Apparatus and method for convective flow assisted penetration assessment of materials against chemicals

Abstract

The present disclosure relates to a penetration test cell (600, 1000) for testing the penetration of a chemical to a material, comprising an upper body (602) provided with an upper cell cover (606) having a first vent hole and a lower body (604) provided with a lower cell cover (608) having a second vent hole. A test sample (612, 1006) is disposed in a penetration test cell (600, 1000). A liquid contaminant (610, 1004) is added to the test sample. After the test sample (612, 1006) is contaminated, the gas flow passes through the upper cell cover (606) and the lower cell cover (608) in a direction perpendicular to the surface of the test sample (612, 1006) to assist penetration of contaminants (610, 1004) through the test sample. The lower cover (608) is provided with a cavity to store an adsorbent material for accumulating permeate contaminants in the adsorbent material.

Description

Technical Field

[0001] The present invention herein generally relates to apparatus and methods for permeation testing of materials, and more particularly to apparatus and methods for permeation testing of materials used in protective clothing for toxic chemicals, especially chemical warfare agents or simulants thereof. Background Art

[0002] Toxic chemicals, especially chemical warfare agents (CWA), are being used in asymmetric warfare across borders and even among civilian populations. There is great concern about exposure of personnel involved in handling these agents to CWAs, or incidents related to personnel coming into contact with these hazardous chemicals in vapor or liquid form. Efforts are ongoing to improve the protective clothing required of individuals to protect against toxic chemicals, especially CWAs. The functional performance of these protective clothing needs to be evaluated against the relevant chemicals in penetration configurations that simulate real-life scenarios.

[0003] There are many methods for measuring the penetration of toxic chemicals. U.S. Army Test Operating Procedures 08-2-501 (TOP) and 08-2-503 (TOP) are one of the methods for measuring the penetration of toxic chemicals (especially CWA) or their irritants. After TOP testing, other conventional techniques must be used to measure the contaminants that have penetrated the protective material. There are a variety of techniques for measuring quantitative penetration density. These techniques include the use of a chemical agent monitor (CAM), or desorption through a sorbent tube placed at the outlet of the lower body of the penetration test cell, followed by evaluation by chromatographic or spectroscopic techniques.

[0004] TOP specifies the devices and protocols for permeation measurements based on the permeation configuration and permeation mode. The permeation configuration is based on the physical state of the chemical under permeation conditions. The permeation configuration includes liquid contaminant vapor detection (L / V) configuration or vapor contaminant vapor detection (V / V) configuration or liquid contaminant liquid detection (L / L) configuration. The permeation mode is based on the flow of air / gas and its influence on the direction of permeation caused by it. The permeation modes include static diffusion mode, dual flow mode and convection flow mode, which conform to the real permeation scenarios under the action of airflow. In static diffusion mode, there is no flow of dry air / inert gas and permeation drive due to the concentration gradient between the upper and lower bodies of the permeation cell and gravity. Only with L / V and L / L configurations can the permeation of chemicals in protective materials be evaluated in static diffusion mode. In dual flow mode, the dry air / inert gas flow or contaminant in the form of vapor passes above and parallel to the contaminated sample and affects the permeation due to the flow of dry air / inert gas above the contaminant. The permeation of chemicals in protective materials can be evaluated in dual flow mode with the three permeation configurations of L / V, L / L and V / V. In counterflow mode, contaminants in the form of air / inert gas stream or vapor are delivered through the sample. Evaluation of chemical penetration through barrier materials in counterflow mode is only possible with L / V and V / V permeation configurations.

[0005] Figure 1A A schematic diagram showing a sealed view of a penetration test cell (100) according to the prior art as described in TOP 08-2-501 is shown. Figure 1B An unassembled view of a permeation cell (100) for L / V and V / V configurations in static diffusion and dual flow modes according to the prior art as described in TOP 08-2-501 is shown. Figure 2A An unassembled view of a penetration test cell according to the prior art as described in TOP 08-2-501 is shown. Figure 2B A sealed view of a penetration test cell (200) for L / V and V / V configurations in convection flow mode as described in TOP 08-2-501 according to the prior art is shown.

