Biodegradable highly absorbent material, method of making and using thereof

Abstract

The present disclosure is directed to a biodegradable absorbent material comprising pulp extracted from at least one of rice husk, sugar cane, maize husk, pineapple leaves, hemp, powdered maize husk, cottonized pineapple leaf fibers, or combinations thereof. The biodegradable absorbent material may be highly absorbent. The present disclosure is directed to a menstrual pad comprising the biodegradable absorbent material.

Description

BIODEGRADABLE HIGHLY ABSORBENT MATERIAL, METHOD OF MAKING AND USING THEREOFCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application the benefit of US Provisional Application No. 63 / 528,243 filed on July 21, 2023, the entire contents of which are entirely incorporated by reference herein.BACKGROUND

[0002] The growing interest for ecofriendly products to save the planet has led to the valorization of biomass / crop residue or side streams to become a commercially viable venture. The utilization of the abundant biomass residues would be economically beneficial to humans and also to the environment by reducing the waste burden.

[0003] The absorbent material in commercial hygiene products, in particular menstruation products, is derived mostly from wood sources. Wood cellulose pulp causes the denudation of the diminishing forests not to mention the chemical invasive process such as chlorine bleaching that releases harmful toxic gases and the dangerous residues transferred to the final product. In addition, huge quantities of chemicals and elevated temperatures are required to delignify the materials from wood sources with high lignin content. On the other hand, cotton wool is the world's most heavily sprayed crop, using an alarming 25 per cent of the world's pesticides making the residual product showing traces of carcinogenic compounds. Compared to wood pulp production process, valorization of non-woody side streams biomass may be an option.BRIEF SUMMARY OF THE INVENTION

[0004] The present disclosure is directed to a biodegradable absorbent material comprising pulp extracted from at least one of rice husk, sugar cane, hemp, powdered maize husk, cottonized pineapple leaf fibers, or combinations thereof.

[0005] The present disclosure is further directed to a biodegradable absorbent material comprising pulp extracted from at least one of rice husk, sugar cane, hemp, powdered maize husk, cottonized pineapple leaf fibers, maize husk, pineapple leaves, or combinations thereof, wherein the pineapple pulp, maize pulp, hemp, powdered maize husk, cottonized pineapple leaf fibers, and sugarcane pulp is bleached, semi-bleached, or unbleached.

[0006] The present disclosure is also directed to a menstrual pad comprising a core and a core wrap; wherein the core comprises a biodegradable absorbent material comprising pulp extracted from at least one of rice husk, sugarcane, maize husk, pineapple leaves, hemp pulp, powdered maize husk pulp, cottonized pineapple leaf fibers pulp, or combinations thereof.

[0007] Aspects of the present disclosure are directed to a method of making the absorbent and biodegradable absorbents material.

[0008] Aspects of the present disclosure are directed a method of making a menstrual pad comprising the biodegradable absorbents material.

[0009] Aspects of the present disclosure are directed to a method of making an unbleached pulp from a biological source, the method comprising: preconditioning the biological source to form preconditioned biological source; adding water a specified amount of water, the preconditioned biological source, and a specified amount of basic solution to a boiler, wherein water is added at a specified volume ensuring a specified ratio of the preconditioned biological source to water; wherein a basic solution is added at a specified volume ensuring a specified ratio of the preconditioned biological source to the basic solution; heating the basic solution, the preconditioned biological source, water, and the boiler for a specified time to form a mixture of individual fibers of the biological source and lignin; removing the mixture of individual fibers of the biological source and lignin from the boiler and cooling the mixture of individual fibers of the biological source and lignin to form a cooled mixture of individual fibers of the biological source and lignin; rinsing the mixture of individual fibers of the biological source and lignin to separate the individual fibers of the biological source and the lignin by passing the mixture through one or more screens, wherein the rinsing is continued until the pH of the mixture is between about 6.5 to about 7.5; pureeing the individual fibers of the biological source to form an unbleached pulp puree; rinsing the unbleached pulp puree by placing the bleached pulp puree in a tank comprising water and one or more screens, wherein the ratio of the unbleached pulp puree to water is specified, and wherein the tank comprises a screen at an angle; and drying the unbleached pulp for a specified time forming a sheet of the unbleached pulp; wherein drying is performed in an oven or in the sun for a specified time; wherein the biological source is sugarcane, maize husk, pineapple leaves, hemp, powdered maize husk, cottonized pineapple leaf fibers or a combination thereof.

[0010] Aspects of the present disclosure are directed to a method of making a bleached pulp from a biological source, the method comprising: preconditioning the biological source to formpreconditioned biological source; adding water a specified amount of water, the preconditioned biological source, and a basic solution to a boiler, wherein water is added at a specified volume ensuring a specified ratio of the preconditioned biological source to water; wherein a basic solution is added at a specified volume ensuring a specified ratio of the preconditioned biological source to the basic solution; heating the basic solution, the preconditioned biological source, water, and the boiler for a specified time to form a mixture of individual fibers of the biological source and lignin; removing the mixture of individual fibers of the biological source and lignin from the boiler and cooling the mixture of individual fibers of the biological source and lignin to form a cooled mixture of individual fibers of the biological source and lignin; rinsing the mixture of individual fibers of the biological source and lignin to separate the individual fibers of the biological source and the lignin by passing the mixture through one or more screens, wherein the rinsing is continued until the pH of the mixture is between about 6.5 to about 7.5; bleaching the individual fibers of the biological source using a hydrogen peroxide solution and an acetic acid solution to form a bleached pulp; adding a sodium hydroxide solution to neutralize the bleaching after the formation of the bleached pulp; pureeing the bleached pulp to form a bleached pulp puree; and rinsing the bleached pulp puree by placing the bleached pulp puree in a tank comprising water and one or more screens, wherein the ratio of the bleached pulp puree to water is specified, and wherein the tank comprises a screen at an angle; and drying the bleached pulp for a specified time forming a sheet of the bleached pulp; wherein drying is performed in an oven or in the sun for a specified time; wherein the biological source is sugarcane, maize husk, pineapple leaves, hemp, powdered maize husk, cottonized pineapple leaf fibers or a combination thereof.

[0011] Aspects of the present disclosure are directed to a method of extracting fibers from a biomass to make paper, the method comprising: cutting or grinding the biomass to form a plurality of cut or ground biomass; adding the plurality of cut or ground biomass to an alkaline solution in a heating device for a first specified time to form pretreated biomass; filtering the pretreated biomass by passing the pretreated biomass through a screen to form filtered biomass; washing the filtered biomass with distilled or fresh water to remove residual alkaline solution resulting in hemi-cellulose-free biomass; drying the cellulose-free biomass in a heating device at a second specified temperature to form a dried cellulose-free biomass; bleaching the dried hemicellulose-free biomass by combining the dried hemi-cellulose-free biomass with an acidic and basic solution at a third specified temperature forming a residue; treating the residue by filteringand rinsing with distilled water to form a purified residue; adding the purified residue and water with a specified ratio of the purified residue to water in a tank to form a liquid suspension; and passing the liquid suspension through a second screen to make the paper.BRIEF DESCRIPTION OF THE FIGURES

[0012] The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.

[0013] The drawings are provided to enhance understanding of the technical aspects of this application and constitute a part of the specification. They are used in conjunction with the embodiments described in this application to illustrate the technical features and should not be considered as limiting the scope of the technical aspects of this application.

[0014] FIG. 1 illustrates the structure of a core comprising a biodegradable absorbent material in accordance with one embodiment.

