U.S. patent application number 11/972453 was filed with the patent office on 2008-05-08 for thermal properties testing apparatus and methods.
This patent application is currently assigned to L&P PROPERTY MANAGEMENT COMPANY. Invention is credited to James Eric DeBord, Steven E. Ogle, D. Patrick Steagall, Kenneth C. Thompson.
Application Number | 20080107148 11/972453 |
Document ID | / |
Family ID | 34623052 |
Filed Date | 2008-05-08 |
United States Patent
Application |
20080107148 |
Kind Code |
A1 |
Ogle; Steven E. ; et
al. |
May 8, 2008 |
THERMAL PROPERTIES TESTING APPARATUS AND METHODS
Abstract
Various embodiments of methods for testing properties of a
product comprise: (1) heating a sample of the product via an
ignition source and determining a temperature differential across
the sample; or (2) exposing a sample of the product to a flame and
determining thermal transfer resistivity of the sample; or (3)
supporting a sample of the product over an ignition source, heating
the sample via the ignition source, and determining a temperature
differential across the sample. The tested properties of the
product may consist of: open flame resistivity, thermal transfer
resistivity, or both.
Inventors: |
Ogle; Steven E.; (Cary,
NC) ; Thompson; Kenneth C.; (Antioch, TN) ;
Steagall; D. Patrick; (Mooresville, NC) ; DeBord;
James Eric; (Nashville, TN) |
Correspondence
Address: |
CONLEY ROSE, P.C.
5601 GRANITE PARKWAY, SUITE 750
PLANO
TX
75024
US
|
Assignee: |
L&P PROPERTY MANAGEMENT
COMPANY
4095 Firestone Boulevard
South Gate
CA
90280
|
Family ID: |
34623052 |
Appl. No.: |
11/972453 |
Filed: |
January 10, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10981006 |
Nov 4, 2004 |
7329043 |
|
|
11972453 |
Jan 10, 2008 |
|
|
|
60517178 |
Nov 4, 2003 |
|
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|
Current U.S.
Class: |
374/44 |
Current CPC
Class: |
G01N 25/50 20130101;
G01N 25/18 20130101 |
Class at
Publication: |
374/044 |
International
Class: |
G01N 25/18 20060101
G01N025/18 |
Claims
1. A method for testing properties of a product comprising a
thermal barrier layer comprising: heating a sample of the product
via an ignition source; and determining a temperature differential
across the sample.
2. The method of claim 1 wherein determining the temperature
differential across the sample comprises: taking a first
temperature measurement approximately at the ignition source;
taking a second temperature measurement approximately at a surface
of the sample furthest from the ignition source; and calculating
the difference between the first and second temperature
measurements.
3. The method of claim 1 further comprising loading the sample into
a testing apparatus.
4. The method of claim 3 wherein loading the sample into the
testing apparatus comprises placing the sample onto a support plate
that extends over the ignition source.
5. The method of claim 4 wherein loading the sample into the
testing apparatus further comprises lowering a holding plate over
the sample.
6. The method of claim 5 wherein loading the sample into the
testing apparatus further comprises adjusting a displacement
between the support plate and the holding plate.
7. The method of claim 5 wherein loading the sample into the
testing apparatus further comprises leveling the holding plate with
respect to the support plate.
8. The method of claim 1 further comprising weighing the sample
before and after heating to determine the quantity of sample that
burned away during testing.
9. The method of claim 8 wherein the properties consist of: open
flame resistivity, thermal transfer resistivity, or both.
10. The method of claim 1 wherein the sample is heated for a
predetermined test period.
11. The method of claim 10 wherein the temperature differential
across the sample is determined a plurality of times on a specified
time interval during the predetermined test period.
12. The method of claim 1 further comprising determining a
temperature differential across each layer of the sample.
13. The method of claim 1 wherein heating the sample of the product
via the ignition source comprises: flowing a gas to the ignition
source; lighting the ignition source; and regulating the flow of
gas to the ignition source.
14. A method for testing properties of a product comprising a
thermal barrier layer comprising: exposing a sample of the product
to a flame; and determining thermal transfer resistivity of the
sample.
15. The method of claim 14 wherein determining thermal transfer
resistivity of the sample comprises: measuring a first temperature
approximately at a first surface of the sample closest to the
flame; measuring a second temperature approximately at a second
surface of the sample furthest from the flame; and calculating the
difference between the first and second temperature
measurements.
16. The method of claim 14 further comprising determining thermal
transfer resistivity across each layer of the sample.