[0006] According to TOP 08-2-501, in static diffusion and dual flow modes in L / V and V / V configurations, a dry air / inert gas flow is also passed through the lower body of the permeation cell to sweep the permeate contaminants into adsorbent tubes composed of adsorbent materials. The permeate density is quantified using a chemical agent monitor (CAM) or desorbent materials available in adsorbent tubes / bubblers placed at the outlet of the lower body of the test cell, and then quantified using chromatographic / spectroscopic techniques. The dry air / inert gas flow at ambient temperature may not be able to completely vaporize the permeate contaminants, especially in the case of low volatility CWAs (such as VX and Novichokes), and therefore the accuracy of the method is compromised. Figure 3 shows the test conditions in the L / V configuration according to TOP 08-2-501A, and Figure 4 shows the test conditions in the V / V configuration according to TOP 08-2-501A.

[0007] TOP 08-2-501 further covers methods for penetration testing of protective materials using expulsion mode, reverse expulsion mode, and mandrel mode in a liquid contaminant liquid detection (L / L) configuration to qualitatively evaluate the resistance of protective materials to toxic chemicals (especially CWA) or their simulants under external pressure. Expulsion mode is very important for protective materials to be evaluated under external pressure based on real-life scenarios where personnel wearing protective equipment touch contaminated surfaces or grasp contaminated objects. According to TOP 08-2-501, there are differences in the contamination density of penetration testing in conventional L / V, V / V, and L / L expulsion penetration modes. According to TOP 08-2-501, the contamination density is 10g / m in L / V configuration and V / V configuration using all static diffusion modes and dual flow modes. 2 , applied as 8 or 10 drops (1 μL each) of a single chemical formulation to a 10 cm 2 The sample area is 2.5 g / m2, while in the qualitative expulsion mode, the contamination density is 2.5 g / m2. 2 , applied as a single drop of 5 mg of chemical preparation to a 20 cm 2 The evaluation of materials using the expulsion mode is purely qualitative in nature and the breakthrough time is measured by comparing the penetration density of the chemical formulation.

[0008] TOP 08-2-503 provides a standard method for testing the permeability of low volatility chemicals (such as persistent nerve agents, such as VX) through protective material swatches in an L / L configuration. Figure 5 shows a repelling test apparatus (500) as described in TOP 08-2-503 according to the prior art. The apparatus (500) consists of a cylindrical stainless steel weight (502) (453.6 gm) applied to a test sample (504) carrying a drop of chemical agent / contaminant (506). According to TOP 08-2-503, an adsorption disc (508) is used below the test sample (504) to adsorb / absorb the amount of liquid form contaminant (506) that has penetrated. The method is suitable for quantitative repelling mode, in which the permeation is evaluated under pressure to simulate the real-life scenario of a protective clothing wearer contacting a contaminated surface or holding a contaminated object. In the repelling test mode, an external pressure of 1 psi is applied to the material contaminated with a single drop of chemical agent (5 mg pure agent or 8 mg thickened agent). According to TOP 08-2-503, the penetration density is calculated by extracting the contaminant from an adsorption disk placed under the test sample (504) swatch and then evaluating it using chromatographic / spectroscopic techniques. The use of adsorption disks in TOP 08-2-503 makes this method more expensive.

[0009] Low volatility chemical warfare agents (CWA) are the most dangerous due to their low dermal lethal dose (LD60) values ​​and their high ability to penetrate the wearer's skin. Therefore, the accuracy of the assessment of the penetration of low volatility CWA (such as VX and Novichokes) into protective materials in a convective flow mode with an L / V configuration is very important. TOP 08-2-503 does not describe an apparatus and method for quantitatively assessing the penetration of low volatility chemicals into protective materials in a convective flow mode with an L / V configuration. In addition, both TOP 08-2-501 and TOP 08-2-503 describe methods in which larger sample swatches (exposed area 10 cm 2 ) devices and methods, therefore, require large amounts of toxic pollutants, especially chemical warfare agents, to maintain the specified contamination density (10 g / m 2 ), which creates a greater threat of exposure.