[0015] FIG. 2A depicts bar plots showing absorbency of pulp samples according to the present disclosure.

[0016] FIG. 2B depicts bar plots showing specific volume of pulp samples according to the present disclosure.

[0017] FIG. 2C depicts bar plots showing fiber diameter of pulp samples according to the present disclosure.

[0018] FIG. 2D depicts bar plots showing fiber length of pulp samples in according to the present disclosure.

[0019] FIG. 2E is a table summarizing the absorbency, specific volume, fiber diameter, and fiber length of pulps according to the present disclosure.

[0020] FIG. 3 is an optical microscope image showing grooves or bonding points according to the present disclosure.

[0021] FIG. 4A depicts bar plots showing liquid absorptive capacity and liquid retentive capacity of prototype pad cores according to embodiments of the present disclosure.

[0022] FIG. 4B depicts bar plots showing liquid retention of prototype pad cores according to embodiments of the present disclosure.

[0023] FIG. 5A depicts bar plots showing strikethrough time of prototype pad cores according to embodiments of the present disclosure.

[0024] FIG. 5B depicts bar plots showing wetback of prototype pad cores according to embodiments of the present disclosure.

[0025] FIG. 5C is a table summarizing the properties of the pulp and prototype pad cores according to embodiments of the present disclosure.

[0026] FIG. 6A depicts bar plots showing absorbency of pulp samples according to embodiments of the present disclosure.

[0027] FIG. 6B depicts bar plots showing specific volume of pulp samples according to embodiments of the present disclosure.

[0028] FIG. 6C is a table summarizing the absorbency, specific volume, fiber diameter, and fiber length of pulps according to embodiments of the present disclosure.

[0029] FIG. 7A illustrates the structure of a core according to embodiments of the present disclosure.

[0030] FIG. 7B depicts bar plots showing liquid absorptive capacity and liquid retentive capacity of prototype pad cores according to embodiments of the present disclosure.

[0031] FIG. 7C depicts bar plots showing liquid retention of prototype pad cores according to embodiments of the present disclosure.

[0032] FIG. 7D depicts bar plots showing strikethrough time of prototype pad cores according to embodiments of the present disclosure.

[0033] FIG. 7E depicts bar plots showing wetback of prototype pad cores according to embodiments of the present disclosure.

[0034] FIG. 7F is a table summarizing the prototype pad cores according to embodiments of the present disclosure.

[0035] FIG. 7G is a table summarizing the properties of the pulps and prototype pad cores according to embodiments of the present disclosure.DETAILED DESCRIPTION

[0036] The present disclosure is directed towards a biodegradable absorbent material comprising fibers extracted from at least one of rice husk, sugar cane, maize husk, pineappleleaves, hemp, powdered maize husk, cottonized pineapple leaf fibers, or combinations thereof. The biodegradable absorbent material may be highly absorbent.

[0037] Aspects of the present disclosure are directed to the use of hard fibers (e.g., pineapple leaves) and soft fibers (e.g., maize husks) or their blend for the production of biodegradable absorbent materials. The absorbent materials obtained from both hard and soft fibers may be used in production of medical and / or hygiene products, particularly in menstruation products such sanitary pads, diapers, wound treatment, and / or the like.

[0038] The biodegradable absorbent material comprises fibers extracted from pineapple leaves, maize husks, and sugarcane. In some embodiments, the fibers extracted from maize husks may be maize pulp. In some embodiments, the fibers extracted from pineapple may be pineapple fiber. In some embodiments, the fibers extracted from sugarcane may be sugarcane pulp.

[0039] In some embodiments, the maize pulp may be bleached. In other embodiments, the maize pulp may be unbleached. In yet other embodiments, the maize pulp may be semi-bleached. In some embodiments, the maize pulp may be bleached, unbleached, semi-bleached, or a combination thereof.

[0040] In some embodiments, the pineapple pulp may be bleached. In other embodiments, the pineapple pulp may be unbleached. In yet other embodiments, the pineapple pulp may be semibleached. In some embodiments, the pineapple pulp may be bleached, unbleached, semibleached, or a combination thereof.

[0041] In some embodiments, the sugarcane pulp may be bleached. In other embodiments, the sugarcane pulp may be unbleached. In yet other embodiments, the sugarcane pulp may be semibleached. In some embodiments, the sugarcane pulp may be bleached, unbleached, semibleached, or a combination thereof.

[0042] Properties of the menstrual pad cores may be against absorbency, retention,

[0043] Specific volume and absorbency of the pulp are aspects that may play an important role in the biodegradable absorbent material fluid handling properties. Specific volume measures the amount of space occupied by a unit weight of pulp fibers (Method SCAN-C 30:80).

[0044] Bleached maize pulp, unbleached maize pulp, or semi-bleached maize pulp may have a specific volume ranging from about 5 cm3 / g to about 20 cm3 / g. For example, the specific volume may be from about 5 cm3 / g to about 6 cm3 / g, about 6 cm3 / g to about 7 cm3 / g, about 7 cm3 / g to about 8 cm3 / g, about 8 cm3 / g to about 9 cm3 / g, about 9 cm3 / g to about 10 cm3 / g, about 10 cm3 / gto about 11 cm3 / g, about 11 cm3 / g to about 12 cm3 / g, about 12 cm3 / g to about 13 cm3 / g, about 13 cm3 / g to about 14 cm3 / g, about 14 cm3 / g to about 15 cm3 / g, about 15 cm3 / g to about 16 cm3 / g, about 16 cm3 / g to about 17 cm3 / g, about 17 cm3 / g to about 18 cm3 / g, about 18 cm3 / g to about 19 cm3 / g, or about 19 cm3 / g to about 20 cm3 / g.

[0045] Bleached pineapple pulp, unbleached pineapple pulp, or semi-bleached pineapple pulp may have a specific volume ranging from about 10 cm3 / g to about 20 cm3 / g. For example, the specific volume may be from about 5 cm3 / g to about 6 cm3 / g, about 6 cm3 / g to about 7 cm3 / g, about 7 cm3 / g to about 8 cm3 / g, about 8 cm3 / g to about 9 cm3 / g, about 9 cm3 / g to about 10 cm3 / g, about 10 cm3 / g to about 11 cm3 / g, about 11 cm3 / g to about 12 cm3 / g, about 12 cm3 / g to about 13 cm3 / g, about 13 cm3 / g to about 14 cm3 / g, about 14 cm3 / g to about 15 cm3 / g, about 15 cm3 / g to about 16 cm3 / g, about 16 cm3 / g to about 17 cm3 / g, about 17 cm3 / g to about 18 cm3 / g, about 18 cm3 / g to about 19 cm3 / g, or about 19 cm3 / g to about 20 cm3 / g.

[0046] Bleached sugarcane pulp, unbleached sugarcane pulp, or semi-bleached sugarcane pulp may have a specific volume ranging from about 10 cm3 / g to about 20 cm3 / g. For example, the specific volume may be from about 5 cm3 / g to about 6 cm3 / g, about 6 cm3 / g to about 7 cm3 / g, about 7 cm3 / g to about 8 cm3 / g, about 8 cm3 / g to about 9 cm3 / g, about 9 cm3 / g to about 10 cm3 / g, about 10 cm3 / g to about 11 cm3 / g, about 11 cm3 / g to about 12 cm3 / g, about 12 cm3 / g to about 13 cm3 / g, about 13 cm3 / g to about 14 cm3 / g, about 14 cm3 / g to about 15 cm3 / g, about 15 cm3 / g to about 16 cm3 / g, about 16 cm3 / g to about 17 cm3 / g, about 17 cm3 / g to about 18 cm3 / g, about 18 cm3 / g to about 19 cm3 / g, or about 19 cm3 / g to about 20 cm3 / g.

