Description:FORM 2
THE PATENT ACT, 1970
(39 OF 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See section 10 and rule 13)
1. Title of the invention: “Processing of Rice stubble for making Absorbent Sheet”
2. Applicant:
NAME NATIONALITY ADDRESS
1.Marwadi University
2. Khushal Katdare
3. Foram Kundalia
4. Dr Amit Sata
5. Prof Vivek Patel
6. Prof Dhaval Anadkat INDIAN Marwadi University, Rajkot-Morbi Highway, At Gauridad, Rajkot – 360003, Gujarat, India
(M) 9879740982
Email:
shreedattalawconsultancy@gmail.com
Chothani18preeti@gmail.com

3. Preamble to the description
COMPLETE SPECIFICATION
The following specification particularly describes the invention and the manner in which it is to be performed:

Field of the Invention:
The present invention relates to Process Rice stubble for making Absorbent Sheet. More specifically, it relates to the production of absorbent sheets from rice stubble harnessing the inherent absorbing properties of rice while effectively managing crop waste.
Background of the Invention:
Rice serves as a fundamental dietary component for more than half of the global population, particularly in Asia, where it holds significant importance in daily meals. The Food and Agriculture Organisation (FAO) reports that the global rice consumption reached around 484 million metric tonnes in 2020. Rice consumption patterns vary across regions, with Asian countries such as China, India, Indonesia, Bangladesh, and Vietnam consuming substantial amounts due to its nutritional value. India consistently ranks among the leading rice-producing nations worldwide. Additionally, rice holds symbolic significance in religious ceremonies, festivals, and special occasions, representing prosperity, fertility, and blessings.
Rice stubble is abundantly available in India due to its significant rice cultivation. As per a report by the Indian Council of Agricultural Research, India produces approximately 150 million tonnes of rice every year, which results in the generation of around 120 million tonnes of rice stubble annually. While it can be used as fodder for livestock, its low nutritional content and high lignin content make it difficult for digestion and result in low feed intake, weight gain, and health problems due to high amount of silica. It is not used for other purposes as its high silica content makes difficult to decompose and utilize in a range of industries. Additionally, the low calorific value of rice straw makes it an unsuitable fuel source. The high cost of collection, transportation, and processing of rice straw also makes it an uneconomical feedstock for many industries. As a result, it is often burned by farmers to clear their fields, leading to significant air pollution.
Superabsorbent materials are polymers endowed with interconnected pores, facilitating the absorption and retention of water or other liquids through a process known as swelling. They possess the ability to absorb many times their own weight in liquid. Superabsorbent materials typically comprise synthetic polymers like polyacrylates and polypropylenes. Although superabsorbent materials offer numerous advantageous applications, their improper disposal or release into the environment can potentially result in adverse consequences. Particularly, superabsorbent materials containing synthetic polymers are non-biodegradable and can persist in the environment for extended periods, spanning hundreds of years. In the context of menstrual products, the superabsorbent polymers employed are primarily composed of approximately 95% plastic. This significant proportion contributes to the accumulation of 113 kilo tonnes of menstrual waste in Indian landfills on an annual basis.
There is an alarming need to address the above problems for proper utilization of rice stubble. Hence, the aim of the present invention is to employ the abundant supply of rice straw for the production of absorbent sheets.
Object of the Invention:
The main objective of the present invention is to develop absorbing rice sheets with enhanced absorbency compared to existing standards.

Another objective of the present invention is to utilize rice stubble which is commonly burned and contributes to pollution.

Yet another objective of the present invention is to use the natural absorbent properties of rice for specific industrial applications.

Yet another objective of the present invention is to offer an alternative to polymer-based super absorbent sheets.

Yet another objective of the present invention is to mitigate air pollution resulting from stubble burning.

Yet another objective of the present invention is to transform agro waste into a valuable resource.

Yet another objective of the present invention is to decrease dependency on non-renewable resources and promote the adoption of natural, biodegradable, and renewable materials.
Yet another objective of the present invention is to utilize rice-based absorbent sheets for absorbing oil, lubricants, or petroleum-based products.
Yet another objective of the present invention is to employ absorbent sheets in the production of paper bags, envelopes, tableware, sanitary pads, and more.

Summary of the Invention:

The present invention is a method of processing rice stubble for making absorbent sheets. The present invention offers a novel application for rice stubble, an abundant agricultural waste, by utilising it as a raw material. The present invention addresses multiple challenges, particularly the environmental consequences of stubble burning. By utilizing rice stubble, the present invention diverts it from being burned or discarded. The present invention provides an alternative to super absorbent polymers by producing absorbent sheets from rice stubble that demonstrate superior absorbency, in contrast to existing products mainly composed of environmentally harmful plastics. As a result, the present invention has the potential to make a substantial impact in various industries such as sanitary pads and diapers, tableware, paper bags, envelopes, and shoe soles.