[0010] Therefore, in view of the above limitations, there is a need for an apparatus and method to achieve quantitative testing of the penetration of contaminants through protective materials, simulating environmental conditions where air directly impinges on the contaminated surface and supplements the further penetration of contaminants.

[0011] Purpose of the Invention

[0012] The general object of the present invention is to devise an apparatus and method for permeation testing of protective materials in convection mode in order to be able to quantify the permeation density of chemical contaminants.

[0013] Another object of the present invention is to provide an apparatus and method for penetration testing that injects a high degree of confidence into the protective capabilities of the tested material, with low testing costs and minimal variation in test results for the same sample.

[0014] Another object of the present invention is to provide an apparatus and method for permeation testing to measure the resistance of materials used in protective clothing (such as tights, gloves, shoes, masks, backpacks, body bags, etc.) to toxic chemicals (especially chemical warfare agents or their simulants).

[0015] It is yet another object of the present invention to provide an apparatus and method for penetration testing that simulates conditions that reflect more realistic environmental scenarios encountered in real life. Summary of the invention

[0016] This Summary is provided to introduce aspects related to devices and methods for convective flow-assisted assessment of penetration of chemical contaminants through materials, and these aspects are further described below in the Detailed Description. This Summary is not intended to identify essential features of the claimed subject matter, nor is it intended to be used to determine or limit the scope of the claimed subject matter.

[0017] To achieve the above-mentioned object, according to one aspect of the present invention, a penetration test pool is disclosed. The penetration test pool may be designed to include an upper body and a lower body. The upper body may be provided with an upper pool cover having a first vent, and the lower body may be provided with a lower pool cover having a second vent, allowing airflow to be transferred from the upper pool cover to the lower pool cover. Contaminants may be placed on the upper side of a test sample, and the test sample may be placed between the upper body and the lower body. The airflow may be transferred from the upper pool cover to the lower pool cover in a direction perpendicular to the surface of the test sample to assist the penetration of the contaminants through the test sample.

[0018] In one aspect of the present invention, a cavity may be provided in the lower body to store an adsorbent material for accumulating contaminants that permeate through the test sample.

[0019] In one aspect, the permeation test cell may include a first O-ring and a second O-ring to prevent contaminants from leaking from the edge of the test sample. The first O-ring may be positioned to contact the upper body and the test sample, and the second O-ring may be positioned to contact the lower body and the test sample.

[0020] In one aspect, airflow may be supplied through a first vent in the upper pool cover, which serves as an inlet for release through a second vent in the lower pool cover.

[0021] In one aspect, a first perforated polytetrafluoroethylene (PTFE) layer can be placed over the contaminants to contain the contaminants on the test sample.

[0022] In one aspect, a circle of colorimetric test paper may be placed under and around the test sample to determine leakage of contaminants from the edges of the test sample.

[0023] In one aspect, a second PTFE layer can be placed between the test sample and the adsorbent material to block contaminants from penetrating through the test sample and to prevent contaminants from leaking from the edges of the test sample to the adsorbent material.

[0024] In another aspect, a method for testing the penetration of a chemical contaminant through a material is described. The method may include providing an upper body including an upper cell cover for transmitting an airflow to a lower cell cover present in a lower body. The contaminant may be applied to the upper side of a test sample, wherein the test sample is placed between the upper body and the lower body. The upper body of the test cell may be sealed from the lower body. An airflow may be supplied in a direction perpendicular to the surface of the test sample to assist the penetration of the contaminant through the test sample.

[0025] In one aspect, the cavity in the lower body can be filled with an adsorbent material that serves to accumulate contaminants that permeate through the test sample.

[0026] In one aspect, airflow may be supplied through a first vent in the upper pool cover, which serves as an inlet for release through a second vent in the lower pool cover.

[0027] These and other aspects of the embodiments herein will be better understood and appreciated when considered in conjunction with the following description and accompanying drawings. It should be considered, however, that the following description, while indicating preferred embodiments and details thereof, is for illustration only and not limitation. Changes and modifications may be made within the scope of the embodiments described herein without departing from the spirit thereof. The embodiments herein include all such modified embodiments.