[0047] Bleached maize pulp, unbleached maize pulp, or semi-bleached maize pulp may have an absorbency ranging from about 5 g / g to about 12 g / g. For example, the absorbency may be from about 5 g / g to about 6 g / g, about 6 g / g to about 7 g / g, about 7 g / g to about 8 g / g, about 8 g / g to about 9 g / g, about 9 g / g to about 10 g / g, about 10 g / g to about 11 g / g, or about 11 g / g to about 12 g / g.

[0048] Bleached pineapple pulp, unbleached pineapple pulp, or semi-bleached pineapple pulp may have an absorbency ranging from about 5 g / g to about 12 g / g. For example, the absorbency may be from about 5 g / g to about 6 g / g, about 6 g / g to about 7 g / g, about 7 g / g to about 8 g / g, about 8 g / g to about 9 g / g, about 9 g / g to about 10 g / g, about 10 g / g to about 11 g / g, or about 11 g / g to about 12 g / g.

[0049] Bleached sugarcane pulp, unbleached sugarcane pulp, or semi-bleached sugarcane pulp may have an absorbency ranging from about 5 g / g to about 12 g / g. For example, the absorbencymay be from about 5 g / g to about 6 g / g, about 6 g / g to about 7 g / g, about 7 g / g to about 8 g / g, about 8 g / g to about 9 g / g, about 9 g / g to about 10 g / g, about 10 g / g to about 11 g / g, or about 11 g / g to about 12 g / g.

[0050] Fiber length and fiber diameter are properties that may directly impact the properties of the biodegradable absorbent materials. The properties include but are not limited to strength, absorbency, texture, and the like. Understanding fiber length and diameter variations may be key in optimizing the air laying process parameters such as belt speed and fiber feed rate. Fiber length and diameter were measured using an optical microscope.

[0051] Bleached maize pulp, unbleached maize pulp, or semi-bleached maize pulp may have a fiber length ranging from about 0.1 mm to about 30 mm. For example, the fiber length may range from about 0.1 mm to about 1 mm, about 1 mm to about 2 mm, about 2 mm to about 3 mm, about 3 mm to about 4 mm, about 4 mm to about 5 mm, about 5 mm to about 6 mm, about 6 mm to about 7 mm, about 7 mm to about 8 mm, about 8 mm to about 9 mm, about 9 mm to about 10 mm, about 10 mm to about 11 mm, about 11 mm to about 12 mm, about 12 mm to about 13 mm, about 13 mm to about 14 mm, about 14 mm to about 15 mm, about 15 mm to about 16 mm, about 16 mm to about 17 mm, about 17 mm to about 18 mm, about 18 mm to about 19 mm, about 19 mm to about 20 mm, about 20 mm to about 21 mm, about 21 mm to about 22 mm, about 22 mm to about 23 mm, about 23 mm to about 24 mm, about 24 mm to about 25 mm, about 25 mm to about 26 mm, about 26 mm to about 27 mm, about 27 mm to about 28 mm, about 28 mm to about 29 mm, or about 29 mm to about 30 mm.

[0052] Bleached pineapple pulp, unbleached pineapple pulp, or semi-bleached pineapple pulp may have a fiber length ranging from about 0.1 mm to about 30 mm. For example, the fiber length may range from about 0. 1 mm to about 1 mm, about 1 mm to about 2 mm, about 2 mm to about 3 mm, about 3 mm to about 4 mm, about 4 mm to about 5 mm, about 5 mm to about 6 mm, about 6 mm to about 7 mm, about 7 mm to about 8 mm, about 8 mm to about 9 mm, about 9 mm to about 10 mm, about 10 mm to about 11 mm, about 11 mm to about 12 mm, about 12 mm to about 13 mm, about 13 mm to about 14 mm, about 14 mm to about 15 mm, about 15 mm to about 16 mm, about 16 mm to about 17 mm, about 17 mm to about 18 mm, about 18 mm to about 19 mm, about 19 mm to about 20 mm, about 20 mm to about 21 mm, about 21 mm to about 22 mm, about 22 mm to about 23 mm, about 23 mm to about 24 mm, about 24 mm to about 25 mm, about 25 mm to about 26 mm, about 26 mm to about 27 mm, about 27 mm to about 28 mm, about 28 mm to about 29 mm, or about 29 mm to about 30 mm.

[0053] Bleached sugarcane pulp, unbleached sugarcane pulp, or semi-bleached sugarcane pulp a fiber length ranging from about 0.1 mm to about 30 mm. For example, the fiber length may range from about 0.1 mm to about 1 mm, about 1 mm to about 2 mm, about 2 mm to about 3 mm, about 3 mm to about 4 mm, about 4 mm to about 5 mm, about 5 mm to about 6 mm, about 6 mm to about 7 mm, about 7 mm to about 8 mm, about 8 mm to about 9 mm, about 9 mm to about 10 mm, about 10 mm to about 11 mm, about 11 mm to about 12 mm, about 12 mm to about 13 mm, about 13 mm to about 14 mm, about 14 mm to about 15 mm, about 15 mm to about 16 mm, about 16 mm to about 17 mm, about 17 mm to about 18 mm, about 18 mm to about 19 mm, about 19 mm to about 20 mm, about 20 mm to about 21 mm, about 21 mm to about 22 mm, about 22 mm to about 23 mm, about 23 mm to about 24 mm, about 24 mm to about 25 mm, about 25 mm to about 26 mm, about 26 mm to about 27 mm, about 27 mm to about 28 mm, about 28 mm to about 29 mm, or about 29 mm to about 30 mm.

[0054] Bleached maize pulp, unbleached maize pulp, or semi-bleached maize pulp may have a fiber diameter ranging from about 1 pm to about 500 pm. For example the fiber diameter may be from about 1 pm to about 5 pm, about 5pm to about 10 pm, about 10 pm to about 15 pm, about 15pm to about 20 pm, about 20 pm to about 25 pm, about 25pm to about 30 pm, about 30 pm to about 50 pm, about 50pm to about 100 pm, about 100pm to about 150 pm, about 150pm to about 200 pm, about 200pm to about 250 pm, about 250pm to about 300 pm, about 300pm to about 350 pm, about 350pm to about 400 pm, about 400pm to about 450 pm, or about 450 pm to about 500 pm.

[0055] Bleached pineapple pulp, unbleached pineapple pulp, or semi-bleached pineapple pulp may have a fiber diameter from about 1 pm to about 500 pm. For example the fiber diameter may be from about 1 pm to about 5 pm, about 5pm to about 10 pm, about 10 pm to about 15 pm, about 15pm to about 20 pm, about 20 pm to about 25 pm, about 25pm to about 30 pm, about 30 pm to about 50 pm, about 50pm to about 100 pm, about 100pm to about 150 pm, about 150pm to about 200 pm, about 200pm to about 250 pm, about 250pm to about 300 pm, about 300pm to about 350 pm, about 350pm to about 400 pm, about 400pm to about 450 pm, or about 450 pm to about 500 pm.

