U.S. patent application number 10/653379 was filed with the patent office on 2004-03-04 for papermaking process and paper made therefrom.
Invention is credited to Iwasaki, Sachiko.
Application Number | 20040040680 10/653379 |
Document ID | / |
Family ID | 23974974 |
Filed Date | 2004-03-04 |
United States Patent
Application |
20040040680 |
Kind Code |
A1 |
Iwasaki, Sachiko |
March 4, 2004 |
Papermaking process and paper made therefrom
Abstract
A papermaking process, and a paper product made from the
process, wherein a biodegradable plastic is used with papermaking
material. The biodegradeable plastic may be provided as a
substrate, with the papermaking material being applied to the
substrate. The papermaking material may include recycled paper
fibers and/or agricultural crop material. Recycled wood fibers may
be applied in a fibrous state or agricultural plant material may be
powdered and applied to the substrate. The surface material is
affixed to the substrate by the application of heat and pressure or
by the use of vegetable slime juice as an adhesive.
Inventors: |
Iwasaki, Sachiko; (Madison,
WI) |
Correspondence
Address: |
GODFREY & KAHN S.C.
780 NORTH WATER STREET
MILWAUKEE
WI
53202
US
|
Family ID: |
23974974 |
Appl. No.: |
10/653379 |
Filed: |
September 2, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10653379 |
Sep 2, 2003 |
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09496981 |
Feb 2, 2000 |
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Current U.S.
Class: |
162/135 ;
162/147; 162/157.1; 162/95; 162/96; 162/98 |
Current CPC
Class: |
B32B 5/028 20130101;
B32B 7/12 20130101; B32B 2255/02 20130101; D21H 15/06 20130101;
B32B 5/024 20130101; B32B 2554/00 20130101; B32B 2262/02 20130101;
D21H 11/12 20130101; B32B 2262/065 20130101; B32B 2607/02 20130101;
D21H 27/36 20130101; B32B 2307/54 20130101; B32B 2307/51 20130101;
B32B 2262/06 20130101; B32B 2255/24 20130101; B32B 2307/7163
20130101; B32B 2307/56 20130101; B32B 2262/067 20130101; B32B
2272/00 20130101; B32B 2307/5825 20130101; B32B 5/26 20130101 |
Class at
Publication: |
162/135 ;
162/095; 162/096; 162/098; 162/147; 162/157.1 |
International
Class: |
D21F 011/00 |
Claims
I claim:
1. A method of making paper comprising the steps of: drying
agricultural plant material; shredding said agricultural plant
material; providing a biodegradable plastic substrate; depositing
said plant material on said biodegradable plastic substrate; and
affixing the plant material to the biodegradable plastic
substrate.
2. The method of claim 1 further comprising the step of heating
said biodegradable plastic substrate.
3. The method of claim 1 further comprising providing a vegetable
slime juice; creating a paste of the slime juice and the plant
material; and spreading the paste on the biodegradable plastic
substrate.
4. A process for making paper comprising the steps of: providing a
biodegradable substrate; selecting a surface material from the
group including agricultural plant material and recycled paper
fibers; preparing the surface material; applying the surface
material to the substrate; and affixing the surface material on the
substrate.
5. The process of claim 4 in which said step of selecting a surface
material includes choosing from a group of agricultural plants
including hemp, kenaf, bagasse, corn, wheat and cotton.
6. The process of claim 5 in which said step of preparing the
surface material includes the steps of drying plant material and
powdering the plant material.
7. The process of claim 6 further including creating a paste of
prepared surface material and vegetable slime juice.
8. The process of claim 4 in which said preparing step includes the
step of repulping recycled paper.
9. The process of claim 4 further including creating a paste of
prepared surface material and vegetable slime juice.
10. The process of claim 4 including the step of moistening the
substrate.
11. The process of claim 10, further including the step of
powdering plant material; and, wherein said applying step includes
depositing powdered plant material on the moistened substrate.
12. The process of claim 11 wherein said affixing step includes
pressing and heating the substrate.
13. The process of claim 4, further comprising recovering recycled
paper fibers, pulping the recovered fibers, and applying the pulped
recovered fibers on a biodegrable substrate.