[0028] BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings are used to provide a further understanding of the present invention. These drawings illustrate embodiments of the present invention for describing the principles of the present invention. In the pictures of the accompanying drawings, the embodiments are illustrated by way of example and not limitation, wherein similar reference numerals represent similar elements. It should be noted that the "one" or "an" embodiment mentioned in the present invention is not necessarily the same embodiment, and they refer to at least one embodiment. In the drawings:

[0030] FIG. 1(A) shows a schematic diagram of a sealed view of a penetration test cell according to the prior art as described in TOP 08-2-501;

[0031] FIG. 1(B) shows an unassembled view of a permeation cell for L / V and V / V configurations in static diffusion and dual flow modes as described in TOP 08-2-501 according to the prior art;

[0032] FIG. 2(A) shows an unassembled view of a penetration test cell according to the prior art as described in TOP 08-2-501;

[0033] FIG. 2(B) shows a sealed view of a penetration test cell for L / V and V / V configurations in convection flow mode as described in TOP 08-2-501 according to the prior art;

[0034] FIG3 shows the test conditions under the L / V configuration according to TOP 08-2-501A according to the prior art;

[0035] FIG4 shows test conditions in a V / V configuration according to TOP 08-2-501A according to the prior art;

[0036] FIG5 shows an apparatus for an expulsion test according to the prior art as described in TOP 08-2-503;

[0037] FIG. 6(A) shows a sealing view of a penetration test cell according to an embodiment of the present invention;

[0038] FIG6(B) shows an unassembled view of a schematic diagram of a penetration test cell according to an embodiment of the present invention;

[0039] Figure 7 The test parameters of the convective flow assisted quantitative penetration test method in the L / V configuration according to an embodiment of the present invention are shown;

[0040] Figure 8 The characteristics of a three-layer composite material based on activated carbon balls (ACS) and a three-layer composite material based on activated carbon fabric (ACF) tested for relevant chemicals according to an embodiment of the present invention are shown;

[0041] Fig. 9 shows average penetration and standard deviation results for many replicates of ACS and ACF test samples according to embodiments of the present invention;

[0042] 10(A), 10(B) and 10(C) show schematic diagrams of an improved penetration test cell for measuring penetration in an L / V configuration with a convection flow mode according to an embodiment of the present invention; and

[0043] Fig.11 A method of conducting convective flow assisted penetration testing of contaminants in an L / V configuration according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0044] The following detailed description related to the drawings is intended as a description of various embodiments of the present invention, and is not intended to represent the only embodiment in which the present invention can be implemented. Various features of the present invention are fully explained with reference to non-limiting embodiments. In order to simplify the description, the details of commercially available and well-known components and their use processes are not included in the embodiments mentioned here. The examples given herein should not be interpreted as limiting the scope of the embodiments given herein, and are intended to promote the understanding of those skilled in the art to the way in which the embodiments can be practiced.

[0045] The present invention relates to an apparatus and method for convective flow-assisted permeation assessment of materials against chemical contaminants. FIG. 6(A) shows a sealed view of a permeation test pool (600) according to an embodiment of the present invention. As shown in FIG. 6(A), the permeation test pool (600) may include an upper body (602) and a lower body (604). The upper body (602) may include an upper pool cover (606) having a first vent. The lower body (604) may include a lower pool cover (608) having a second vent. The upper pool cover (606) and the lower pool cover (608) may be used to pass airflow from the upper body (602) through the lower body (604) in the permeation test pool (600). In one embodiment, the permeation test pool (600) may be made of 316 grade stainless steel to reduce the possibility of corrosion due to the use of highly corrosive toxic chemicals, especially chemical warfare agents or their simulants.