[0056] Bleached sugarcane pulp, unbleached sugarcane pulp, or semi-bleached sugarcane pulp may have a fiber diameter from about 1 pm to about 500 pm. For example the fiber diameter may be from about 1 pm to about 5 pm, about 5pm to about 10 pm, about 10 pm to about 15 pm, about 15pm to about 20 pm, about 20 pm to about 25 pm, about 25pm to about 30 pm, about 30pm to about 50 pm, about 50pm to about 100 m, about 100pm to about 150 pin, about 150pm to about 200 pm, about 200pm to about 250 pm, about 250pm to about 300 pm, about 300pm to about 350 pm, about 350pm to about 400 pm, about 400pm to about 450 pm, or about 450 pm to about 500 pm.Uses of biodegradable absorbent material

[0057] The biodegradable absorbent material may be used in hygiene products. The hygiene products include but are not limited to menstrual pads, panty liners, tampons, maternity pads, incontinence pads, and the like. The biodegradable absorbent material may also be used in diapers, wound treatment products (e.g., gauze, etc.), pet products (e.g., training pads), cleaning products (e.g., disposable towels, napkins, etc.), and / or the like.

[0058] The present disclosure is directed to a menstrual pad. The menstrual pad comprises a core and a core wrap. In some embodiments, the biodegradable absorbent material may be used to make the core.Core

[0059] The biodegradable absorbent material comprises fibers extracted from pineapple leaves, maize husk, hemp, powdered maize husk, cottonized pineapple leaf fibers, and sugarcane. In some embodiments, the fibers extracted from maize may be maize pulp. In some embodiments, the fibers extracted from pineapple may be pineapple fiber. In some embodiments, the fibers extracted from sugarcane may be sugarcane pulp.

[0060] FIG. 1 shows a pictorial representation of a menstrual pad core in one embodiment. The core may have distribution grooves. The core may have distribution channels. The distribution grooves and distribution channels may be formed by applying heat and pressure. The distribution grooves and distribution channels may facilitate uniform distribution of fluid throughout the pad. The distribution grooves and distribution channels may provide physical integrity to the core layer.

[0061] In some embodiments, the maize pulp may be bleached. In other embodiments, the maize pulp may be unbleached. In yet other embodiments, the maize pulp may be semi-bleached. In some embodiments, the maize pulp may be bleached, unbleached, semi-bleached, or a combination thereof.

[0062] In some embodiments, the pineapple pulp may be bleached. In other embodiments, the pineapple pulp may be unbleached. In yet other embodiments, the pineapple pulp may be semi-bleached. In some embodiments, the pineapple pulp may be bleached, unbleached, semibleached, or a combination thereof.

[0063] In some embodiments, the sugarcane pulp may be bleached. In other embodiments, the sugarcane pulp may be unbleached. In yet other embodiments, the sugarcane pulp may be semibleached. In some embodiments, the sugarcane pulp may be bleached, unbleached, semibleached, or a combination thereof.

[0064] Areal density of the disclosed cores may range from about 300 g / m2to about 500 g / m2. For example, the areal density may range from about 300 g / m2to about 350 g / m2, from about 350 g / m2to about 400 g / m2, from about 400 g / m2to about 450 g / m2, or from about 450 g / m2to about 500 g / m2'

[0065] Specific volume and absorbency of the pulp are aspects that may play an important role in the biodegradable absorbent material fluid handling properties. Specific volume measures the amount of space occupied by a unit weight of pulp fibers. Specific volume may influence the thickness and bulkiness of the pad, contributing to its overall comfort. Pulp with higher specific volume will enable the core to be softer and more absorbent, enhancing the user's comfort.

[0066] Pulp absorption capacity is the ratio of mass of water taken up by a standard test piece of fluff, under specific conditions to the initial mass of the conditioned test piece. The absorption capacity is the ability of pulp fibers to take up and retain liquids. The absorption capacity is directly related to the core’s ability to trap and hold liquid within its structure. Pulp with higher absorbency may enable the core to have increased absorbency and retention resulting in a pad that can handle heavier flows without leaking.

[0067] Liquid Absorptive Capacity (LAC) measures the maximum amount of liquid the core may absorb. Liquid Retention Capacity (LRC) measures the ability of the core to retain liquid after absorption.

[0068] Cores made from bleached maize pulp, unbleached maize pulp, or semi-bleached maize pulp may have a LAC of about 400% g / g to about 1000% g / g. For example, the LAC may be from about 400% g / g to about 450% g / g, about 450% g / g to about 500% g / g, about 500% g / g to about 550% g / g, about 550% g / g to about 600% g / g, about 600% g / g to about 650% g / g, about 650% g / g to about 700% g / g, about 700% g / g to about 750% g / g, about 750% g / g to about 800% g / g, about 800% g / g to about 850% g / g, about 850% g / g to about 900% g / g, about 900% g / g to about 950% g / g, or about 950% g / g to about 1000% g / g.

[0069] Cores made from bleached pineapple pulp, unbleached pineapple pulp, or semi-bleached pineapple pulp may have a LAC of about 400% g / g to about 1000% g / g. For example, the LAC may be from about 400% g / g to about 450% g / g, about 450% g / g to about 500% g / g, about 500% g / g to about 550% g / g, about 550% g / g to about 600% g / g, about 600% g / g to about 650% g / g, about 650% g / g to about 700% g / g, about 700% g / g to about 750% g / g, about 750% g / g to about 800% g / g, about 800% g / g to about 850% g / g, about 850% g / g to about 900% g / g, about 900% g / g to about 950% g / g, or about 950% g / g to about 1000% g / g.

[0070] Cores made from bleached sugarcane pulp, unbleached sugarcane pulp, or semibleached sugarcane pulp may have a LAC of about 400% g / g to about 1000% g / g. For example, the LAC may be from about 400% g / g to about 450% g / g, about 450% g / g to about 500% g / g, about 500% g / g to about 550% g / g, about 550% g / g to about 600% g / g, about 600% g / g to about 650% g / g, about 650% g / g to about 700% g / g, about 700% g / g to about 750% g / g, about 750% g / g to about 800% g / g, about 800% g / g to about 850% g / g, about 850% g / g to about 900% g / g, about 900% g / g to about 950% g / g, or about 950% g / g to about 1000% g / g.

[0071] Cores made from bleached maize pulp, unbleached maize pulp, or semi-bleached maize pulp may have a LRC of about 400% g / g to about 1000% g / g. For example, the LAC may be from about 400% g / g to about 450% g / g, about 450% g / g to about 500% g / g, about 500% g / g to about 550% g / g, about 550% g / g to about 600% g / g, about 600% g / g to about 650% g / g, about 650% g / g to about 700% g / g, about 700% g / g to about 750% g / g, about 750% g / g to about 800% g / g, about 800% g / g to about 850% g / g, about 850% g / g to about 900% g / g, about 900% g / g to about 950% g / g, or about 950% g / g to about 1000% g / g.

[0072] Cores made from bleached pineapple pulp, unbleached pineapple pulp, or semi-bleached pineapple pulp may have a LRC of about 400% g / g to about 1000% g / g. For example, the LAC may be from about 400% g / g to about 450% g / g, about 450% g / g to about 500% g / g, about 500% g / g to about 550% g / g, about 550% g / g to about 600% g / g, about 600% g / g to about 650% g / g, about 650% g / g to about 700% g / g, about 700% g / g to about 750% g / g, about 750% g / g to about 800% g / g, about 800% g / g to about 850% g / g, about 850% g / g to about 900% g / g, about 900% g / g to about 950% g / g, or about 950% g / g to about 1000% g / g.

