U.S. patent application number 15/640503 was filed with the patent office on 2018-02-15 for preparation for fiberglass air filtration media.
The applicant listed for this patent is Charles Douglas Spitler, Rodney Ray Wilkins. Invention is credited to Charles Douglas Spitler, Rodney Ray Wilkins.
Application Number | 20180044230 15/640503 |
Document ID | / |
Family ID | 57249563 |
Filed Date | 2018-02-15 |
United States Patent
Application |
20180044230 |
Kind Code |
A1 |
Spitler; Charles Douglas ;
et al. |
February 15, 2018 |
Preparation For Fiberglass Air Filtration Media
Abstract
A system and method of forming fiberglass air filtration media
is disclosed which does not require the use of oil additives. A
mixture of resin binder, polymer, and dry adhering agent is formed
and applied to the fiberglass as it spins onto the drum.
Additionally, the fiberglass filtration media density can vary such
that the fiber on the air inflow is less dense than the fiber on
the air outflow. After oven curing, the finished air filtration
media has an improved ability to attract and hold dust and other
contaminants.
Inventors: |
Spitler; Charles Douglas;
(Southlake, TX) ; Wilkins; Rodney Ray; (Granville,
OH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Spitler; Charles Douglas
Wilkins; Rodney Ray |
Southlake
Granville |
TX
OH |
US
US |
|
|
Family ID: |
57249563 |
Appl. No.: |
15/640503 |
Filed: |
July 1, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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15151478 |
May 10, 2016 |
9695084 |
|
|
15640503 |
|
|
|
|
62179572 |
May 11, 2015 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B01D 2239/0478 20130101;
C03C 25/30 20130101; D04H 3/004 20130101; B01D 2239/10 20130101;
C09J 133/08 20130101; B01D 46/0035 20130101; C03C 25/34 20130101;
B01D 2239/0492 20130101; B01D 2239/1258 20130101; C03C 25/285
20130101; B29C 67/248 20130101; B01D 39/163 20130101; B01D
2239/1233 20130101; B29C 53/66 20130101; C09J 133/02 20130101; B01D
2239/1208 20130101; D04H 3/12 20130101; C09J 161/24 20130101; B01D
2239/0627 20130101; C03C 17/32 20130101; C03C 17/3405 20130101;
B01D 39/2024 20130101 |
International
Class: |
C03C 17/34 20060101
C03C017/34; C03C 25/28 20060101 C03C025/28; C09J 161/24 20060101
C09J161/24; D04H 3/004 20060101 D04H003/004; B29C 67/24 20060101
B29C067/24; B01D 46/00 20060101 B01D046/00; C03C 25/34 20060101
C03C025/34; C09J 133/02 20060101 C09J133/02; D04H 3/12 20060101
D04H003/12; B01D 39/20 20060101 B01D039/20; B01D 39/16 20060101
B01D039/16; C03C 17/32 20060101 C03C017/32; B29C 53/66 20060101
B29C053/66; C03C 25/30 20060101 C03C025/30 |
Claims
1-18. (canceled)
19. A method for producing fiberglass filtration media, comprising:
preparing a mixture comprising: an isotactic polymeric acrylate; a
polybutene; and a urea formaldehyde; and applying the mixture to
continuous fiberglass filaments.
20. The method in accordance with claim 19, comprising: forming the
continuous fiberglass filaments into a fiberglass media wherein
volumetric weight is lower on an air inflow surface of the
fiberglass media and volumetric weight is higher on an air exit
surface of the fiberglass media.
21. The method in accordance with claim 19, comprising: forming the
continuous fiberglass filaments into a fiberglass mat; and
expanding the fiberglass mat to form a fiberglass comprising a
progressive density of continuous fiberglass filaments between an
air inflow surface of the fiberglass media and an air exit surface
of the fiberglass media.
22. The method in accordance with claim 19, wherein the continuous
fiberglass filaments comprise filaments with a diameter of 21 to 25
microns.
23. The method in accordance with claim 19, wherein the mixture
comprises: from 20 to 40 percent isotactic polymeric acrylate; from
1 to 5 percent polybutene; and from 55 to 79 percent urea
formaldehyde.