17. A method for testing properties of a product comprising a
thermal barrier layer comprising: supporting a sample of the
product over an ignition source; heating the sample via the
ignition source; and determining a temperature differential across
the sample.
18. The method of claim 17 wherein determining the temperature
differential across the sample comprises: taking a first
temperature measurement approximately at the ignition source;
taking a second temperature measurement approximately at a surface
of the sample furthest from the ignition source; and calculating
the difference between the first and second temperature
measurements.
19. The method of claim 17 further comprising weighing the sample
before and after heating to determine the quantity of sample that
burned away during testing.
20. The method of claim 19 wherein the properties consist of: open
flame resistivity, thermal transfer resistivity, or both.
21. The method of claim 17 further comprising determining a
temperature differential across each layer of the sample.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a Divisional Application of U.S.
patent application Ser. No. 10/981,006, filed Nov. 4, 2004 and
entitled "Thermal Properties Testing Apparatus and Methods," which
is based on and claims priority to U.S. Provisional Patent
Application Ser. No. 60/517,178 filed Nov. 4, 2003 and entitled
"Thermal Properties Testing Apparatus and Methods," both of which
are hereby incorporated herein by reference for all purposes.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
REFERENCE TO A MICROFICHE APPENDIX
[0003] Not applicable.
FIELD OF THE INVENTION
[0004] The present disclosure relates to apparatus and methods for
testing the thermal properties of a product comprising a thermal
barrier layer. More particularly, the present disclosure relates to
apparatus and methods for testing the open flame resistance and
thermal transfer resistance of a thermal barrier product comprising
a fibrous batt.
BACKGROUND
[0005] Thermal barrier products comprising fibrous batts may be
used in home furnishings such as couches, mattresses, upholstery,
draperies, and the like; protective clothing; building
construction; vehicle or airplane seating; insulation; or any other
industrial or commercial application for the purpose of fire
abatement. In a home furnishings application, for example, a
thermal barrier layer comprising a fibrous batt may encase one or
more flammable products. Most mattresses and furniture, for
example, are filled with polyurethane foam, which is highly
flammable. Therefore, a thermal barrier layer may be disposed
directly below the ticking provided across the seating surfaces and
the borders of a mattress, thereby encasing the subassembly that
includes layers of polyurethane foam. Thus, the thermal barrier
layer is a fire retardant product that resists burn through due to
exposure to an open flame, and also resists thermal transfer to
reduce melting and prevent ignition of the more flammable products
in the subassembly.
[0006] To ensure compliance with state and/or federal flammability
standards for industrial and residential furnishings, open flame
testing has conventionally been conducted on furniture and bedding
as a composite. For example, the state of California has issued
Technical Bulletin 603 (TB603), which is a flammability test
standard for residential mattresses comprising open flame testing
on a foundation and mattress assembly. This approach has inherent
drawbacks in that such testing is costly and does not allow for the
evaluation of the thermal properties of individual thermal barrier
products. Therefore, a need exists for apparatus and methods to
test and evaluate the open flame resistance and thermal transfer
resistance of thermal barrier products without the cost and
complexity of composite open flame testing.
SUMMARY
[0007] An apparatus for testing properties of a product comprising
a thermal barrier layer comprises an ignition source, a test stand
that extends a sample of the product over the ignition source, and
a means for measuring thermal transfer across the sample. The test
stand may comprise a support plate that supports the sample and a
holding plate that holds the sample in place during testing. The
apparatus may further comprise an adjustment mechanism for
adjusting a displacement between the support plate and the holding
plate, and adjustable extensions for leveling the holding plate
relative to the support plate. In one embodiment, the holding plate
is rotatably moveable with respect to the support plate. The
ignition source may comprise a Bunsen burner fueled by a gas. The
apparatus may further comprise a shut-off valve for controlling
whether gas flows to the ignition source, and a regulator valve for
controlling a quantity of gas that flows to the ignition source. In
an embodiment, the means for measuring thermal transfer across the
sample comprises a thermometer, a first temperature measurement
device connected to the thermometer and positioned to measure
temperature approximately at the ignition source, and a second
temperature measurement device connected to the thermometer and
positioned to measure temperature approximately at a surface of the
sample furthest from the ignition source. In various embodiments,
the first and second temperature measurement devices consist of
thermocouples, plate calorimeters, or a combination thereof. The
apparatus may further comprise a data collection device, such as a
data logger, a computer, or a combination thereof. In an
embodiment, the apparatus further comprises means for measuring
thermal transfer across each layer of the sample.