14. A papermaking process comprising the steps of: preparing
papermaking fibers; mixing biodegradable plastic filaments with the
papermaking fibers; and forming a web of the mixed papermaking
fibers and biodegradable plastic filaments.
15. The papermaking process of claim 14, further comprising the
steps of recovering papermaking fibers and biodegradable plastic
from previously formed products.
16. An additive for paper products formed of papermaking fibers,
said additive comprising discrete filaments intermingled with said
papermaking fibers, said filaments being a biodegradable
plastic.
17. A fabric comprising a woven matrix of biodegradeable plastic
filaments, said filaments containing therein at least one of
agricultural crop residue and recycled paper material.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This is a divisional application of U.S. application Ser.
No. 09/496,981, filed on Feb. 2, 2000 which is incorporated herein
by reference in its entirety for all purposes.
BACKGROUND OF THE INVENTION
[0002] 1. Technical Field
[0003] The present invention relates to processes for making paper,
and more particularly to processes using agricultural crop material
or recycled paper products, and to paper products made from the
process.
[0004] 2. Description of Related Art
[0005] In conventional papermaking processes, virgin wood fibers
are commonly used for making various types of paper and paper board
products. The treatment of virgin wood fibers prior to paper
formation may include debarking of logs, wood chipping or
mechanical defibration, chemical cooking, various washing and
chemical bleaching steps and refining or other further mechanical
conditioning of the fibers. Screening, cleaning, thickening and
diluting-steps may be repeated numerous times through out the
relatively complex process. The treatment of virgin wood fibers is
energy intensive, is dependent on many chemical processes, and is
expensive. Many of the cooking and bleaching processes used for
pulp delignification are sulfur or chlorine based, producing
significant environmental hazards from the chemical processes
themselves and from the by-product handling and disposal.
Alternatives to chlorine based bleaching are often very expensive.
Conventional papermaking processes also use large volumes of water
for transporting and treating the fiber. While many mills are
converting to closed loop systems, process requirements remain
complex and expensive.
[0006] In some areas of the world, trees are not readily available,
and the logs for papermaking are imported. In economically emerging
countries, capital investment may not be available for complex and
expensive conventional papermaking processes. The necessary
infrastructure, including long range transportation, chemical
supply and available energy for practicing conventional papermaking
processes, often, are not present.
[0007] While trees are a renewable resource, in many parts of the
world, including North America, tree growth is relatively slow, and
even fast growing species may require ten or more years from crop
planting to harvest. As a result, large tracts of land are
dedicated to tree growth and paper fiber supply. In heavily
populated areas, or in climates not conducive to tree growth, it is
necessary to transport logs or wood fiber for papermaking, or the
finished paper for use. Transportation over long distances can
increase costs significantly.
[0008] Secondary fiber utilization has become more common in recent
years; however, new problems have been encountered as paper
products are recycled repetitively. When paper products made of
recycled fiber are recycled again, fiber quality is reduced as
fiber length shortens in each subsequent recycling generation.
Conventional paper forming processes require fiber bonding in the
paper sheet. Reduced fiber lengths, and diminished fiber quality
resulting from multiple recycling generations reduces bonding and
thereby paper strength. As a result, it is common and often
necessary to add virgin wood fibers to the recycled pulp, to
increase sheet strength.
[0009] As an alternative to wood fibers, other cellulosic materials
have been used for papermaking. These alternative materials have
included agricultural based materials such as corn stalk, kenaf,
sugar cane, banana and pineapple leaves. Many of the agricultural
crop based fiber sources can be harvested in one growing season,
and can be grown in regions not suitable for tree growth. An
additional advantage occurs in that lignin content is lower in
grassy plants than in wood fibers, and bleaching or washing
requirements are less, even when a white sheet is desired. For
example, the inner core of industrial hemp, called hurd, is
naturally white, and little or no bleaching is required if herd is
used to form writing papers.
[0010] The pulping and pulp treating processes for alternative
fiber papermaking differ from those used for wood fiber
papermaking. However, the papermaking process itself, once the pulp
is prepared, is substantially similar to that used for wood fiber
papermaking. In the conventional process, a very dilute slurry of
papermaking fibers is discharged from a headbox onto a forming
wire. Water is drained from the slurry on the wire, referred to as
a web. The web passes through a plurality of stages for the removal
of water, including pressing the web between nipped rollers and
drying the web by passing the web through an area of heated air
and/or heated rollers. Throughout a substantial extent of the
process just described, the web must be fully supported, as the wet
strength of the web is insufficient to support the web by itself.
