DESC:“Binderless Boards From Coir Pith and a process for preparation thereof”

FIELD OF INVENTION:

[001] This invention relates to binderless boards from coir pith and a process for preparation thereof.

BACKGROUND OF INVENTION:

[002] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.

[003] Coir or coconut fibre, is a natural fibre extracted from the outer husk of coconut and used in products such as floor mats, doormats, brushes and mattresses. Coir is the fibrous material found between the hard, internal shell and the outer coat of a coconut. Other uses of brown coir (made from ripe coconut) are in upholstery padding, sacking and horticulture. White coir, harvested from unripe coconuts, is used for making finer brushes, string, rope and fishing nets. It has the advantage of not sinking, so can be used in long lengths on deep water without the added weight dragging down boats and buoys.

[004] Coir fibres are found between the hard, internal shell and the outer coat of a coconut. The individual fibre cells are narrow and hollow, with thick walls made of cellulose. They are pale when immature, but later become hardened and yellowed as a layer of lignin is deposited on their walls. Each cell is about 1 mm (0.04 in) long and 10 to 20 µm (0.0004 to 0.0008 in) in diameter. Fibres are typically 10 to 30 centimetres (4 to 12 in) long. The two varieties of coir are brown and white. Brown coir harvested from fully ripened coconuts is thick, strong and has high abrasion resistance. It is typically used in mats, brushes and sacking. Mature brown coir fibres contain more lignin and less cellulose than fibres such as flax and cotton, therefore are stronger but less flexible. White coir fibres harvested from coconuts before they are ripe are white or light brown in color and are smoother and finer, but also weaker. They are generally spun to make yarn used in mats or rope.

[005] Coir is a biomass residue obtained from coconut husk that decomposes very slowly due to its lignocellulosic nature. The eco- friendly production of binderless boards from coir pith as wood substitute could create novel economic activities in rural areas. The binderless board produced from coir is 100% eco-friendly as there are no harmful emissions, no chemical treatment required for the production and there are no byproducts during the production process of the boards. The binderless boards are developed using the intrinsic resin properties of lignin under high temperature and pressure. The boards so produced can be utilized for the application as acoustic absorbing panels, since coir fibre and pith contains large number of voids in it.

OBJECTS OF THE INVENTION:

[006] Primary object of the present invention is to provide binderless boards from coir pith and a process for preparation thereof.

[007] Another object of the present invention is to provide binderless boards from coir pith and a process for preparation thereof, which is very eco-friendly.

[008] Yet another object of the present invention is to provide binderless boards from coir pith and a process for preparation thereof,which can be utilized as acoustic absorbing panels.

[009] At the outset of the description that follows, it is to be understood that the ensuing description only illustrates a particular form of this invention. However, such a particular form is only an exemplary embodiment and is not intended to be taken restrictively to imply any limitation on the scope of the present invention.

[0010] These and other objects and advantages of the present invention will be apparent to those skilled in the art after a consideration of the following detailed description taken in conjunction with the accompanying drawings in which a preferred form of the present invention is illustrated.

SUMMARY OF THE INVENTION :

[0011] One or more drawbacks of conventional systems and process are overcome, and additional advantages are provided through the apparatus/composition and a method as claimed in the present disclosure. Additional features and advantages are realized through the technicalities of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered to be part of the claimed disclosure.

[0012] According to this invention, there is provided a process for preparation of binderless boards from coir pith comprising steps of:
- drying of coir material;
- sieving of dry coir material to remove the foreign materialsand to obtain a uniform particle size distribution;
- hot pressing of board;
- cooling to obtain the binderless board.

[0013] The coir material includes coir bit fibres, used coir mattings, coir pith, coir needled felt.

[0014] The coir material can be dried in Sun.

[0015] In case of used coir matting and coir needled felt, the matting/felt are cut into the required size and placed in the mould to be compressed.

[0016] The hot pressing of board is carried out at temperature of 140-170°C and pressure of 180-250 kgf/cm2 at compression ratio of for example 1:15.

[0017] The boards are compressed for the time period of 15-30min depending up on the thickness of the product.

[0018] The boards are cooled under pressure of for example 100 kgf/cm2 for for example 30 minutes and ejected from the mould.

[0019] Binderless boards from coir pith comprising of coir.

[0020] Various objects, features, aspects, and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.

[0021] It is to be understood that the aspects and embodiments of the disclosure described above may be used in any combination with each other. Several of the aspects and embodiments may be combined to form a further embodiment of the disclosure.

[0022] The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the following detailed description.