[0046] Fig. 6 (B) shows an unassembled view of a schematic diagram of a penetration test pool (600) according to an embodiment of the present invention. A test sample (612) may be placed between the lower body (604) and the upper body (602). The lower body (604) may be provided with a cavity to be filled with an adsorbent material for accumulating pollutants (610) that have penetrated the test sample (612). To ensure that the adsorbent material contacts the surface of the test sample (612) fabric sample, the lower pool cover (608) may be filled with glass wool and tightened to the lower body (604). The pollutant (610) may be placed on the upper side of the test sample (612). The penetration test pool (600) may include an O-ring (614-n) positioned between the upper body (602) and the lower body (604). The O-ring (614-n) may be used to prevent the pollutant (610) from leaking from the edge of the test sample (612). For example, a first O-ring (614-1) can be positioned to contact the upper body (602) and the test sample (612). A second O-ring (614-2) can be positioned to contact the lower body (604) and the test sample (612). Glass wool can also help retain the adsorbent material in the lower body (604). After the test sample (612) with the contaminant (610) is placed between the upper body (602) and the lower body (604), the upper body (602) and the lower body (604) of the permeation test cell (600) can be sealed using screws (616-n).

[0047] In one embodiment, the penetration test cell (600) can be adapted to a minimum diameter of 1.5 cm and an exposed surface area of ​​1.0 cm 2 The protective material sample swatch. The penetration quantification of the contaminant (610) can be performed in a liquid contaminant vapor detection (L / V) configuration with a limited number of test samples (612) and a limited number of contaminants (610) in a convection flow mode. The upper surface of the protective material test sample (612) can be challenged with a single drop of 1.0 mg / 0.8 mg of the contaminant (610) to maintain 10 g / m 2 The desired contamination density can be measured. After placing the contaminant (610), the upper pool cover (606) of the penetration test pool (600) can be closed. Airflow can pass through the upper pool cover (606) above the test sample (612) to assist the contaminant (610) in penetrating the test sample (612) by convective flow. The contaminant (610) that penetrates the test sample (612) can be adsorbed by the adsorbent material below the test sample (612). The penetration test pool (600) can be placed in a constant temperature box for temperature control to simulate the desired environmental control. Then, in a scenario where air flows over / through the test sample (612) to affect the penetration of the contaminant (610), the penetration density of the material can be quantified. The penetration is quantitatively determined by desorbing the contaminant from the adsorbent material using a solvent and analyzing it using chromatographic techniques. Figure 7 The test parameters of the convective flow assisted quantitative penetration test method in the L / V configuration according to an embodiment of the present invention are shown. The contamination density can be varied according to the requirements of the penetration test conditions.

[0048] The permeation test cell (600) is suitable for evaluating materials for permeation against low volatility agents such as VX and Novichokes because by filling the lower body (604) with an adsorbent material, the contamination path length is minimized, thereby eliminating the need for an adsorbent tube. Therefore, there is no possibility of low volatility contaminants remaining on the walls of the lower body (604) causing misleading permeation results. By using limited test samples (612), limited challenge contaminants (610), and using adsorbent materials instead of adsorbent discs or adsorbent tubes, the method used to perform permeation testing on materials using the permeation test cell (600) increases the confidence in the material's protective capabilities and reduces the cost of operating the test.

[0049] Some test methods performed to measure the penetration of contaminants through materials are described below by way of non-limiting examples. Figure 8Two materials, a three-layer composite based on activated carbon spheres (ACS) and a three-layer composite based on activated carbon fabric (ACF), are shown for testing against a related compound, VX, a CWA. The permeation test was conducted for six hours. More than 10 replicates were tested for each composite and a minimum of 10 control samples were tested. The test method used was based on the permeation test developed in the convection mode in the L / V configuration described above. Figure 8 The test parameters mentioned in . Fig. 9 The average permeation and standard deviation results for each replicate of the test sample tested are shown. It is observed that the standard deviation (SD) of the contaminant permeation is larger, especially for the ACS composite material, which may be caused by the non-uniformity of the replicate test samples. Obviously, the present invention provides an improvement over the conventional test method to achieve quantification of permeation and temperature control.

[0050] Even though the O-ring (614-n) is tightened at the edge, it is still possible for the contaminant (610) to pass through the edge of the test sample (612) and reach the lower body (604) instead of passing through the test sample (612). Such leakage of the contaminant (610) may cause the test method to fail. To rule out this situation, the integrity of the permeation test cell (600) can be checked to ensure that the contaminant (610) does not leak from the edge of the test sample (612) in the adsorbent material.