Brief Description of drawings:
Figure 1 shows Rice stubble collected from farm
Figure 2 shows Flaked/Chopped rice stubble
Figure 3 shows Stubble solution with NaOH on magnetic stirrer
Figure 4 shows Bleaching on magnetic stirrer
Figure 5 shows Absorbent layer from rice stubble

Detailed Description of the Invention:
The following description relates to a particular manifestation of the present invention. The present invention relates to development of absorbing sheets using rice stubble which is an abundant agricultural waste.
The present invention relates to creating absorbent sheets. The invention aims to make use of the abundant but neglected rice stubble, which is typically burned, and turn it into a valuable resource.
Rice stubble which frequently runs the danger of being burnt are collected from Farmers and has no particular size requirements for later stages as shown in figure 1. The rice stubble used in the construction of the absorbent sheet was sourced from normal farms.
The rice stubble is collected and chopped into pieces by using a stainless-steel butcher knife, and having length about 5 cm as shown in figure 2. After being chopped, the stubble is processed into flakes using a pulverizer machine that has a sieve size of 6. The resultant pieces are about 0.5 cm long, and they are kept in airtight containers until they are needed again in order to prevent them from absorbing moisture.
12% concentrated Sodium Hydroxide (NaOH) (LR Grade - Laboratory Reagent, 96% pure) solution is made by combining 12 grams of NaOH with 100 ml of water. The solution is poured into a 250 ml glass beaker. The NaOH solution is followed by adding with 10 grams of flaked (fibered) rice stubble. The glass beaker is placed on a magnetic stirrer with rpm and temperature controller. The solution is stirred at a rate of 1215 revolutions per minute and stirred at a temperature of 60-70°C for 3 hours as shown in figure 3.
Following the stirring process, the resulting slurry is washed with distilled water through a 75 micron mesh until it reaches a neutral pH (pH 7). A 100 ml solution of 2.5% concentrated Sodium hypochlorite (NaOCl) is made from a 4% chlorine concentrated w/v solution of LR grade for bleaching. This mixture is transferred in a 500 ml clean glass beaker. The obtained wet slurry is added to the solution and rotated for 45 minutes at 60°C on a magnetic stirrer with a hot plate at 450 revolutions per minute as shown in figure 4. After half of the process is completed, 20 ml of Hydrogen peroxide (H2O2, 30% concentrated, AR [Analytical Reagent] grade) is added to the mixing slurry and the process is allowed to continue. The pulp is then rinsed with distilled water through a 75-micron mesh until its pH is neutral (pH 7).
The bleached pulp, which is now white in color, is churned in a mixer after being combined with distilled water in a 1:2 ratio, for 5 minutes at 22000 rpm approximately. The resultant combined pulp is then collected and kept in an airtight container until future usage. The pulp is collected in a designated container, which is then combined with distilled water in a 1:5 ratio. The mixture is stirred either manually or mechanically at an appropriate speed to ensure the pulp particles remain suspended at the surface. A 100 micron sieve with a diameter suitable for the purpose is immersed into the pulp-water mixture to collect the pulp particles on its surface. The collected pulp is subsequently dried using heat at a temperature range of 50-60 ? for a duration of 5-10 minutes, resulting in the formation of a thin absorbent layer.
Each layers weighs about 5 grams. Thin absorbent layer is then cut into required shape. The rest of the material, excluding the shape, is collected and pulverized into pulp for future use as an alternative to cotton. The absorbent layer derived from rice stubble was subjected to absorbency testing. It was found that the stubble-based absorbent layer could absorb 27 ml of water within a span of 70 seconds. While the IS 5405:2019 (Sanitary Napkins: Specification) does not specify any specific requirements regarding absorbency capacity, it can be noted that the absorbent capacity of the rice stubble-based absorbent layer is competitive and meets the desired standards.
Main embodiment of the present invention a process for making absorbent sheet from Rice stubble comprising of:
a) Rice stubble are collected from farms and chopped into pieces by using a stainless steel butcher knife and having about 5 cm length;
b) Chopped stubble is processed into flakes using a pulverizer machine and having sieve size of 6 and the resultant pieces are about 0.5 cm long which kept in airtight containers to prevent from absorbing moisture;
c) 12% concentrated Sodium Hydroxide solution is made by mixing 12 grams of NaOH with 100 ml of water and the solution is poured into a 250 ml glass beaker, then 10 grams rice stubble flaked added in NaOH solution;
d) The glass beaker is placed on a magnetic stirrer and stirred at a rate of 1215 revolutions per minute and at a temperature of 60-70°C for 3 hours;
e) The resulting slurry is washed with distilled water through a 75 micron mesh until it reaches a neutral pH;
f) 100 ml solution of 2.5% concentrated Sodium hypochlorite is made from a 4% chlorine concentrated w/v solution of laboratory grade for bleaching.;
g) This mixture is transferred in a 500 ml clean glass beaker then obtained wet slurry is added to the solution and rotated for 45 minutes at 60°C on a magnetic stirrer with a hot plate at 450 revolutions per minute;
h) After half of the process is completed, 20 ml of 30% concentrated Hydrogen peroxide is added to the mixing slurry and the process is allowed to continue then the pulp is then rinsed with distilled water through a 75-micron mesh until its pH is neutral;
i) The bleached pulp which is white in color, is churned in a mixer after being combined with distilled water in a 1:2 ratio, for 5 minutes at 22000 rpm approximately;
j) The resultant combined pulp is then collected and kept in an airtight container until future usage;
k) The pulp is then mixed with distilled water in a 1:5 ratio;
l) The mixture is stirred either manually or mechanically at an appropriate speed to ensure the pulp particles remain suspended at the surface;
m) The 100 micron sieve with a diameter suitable for the purpose is immersed into the pulp-water mixture to collect the pulp particles on its surface;
n) The collected pulp is subsequently dried using heat at a temperature range of 50-60 ? for a duration of 5-10 minutes, resulting in the formation of a thin absorbent sheet; and
o) Said each sheet weighs about 5 grams and thin absorbent sheet is then cut into required shape.
Another embodiment of the present invention, the absorbent sheet is tested for absorbent capacity to absorb 27 ml of water within a span of 70 seconds.