[0008] A method for testing properties of a product comprising a
thermal barrier layer comprises heating a sample of the product via
an ignition source and determining a temperature differential
across the sample. In an embodiment, heating the sample via the
ignition source comprises flowing a gas to the ignition source,
lighting the ignition source, and regulating the flow of gas to the
ignition source. In an embodiment, determining the temperature
differential across the sample comprises taking a first temperature
measurement approximately at the ignition source, taking a second
temperature measurement approximately at a surface of the sample
furthest from the ignition source, and calculating the difference
between the first and second temperature measurements. The method
may further comprise loading the sample into a testing apparatus.
In various embodiments, loading the sample into the testing
apparatus further comprises placing the sample onto a support plate
that extends over the ignition source, lowering a holding plate
over the sample, adjusting a displacement between the support plate
and the holding plate, and/or leveling the holding plate with
respect to the support plate. The method may further comprise
weighing the sample before and after heating to determine the
quantity of sample that burned away during testing. In various
embodiments, the properties tested by the method consist of open
flame resistivity, thermal transfer resistivity, or both. The
method may further comprise determining a temperature differential
across each layer of the sample. In an embodiment, the sample is
heated for a predetermined test period, and the temperature
differential across the sample may be determined a plurality of
times on a specified time interval during the predetermined test
period.
[0009] In another aspect, a method for testing properties of a
product comprising a thermal barrier layer comprises exposing a
sample of the product to a flame and determining thermal transfer
resistivity of the sample. In yet another aspect, a method for
testing properties of a product comprising a thermal barrier layer
comprises supporting a sample of the product over an ignition
source, heating the sample via the ignition source, and determining
a temperature differential across the sample.
[0010] Thus, the embodiments of the apparatus and methods for
testing the properties of a product comprising a thermal barrier
layer comprise a combination of features and advantages that
overcome various problems of the prior art. The various
characteristics described above, as well as other features, will be
readily apparent to those skilled in the art upon reading the
following detailed description of the embodiments of the apparatus
and methods for testing a product comprising a thermal barrier
layer, and by referring to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] For a more complete understanding of the present disclosure,
and for further details and advantages thereof, reference is now
made to the following Brief Description of the Drawings, taken in
conjunction with the accompanying drawings, in which:
[0012] FIG. 1 provides a perspective front view of one embodiment
of a testing apparatus for a product comprising a thermal barrier
layer;
[0013] FIG. 2 provides another perspective front view of the
apparatus of FIG. 1, showing the holding plate in the raised
position;
[0014] FIG. 3 provides an elevational back view of the apparatus of
FIG. 1; and
[0015] FIG. 4 provides a perspective back view of the apparatus of
FIG. 1.
DETAILED DESCRIPTION
[0016] The apparatus and methods for testing the properties of a
product comprising a thermal barrier layer are susceptible to
embodiments of different forms. There are shown in the drawings,
and herein will be described in detail, specific embodiments of the
testing apparatus and methods of testing the properties of the
product with the understanding that the present disclosure is for
purposes of example only, and is not limiting.
[0017] In particular, the apparatus and methods disclosed herein
enable evaluation of various properties, such as the open flame
resistance and thermal transfer resistance, of an individual
thermal barrier product comprising a fibrous batt that may be used
in a wide variety of applications, such as, for example, home
furnishings such as mattresses, upholstery, draperies, and the
like; protective clothing; building construction; vehicle or
airplane seating; insulation; or any other industrial or commercial
application for the purpose of fire abatement. The testing
apparatus and methods disclosed herein may be used for quality
control by manufacturers of thermal barrier products, for example,
or may be used by purchasers of such thermal barrier products to
evaluate their effectiveness.
[0018] Further, the testing apparatus and test methods disclosed
herein may be used to aid in the selection of various material
components for a multi-layered product comprising a thermal barrier
layer. One such multi-layered product may comprise a layer of
ticking, a layer of thermal barrier product, and one or more layers
of foam or other cushioning components, for example. Thus, in the
discussion that follows, whenever the testing apparatus and test
methods are described with respect to an individual thermal barrier
product, one of ordinary skill in the art will readily appreciate
that the same apparatus and test methods may also be used to
evaluate properties of a multi-layered product comprising a thermal
barrier layer.