[0051] Figures 10(A), 10(B) and 10(C) show schematic diagrams of a permeation test cell (1000) for measuring permeation in an L / V configuration with convective flow according to an embodiment of the present invention. As shown in Figure 10(A), a first perforated polytetrafluoroethylene (PTFE) layer (1002) may be placed above the contaminant (1004). The first PTFE layer (1002) contains the contaminant (1004) on the test sample (1006) and may also evenly diffuse the contaminant (1004) onto the test sample (1006).

[0052] As shown in FIG10(B), a circle of colorimetric detection paper (1008) may be placed below the test sample (1006) and around the periphery of the test sample (1006). The colorimetric detection paper (1008) may assist in determining leakage of the contaminant (1004) from the edge of the test sample (1006). If the contaminant passes through the edge instead of through the sample swatch, the colorimetric detection paper (1008) will change its color.

[0053] Further, in order to establish the integrity of the penetration test cell (1000), i.e., for a given combination of contaminants and protective materials, the contaminants penetrate the test sample (1006) instead of penetrating the edge of the test sample (1006), characterization samples can be added before each batch of test samples. These characterization samples can be used to prove that the contaminants (1004) will not penetrate the edge of the test sample (1006). As shown in Figure 10 (C), the penetration test cell (1000) may include a second PTFE layer (1010). The second PTFE layer (1010) can be placed between the test sample (1006) and the adsorbent material. The second PTFE layer (1010) can block the contaminants (1004) from penetrating the test sample (1006) and can determine the leakage of the contaminants (1004) from the edge of the test sample (1006) to the adsorbent material. If any contaminants are detected in the adsorbent material, the test of the device, material and contaminant combination fails.

[0054] Various quality controls are incorporated into the test protocol for the permeation test, including purity analysis of contaminants, efficiency of the adsorbent material, positive control samples, negative control samples, verification of the amount of contaminants, testing for leaks around the edges of the test sample, and analytical controls. Quality controls are further described below with non-limiting examples.

[0055] The swatches are cut using a sharp steel die and press. For protective tights, equal amounts of swatches are taken from the front, back, arms and legs. Liquid contaminants may be added to the sample swatches using a gas-tight syringe. A calibrated balance may be used to verify the weight of the added contaminant. Solvents used in the test are of chromatography grade.

[0056] As part of the system quality control, it was determined that Fluka made ORBO TM 609 Efficiency of adsorbent material. To determine the efficiency of the adsorbent material for a specific chemical, solutions of 5 μg, 10 μg, 100 μg, 500 μg and 5 mg of the chemical in a solvent were added to 500 mg of the adsorbent material, respectively. A larger area of ​​the adsorbent material becomes wet. The total mass adsorbed conforms to the calibration curve of the analytical instrument and is within the concentration range expected to be achieved by the adsorbent material. After the solvent evaporates, the adsorbent material is taken and extracted with 20 mL of ethyl acetate for about 30 minutes, and the data is fitted to the calibration curve for quantitative determination based on a standard solution of the chemical. Other solvents may also be used as required for specific pollutants and / or analytical techniques. The extractant is analyzed by a gas chromatography-mass spectrometer (GC-MS) (not shown) with a quantitative limit of about 1 μg / mL. The detection limit can be improved using other analytical tools.

[0057] Another quality control parameter is the purity of the contaminant. Using a low purity contaminant may lead to incorrect results. In another embodiment of the present invention, an analytical technique such as a nuclear magnetic resonance (NMR) spectrometer (not shown) can be used to check the purity of the contaminant.

[0058] In another embodiment of the present invention, the repeatability of the gas-tight syringe can be checked using a gravimetric method. A calibrated electronic balance (not shown) can be used to accurately weigh the target amount into the gas-tight syringe by taking it into a vial, and the change is recorded.

[0059] In another embodiment of the present invention, the temperature of the incubator (not shown) may be set to about 32°C or any other desired value and verified using a calibrated temperature recorder (not shown). The permeation test cell (1000) may be allowed to equilibrate for at least 24 hours prior to each test. The temperature may be recorded every minute to note changes. Other temperatures may be used as required by the test conditions.