24. The method in accordance with claim 19, wherein the mixture
comprises: 30 percent isotactic polymeric acrylate; 3 percent
polybutene; and 67 percent urea formaldehyde.
25. A method for forming air filtration media, comprising:
combining an isotactic polymeric acrylate, a dry adhering agent,
and a resin binder together to form a composition; spraying the
composition onto continuous fiberglass filaments collected on a
surface.
26. The method of claim 25, wherein the dry adhering agent
comprises polybutene; and the resin binder comprises urea
formaldehyde.
27. The method in accordance with claim 25, wherein the mixture
comprises: from 20 to 40 percent isotactic polymeric acrylate; from
1 to 5 percent dry adhering agent; and from 55 to 79 percent resin
binder.
28. The method in accordance with claim 25, wherein the mixture
comprises: 30 percent isotactic polymeric acrylate; 3 percent dry
adhering agent; and 67 percent resin binder.
29. The method in accordance with claim 25, comprising: forming the
continuous fiberglass filaments into a fiberglass media wherein
volumetric weight is lower on an air inflow surface of the
fiberglass media and volumetric weight is higher on an air exit
surface of the fiberglass media.
30. The method in accordance with claim 25, comprising: forming the
continuous fiberglass filaments into a fiberglass mat; and
expanding the fiberglass mat to form a fiberglass comprising a
progressive density of continuous fiberglass filaments between an
air inflow surface of the fiberglass media and an air exit surface
of the fiberglass media.
31. The method in accordance with claim 25, wherein the continuous
fiberglass filaments comprise filaments with a diameter of 21 to 25
microns.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of U.S. patent
application Ser. No. 15/151,478, filed on May 10, 2016, now U.S.
Pat. No. 9,695,084, which claims the benefit of U.S. Patent
Application No. 62/179,572, filed on May 11, 2015.
TECHNICAL FIELD
[0002] The present disclosure relates to air filtration media and,
more particularly, to air filtration media manufactured to a
Minimum Efficiency Reporting Value (MERV) 8 rating and above with
an initial pressure drop of less than or equal to 0.20 inches water
gravity (WG). The MERV 8 rating and greater can be achieved with
fiberglass media without the addition of an undesirable oil
coating.
BACKGROUND
[0003] Today, fiberglass air filtration manufacturing methods and
formulations can involve the use of oil added after the fiberglass
media exits the curing oven to provide for increased entrainment of
air contaminants such as dust and particulates. Present solutions
handle the problem of capturing increased amounts of dust using the
oil method.
[0004] The oil additive is undesirable since the oil makes the
process more expensive in additive costs, handling costs, and
environmental costs and is cosmetically undesirable. Binders are
applied to the fibers as they are wound on the drum. Binder
mixtures often are comprised of 65% urea formaldehyde and 35%
water. In other methods, 1 butyl tackifiers may be mixed into a
water emulsion and then mixed with a urea formaldehyde emulsion
binder. Urea formaldehyde emulsion is typically used as a binder of
glass fibers in the fiberglass filtration industry.
[0005] Other patents have mentioned the use of a dry tackifier
binder such as polybutene added to a composition to create a
tackifier for spraying fiberglass filtration media. For example,
see Miller U.S. Pat. No. 6,136,058, entitled "Uniformly Tacky
Filter Media," and Miller U.S. Pat. No. 5,846,603, entitled
"Uniformly Tacky Filter Media." However, the addition of
polybutene, while useful, does not reach the MERV 8 rating and
higher. In fact, the addition of polybutene barely achieves a MERV
7 rating by itself and then not routinely. Modigliani U.S. Pat. No.
2,546,230, entitled "Glass Product and Method of Making the Same,"
and Modigliani U.S. Pat. No. 2,729,582, entitled "Method for Making
Unwoven Fabrics," both mention the use of additives to the
fiberglass media. However, in Modigliani U.S. Pat. No. 2,546,230,
the binder cited is being utilized for fiber board insulation and
is water mixed with urea formaldehyde resin with the addition of an
acrylic resin. In Modigliani U.S. Pat. No. 2,729,582, the resin is
a vinyltrichlorosilane in a 3.5% solution of xylol, which is not
suitable for fiberglass filtration media, but rather more suitable
for composites. This disclosure presents a composition that
achieves and sustains a MERV 8 rating and higher.
