5 and 6 include a sampling bag with flexible walls. A sampling bag having a flexible wall comprises a particular volume when in an open or relaxed state with no substantial force applied to the flexible wall. In this open or relaxed position, a sampling bag with flexible walls may include a shape memory component that is not in its original position. The flexible wall prevents the shape memory component from returning completely to its original shape. However, the sampling bag in this position comprises a tensioned side wall 11, and thus the volume of the bag remaining open is limited to a certain volume that is reproducible. The shape of the shape memory component and the sampling bag wall can be modified to work together to create a sampling bag that can be flattened to reduce volume and inflated to a reproducible volume. The embodiment of the sampling bag shown in fig. 2-E comprises a combination of rectangular walls and a shape memory component, which can be inflated to a configuration with a taut sidewall 11, thus providing better reproducibility of the sampling volume. In the embodiment of fig. 4, a sorbent-containing sampling tube 32, such as one having charcoal or silica gel, is coupled to inlet 24 of the sampling bag. In this embodiment, the flow restrictor 27 is installed in the conduit 44 after the sampling tube 27. A flow restrictor may be used to allow only a particular flow rate of fluid therethrough. The type of flow restrictor may adjust the appropriate sampling rate. The traffic limiter may be, for example, one of the group relating to: a particulate flow resistor (filled with glass or ceramic powder), a filter or a membrane with a known flow rate per unit area, or a limited or critical orifice fitted in a convenient manner in the tube 27 or directly in the valve 22 or 24. Sampling volumes from one liter up to several liters can be easily achieved using this scheme. The use of the flow restrictor 27 may serve the need for medium (minutes to hours) to long term sampling of more than one work shift, week or even month. The great advantage is that not only are pump flow meters and other equipment not used, but also no manpower is involved in the sampling process. As such, some of these embodiments may be considered self-sampling devices. One person can perform long-term sampling at several different locations simultaneously. Another great advantage is that the device can easily be designed to be cost-safe and can even be used in harsh environments where the use of other devices would be problematic. Embodiments of the sampling device may be a self-sampling device. The self-sampling device may be placed in a location and allowed to "self-inflate" over a period of time. The sampling bag can then be collected and sent for analysis.

A great advantage in all the shown sampling designs is their versatility. The sampling may be set to a predetermined volume, a predetermined sampling time, or to a predetermined gas flow using a different flow restrictor, if necessary. No flow meter and no pump are required.

The use of the basic design of the container of the present invention is not limited to sampling as explained herein and can be used in many situations when a moderate negative pressure differential is required as the driving force for fluid flow, including industrial or medical uses.

Embodiments of both basic types of air sampling containers according to the present invention may have many unique features and thus advantages over conventional sampling bags, for example, some embodiments have some or all of the following enumerated features:

without any type of pump to expel or fill the fluid into the container

No battery charging and maintenance

No pump calibration

Extremely simple to operate

-inexpensive sampling procedure

Higher recovery at sampling-in some applications, the recovery may be close to 100%

Potential reduced adsorption onto the walls of the pipeline or internal pump

Potential reduced non-cross-contamination

All directly sampled volumes are available compared to using smaller parts of the tank and bottle

Light and energy-independent containers

The container is intrinsically safe and provides intrinsically safe sampling

Ready for sampling

Many containers can be fitted with relatively small volumes when empty and the inlet closed, portability being extremely important for field sampling.

The extreme versatility required for sampling, as follows:

-the container can be used as a main sampling volume to store sampled air, gas or gas mixture;

the container can be used as a main driving force source in combination with an adsorption sampling tube at a fixed sampling volume (sampling volumes from 10ml to 5,000 or even 10,000ml are achievable);

the container can be used as a driving force source in combination with a cuvette, provided that the system container/tube is calibrated together at a fixed sampling volume. Any finite time of 15 minutes STEL sampling or 30 minutes. The highest concentration or 480 minute (all shift length) TWA or TLV sampling can be achieved with a predetermined volume of 100, 200, 500 to > 10000 ml/sample;

the container according to the invention can be calibrated in conjunction with a filter cartridge for an aerosol or liquid impactor of predetermined sampling volume.

The embodiments of the described methods and sampling bags with flexible walls are not limited to the specific embodiments, method steps, and materials disclosed herein, as such formulations, process steps, and materials may vary somewhat. Also, the terminology used herein is for the purpose of describing exemplary embodiments only and is not intended to be limiting, as the scope of the various embodiments of the present invention will be limited only by the appended claims and equivalents thereof.

Thus, although embodiments of the present invention have been described with reference to exemplary embodiments, those skilled in the art will appreciate that variations and modifications may be effected within the scope of the invention as defined by the appended claims. Accordingly, the scope of various embodiments of the present invention should not be limited to the embodiments discussed above, but should be defined only by the appended claims and all equivalents thereof.

Claims (18)

1. A fluid container, comprising:

a flexible wall having an initial configuration, wherein the flexible wall comprises an interior layer defining an interior volume and a shape memory layer comprising a memory shape component; and wherein upon deformation of the memory shape member, the memory shape member provides a biasing force toward an initial configuration; and an outer layer, wherein the memory shape member is incorporated into the flexible wall such that the memory shape member is not in contact with fluid within the container, and wherein the memory shape member comprises a material capable of being deformed from an initial shape by application of a force and returning to its original shape after removal of the force;

an inlet/outlet in communication with the interior layer, wherein the inlet/outlet provides access to the interior volume of the fluid container; and

a shut-off valve connected to the inlet/outlet.

2. The fluid container of claim 1, wherein the inner layer comprises at least one of a polyolefin, polypropylene, polyethylene, polyfluoro plastic, PTFE, teflon.

3. The fluid container of claim 1, wherein the initial shape of memory shape component comprises a U-shaped, V-shaped, circular, arcuate, or parabolic cross-section.

4. The fluid container of claim 3, wherein the memory shape component has a rectangular, square, triangular, circular, "pillow" shape with two parallel sidewalls, or oval shape.

5. The fluid container of claim 1, wherein the memory shape component is capable of biasing the fluid container toward an inflated configuration.

6. The fluid container of claim 5, wherein the fluid container is a fluid sampling bag.

7. The fluid container of claim 1, wherein the memory shape member is configured to bias the fluid container toward a deflated configuration.

8. The fluid container of claim 7, wherein the fluid container is a fluid delivery pouch.

9. The fluid container of claim 6, comprising two memory shape members, wherein each memory shape member comprises concave sides, and in the sampling bag, the concave sides face each other.

10. The fluid container of claim 8, comprising two memory shape members, wherein each memory shape member comprises raised sides, and the raised sides face each other in the fluid delivery bag.

11. The fluid container of claim 1, wherein the inner layer comprises stainless steel, nickel, or aluminum.

12. The fluid container according to claim 1, wherein the inner layer comprises stainless steel comprising a thin surface sublayer or a chemically inert metal oxide coating.

13. The fluid container of claim 12, wherein the outer layer comprises at least one material selected from the group comprising: metallized polyester, polyurethane, nylon.

14. The fluid container of claim 1, wherein the fluid container is configured such that an internal sampling volume is compressed to substantially zero volume.

15. The fluid container of claim 1, comprising a sorbent-containing coupon coupled to the inlet of the fluid container.

16. The fluid container of claim 15, comprising tubing and a flow restrictor after the sampling tube.

17. The fluid container of claim 1, wherein the shut-off valve includes a means to regulate flow through the shut-off valve, and the adjustment provides long-term sampling for a 15, 30, 60 minute, or 8 hour period.

18. The fluid container of claim 1, comprising a diaphragm mounted within the shut-off valve.