The need to support the web on felts or fabrics complicates the
structure and operation of conventional paper machines.
[0011] The mechanical treatment of virgin wood during chipping,
chip screening, rechipping or chip slicing and refining, as well as
the treatment of recycled fibers produces undesirable short wood
fibers called pins or fines. While a small amount of pins or fines
can be used in conventional papermaking processes, the use of too
many short fiber components weakens the sheet. If a process
generates more fines or pins than can be used, the excess is
wasted. It would be advantageous to have a papermaking process that
can make use of fines and pins.
[0012] It would be advantageous to reduce energy, water and
chemical consumption in the papermaking process, while decreasing
the dependence on wood fibers by utilizing fast growing
agricultural crop fibers for papermaking. It would be further
advantageous to have a simplified papermaking process that can be
used on a small scale.
[0013] A feature of the present invention is a papermaking process
with reduced energy, water and chemical requirements as compared to
conventional papermaking processes.
[0014] Another feature of the present invention is a papermaking
process which can utilize agricultural crop based materials, with
lessened reliance on virgin wood fibers.
[0015] A further feature of the present invention is a papermaking
process which can utilize lower quality papermaking materials than
needed for conventional papermaking processes, and which can make a
higher quality paper from recycled paper products.
[0016] Yet another feature of the present invention is a simplified
papermaking process which can be used without significant capitol
investment and is suitable and economical for use in small output
volume operations.
[0017] Still another feature of the present invention is providing
a process for making paper products which eliminates the need for
conventional pulping.
BRIEF SUMMARY OF THE INVENTION
[0018] The present invention comprises a process from making paper
in which a biodegradable plastic is used to provide strength in a
paper web. In one aspect of the invention, a biodegradable plastic
substrate is provided, and a surface material of papermaking fibers
is deposited on the substrate. In one form of the process, the
substrate is wetted, and the surface material is powdered. The
powdered material is applied to the wetted surface of the
substrate, which is thereafter pressed and dried.
[0019] In another form of the process, the powdered surface
material is mixed with vegetable mucilage or slime, to create a
paste which is then applied to the substrate. Drying may occur with
or without the application of heat.
[0020] In yet another form of the process, recycled paper products
are repulped, deinked if necessary and fiberized. A slurry of the
recycled pulp is applied to the biodegradable plastic substrate,
which is dried.
[0021] Another aspect of the invention is the use of biodegradable
plastic fibers as an additive to paper pulp slurry, to increase
strength. Discrete filaments may be added to the papermaking
slurry. Hollow fibers may be filled with powdered or fine
papermaking fibers.
[0022] Yet another aspect of the present invention is a paper
product comprising a biodegradable plastic substrate with at least
one surface coated with papermaking materials selected from
agricultural crop based grassy plants and recycled paper
products.
[0023] Further features and advantageous of the present invention
will become apparent from the following detailed description and
the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1 is a process diagram of the papermaking process
according to the present invention;
[0025] FIG. 2 is a more detailed process diagram of a first
embodiment of the present invention of a process for
papermaking;
[0026] FIG. 3 is a process diagram of a second embodiment of the
present invention for a papermaking process;
[0027] FIG. 4 is a process diagram of the present invention for a
papermaking process as utilized for recycled fiber;
[0028] FIG. 5 is an enlarged cross sectional view of paper made
according to the present invention; and
[0029] FIG. 6 is a process diagram of yet another papermaking
process in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0030] Referring now more specifically to the drawings, and to FIG.
1 in particular, numeral 10 designates the papermaking process of
the present invention, and more particularly the preferred life
cycle of paper made according to the present invention.
[0031] Papermaking process 10 is useful in the formation of a paper
product 12, shown in FIG. 5. Paper product 12 has a substrate 14
and top and bottom layers 16 and 18 respectively. The nature and
content of substrate 14, top layer 16 and bottom layer 18 will be
described and explained in greater detail hereinafter.