[0073] Cores made from bleached sugarcane pulp, unbleached sugarcane pulp, or semibleached sugarcane pulp may have a LRC of about 400% g / g to about 1000% g / g. For example, the LAC may be from about 400% g / g to about 450% g / g, about 450% g / g to about 500% g / g, about 500% g / g to about 550% g / g, about 550% g / g to about 600% g / g, about 600% g / g to about650% g / g, about 650% g / g to about 700% g / g, about 700% g / g to about 750% g / g, about 750% g / g to about 800% g / g, about 800% g / g to about 850% g / g, about 850% g / g to about 900% g / g, about 900% g / g to about 950% g / g, or about 950% g / g to about 1000% g / g.

[0074] Strikethrough time (STT) is a measure of the time taken for a known volume of liquid to pass through a sample. STT may be by European Disposables And Nonwovens Association (EDANA) standards.

[0075] Cores made from bleached maize pulp, unbleached maize pulp, or semi-bleached maize pulp may have a STT from about 1 second to about 30 seconds. For example, the STT may range from about 1 second to about 2 seconds, about 2 seconds to about 3 seconds, about 3 seconds to about 4 seconds, about 4 seconds to about 5 seconds, about 5 seconds to about 6 seconds, about 6 seconds to about 7 seconds, about 7 seconds to about 8 seconds, about 8 seconds to about 9 seconds, about 9 seconds to about 10 seconds, about 10 seconds to about 1 1 seconds, about 1 1 second to about 12 seconds, about 12 seconds to about 13 seconds, about 13 seconds to about 14 seconds, about 14 seconds to about 15 seconds, about 15 seconds to about 16 seconds, about 16 seconds to about 17 seconds, about 17 seconds to about 18 seconds, about 18 seconds to about 19 seconds, about 19 seconds to about 20 seconds, about 20 seconds to about 21 seconds, about 21 seconds to about 22 seconds, about 22 seconds to about 23 seconds, about 23 seconds to about 24 seconds, about 24 seconds to about 25 seconds, about 25 seconds to about 26 seconds, about 26 seconds to about 27 seconds, about 27 seconds to about 28 seconds, about 28 seconds to about 29 seconds, or about 29 seconds to about 30 seconds. In some embodiments, bleached maize pulp, unbleached maize pulp, or semi-bleached maize pulp may have a STT from about 1 second to about 10 second.

[0076] Cores made from bleached pineapple pulp, unbleached pineapple pulp, or semi-bleached pineapple pulp may have a STT from about 1 second to about 30 seconds. For example, the STT may range from about 1 second to about 2 seconds, about 2 seconds to about 3 seconds, about 3 seconds to about 4 seconds, about 4 seconds to about 5 seconds, about 5 seconds to about 6 seconds, about 6 seconds to about 7 seconds, about 7 seconds to about 8 seconds, about 8 seconds to about 9 seconds, about 9 seconds to about 10 seconds, about 10 seconds to about 11 seconds, about 11 second to about 12 seconds, about 12 seconds to about 13 seconds, about 13 seconds to about 14 seconds, about 14 seconds to about 15 seconds, about 15 seconds to about 16 seconds, about 16 seconds to about 17 seconds, about 17 seconds to about 18 seconds, about 18 seconds to about 19 seconds, about 19 seconds to about 20 seconds, about 20 seconds to about 21 seconds,about 21 seconds to about 22 seconds, about 22 seconds to about 23 seconds, about 23 seconds to about 24 seconds, about 24 seconds to about 25 seconds, about 25 seconds to about 26 seconds, about 26 seconds to about 27 seconds, about 27 seconds to about 28 seconds, about 28 seconds to about 29 seconds, or about 29 seconds to about 30 seconds. In some embodiments, bleached pineapple pulp, unbleached pineapple pulp, or semi-bleached pineapple pulp may have a STT from about 1 second to about 10 second.

[0077] Cores made from bleached sugarcane pulp, unbleached sugarcane pulp, or semibleached sugarcane pulp may have a STT from about 1 second to about 30 seconds. For example, the STT may range from about 1 second to about 2 seconds, about 2 seconds to about 3 seconds, about 3 seconds to about 4 seconds, about 4 seconds to about 5 seconds, about 5 seconds to about 6 seconds, about 6 seconds to about 7 seconds, about 7 seconds to about 8 seconds, about 8 seconds to about 9 seconds, about 9 seconds to about 10 seconds, about 10 seconds to about 11 seconds, about 1 1 second to about 12 seconds, about 12 seconds to about 13 seconds, about 13 seconds to about 14 seconds, about 14 seconds to about 15 seconds, about 15 seconds to about 16 seconds, about 16 seconds to about 17 seconds, about 17 seconds to about 18 seconds, about 18 seconds to about 19 seconds, about 19 seconds to about 20 seconds, about 20 seconds to about 21 seconds, about 21 seconds to about 22 seconds, about 22 seconds to about 23 seconds, about 23 seconds to about 24 seconds, about 24 seconds to about 25 seconds, about 25 seconds to about 26 seconds, about 26 seconds to about 27 seconds, about 27 seconds to about 28 seconds, about 28 seconds to about 29 seconds, or about 29 seconds to about 30 seconds. In some embodiments, bleached sugarcane pulp, unbleached sugarcane pulp, or semi-bleached sugarcane pulp may have a STT from about 1 second to about 10 second.

[0078] Wetback (WB) is a measure resistance of a biodegradable absorbent material to rewetting of the penetrated liquid to skin. Wetback is a measure of liquid that is released by the product after absorption when pressure is applied to the product. Wetback may be measured by EDANA standards.

[0079] Cores made from bleached maize pulp, unbleached maize pulp, or semi-bleached maize pulp may have a WB ranging from about 1 g to 6 g. For example, the WB may be about 1 g to about 1.1 g, from about 1.1 g to about 1.2 g, from about 1.2 g to about 1.3 g, from about 1.3 g to about 1.4 g, from about 1.4 g to about 1.5 g, from about 1.5 g to about 1.6 g, from about 1.6 g to about 1.7 g, from about 1.7 g to about 1.8 g, from about 1.8 g to about 1.9 g, from about 1.9 g to about 2.0 g, from about 2.1 g to about 2.2 g, from about 2.2 g to about 2.3 g, from about 2.3 gto about 2.4 g, from about 2.4 g to about 2.5 g, from about 2.5 g to about 2.6 g, from about 2.6 g to about 2.7 g, from about 2.7 g to about 2.8 g, from about 2.8 g to about 2.9 g, from about 2.9 g to about 3.0 g, from about 3.1 g to about 3.2 g, from about 3.2 g to about 3.3 g, from about 3.3 g to about 3.4 g, from about 3.4 g to about 3.5 g, from about 3.5 g to about 3.6 g, from about 3.6 g to about 3.7 g, from about 3.7 g to about 3.8 g, from about 3.8 g to about 3.9 g, from about 3.9 g to about 4.0 g, from about 4.1 g to about 4.2 g, from about 4.2 g to about 4.3 g, from about 4.3 g to about 4.4 g, from about 4.4 g to about 4.5 g, from about 4.5 g to about 4.6 g, from about 4.6 g to about 4.7 g, from about 4.7 g to about 4.8 g, from about 4.8 g to about 4.9 g, from about 4.9 g to about 5.0 g, from about 5.1 g to about 5.2 g, from about 5.2 g to about 5.3 g, from about 5.3 g to about 5.4 g, from about 5.4 g to about 5.5 g, from about 5.5 g to about 5.6 g, from about 5.6 g to about 5.7 g, from about 5.7 g to about 5.8 g, from about 5.8 g to about 5.9 g, from about 5.9 g to about 6.0 g. In some embodiments, the bleached maize pulp may have a wetback ranging from about 1.0 g to about 4.0 g. In some embodiments, the unbleached maize pulp may have a wetback ranging from about 1.0 g to about 4.0 g. In some other embodiments, the semi-bleached maize pulp may have a wetback ranging from about 1.0 g to about 4.0 g.