[0019] FIG. 1 and FIG. 2 depict a perspective front view of an
exemplary testing apparatus 10 in the testing position and in the
loading position, respectively. FIG. 3 and FIG. 4 depict an
elevational back view of the testing apparatus 10 and a perspective
back view of the testing apparatus 10, respectively. As used
herein, the term "front" refers to the side of the apparatus 10
that faces the technician during testing, and the term "back"
refers to the side of the apparatus 10 opposite the technician
during testing.
[0020] The testing apparatus 10 comprises a test stand 20, a height
adjustment mechanism 30, an ignition source 40, and means 50 for
measuring the thermal transfer across a sample of an individual
thermal barrier product or a multi-layered product. The test stand
20 comprises an optional base 21, vertical members 22, 23, a
support plate 24 for supporting a sample of the product over the
ignition source 40, and a holding plate 26 for holding the sample
during testing. In an embodiment, the support plate 24 comprises an
expanded metal plate with a hole therein to allow flame from the
ignition source 40 to heat the bottom surface of the sample, as
best depicted in FIG. 2. However, for smaller size samples, the
support plate 24 may comprise a solid plate with a hole disposed
therein, the hole being sized to allow flame from the ignition
source 40 to heat the bottom surface of the sample, while
preventing the flame from wrapping around the sides or reaching the
top surface of the sample. In an embodiment, the holding plate 26
comprises a thin solid plate having a meshed area therein, and the
holding plate 26 may be hinged 27 as depicted in FIG. 2 to be
rotatably moveable with respect to the support plate 24, thereby
enabling easy loading of the sample to be tested.
[0021] As best depicted in FIG. 3, the adjustment mechanism 30
comprises a jack screw 32 connected at 34 to the holding plate 26.
A knob 36 is provided at the top of the jack screw 32 to allow
height adjustment of the holding plate 26 with respect to the
support plate 24, thereby setting the displacement 38 therebetween.
The size of the displacement 38 is set according to the thickness
of the sample. In an embodiment, the holding plate 26 is provided
with adjustable extensions 28 at the end of the plate 26 opposite
the adjustment mechanism 30. These extensions 28 allow for the
holding plate 26 to be leveled and maintained in a substantially
parallel position relative to the support plate 24 at the desired
displacement 38. Also, the extensions 28 allow for adjustments of
the holding plate 26 position if there are variations in the sample
thickness.
[0022] Referring again to FIG. 1, the ignition source 40 may
comprise a Bunsen burner fueled by a gas, such as propane, for
example, supplied via a gas line 44. In one embodiment, the Bunsen
burner is a "High-Temperature Bunsen Burner" with 11/2 inch grid
diameter, available from Cole-Parmer catalog model number
U-36130-XX. In an embodiment, the Bunsen burner is capable of
producing a 35-kilowatt flame that is 4 to 6-inches in diameter. A
shut-off valve 46 and a regulator valve 48 may be operatively
connected between the ignition source 40 and the gas line 44. The
shut-off valve 46 allows the technician to control whether or not
gas flows to the ignition source 40, and the regulator valve 48
allows the technician to control the quantity of gas that flows to
the ignition source 40.
[0023] The means 50 for measuring the thermal differential across a
sample of thermal barrier product comprises a temperature
measurement device, such as a digital thermometer 52 operatively
connected to a first thermocouple 54 and a second thermocouple 56.
In an embodiment, the digital thermometer 52 is capable of reading
temperatures in excess of 2000 degrees F. and comprises a dual
input thermometer or similar device. A data collection device, such
as a data logger and/or a computer, for example, may be connected
to the digital thermometer 52 to automatically record temperature
readings taken by the thermocouples 54, 56. In an embodiment, the
digital thermometer 52 and data logger comprise an "EXTECH EA-15
Thermometer, Data Logger", available from Grainger catalog item
number 3WU66, for example.
[0024] The first thermocouple 54 takes temperature measurements
adjacent the ignition source 40, which represents the temperature
at the surface of the sample closest to the ignition source 40, and
the second thermocouple 56 takes temperature measurements on the
surface of the sample furthest from the burner 40. In an
embodiment, the thermocouples 54, 56 comprise type K, Chromel and
Alumel thermocouples, such as "Type K High-Temperature Ceramic
Fiber-Insulated Thermocouple Probe", available from Cole-Parmer
catalog model number 08467-64, for example. In an alternative
embodiment, one or both of the thermocouples 54, 56 may be replaced
with plate calorimeters, which are capable of making temperature
measurements over a wider area, such as 8-inches, for example.