DETAIL DESCRIPTION OF THE PRESENT INVENTION WITH REFERENCE TO THE ACCOMPANYING DRAWINGS OF PREFERRED EMBODIMENTS :

[0023] While the embodiments of the disclosure are subject to various modifications and alternative forms, specific embodiment thereof have been shown by way of example in the figures and will be described below. It should be understood, however, that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternative falling within the scope of the disclosure.

[0024] The present invention makes a disclosure regarding a technology pertaining to binderless boards from coir pith and a process for preparation thereof.

[0025] In the present invention coir bit fibres, used coir mattings and coir pith each is used separately for the production of binderless boards without any mechanical pretreatment. The use of coir bit fibres and used matting leads to the utilization of waste material that may otherwise be burnt or accumulated causing disposal problems. The raw materials are dried in Sun to remove the moisture present in it to obtain good quality binderless boards followed by seiving. The coir bit fibres and pith are compressed in a hydraulic press.

[0026] In the case of used coir matting and coir needled felt, the compression ratio is comparatively less and pieces of the matting/felt (depending up on the thickness required for the end product) are cut into the required size and placed in the mould and compressed.

[0027] The steps involved in the process of preparing Binderless boards from coir pithare as follows:

• Drying of the materials
The raw materials need to be dried before hot pressing so as to remove the moisture present in the materials. The presence of moisture in the material creates air entrapments in the board and may lead to deterioration in the strength of the boards.

• Sieving
The dry (coir bit fibres and coir pith) material thus obtained is sieved to remove the foreign materials present and to ensure a uniform particle size distribution.

• Hot pressing
The material (coir bit fibres and coir pith) thus obtained after sieving are compressed in a hydraulic press at elevated temperature and pressure at compression ratio of for example 1:15 i.e. the material fills in the mould at a height of for example 15cm and compressed to a thickness of for example 1cm. The temperature used in the process is 140-170°C and pressure at 180-250 kgf/cm2.
The boards are compressed for the required time period of 15-30min depending up on the thickness of the product. The boards are allowed to cool under pressure of for example 100 kgf/cm2 for another for example 30 minutes and ejected from the mould.

The binderless Boards are made out of coir and does not contain any other materials.

• WORKING EXAMPLE

For preparing Binderless boards from coir pith, the coir bit fibres and coir pith are dried in sun. Thereafter, the dry coir material is sievedin a standard IS 100 mesh sieve.

The sieved material is compressed in a hydraulic press at elevated temperature of 150°C and pressure of 200 kgf/cm2 at compression ratio of 1:15 i.e. the material fills in the mould at a height of 15cm and compressed to a thickness of 1cm. The boards are compressed for the time period of 25 minutes. The boards are cooled under pressure of 100 kgf/cm2 for30 minutes and ejected from the mould.

• Test Results

Physical properties of Binderless Boards
Sl.No. Tests Result Requirement as per IS 3087:2005
1 Density, Kg/m3
a. Average
b. Variation from mean density %
1355
± 1.47
500-900kg/m3

2 Water absorption, %
a. After 2hr Soaking
b. After 24hr soaking
5.2
19.1
25 (Max.)
50 (Max.)
3 Swelling due to general absorption (after 2hr soaking), %
a. Thickness
b. Width
c. Length

3.4
0.14
0.14

10 (Max.)
0.5 (Max.)
0.5 (Max.)
4 Tensile strength, N/mm2 9.73 0.8 (Min.)
5. Modulus of Rupture, N/mm2
a. Average
b. Min. Individual
19.0
15.7
11
10
6 Modulus of Elasticity, N/mm2
a. Average
b. Min. individual
2477
2072
2000
1800
7 Compressive strength, Perpendicular to surface, N/mm2
57.80 -
8 Screw Withdrawal Strength, N
a. Face

2410
1250 (Min.)
9 Nail Withdrawal Strength, N
a. Face

1930
-
10 Abrasion Resistance, mg/rev
0.29 -
11 Hardness (Face), N
9725 -
12 Thermal Conductivity, W/m-K
0.48 -

• SOUND ABSORPTION STUDY
The binderless boards produced from coir pith has been tested as per IS 10420:1982 (Indian standardMethod of Determination of Sound Absorption Coefficient of timber by Standing Wave method) at Indian Ply wood Industries Research and Training Institute. The parameters tested were.