[0032] With reference again to FIG. 1, papermaking process 10
includes a surface material preparation subprocess 20 and a
substrate preparation subprocess 22. The prepared surface material
and substrate are combined in a paper formation subprocess 24. The
formed paper product continues through a converting and use
subprocess 26. Thereafter, the paper product may be, and preferably
is, recycled in a recycling subprocess 28, and returned in one of
several ways, to be described hereinafter, to the surface material
preparation subprocess 20.
[0033] Substrate material 14 used in the present invention is a
biodegradable plastic. Some biodegradable plastics contain
aliphatic polyester resin skeletons. Others have polyvinyl alcohol
molecular skeletons, while still others utilize molecular skeletons
based on polysaccharides. Some characteristics of an appropriate
biodegradable plastic for the present invention include strength,
chemical resistance and water resistance, in addition to
biodegradability when disposed of in nature. Preferred
characteristics of the biodegradable plastic substrate may differ
depending on the ultimate use of the paper product being formed.
For example, if heavy weight material is to be formed, for possible
use in containers, grocery bags, or the like, the desired strength
characteristic may be different than if the product being formed is
a light weight paper product to be used more for its appearance or
surface characteristics than for strength.
[0034] One suitable biodegradable plastic for use in the present
invention is marketed by Shimadzu Corporation of Japan under the
product name Lacty. Another suitable biodegradeable plastic is
marketed by Kanebo, Ltd. Of Japan under the product name Lactron.
Each is a plant starch based product having characteristics similar
to petroleum based plastics, except that each is biodegradable in
nature, unlike petroleum based plastics. The physical structure of
substrate 14 may take several forms. A scrim or felt of randomly
oriented fibers has been found to work well for some applications.
In other applications, individual biodegradeable plastic fibers,
hollow fibers, and fibers oriented as a strand or twine can be
used. Alternatively, a fine mesh or screen with discrete openings
may also be used. Much of the tear, tensile and burst strength of
the resultant paper product results from the similar strength
properties of substrate 14. Therefore, selection of the particular
structure for substrate 14 should take into consideration these and
other characteristics preferred in the resultant product.
[0035] Top layer 16 and bottom layer 18 are formed of the prepared
surface material, which may include different types of agricultural
fibers and/or recycled fibers. The terms top and bottom are used
herein only as a way of differentiating between the layers, as
shown in FIG. 5, separated by the substrate 14. It should be
understood that the two layers may be the same, and used
interchangeably. Alternatively, the components of the layers may
differ, being selected for particular desirable characteristics of
one compared to the other. The desirable characteristics may
include color, texture, moisture resistance or the like. Virgin or
recycled wood fibers may be used for top layer 16 and bottom layer
18. However, one of the advantages of the present invention is that
lower quality, lesser used but more easily grown and obtained
fibers may also be used. Additionally, by-products or remains from
agricultural crops can be used. Such can include the remaining
portions after crop processing for other purposes. For example,
corn stalk, grain husks, sugar cane, banana and pineapple leaves
may be used as surface material. Additionally, hemp, wheat and rice
stalks, jute, bamboo, coconut fibers, papyrus or virtually any kind
of grassy plant may be used to provide unique surface appearance
and characteristics.
[0036] Referring now to FIG. 2, a more detailed moist process 40 is
shown, which utilizes virgin agricultural fibers. Surface material
preparation sub-process 20 of virgin fiber moist process 40
includes steps of crop growth 42, which may occur in a cultivated
agricultural setting or may be natural growth of the desired
material, and a harvesting and drying step 44. The method of
harvesting may differ for different plant sources, depending upon
the nature of the agricultural crop or material being used.
Harvesting may include mechanized cutting and removal from
cultivated fields, or harvesting may include a simple gathering
step of naturally growing vegetation. Harvesting may occur as part
of a processing procedure for an agricultural crop grown
principally for another purpose.
[0037] Drying may be performed in mechanized crop dryers. Direct
fired, rotary drum dryers can be used advantageous, as can waste
heat dryers using heat from other processes. However, in a low
energy consumption process embodying the present invention, the
harvested crop of material may be air dried in fields or collection
areas. The complexity of the drying step may depend upon the nature
of the material being used and the stage of dryness at which it is
harvested. If by-product material is used, it may have been dried
in previous processing. The harvested and dried material is
conditioned in a mechanical treatment step 46, which may include
shredding and powdering of the dried material. Shredding and/or
powdering may be accomplished with conventional apparatus including
hammer mills, shredders, rolling mills, refiners, beaters and the
like. Since paper made according the present invention does not
rely on fiber to fiber bonding for strength, low quality material
can be used, and fiber integrity is not critical. Even pins or
fines from conventional papermaking pulp preparation processes can
be used.