[0080] Cores made from bleached pineapple pulp, unbleached pineapple pulp, or semi-bleached pineapple pulp may have a WB ranging from about 1 g to 6 g. For example, the WB may be about 1 g to about 1.1 g, from about 1.1 g to about 1.2 g, from about 1.2 g to about 1.3 g, from about 1.3 g to about 1.4 g, from about 1.4 g to about 1.5 g, from about 1.5 g to about 1.6 g, from about 1.6 g to about 1.7 g, from about 1.7 g to about 1.8 g, from about 1.8 g to about 1.9 g, from about 1 .9 g to about 2.0 g, from about 2. 1 g to about 2.2 g, from about 2.2 g to about 2.3 g, from about 2.3 g to about 2.4 g, from about 2.4 g to about 2.5 g, from about 2.5 g to about 2.6 g, from about 2.6 g to about 2.7 g, from about 2.7 g to about 2.8 g, from about 2.8 g to about 2.9 g, from about 2.9 g to about 3.0 g, from about 3.1 g to about 3.2 g, from about 3.2 g to about 3.3 g, from about 3.3 g to about 3.4 g, from about 3.4 g to about 3.5 g, from about 3.5 g to about 3.6 g, from about 3.6 g to about 3.7 g, from about 3.7 g to about 3.8 g, from about 3.8 g to about 3.9 g, from about 3.9 g to about 4.0 g, from about 4.1 g to about 4.2 g, from about 4.2 g to about 4.3 g, from about 4.3 g to about 4.4 g, from about 4.4 g to about 4.5 g, from about 4.5 g to about 4.6 g, from about 4.6 g to about 4.7 g, from about 4.7 g to about 4.8 g, from about 4.8 g to about 4.9 g, from about 4.9 g to about 5.0 g, from about 5.1 g to about 5.2 g, from about 5.2 g to about 5.3 g, from about 5.3 g to about 5.4 g, from about 5.4 g to about 5.5 g, from about 5.5 g to about 5.6 g, from about 5.6 g to about 5.7 g, from about 5.7 g to about 5.8 g, from about 5.8 g to about 5.9 g, fromabout 5.9 g to about 6.0 g. In some embodiments, the bleached pineapple pulp may have a wetback ranging from about 1.0 g to about 4.0 g. In some embodiments, the unbleached pineapple pulp may have a wetback ranging from about 1.0 g to about 4.0 g. In some other embodiments, the semi-bleached pineapple pulp may have a wetback ranging from about 1.0 g to about 4.0 g.

[0081] Cores made from bleached sugarcane pulp, unbleached sugarcane pulp, or semibleached sugarcane pulp may have a WB ranging from about 1 g to 6 g. For example, the WB may be about 1 g to about 1.1 g, from about 1.1 g to about 1.2 g, from about 1.2 g to about 1.3 g, from about 1.3 g to about 1.4 g, from about 1.4 g to about 1.5 g, from about 1.5 g to about 1.6 g, from about 1.6 g to about 1.7 g, from about 1.7 g to about 1.8 g, from about 1.8 g to about 1.9 g, from about 1.9 g to about 2.0 g, from about 2.1 g to about 2.2 g, from about 2.2 g to about 2.3 g, from about 2.3 g to about 2.4 g, from about 2.4 g to about 2.5 g, from about 2.5 g to about 2.6 g, from about 2.6 g to about 2.7 g, from about 2.7 g to about 2.8 g, from about 2.8 g to about 2.9 g, from about 2.9 g to about 3.0 g, from about 3.1 g to about 3.2 g, from about 3.2 g to about 3.3 g, from about 3.3 g to about 3.4 g, from about 3.4 g to about 3.5 g, from about 3.5 g to about 3.6 g, from about 3.6 g to about 3.7 g, from about 3.7 g to about 3.8 g, from about 3.8 g to about 3.9 g, from about 3.9 g to about 4.0 g, from about 4. 1 g to about 4.2 g, from about 4.2 g to about 4.3 g, from about 4.3 g to about 4.4 g, from about 4.4 g to about 4.5 g, from about 4.5 g to about 4.6 g, from about 4.6 g to about 4.7 g, from about 4.7 g to about 4.8 g, from about 4.8 g to about 4.9 g, from about 4.9 g to about 5.0 g, from about 5.1 g to about 5.2 g, from about 5.2 g to about 5.3 g, from about 5.3 g to about 5.4 g, from about 5.4 g to about 5.5 g, from about 5.5 g to about 5.6 g, from about 5.6 g to about 5.7 g, from about 5.7 g to about 5.8 g, from about 5.8 g to about 5.9 g, from about 5.9 g to about 6.0 g. In some embodiments, the bleached sugarcane pulp may have a wetback ranging from about 1.0 g to about 4.0 g. In some embodiments, the unbleached sugarcane pulp may have a wetback ranging from about 1.0 g to about 4.0 g. In some other embodiments, the semi-bleached sugarcane pulp may have a wetback ranging from about 1.0 g to about 4.0 g.Core wrapIn some embodiments, the core wrap may comprise spunlace cotton fabric. The spunlace cotton fabric may have an areal density ranging from about 30 g / m2to about 40 g / m2. For example the areal density may be from about 30 g / m2to about 31 g / m2, about 31 g / m2to about32 g / m2, about 32 g / m2to about 33 g / m2, about 33 g / m2to about 34 g / m2, about 34 g / m2to about35 g / m2, about 35 g / m2to about 36 g / m2, about 36 g / m2to about 37 g / m2, about 37 g / m2to about38 g / m2, about 38 g / m2to about 39 g / m2, or about 39 g / m2to about 40 g / m2.Method of making / extracting pulp

[0082] The present disclosure is further directed to a method of making an unbleached pulp from a biological source. The present disclosure is further directed to a method of making a bleached pulp from a biological source. The present disclosure is further directed to a method of making a semi-bleached pulp from a biological source. The biological source includes but is not limited to maize husk, pineapple leaf fibers, rice husk, sugarcane, hemp, powdered maize husk, cottonized pineapple leaf fibers and the like.

[0083] Pineapple leaf fibers, maize husks, rice husks, sugarcane, and hemp are abundant agricultural by-products that have the potential to be used in sustainable, environmentally- friendly products. Pulping these materials results in breaking down the fibers into a pulp that may be processed and formed into a biodegradable absorbent material. The biodegradable absorbent material may be used to make a menstrual pad core.

[0084] Method of unbleached pulp

[0085] The first step in the method of making an unbleached pulp from a biological source may include preconditioning the biological source to form preconditioned biological source. The preconditioning step may include chopping the biological source into smaller sizes using a suitable tool. An example of a suitable tool is a pair of scissors. The biological source may be cut into uniform smaller sizes. The preconditioning step may also include air drying the biological source to reduce the moisture content. The biological source may be air dried for up to three days. For example, the biological source may be air dried for about 6 hours, about 12 hours, about one day, about two days, or about three days.

[0086] The second step in the method of making an unbleached pulp may include adding a water, the preconditioned biological source, and a basic solution to a boiler. The ratio of water to the preconditioned biological source from range from about 8: 1 to about 5: 1. For example, the ratio may be from about 8: 1 to about 7: 1, from about 7: 1 to about 6: 1, or from about 6: 1 toabout 5: 1. In some embodiments the ratio may be 7.4: 1. In other embodiments the ratio may be 5.2: 1.