1. Transmission loss Co-efficient
2. Sound absorption Co-efficient

The results obtained are shown in Table 1.
Table 1. Results of sound absorption study
Frequency Hz Transmission Loss Co-efficient (dB/1.0)
Sound Absorption Co-efficient
125 5.04 0.00
250 7.01 0.03
500 9.82 0.03
1000 13.22 0.07
1500 15.54 0.15
2000 16.49 0.13
2500 17.38 0.11
3000 17.92 0.10
3500 17.85 0.09
4000 17.33 0.08

• RESISTANCE TO TERMITE AND BORER
The binderless boards produced from coir pith has been tested as per IS 4833:1993 (Indian standardMethods for Field testing of Preservatives in Wood) and IS 4873: 2008 (Indian standardMethods of Laboratory testing of Wood preservatives against Fungi and Borers) at Indian Ply wood Industries Research and Training Institute. The parameters tested were.

1. Termite resistance
2. Borer resistance

The results obtained are shown in Table 2.

Table 2. Results of termite and borer resistance of binderless boards
Sample Termite Test Borer Test Results
Binderless Coir Board Samples received are tested for the termite resistance for the duration of 6 months.
(10.09.2017-10.03.2018)

As per IS-4833 (1993)
Samples received are tested for the borer resistance for the duration of 6 months.
(10.09.2017-10.03.2018)

As per IS-4873:2008 Samples showed resistance against termites and borers.

Advantageous Features of the Present Invention :-

• Good quality binderless boards from coir pith and used coir matting under high temperature and pressure.
• The lignin containing in coir can act as a good binder in the development of binderless boards.
• 100% natural board without any harmful emissions.
• The binderless boards developed from coir pith are high density boards. Hence its application areas needs to be selected based on consideration of its density.
• The boards produced from used mattings are very good in quality and the density also less comparing to the pith boards.
• The water absorption properties and thickness swelling due to absorption is very good when tested as per IS 2380:1977 (Indian standard of test for wood particle Boards and boards from other Lignocellulosic materials).
• Tensile strength, Modulus of rupture, Modulus of elasticity, compressive strength, screw withdrawal strength, abrasion resistance are all very good when tested as per IS 2380:1977 (Indian standard Methods of test for wood particle Boards and boards from other Lignocellulosic materials).
• Good resistance of the binderless boards against termite and borers.

[0021] Each of the appended claims defines a separate invention, which for infringement purposes is recognized as including equivalents to the various elements or limitations specified in the claims. Depending on the context, all references below to the “invention” may in some cases refer to certain specific embodiments only. In other cases, it will be recognized that references to the “invention” will refer to subject matter recited in one or more, but not necessarily all, of the claims.

[0022] Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description of all groups used in the appended claims.

[0023] It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particulars claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogues to “at least one of A, B and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B”.

[0024] The above description does not provide specific details of manufacture or design of the various components. Those of skill in the art are familiar with such details, and unless departures from those techniques are set out, techniques, known, related art or later developed designs and materials should be employed. Those in the art are capable of choosing suitable manufacturing and design details.
[0025] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. It will be appreciated that several of the above-disclosed and other features and functions, or alternatives thereof, may be combined into other systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may subsequently be made by those skilled in the art without departing from the scope of the present disclosure as encompassed by the following claims.

[0026] The claims, as originally presented and as they may be amended, encompass variations, alternatives, modifications, improvements, equivalents, and substantial equivalents of the embodiments and teachings disclosed herein, including those that are presently unforeseen or unappreciated, and that, for example, may arise from applicants/patentees and others.

[0027] While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.
,CLAIMS:WE CLAIM:

1. A process for preparation of binderless boards from coir pith comprising steps of:
- drying of coir material;
- sieving of dry coir material to remove the foreign materials and to obtain a uniform particle size distribution;
- hot pressing of board;
- cooling to obtain the binderless board.

2. The process as claimed in claim 1, wherein the coir material includes coir bit fibres, used coir mattings, coir pith, coir needled felt.

3. The process as claimed in claim 1or 2, wherein the coir material can be dried in Sun.

4. The process as claimed in claims 1-3, wherein in case of used coir matting and coir needled felt, the matting/felt are cut into the required size and placed in the mould to be compressed.

5. The process as claimed in claims 1-4, wherein the hot pressing of board is carried out at temperature of 140-170°C and pressure of 180-250 kgf/cm2 at compression ratio of for example 1:15.

6. The process as claimed in claims 1-5, wherein the boards are compressed for the time period of 15-30min depending up on the thickness of the product.

7. The process as claimed in claims 1-6, wherein the boards are cooled under pressure of for example 100 kgf/cm2 for 30 minutes and ejected from the mould.

8. Binderless boards from coir pith comprising of coir.