Referring now to FIG. 4, in one embodiment the first thermocouple
54 is routed through and held in place by a fixture 55 comprising
copper tubing, for example. In another embodiment, the second
thermocouple 56 is routed through tubing 57, such as copper tubing,
for example, and held in position by a fixture 58.
[0025] In another aspect, the present disclosure relates to a
method for testing the properties of an individual thermal barrier
layer or a multi-layered product comprising a thermal barrier
layer. In one embodiment, an individual thermal barrier layer
comprises Pyro.about.Gon.RTM., an engineered blend of polyester and
oxidized polyacrylonitrile (PAN) fibers that may be formed into a
unified, flame-resistant fibrous batt by garneting or carding. The
PAN fibers are thermal insulating and flame resistant such that
when the Pyro.about.Gon.RTM. is subjected to an open flame, the
polyester fibers rapidly retreat, leaving a layer of the inert PAN
to absorb and disperse the heat.
[0026] Sample sections of the thermal barrier product are cut from
a finished roll for testing. The first thermocouple 54 is connected
to the digital thermometer 52 and positioned adjacent the ignition
source 40 so as to extend into the flame. The second thermocouple
56 is connected to the digital thermometer 52 and positioned so as
to extend through the holding plate 26 to engage the top surface of
the sample furthest from the ignition source 40. As one of ordinary
skill in the art will understand, if the test sample comprises a
multi-layered product, additional thermocouples may be positioned
to engage the top and/or bottom surface of each layer.
[0027] The holding plate 26 is then raised as shown in FIG. 2 to
load a sample of the thermal barrier product or multi-layered
product into the testing apparatus 10. The sample may be placed
directly onto the support plate 24, or optionally, a piece of kraft
paper may be placed on the support plate 24, with the product
sample placed on top of the kraft paper. The holding plate 26 is
then lowered as shown in FIG. 1, with the sample being held between
the plates 24, 26 for testing. The height adjustment mechanism 30
may be adjusted to change the size of the displacement 38 between
the plates 24, 26 according to the sample thickness, and the
extensions 28 may be adjusted to level the holding plate 26 as
needed.
[0028] Once the sample is in place, the shut-off valve 46 is then
opened to allow flow through the gas line 44 to light the ignition
source 40. The regulator valve 48 may also be adjusted to control
the height of the flame from the ignition source 40. The digital
thermometer 52 is set to read temperature measurements from both
thermocouples 54, 56 while those measurements are recorded at
specified time intervals for the duration of the test period. In an
embodiment, the specified time interval is 30 seconds, and the
duration of the test period is 90 seconds. The technician may
manually record these temperature measurements. Alternatively, the
temperature measurements may be captured electronically by a data
logger or a computer, for example. The temperature differential
between the temperature readings taken by thermocouple 54 and
thermocouple 56 at each time interval provides a measure of the
thermal transfer resistivity of the thermal barrier product. The
thermal barrier layer should be effective to prevent ignition of
the cushioning layers below it in a mattress subassembly, for
example. In one embodiment, the thermal barrier layer is effective
in reducing thermal transfer by approximately 70 percent.
[0029] The sample is then removed from the testing apparatus 10 and
weighed. This weight is compared to the weight of the sample before
the burn test to determine the amount of thermal barrier product
that was burned away during testing. This evaluation provides a
measure of the open flame resistivity of the sample.
[0030] Following is a description of one example procedure for
testing samples of a thermal barrier product, such as
Pyro.about.Gon.RTM., for example.
EXAMPLE TEST PROCEDURE
[0031] The technician obtains a minimum of three cut samples of the
thermal barrier product from the production line for testing
purposes. Cut samples are taken from a strip, 12 to 16 inches wide
cut across the width of the production line or finished roll. The
samples are taken from the middle of the floor apron, and from each
side of the floor apron. 12-inch by 12-inch samples are prepared by
trimming excess material from the cut strip.
[0032] The technician weighs each sample and records that weight on
a log sheet. If the sample weight falls within specified limits,
the technician proceeds to the next step.
[0033] The technician measures the loft by placing the sample in a
thickness tester under a 1-pound load, or a 5-pound load for
densified, needled products. If the sample thickness falls within
specified limits, the technician proceeds to the next step.
[0034] The technician turns on the gas via the shut-off valve, and
adjusts the gas pressure to 20 psig via the regulator valve. The
technician then ignites the Bunsen burner, and adjusts the
regulator valve so that the floating ball falls between 45 and 55
on the scale, corresponding to about 800 milliliters per minute. At
this rate the blue flame should extend no further than 1/8-inch
beyond the orifice of the burner. Once the gas flow is set, the
technician turns off the gas and proceeds to the next step.