[0006] MERV, Minimum Efficiency Reporting Value, commonly known as
MERV rating, is a measurement scale designed in 1987 by the
American Society of Heating, Refrigerating and Air-Conditioning
Engineers (ASHRAE) to rate the effectiveness of filters. The scale
"represents a quantum leap in the precision and accuracy of
air-cleaner" and allows for improved health, reduced cost and
energy efficiency in heating, ventilation and air conditioning
(HVAC) design as well as increased efficiency. For example, a HEPA
filter is often impractical in central HVAC systems due to the
large initial pressure drop the dense filter material causes.
Experiments indicate that less obstructive, medium-efficiency
filters of MERV 7 to 13 are almost as effective as true HEPA
filters at removing allergens, with much lower associated system
and operating costs. In like fashion, the addition of a polymer
compounded with a dry adherent and a resin binder provides for a
filter media without a high initial pressure drop.
[0007] The scale is designed to represent the worst-case
performance of a filter when dealing with particles in the range of
0.3 to 10 micrometers. The MERV rating is from 1 to 16. Higher MERV
ratings correspond to a greater percentage of particles captured on
each pass, with a MERV 16 filter capturing more than 95% of
particles over the full range.
[0008] Shown in FIG. 1 is a table grouping MERV ratings by particle
size:
[0009] Prior techniques exist however for the addition of resins
such as acrylate polymers to polyester pleat filtration media and
binder (with no urea formaldehyde). However, acrylate polymers have
never been combined with urea formaldehyde and polybutene and then
applied to fiberglass filtration media.
[0010] It would be advantageous to provide a system and method of
air filtration formation and media that increase dust holding
capacity.
[0011] It would also be advantageous to provide a method of
formation of MERV 8 or higher air filtration media with fiberglass
that does not require the use of oil.
[0012] It would further be advantageous to provide a method of
controlling the cross-sectional density of the fiber to maximize
the dust holding capacity of the filter media while controlling the
initial pressure drop.
[0013] It would also be advantageous to provide for a finished
filter media that feels and looks different from fiberglass.
[0014] It would also be advantageous to provide for a fiber that is
relatively soft, springy and dry to the touch, with fibers that
look more like plastic than fiberglass.
[0015] Thus there remains considerable need for binder compositions
that provide for less mess and are cosmetically more pleasing to
customers while providing for increased dust holding capability at
a MERV 8 or better. Additionally, the fiber should be capable of
progressive density with a soft springy texture.
SUMMARY
[0016] In accordance with the present disclosure, there is provided
a system and method of forming air filtration media that does not
involve the use of an oil additive to fiberglass, yet creates a
MERV filter rating of 8 or better. The manufacturing method of
forming the air filtration media is mentioned in a co-pending U.S.
patent application Ser. No. 14/181,426, filed on Feb. 14, 2014,
which is incorporated by reference herein.
[0017] To achieve MERV 8 or better without undesirable oil
additives, a polymer, wherein the polymer is one of a group of
polymers consisting of acrylates and methyl acrylic acids, is added
to a dry adhering agent consisting essentially of a group of
polybutene during the fiberglass air filtration media formation.
Both the polymer and the dry adhering agent mix in varying
percentages with a resin binder (urea formaldehyde) and are applied
to the fiberglass as it is spun onto a drum. In varying the
application rates of the combined binder resin mixed with a polymer
selected from a group of polymers formed from acrylic acid or
methyl-acrylic acid and a dry adhering agent, e.g. polybutene in a
specific formulation, so that the end result can be controlled with
greater precision.
[0018] Various objects, features, aspects, and advantages of the
present disclosure will become more apparent from the following
description of the disclosure, along with the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The detailed description makes reference to the accompanying
figures wherein:
[0020] FIG. 1 shows a table grouping MERV ratings by particle
size.
[0021] FIG. 2 depicts a chemical structure indicative of a selected
group of acrylate polymers, consisting of a 1-butyl, a methyl, an
n-butyl acrylate and others in a polymeric structure.