[0087] The basic solution may include a solution of any appropriate base. Examples of appropriate bases include but are not limited to sodium hydroxide, potassium hydroxide, and the like. In some embodiments, the basic solution is a 2 wt% solution of sodium hydroxide in water.

[0088] The third step in the method of making an unbleached pulp may include heating the basic solution, the preconditioned biological source, water, and the boiler for a specified time to form a a mixture of individual fibers of the biological source and lignin. The basic solution, the preconditioned biological source, water, and the boiler may be heated for about 30 mins, about 1 hour, about 2 hours, about 3 hours, about 4 hours, or about 5 hours. The heating time may range from about 30 mins to about 24 hours. In some embodiments, the basic solution, the preconditioned biological source, water, and the boiler may be heated for 3 hours.

[0089] The fourth step in the method of making an unbleached pulp may include removing the mixture of individual fibers of the biological source and lignin from the boiler and cooling the mixture of individual fibers of the biological source and lignin to form a cooled mixture of individual fibers of the biological source and lignin.

[0090] The fifth step in the method of making an unbleached pulp may include rinsing the cooled mixture of individual fibers of the biological source and lignin to separate the individual fibers of the biological source and the lignin by passing the mixture through one or more screens. The rinsing step may be continued with water until the pH of the mixture is between about 6.5 to about 7.5. Examples of types of water that may be used include but are not limited to fresh water, distilled water, a combination of fresh water and distilled water, and the like.

[0091] The sixth step in the method of making an unbleached pulp may include pureeing the individual fibers of the biological source to form an unbleached pulp puree.

[0092] The seventh step in the method making an unbleached pulp may include further rinsing the unbleached pulp puree by placing the bleached pulp puree in a tank comprising water and one or more screens. The ratio of the unbleached pulp puree to water may be from about 1 :3 to about 1 :6. For example the ratio may be from about 1 :3 to about 1 :4, from about 1 :4 to about 1 :5, or from about 1 :5 to about 1 :6. The tank may include one or more screens at an angle. The angle may be any angle between about 40° to about 70°. In some embodiments, the angle may be 65°. In other embodiments, the angle may be 45°.

[0093] The eighth and final step in the method of making an unbleached pulp may include drying the unbleached pulp for a specified time forming a sheet of the unbleached pulp. The drying may be performed in an oven or in the sun for a specified time.

[0094] In some embodiments, the biological source may be sugarcane. In some embodiments, the biological source may be maize husk.

[0095] In some embodiments, the biological source may be pineapple leaves.

[0096] In some embodiments, the biological source may be hemp.

[0097] In some embodiments, the biological source may be powdered maize husk.

[0098] In some embodiments, the biological source may be cottonized pineapple leaf fibers.

[0099] In some embodiments, the biological source may be a combination of maize husk, pineapple leaf fibers, rice husk, sugarcane, hemp, powdered maize husk, cottonized pineapple leaf fibers.Method of extracting bleached pulp

[0100] The first step in the method of making a bleached pulp from a biological source may include preconditioning the biological source to form preconditioned biological source. The preconditioning step may include chopping the biological source into smaller sizes using a suitable tool. An example of a suitable tool is a pair of scissors. The biological source may be cut into uniform smaller sizes. The preconditioning step may also include air drying the biological source to reduce the moisture content. The biological source may be air dried for up to three days. For example, the biological source may be air dried for about 6 hours, about 12 hours, about one day, about two days, or about three days.

[0101] The second step in the method of making a bleached pulp may include adding a water, the preconditioned biological source, and a basic solution to a boiler. The ratio of water to the preconditioned biological source from range from about 8: 1 to about 5:1. For example, the ratio may be from about 8:1 to about 7: 1, from about 7: 1 to about 6: 1, or from about 6: 1 to about 5:1. In some embodiments the ratio may be 7.4: 1. In other embodiments the ratio may be 5.2: 1.

[0102] The basic solution may include a solution of any appropriate base. Examples of appropriate bases include but are not limited to sodium hydroxide, potassium hydroxide, and the like. In some embodiments, the basic solution is a 2wt% solution of sodium hydroxide in water.

[0103] The third step in the method of making a bleached pulp may include heating the basic solution, the preconditioned biological source, water, and the boiler for a specified time to forma a mixture of individual fibers of the biological source and lignin. The basic solution, the preconditioned biological source, water, and the boiler may be heated for about 30 mins, about 1 hour, about 2 hours, about 3 hours, about 4 hours, or about 5 hours. The heating time may range from about 30 mins to about 24 hours. In some embodiments, the basic solution, the preconditioned biological source, water, and the boiler may be heated for 3 hours.

[0104] The fourth step in the method of making n bleached pulp may include removing the mixture of individual fibers of the biological source and lignin from the boiler and cooling the mixture of individual fibers of the biological source and lignin to form a cooled mixture of individual fibers of the biological source and lignin.

[0105] The fifth step in the method of making a bleached pulp may include rinsing the cooled mixture of individual fibers of the biological source and lignin to separate the individual fibers of the biological source and the lignin by passing the mixture through one or more screens. The rinsing step may be continued until the pH of the mixture is between about 6.5 to about 7.5.

[0106] The sixth step in the method of making bleached pulp may include adding the individual fibers of the biological source, hydrogen peroxide, acetic acid, and analytical grade sodium hydroxide pellets to a boiler and heating the boiler for from about 5 minutes to about 30 minutes. For example, the boiler may be heated for about 5 minutes, about 10 minutes, about 15 minutes, about 20 minutes, about 25 minutes, or about 30 minutes.

[0107] The seventh step in the method of making a bleached pulp may include pureeing the individual fibers of the biological source to form an unbleached pulp puree.

[0108] The eighth step in the method making an unbleached pulp may include further rinsing the unbleached pulp puree by placing the bleached pulp puree in a tank comprising water and one or more screens. The ratio of the unbleached pulp puree to water may be from about 1 :3 to about 1 :6. For example the ratio may be from about 1 :3 to about 1 :4, from about 1 :4 to about 1 :5, or from about 1 :5 to about 1 :6. The tank may include one or more screens at an angle. The angle may be any angle between about 40° to about 70°. In some embodiments, the angle may be 65°. In other embodiments, the angle may be 45°.

[0109] The ninth and final step in the method of making an unbleached pulp may include drying the unbleached pulp for a specified time forming a sheet of the unbleached pulp. The drying may be performed in an oven or in the sun for a specified time.

[0110] In some embodiments, the biological source may be sugarcane. In some embodiments, the biological source may be maize husk.

[0111] In some embodiments, the biological source may be pineapple leaves.

[0112] In some embodiments, the biological source may be hemp.

[0113] In some embodiments, the biological source may be powdered maize husk.

[0114] In some embodiments, the biological source may be cottonized pineapple leaf fibers.

[0115] In some embodiments, the biological source may be a combination of maize husk, pineapple leaf fibers, rice husk, sugarcane, hemp, powdered maize husk, cottonized pineapple leaf fibers.

[0116] This disclosure describes inventive concepts with reference to specific examples. However, the intent is to cover all modifications, equivalents, and alternatives of the inventive concepts that are consistent with this disclosure.

[0117] As used in the specification and the appended claims, the singular forms “a”, “an”, and “the” include plural referents unless the context clearly dictates otherwise.

[0118] As used herein, the term “bleached” refers to pulp that is processed to lighten its color and whiten the pulp.

[0119] As used herein, the term “unbleached” refers to pulp that is not processed to lighten its color.