[0038] Preparation of the substrate, as shown in FIG. 2, includes a
substrate presentation step 50 which, in a continuous process, may
include unwinding substrate material from a supply roll of the
material. In a batch process, presentation step 50 may include
flattening a sheet of substrate material. A moistening step 52
readies the substrate for formation of the paper product.
Moistening step 52 can be accomplished by passing an unrolling web
of substrate material 14 through a shower or misting area wherein
water or other liquid is deposited on the surface of substrate 14.
In a low volume or batch process, which can be essentially a hand
performed process, moistening step 52 can be performed by use of a
hand sprayer, sprinkler of the like.
[0039] Paper formation subprocess 24, in accordance with virgin
fiber moist process 40 shown in FIG. 2, includes a deposit step 54
in which the prepared surface material is placed on the moistened
substrate, and a subsequent pressing and drying step 56. Deposit
step 54 can be performed by blowing or spraying the dried powdered
material onto the moistened substrate or, in a smaller process, may
be performed by hand spreading the powdered material on the
substrate. Deposit step 54 may be performed on both sides of the
substrate simultaneously, prior to rolling and drying step 56, or a
first side may be prepared, rolled and dried, with the second side
completed thereafter. Rolling and drying step 56 may include
pressing the substrate and deposited material between nipped
rollers, or may include simply air drying the formed sheet without
an initial or simultaneous pressing. Heat 58 may be used to assist
in the process. When heat is used, the temperature may be selected
to slightly melt the biodegrable plastic substrate, causing the
surface materials to adhere readily to the substrate. If nipped
rollers are used, one or both may be heated, internally or
externally. The roller surface characteristics should be such as to
allow ready release of the sheet from the rollers, without
sticking.
[0040] In the process shown on FIG. 2, if a heating step 58 is
included with rolling and drying step 56, to partially melt the
biodegradable plastic, the formed product can be created with a
relatively hard surface. Such may be useful in forming tree plugs
for nursery seedlings and the like. Slight melting of substrate 14
enhances bonding of top layer 16 and bottom layer 18 to substrate
14, and may improve moisture resistance.
[0041] From paper formation subprocess 24, the material proceeds to
the converting and use subprocess 26. It should be understood that
converting and use subprocess 26 may directly follow paper
formation subprocess 24, or the paper product formed may be rewound
or otherwise accumulated and stored for later converting and use.
Depending on the material having been made, converting and use
subprocess 26 may include sheeting to individual sheets, bonding in
tablets, formation into bags, boxes and the like. Conventional
slitters, sheeters, perforators, folders and the like may be
used.
[0042] Recycling subprocess 28 follows converting and use
subprocess 26. It should be recognized that while it is preferred
that the used or discarded materials be recycled, and that the
process of the present invention is particularly useful for
subsequent recycling, recycling may not occur in all instances. In
such situations, used product may be disposed of in landfills and
will breakdown quickly, due to the biodegradability of the
substrate as well as all other materials used. One suitable
recycling subprocess is shown in FIG. 2, wherein the used product
is acquired in a collecting step 60. Depending upon the manner in
which the product is collected, cleaning and separating may be
necessary to remove particularly undesirable elements. For example,
in a municipal waste collecting process, screening and separating
may be used to remove recyclable metals, glass and other objects.
Thereafter, the remaining material is processed in a composting
step 62. The composted material may then be returned to the crop
growth step 42 of surface material subprocess 20, wherein the
composted material is used as a fertilizer or soil amendment for
the growing crop.