[0022] FIG. 3 depicts a chemical structure representative of the
structures of acrylic and methyl-acrylic acid which are the basis
of the methyl-acrylic polymers discussed herein.
[0023] FIG. 4A shows an electron micrograph of a polymer discussed
herein.
[0024] FIG. 4B shows information presented by an analysis of the
polymer by electron micrograph.
[0025] FIG. 5 is a chemical formula for the most common form of an
acrylate polymer 10 utilized in one embodiment of this
disclosure.
[0026] Other objects, features, and characteristics will become
more apparent upon consideration of the following detailed
description with reference to the accompanying figures.
DETAILED DESCRIPTION
[0027] The chemical structure shown in FIG. 2 is the general
structure that is indicative of a selected group of acrylate
polymers, consisting of a 1-butyl, a methyl, an n-butyl acrylate
and others in a polymeric structure. For purposes of comparison,
the IUPAC lists this selection of acrylates as -prop-2-enoate
(either butyl or methyl). The chemical reaction of a selected
polymer with a dry adherent and a resin binder (which also acts as
an additional adherent) creates a polymeric-based tackifying agent
with substantial dust holding capabilities. Ingredients in the
acrylates copolymer group all contain the monomers acrylic acid and
methyl-acrylic acid or one of their salts or esters. The drawing
shown in FIG. 3 is more closely representative of the structures of
acrylic and methyl-acrylic acid which are the basis of the
methyl-acrylic polymers discussed.
[0028] These ingredients are considered similar in that they are
uniformly produced in chemical reactions that leave very little
residual monomer. Although residual acrylic acid may be as high as
1500 ppm, typical levels are 10 to 1000 ppm. Concentrations may be
as high as 25% if used as a binder, film former, or fixative; or as
low as 0.5% if used as a viscosity-increasing agent, suspending
agent, or emulsion stabilizer.
[0029] Analysis of polymer 10 (shown in FIG. 5) by electron
micrograph presents the information shown in FIGS. 4A and 4B.
[0030] The structure presented provides a desirable basis for
binding and adhesive properties with the carbon and oxygen bonds
being of the most significance with the sulfur presenting minimally
in the base formulation. The sodium presents as a salt of the
acrylic or meth-acrylic acid.
[0031] The dry adhering agent is a polymer of the group consisting
essentially of 1-butene and 2-butene and isobutene. The structure
of the 1-butene and the 2-butene is seen in the repeat units,
where, in the case of 1-butene, the structure is:
-[--CH2-CH(CH2CH3)-].sub.n-
and in the case of 2-butene, the repeat unit structure is:
-[--CH(CH3)-CH(CH3)-].sub.n-
[0032] The C4 polymer typically includes various forms of butene,
for example isobutene, 1-butene, 2-butene, and others, and can
contain a small amount of propene and minor amounts of
polymerization byproducts. For simplicity, the polymer is referred
to herein as polybutene polymer. Typically, isobutene constitutes
from about 80% to about 95% of the total polybutene polymer. The
polybutene polymer has at least one double bond per molecule.
[0033] The thickness of the skinning of the fiberglass on the air
outflow surface and the air inflow surface are controlled such that
the skinning process on the air outflow can be densified while
still maintaining an initial pressure drop of less than 0.20 WG for
the finished fiberglass air filtration media. Furthermore, the
skinning on the air inflow surface can be maintained as thin as
varying needs require preventing stray fibers from projecting
randomly from the surface. The fiber media between the two skins
progressively increases in density such that the fiber on the air
inflow is less dense than the fiber on the air outflow of the
fiberglass filtration media. Progressive density is achieved by
varying the speed of the traverses of the furnace over the drum.
This density control is achieved in a substantially linear
fashion.
[0034] After oven curing of the fiber, the finished media feels and
looks different from normal fiberglass. It is relatively soft,
springy and dry to the touch. The fibers look more like plastic
than fiberglass, due in part to the polymeric spray mixture bound
to the fiberglass media. The progressive density of the skin of the
fiberglass filtration media along with the polymer, resin binder
and the dry adhering agent mixture provide for increased dust
holding capability by allowing for proper airflow and help to hold
the initial pressure drop to 0.20 WG.