[0060] Positive control samples may be required prior to testing the actual samples or concurrently with testing. The purpose of positive control samples is to ensure the performance of the test method and apparatus used. Butyl rubber / material with known permeation density (assuming HD) and Neoprene / material with known permeation density of nerve agents (GB, GD, GA, VX, Novichokes) can be used as positive control samples under controlled conditions.

[0061] Negative control samples may also be required before or at the same time as the actual samples. Negative control samples can be identical to positive control samples, but without any contamination. The purpose of negative controls is to demonstrate that the test apparatus and method are working properly and that there is no cross contamination that may have come from tools or other test cells. For any negative control sample, no contaminants were detected above the limit of quantitation.

[0062] The analytical method used in this paper includes a calibration curve prepared from quality check samples to increase the confidence of the data. The limit of quantitation is determined by the lowest concentration standard in the calibration curve. The calibration curve should be linear with R 2 The value of is in the range of 0.995 and 0.999.

[0063] In another embodiment of the present invention, an upper limit of the deviation is evaluated and sample loss due to the interaction of the contaminants with the second PTFE layer (1010) is considered. The second PTFE layer (1010) can be added with contaminants and placed above the lower body (604). The contaminants can be covered by the first PTFE layer (1002). The sample follows the same test process, but without the adsorbent material. After a certain period of time, both PTFE layers can be extracted independently and the sample loss is checked by comparing the amount of extracted contaminants to the original amount of contaminants. The sum of the extraction results of the two PTFE layers is expected to be equal to the original contaminant level. The difference is attributed to potential losses in the entire process.

[0064] The present invention can be used to permeate through any breathable and semi-permeable protective material. The method and apparatus can evaluate performance under conditions that reflect more realistic use in different environmental scenarios, such as simulating the forces associated with air directly impinging on a contaminated surface. The present invention provides a quantitative test method to show that the lack of measured permeation mass through a negative control sample in a protective material can provide adequate protection for about 6 hours.

[0065] Fig.11 A method (1100) for performing convective flow assisted penetration testing of contaminants in an L / V configuration according to an embodiment of the present invention is described. It should be noted that in some alternative embodiments, the steps may be performed out of sequence, may be performed substantially simultaneously, or may be modified so as to perform the method in conjunction with other components of the present invention according to an embodiment of the present invention.

[0066] In frame 1102, in order to start the penetration test of the test sample (612) in the penetration test pool (600), the test sample (612) can be placed in the penetration test pool (600) between the upper body (602) and the lower body (604) of the penetration test pool (600). In frame 1104, the cavity in the lower pool cover (608) provided in the lower body (604) can be filled with an adsorbent material to ensure that the adsorbent material contacts the test sample (612) from below. In frame 1106, the contaminant (610) can be applied to the test sample (612). The contaminant (610) can exist in liquid form. The penetration test pool (600) can then be sealed. In frame 1108, an airflow can be supplied through the upper pool cover (606) above the test sample (612). In block 1110, contaminants (610) that permeate through the test sample (612) may be accumulated in an adsorbent material and measured using chromatographic techniques to quantitatively determine the permeate density of the test sample (612).

[0067] The above detailed description related to the drawings is intended as a description of various embodiments of the present invention, and is not intended to represent the only embodiment in which the present invention can be implemented. Each embodiment described in this disclosure is only an example or illustration of the present disclosure, and should not necessarily be interpreted as being better or more advantageous than other embodiments.

[0068] According to one or more embodiments, any combination of the above features and functions may be used. In the above description, embodiments have been described with reference to numerous specific details, which may vary depending on the implementation. Therefore, this description and the drawings are considered to be illustrative rather than restrictive. The only and exclusive indicator of the scope of the present disclosure, and the scope of the present disclosure intended by the applicant, is the literal and equivalent scope of a set of claims proposed in this application, which are proposed in their specific form, including any subsequent corrections.

Claims

1. A penetration test cell (600, 1000) for testing the penetration of chemical contaminants through a material, the penetration test cell (600, 1000) comprising: An upper body (602) including an upper pool cover (606) and a lower body (604) including a lower pool cover (608), wherein after placing a contaminant (610, 1004) on the upper side of a test sample (612, 1006), the upper body (602) and the lower body (604) are sealed together, and the test sample (612, 1006) is placed between the upper body (602) and the lower body (604), The upper pool cover (606) allows airflow through the lower pool cover (608) in a direction perpendicular to the surface of the test sample (612, 1006) to assist the penetration of the contaminants (610, 1004) through the test sample (612, 1006).