[0043] Referring now to FIG. 3, a dry substrate process 70 is
shown. Substrate preparation subprocess 24 is similar to that
described previously for virgin fiber moist process 40, except that
it is not necessary to moisten the substrate. Surface material
preparation subprocess 20 in dry substrate process 70 also is
similar to that shown and explained for virgin fiber moist process
40. In dry substrate process 70, however, the powdered surface
material is mixed with a mucilage or vegetable slime juice created
in a vegetable slime juice preparation step 72. Pulp from Okra
fruits may be mixed with water to create the mucilage or vegetable
slime juice. Other suitable vegetable slimes may be obtained from
other plants including Jew's Mellow leaves, Fenugreek seeds and
tubers of Tororo Aoi, which is a vegetable additive used to
increase bonding and improve fiber distribution in traditional
Japanese papermaking processes. These and other suitable vegetable
components, when mixed with water, produce a viscose, stringy
mucilage slime, which can act as an adhesive. The mucilages are
polysaccharides, found in a number of plants, that form viscous,
colloidal dispersions in water. Such mucilages are used in the
preparation of certain ethnic dishes, and are valued for their
slimy consistency. The suitable substances differ from starch based
adhesives in that mucilages produced from Okra, Tororo Aoi, Jew's
Mellow and Fenugreek remain flexible when dried, as contrasted with
starched based adhesives which become brittle upon drying.
[0044] A paste is made from the powdered surface material by mixing
the powdered material with vegetable slime juice in a paste
creating step 74. During an application step 76, the paste is
applied to the substrate. Application step 76 may include spraying
or spreading the paste on the substrate, depending upon the
consistency of the paste. The paste coated substrate is pressed to
remove excess water, and is allowed to dry. Drying may occur
naturally, or may be forced through the use of air movement, heated
air or the like. The vegetable slime juice works much as an
adhesive in adhering the surface material to the substrate.
Therefore, pressing of the coated substrate will not require the
application of heat to bond the surface material to the substrate.
Heat can be used, if desired, to obtain the physical
characteristics, including moisture resistance, that result from
slightly melting the biodegradable plastic.
[0045] If paper products made in accordance with the dry mesh
process 70 are not hardened by the application of heat, the paper
made in accordance with dry mesh process 70 will remain soft and
flexible. The dry mesh process may be particularly suited for the
preparation of thinner papers such as stationary and office paper
or artistic papers. A further advantage of the process using a
vegetable slime adhesive is realized during recycling. Upon
reliquification of the slime, the surface material is released
readily from the substrate, allowing separate processing of each,
and possible reuse of the substrate.
[0046] Following paper formation subprocess 24 in dry substrate
process 70, converting and use 26 and recycling 28 may occur as
described previously for virgin fiber moist process 40. Converting
will be as appropriate for the material being made and the use to
which it is applied. Recycling again may include steps of
collecting 60 and composting 62.
[0047] Referring now to FIG. 4, a recycled fiber process 80 is
shown. In surface material preparation subprocess 20, recycled
fibers are gathered and undergo a plurality of steps, including
pulping 82, deinking 84 and cleaning 86. Shredding 88 or powdering
may be used to ready the fibers for application on the substrate. A
final slurry preparation step 90 includes consistency adjustment by
adding water or by thickening to achieve the desired consistency.
The recycled fibers are then deposited on the substrate in a
deposit step 92. Pressing and drying step 56 follows, which
normally will include the application of heat. Converting and use
subprocess 26, as needed, follows. Used or excess product is
collected and recycled, being returned to the preparation step 82.
In this regard, the recycling subprocess 26 of process 80 differs
from that shown for process 40, in which recycling includes
returning the recycled material to the soil as fertilizer or as a
soil amendment. In recycled fiber process 80, recycled fibers are
returned for use in another paper product. Typically, recycled
fiber process 80 will be used for recycling conventional
papermaking fibers such as wood fibers, and recycling subprocess 28
will include the accumulation of suitable surface material from a
number of sources. Because of the gluing effect created by heating
the biodegradable substrate, low quality recycled fibers may be
used. The problem associated with repeatedly recycling fibers,
which reduces fiber length and fiber to fiber bonding strength, is
overcome, since fiber to fiber bonding is not critical for the
generation of strength in the completed paper product.
[0048] Biodegradable plastic can also be used advantageously as an
additive in a more conventional papermaking process, and need not
be used only as a substrate as described previously herein. In FIG.
6, a biodegradable plastic fiber additive process 110 is shown, in
which biodegradable plastic fibers are added to a papermaking
slurry or pulp prior to web formation. As mentioned previously,
during recycling of paper products formed using the dry substrate
process, wherein vegetable slime juice is used to adhere surface
material to the substrate, the substrate is separated readily from
the surface material. The biodegradable plastic substrate may then
be fiberized and added to papermaking pulp in fiber additive
process 110. Addition of the biodegradable plastic fibers adds
strength to the resultant paper sheet, and can reduce the need for
virgin fiber in paper products made using primarily recycled wood
fiber.