[0035] The addition of a polymer 10 combined with a dry adhering
agent and resin binder increases the ability of the fibers to
attract and hold dust such that a MERV 8 rating and above can be
achieved with a sustainably low initial pressure drop of 0.20 WG.
This is achieved with a fiberglass based media without the addition
of an undesirable oil coating. The low initial pressure drop is due
in part to the substantially linear progressive density of the
fiberglass media coupled with the high dust holding capability.
This prevents face loading of the skin surface by large
particles.
[0036] As indicated in the enclosed drawing and discussion, the
polymer 10 is an isotactic polymeric acrylate, which is sticky and
typically used in formulations to aid in viscosity and ability to
emulsify. In accordance with the present disclosure, there is
provided a system and method of forming air fiberglass filtration
media that does not involve the addition of oil during the
fiberglass manufacture process. A spray composition is formed by
combining an acrylate polymer 10 (consisting essentially of the
group of polymers such as -prop-2-enoate), a dry adhering agent (a
polybutene consisting essentially of a group of 1-butene, 2-butene,
and isobutene), and a resin binder. The spray composition is
applied during the fiberglass air filtration media formation, as
the fiberglass is wound onto the rotating drum. The addition of a
polymer 10 and varying percentages of the dry adhering agent with
the resin binder mixture increases the dust holding capacity of the
resulting fiberglass filtration media.
[0037] The progressive density of the fiberglass media progresses
from a lower density of fiberglass media at the air inflow surface
to higher density of the fiberglass media at the air outflow
surface. In the preferred embodiment, the fibers are 21-25 microns
with a median size of 23 microns. However, the principles disclosed
herein may be used with fibers of other sizes. The progressive
density of the fiberglass media, along with the application of the
spray composition, acts to impede large particulate movement within
the fiberglass media bulk. This increased impedance occurs between
the two faces of the skin surfaces from the air inflow skin surface
to the air outflow skin surface. These large particulates move less
freely through the progressively denser fiberglass bulk and are
trapped by the lower density in the region of the air inflow
surface of the fiberglass media. This allows finer particles to be
trapped in the higher density region of the air outflow surface and
outflow side skin.
[0038] The spray composition (acrylates, polybutene, and urea
formaldehyde) is applied without clogging and is applied to the
fiberglass as it is spun onto a drum. The spray composition may
comprise 55-79% urea formaldehyde, 20-40% polymer compound, and
1-5% polybutene. In the preferred embodiment, the spray composition
comprises 67% urea formaldehyde resin, 30% polymer compound, and 3%
polybutene. The spray composition along with the progressive
density of the fiberglass media provides an excellent means to
capture and hold large dust particulates while avoiding the
face-loading of the media common in other types of filtration
media. By varying application rates of the spray composition, a
specific formulation can be achieved that provides for greater
precision.
[0039] The density of the skin surfaces on the air outflow and air
inflow can be controlled while still maintaining an initial
pressure drop of less than 0.20 WG for the finished filter. The
skinning on the air inflow surface can be maintained as thin as
various needs require, preventing stray fibers from projecting
randomly from the surface and facilitating glue adhesion in the
customers' filter framing processes. The fiber is then oven cured.
After oven curing, the finished media feels and looks different
from fiberglass. It is relatively soft, springy and dry to the
touch. The fibers look more like plastic than fiberglass.
[0040] As disclosed herein, a fiberglass filtration media with the
ability to attract and hold dust and achieve a MERV 8 rating and
above, without the addition of an undesirable oil coating, is made
possible by producing a fiberglass filtration media with
progressively increasing density from air inflow to air outflow
comprising thin filaments (for example, 21 to 25 microns) and
adding polymer combined with a dry adhering agent and a resin
binder (urea formaldehyde).
[0041] Since other modifications and changes varied to fit
particular operating requirements and environments will be apparent
to those skilled in the art, the invention is not considered
limited to the examples chosen for purposes of disclosure, and
covers all changes and modifications which do not constitute
departures from the true spirit and scope of the disclosure
herein.
* * * * *