2. The penetration test cell (600, 1000) according to claim 1, comprising a cavity in the lower body (604) to store an adsorbent material for accumulating the contaminants (610, 1004) that penetrate through the test sample (612, 1006).

3. The penetration test cell (600, 1000) according to claim 1 comprises a first O-ring (614-1) and a second O-ring (614-2) to prevent the contaminant (610, 1004) from leaking from the edge of the test sample (612, 1006), wherein the first O-ring (614-1) is positioned to contact the upper body (602) and the test sample (612, 1006), and the second O-ring (614-2) is positioned to contact the lower body (604) and the test sample (612, 1006).

4. A penetration test pool (600, 1000) according to claim 1, wherein the air flow is supplied through a first vent in the upper pool cover (606), and the first vent serves as an inlet for release through a second vent in the lower pool cover (608).

5. The penetration test cell (600, 1000) of claim 1, comprising a first perforated polytetrafluoroethylene (PTFE) layer (1002) placed above the contaminant (610, 1004) to contain the contaminant (610, 1004) on the test sample (612, 1006).

6. The penetration test cell (600, 1000) according to claim 1 includes a circle of colorimetric detection paper (1008) placed below and around the test sample (612, 1006), wherein the colorimetric detection paper (1008) determines leakage of the contaminant (610, 1004) from the edge of the test sample (612, 1006).

7. The penetration test cell (600) according to claim 2 comprises a second PTFE layer (1010) placed between the test sample (612, 1006) and the adsorbent material, wherein the second PTFE layer (1010) blocks the contaminants (610, 1004) from penetrating through the test sample (612) and determines the leakage of the contaminants (610, 1004) from the edge of the test sample (612, 1006).

8. A method for testing the penetration of chemical contaminants through a material, the method comprising: providing an upper body (602) including an upper pool cover (606) for transmitting airflow to a lower pool cover (608) presenting a lower body (604); wherein a test sample (612, 1006) is placed between the upper body (602) and the lower body (604), and a contaminant (610, 1004) is applied to the upper side of the test sample (612, 1006); sealing the upper body (602) and the lower body (604) of the test cell; and An air flow is supplied in a direction perpendicular to the surface of the test sample (612, 1006) to assist the penetration of the contaminants (610, 1004) through the test sample (612, 1006).

9. The method of claim 8, comprising filling a cavity in the lower body (604) with an adsorbent material for accumulating the contaminants (610, 1004) that permeate through the test sample (612, 1006).

10. The method of claim 8, comprising positioning a first O-ring (614-1) and a second O-ring (614-2) to prevent the contaminant (610, 1004) from leaking from an edge of the test sample (612, 1006), wherein the first O-ring (614-1) is positioned to contact the upper body (602) and the test sample (612, 1006), and the second O-ring (614-2) is positioned to contact the lower body (604) and the test sample (612, 1006).

11. The method of claim 8, comprising supplying the airflow through a first vent in the upper pool cover (606), the first vent serving as an inlet for release through a second vent in the lower pool cover (608).

12. The method of claim 8, comprising placing a first perforated polytetrafluoroethylene (PTFE) layer (1002) over the contaminant (610, 1004) to contain the contaminant (610, 1004) on the test sample (612, 1006).

13. The method of claim 8, comprising placing a circle of colorimetric detection paper (1008) below and around the test sample (612, 1006), wherein the colorimetric detection paper (1008) determines leakage of the contaminant (610, 1004) from the edge of the test sample (612, 1006).

14. The method of claim 9, comprising placing a second PTFE layer (1010) between the test sample (612, 1006) and the adsorbent material, wherein the second PTFE layer (1010) blocks the contaminants (610, 1004) from penetrating through the test sample (612, 1006), and determining leakage of the contaminants (610, 1004) from the edge of the test sample (612, 1006).

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