[0049] While the biodegradable plastic fiber additive process 110
shown in FIG. 6 may take several forms, as shown in FIG. 6 process
110 includes several sources of material for the formation of the
paper product. An agricultural crop growth and harvesting step 112
supplies material to a conventional crop pulping step 114.
Alternatively, or I additionally, papermaking fibers may be
provided from a repulping recycled fiber process I step 116,
supplying fiber to a deinking and screening step 118. A recovery
step 120 may provide material to a composting step 122 for
fertilization or soil enhancement of the crop growth and harvesting
step 112. Additionally, recovery step 120 may provide material to a
recovered material separation step 124 which, depending upon the
material having been recovered, may forward material to the
repulping recycled fiber step 116 or may provide material directly
to a combining organic material step 126. Recovered material
separation step 124 may also provide biodegradable plastic material
to a fiberizing step 128, wherein discrete fibers or filaments are
created. Additionally, virgin plastic fiber may be provided in a
step 130 to the fiberizing biodegradable plastic step 128.
Fiberized biodegradable plastic is combined with the organic fibers
in a mixed fibers step 132. Thereafter, the mixed fibers are
provided to formation, pressing, drying, converting and use step
134. While the formation, pressing, drying, converting and use step
134 may be conventional, it may also incorporate some of the
processes described previously herein, and may utilize a vegetable
slime preparation step 136, with deposit of the fibers on a
substrate 14.
[0050] The various processes disclosed herein can be modified to
achieve a variety of desired physical characteristics for the
resulting product. As mentioned previously, the application of heat
during pressing or drying increases water resistance of the
resulting material, by melting the surface of substrate 14 or of
individual fibers in the fiber additive process shown in FIG. 6.
Combining a number of the previously described methods can produce
a variety of products, depending on the varying functions of the
material. Layering of the sheets, including a felt or scrim of
recycled fiber, agricultural material residue powder and thin
biodegradable plastic substrate may be suitable for diapers,
feminine napkins and other hygienic products. Subsequent breakdown
in landfills or the like is improved when compared with
conventional products, since all materials are biodegradable in
nature.
[0051] Through proper selection of materials, artistic papers
having unique surface characteristics and appearance may be
created. Further, waterproof wall papers may also be formed. In yet
a further modified use of the materials, hollow biodegradable
plastic filaments may be filled with recycled papers fibers or crop
material, and woven conventionally into fabric. Surface coatings as
described previously herein may then be applied.
[0052] In yet another modified application for using a paper
product made in accordance with the present invention, strips or
strands can be cut from the powder coated substrate, and
subsequently woven or knitted into fabrics having elasticity and
conformability. Fabric made in such a manner may have particular
suitability for wall coverings with distinctive textures and
patterns, and for packaging materials with shock absorbability.
[0053] Processes according to the present invention are not complex
when compared to conventional processes for making paper. The
biodegradable plastic substrate provides wet strength in the web
being formed and in the end product, making handling easier.
[0054] Processes according the present invention readily make use
of low quality fiber and easily renewable fiber sources such as
agricultural products. Additionally, processes according to the
present invention may utilize papermaking materials which otherwise
would be wasted, such as left over leaf and stalk components from
other agricultural processes and fines and pins from conventional
papermaking. The present processes may also utilize naturally white
materials, thereby reducing or eliminating the need for chemical
bleaching of the papermaking material to achieve a white surface.
Chemical pulping of the papermaking material is eliminated.
[0055] Processes according to the present invention are amenable to
use in low tech configurations including manufacture by hand. Thus,
art and specialty papers may be made in small batches at reasonable
expense. Further, the processes are adaptable to use in emerging
countries with readily available materials and can be used locally,
at small volume locations where infrastructure necessary for
conventional papermaking processes, such as utilities, roads for
transporting materials and the like are not readily available.
[0056] While the present invention has been described in detail
herein, including several embodiments thereof, it should be
understood that additional modifications and changes thereto may be
made without departing from the scope of the present invention, as
defined in the claims to follow.
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