Further, the details of the items used in the making of absorbent sheets is as follows:
No. Item description Details
1 Stainless steel butcher knife Name: SS Steel knife
Weight: 3 kg
2 Pulveriser Name: Multipurpose pulveriser
Class: Heavy
Frequency: 50 Hz
Current: 10A
Rated speed: 2800 RPM
3 Glass container Name: Glass Container
Capacity: 250 ml, 500 ml
4 Magnetic stirrer with hot plate Name: Magnetic stirrer with hot plate
Frequency: 50 Hz
Current: 10A
Rated speed: 100 to 1300 RPM
5 Stainless steel spatula Name: Stainless steel lab spatula
6 Air tight plastic container Name: Air tight containers
Capacity: 20 litres
7 Stainless steel mesh (20, 24 cm diameter) Name: Stainless steel mesh for straining

8 Plastic tank Capacity: 15 litres
9 Rubber gloves Name: Chemical resistant gloves
Material: Latex rubber
10 Chemical Name: Sodium Hydroxide Pellets [NaOH]
Net Content: 500 grams
Grade: LR
11 Chemical Name: Hydrogen peroxide[H2O2]
Concentration: 30%
Net Content: 500 ml
Grade: AR
12 Chemical Name: Sodium hypochlorite solution [NaOCl]
Chlorine concentration: 4% w/v
Net Content: 500 ml
Grade: LR
13 pH paper Name: pH paper
Range: 2 to 10.5
14 Magnetic stirring bar Name: Magnetic stirring bar
Size: 9*25 mm

15 Heat gun for drying Name: Heat Gun
Power: 1800 W
16 Mixer Grinder Name: Mixer Grinder
Capacity: 900 W
Maximum Revolutions: 22000 RPM , Claims:We claim,
1. A process for making absorbent sheet from Rice stubble comprising of:
a) Rice stubble are collected from farms and chopped into pieces by using a stainless steel butcher knife and having about 5 cm length;
b) Chopped stubble is processed into flakes using a pulverizer machine and having sieve size of 6 and the resultant pieces are about 0.5 cm long which kept in airtight containers to prevent from absorbing moisture;
c) 12% concentrated Sodium Hydroxide solution is made by mixing 12 grams of NaOH with 100 ml of water and the solution is poured into a 250 ml glass beaker, then 10 grams rice stubble flaked added in NaOH solution;
d) The glass beaker is placed on a magnetic stirrer and stirred at a rate of 1215 revolutions per minute and at a temperature of 60-70°C for 3 hours;
e) The resulting slurry is washed with distilled water through a 75 micron mesh until it reaches a neutral pH;
f) 100 ml solution of 2.5% concentrated Sodium hypochlorite is made from a 4% chlorine concentrated w/v solution of laboratory grade for bleaching.;
g) This mixture is transferred in a 500 ml clean glass beaker then obtained wet slurry is added to the solution and rotated for 45 minutes at 60°C on a magnetic stirrer with a hot plate at 450 revolutions per minute;
h) After half of the process is completed, 20 ml of 30% concentrated Hydrogen peroxide is added to the mixing slurry and the process is allowed to continue then the pulp is then rinsed with distilled water through a 75-micron mesh until its pH is neutral;
i) The bleached pulp which is white in color, is churned in a mixer after being combined with distilled water in a 1:2 ratio, for 5 minutes at 22000 rpm approximately;
j) The resultant combined pulp is then collected and kept in an airtight container until future usage;
k) The pulp is then mixed with distilled water in a 1:5 ratio;
l) The mixture is stirred either manually or mechanically at an appropriate speed to ensure the pulp particles remain suspended at the surface;
m) The 100 micron sieve with a diameter suitable for the purpose is immersed into the pulp-water mixture to collect the pulp particles on its surface;
n) The collected pulp is subsequently dried using heat at a temperature range of 50-60 ? for a duration of 5-10 minutes, resulting in the formation of a thin absorbent sheet; and
o) Said each sheet weighs about 5 grams and thin absorbent sheet is then cut into required shape.

2. The process for making absorbent sheet from Rice stubble as claimed in claim 1, wherein said absorbent sheet is tested for absorbent capacity to absorb 27 ml of water within a span of 70 seconds.

Dated 28th July, 2023

Chothani Pritibahen Bipinbhai
Reg. No.: IN/PA-3148
For and on behalf of the applicant