[0035] The technician places a type K, ceramic-tipped probe
thermocouple in the holding fixture adjacent to the Bunsen burner.
The technician ensures that the lead of the thermocouple is
connected to the digital thermometer at the T2 terminal. The
technician also ensures that the thermocouple is placed between
1/2-inch and 1-inch away from the orifice of the burner and that it
extends approximately 1/8-inch to 1/4-inch into the flame.
[0036] The technician then connects a type K, ceramic-tipped probe
thermocouple to the digital thermometer at the T1 terminal. The
technician places a sample onto the support plate and lowers the
holding plate onto the sample. The technician ensures that the top
thermocouple contacts the surface of the sample by checking for
fiber as it is gently raised up. The technician may raise or lower
the top thermocouple by adjusting the holding fixture. The
technician then removes the sample once all adjustments are
made.
[0037] The technician turns on the digital thermometer and ensures
that readings are being received from both thermocouples, and that
the thermocouples are connected to the correct terminals. To verify
that the thermocouples are correctly connected, the holding plate
may be raised and the burner ignited. In this position, the
readings from the top thermocouple should remain approximately at
room temperature, while the readings from the lower thermocouple
should read the flame temperature, which is normally between 1200
degrees and 1300 degrees F. The technician should ensure that both
thermocouples are set to the "K" input on the digital thermometer
since a "J" input will produce false readings.
[0038] Once the gas flow, flame configuration, and thermocouples
are within their specified limits, the technician turns off the gas
via the shut-off valve and proceeds to test the samples for thermal
properties.
[0039] The technician first resets all readings to zero on the
digital thermometer by turning the digital thermometer off and
turning it on again.
[0040] The technician may place a piece of brown kraft paper on the
support plate of the test stand, and place the sample on top of the
kraft paper. For bi-lofted samples or samples with a sacrificial
layer, the sample should be placed with the white polyester or
sacrificial layer against the kraft paper. Note: the kraft paper is
optional, and it does not affect the outcome of the test. The
purpose of the kraft paper is to help keep the sample flat in the
test stand, and prevent the sample from bulging through the opening
in the support plate.
[0041] Once the sample is in place, the technician lowers the
holding plate over the sample and verifies that the top
thermocouple is making contact with the top of the sample. Then the
technician opens the shut-off valve on the gas line and ignites the
burner.
[0042] The technician presses the "ENTER" button on the digital
thermometer and begins recording the time and temperature readings.
Specifically, at 30-second intervals, over a 90-second total test
period, the technician records the top and bottom thermocouple
temperatures in the worksheet provided. Alternatively, a data
logger may be set to store the temperature readings
electronically.
[0043] At the end of the test, the gas is turned off, the holding
plate is raised, and the sample is removed. Note: The technician
should be wearing leather or heat resistant gloves when lifting the
holding plate and removing the sample from the test stand. Also a
wet cloth should be on hand, in case the burner overheats causing a
flash-back situation. With the gas turned off, the technician may
cool the burner by wrapping a wet cloth around it, being careful to
avoid steam burns.
[0044] The technician repeats these test steps for each of the
samples specified in the inspection plan. When all samples have
been tested, the technician enters the information collected into
the appropriate database or spreadsheet program.
[0045] The maximum allowable heat transfer for all
Pyro.about.Gon.RTM. products shall be 400 degrees F. The maximum
number of failures per production lot shall be no more than 1
failure for every 30 samples tested.
[0046] Hourly samples may be drawn from each production lot of
material. Samples are taken from a single strip cutting, 14-inches
to 16-inches long, across the width of the line, in such a manner
that the technician will obtain a minimum of three samples from
each cutting representative of the whole line width.
[0047] Testing takes place during the day of production. In the
case of a failure, the technician identifies which group of rolls
the failed strip cutting was obtained from, and an additional
sample strip from one roll out of that group is obtained. Should
the retest fail, the product is held for further disposition.
[0048] While preferred embodiments of the testing apparatus and
methods have been shown and described, various modifications and
substitutions may be made thereto without departing from the spirit
and scope of the disclosure. Those skilled in the art will readily
see other embodiments within the scope of the disclosure.
Accordingly it is to be understood that the example testing
apparatus and test methods have been described by way of
illustration only and not by way of limitation.
* * * * *