[0120] The phrase “consisting essentially of’ limits the scope of a claim to the recited components in a composition or the recited steps in a method as well as those that do not materially affect the basic and novel characteristic or characteristics of the claimed composition or claimed method. The phrase “consisting of’ excludes any component, step, or element that is not recited in the claim. The phrase “comprising” is synonymous with “including”, “containing”, or “characterized by”, and is inclusive or open-ended. ‘Comprising’ does not exclude additional, unrecited components or steps.

[0121] As used herein, when referring to any numerical value, the term “about” means a value falling within a range that is ± 10% of the stated value.

[0122] Ranges can be expressed herein as from ‘about’ one particular value, and / or to ‘about’ another particular value. When such a range is expressed, a further aspect includes from the one particular value and / or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent ‘about,’ it will be understood that the particular value forms a further aspect. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint and independently of the other endpoint. It isalso understood that there are a number of values disclosed herein, and that each value is also herein disclosed as ‘about’ that particular value in addition to the value itself. For example, if the value ‘ 10’ is disclosed, then ‘about 10’ is also disclosed. It is also understood that each unit between two particular units are also disclosed. For example, if 10 and 15 are disclosed, then 11, 12, 13, and 14 are also disclosed.

[0123] References in the specification and concluding claims to parts by weight of a particular element or component in a composition denotes the weight relationship between the element or component and any other elements or components in the composition or article for which a part by weight is expressed. Thus, in a compound containing 2 parts by weight component X and 5 parts by weight component Y, X and Y are present at a weight ratio of 2:5, and are present in such ratio regardless of whether additional components are contained in the compound.

[0124] As used herein, the terms “optional” or “optionally” means that the subsequently described event or circumstance can or cannot occur, and that the description includes instances where said event or circumstance occurs and instances where it does not. In an aspect, a disclosed method can optionally comprise one or more additional steps, such as, for example, repeating an administering step or altering an administering step.

[0125] The terms "comprising," "including" and "having" are used interchangeably in this disclosure. The terms "comprising," "including" and "having" mean to include, but not necessarily be limited to the things so described.

[0126] Lastly, the terms “or” and “and / or,” as used herein, are to be interpreted as inclusive or meaning any one or any combination. Therefore, “A, B or C” or “A, B and / or C” mean any of the following: “A,” “B” or “C”; “A and B”; “A and C”; “B and C “A, B and C.” An exception to this definition will occur only when a combination of elements, functions, steps or acts are in some way inherently mutually exclusive.EXAMPLESEXAMPLE 1Extraction of maize husk fibers and pulping process

[0127] The first stage in pulping maize husk fibers is the collection and preparation of the raw material. Maize husks are typically sourced from the agricultural produce from markets. In thisexperiment, maize husks were collected, sorted out only selecting only the best fresh and desired quality. The materials were then chopped into smaller sizes using scissors into uniform sizes. The materials (maize husks) were then air dried for 3 days to ensure that moisture content reduced considerably before continuing with subsequent processes. The pulping process involves breaking down the maize husks into individual fibers. After the pulping process, the mixture of dissolved lignin and fibers needs to be separated. This is typically achieved by passing the mixture through a series of screens, where the fibers are retained while the liquid portion, known as black liquor, is removed. This step involves the application of chemicals, such as peracetic acid.

[0128] Bleached maize husks

[0129] 20L of water was added to the boiler under heat immediately after 9.5kgs of maize husk fibers were added to the boiler. An additional 20L of water was added to the boiler with the maize husks. 10L of water was added to the boiler. 2wt% Analytical Reagent / 894g of NaOH was slowly added into the boiler as it was being mixed. Three scopes were removed from the boiler, rinsed and blended to check the consistency. The boiler was removed from heat and 40L was added to drop the temperature in the boiler.

[0130] A screen was used, where the pulp was rinsed 5-6 times as the pH was monitored and rinsing was stopped when the pH was in the 6.5-7.5 range. The retained fibers were washed thoroughly to remove any remaining chemical residue and impurities.

[0131] The rinsed pulp was put back into the boiler with elevated temperatures and 20L of water was added. Hydrogen peroxide was added into the boiler and 10g of analytical reagent (AR) NAOH pellets dissolved in 50ml water was added to catalyze the reaction. Thereafter 400g of AR acetic acid was added into the boiler and it was mixed and let to boil for 20 minutes. The boiler was removed from the fire and the fibers were rinsed thoroughly water to remove residual chemicals and to neutralize the puree. The rinsed fibers were placed in a container and blended for 10 minutes into a puree.

[0132] The puree was then blended further and poured into a stainless-steel tank with adequate water. The ratio of the puree with volume of water was 1 :5. Turbulence was introduced in the water to distribute the puree throughout the tank. The screen was then allowed to rest for about 1.5-2 minutes before being removed from the suspension tank, with slight tilting, to ensure that all the captured puree is uniformly distributed onto the screens. The screens were then inclined at initially 65° as the angle of elevation then later adjusted to 45° as the new angle of elevationin an open environment to allow the water to drain out and to dry, since the weather was conducive. The fibers are dried to reduce their moisture content. The sheet was removed from the screen and well stored in airtight polythene bag after it has completely dried for between 1 -2 days at most, depending on atmospheric and / or room conditions.

[0133] Unbleached maize husks

[0134] 9.5kgs of maize husks underwent the same preparation, air drying, pulping and rinsing processes as in the bleached maize husks. They were not bleached instead were beaten using a high-speed fabricated blender and screened.

[0135] Small particle maize husks

[0136] 9.5kgs of maize husks were chopped into smaller sizes using scissors into uniform sizes. In this experiment, maize husks were collected, sorted out only selecting only the best fresh and desired quality. Instead of being air dried for three days the fresh cut uniform size maize husk fibers were poured in the boiler and underwent the pulping, rinsing, bleaching and screening processes as the bleached maize husks.

[0137] Semi-bleached maize husks

[0138] 9.5kgs of maize husks were chopped into smaller sizes using scissors into uniform sizes. In this experiment, maize husks were collected, sorted out only selecting only the best fresh and desired quality. Instead of being air dried for three days the fresh cut uniform size maize husk fibers were poured in the boiler and underwent the pulping process using the black liquor from the small particle maize husk. The pulp then underwent the rinsing, bleaching and screening processes as the small particle maize husks.Extraction of pineapple leaf fibers (PALE) and pulping process

[0139] The first stage in pulping PALF is the preparation of the raw material. In this experiment, clean and dried PALF were chopped into smaller sizes using both scissors into uniform sizes. The pulping process involves breaking down the maize husks into individual fibers.

[0140] Bleached pineapple leaf fibers

[0141] In this process 10% Analytical Reagent grade (AR grade) caustic soda. lOOKgs of tap water was added to the boiler. 13.5kgs PALFs and 2.5kgs of caustic soda were carefully added. The boiler lid was replaced to control both temperature and pressure. The boiler was constantly fired for 3 hours before the slurry (cooked PALFs+ liquor) was removed on heat for subsequent stages / steps.

[0142] After the pulping process, the mixture of dissolved lignin and fibers was separated. This was achieved by passing the mixture through a series of screens, where the fibers were retained while the liquid portion, known as black liquor, was removed. In this experiment, a screen was used, where the pulp was rinsed 5-6 times as the pH was monitored and rinsing was stopped when the pH was in the 6.5-7.5 range. The retained fibers were washed thoroughly to remove any remaining chemical residue and impurities. The rinsed pulp was put back into the boiler with elevated temperatures and 50% of water was added. The materials in step 3 above were added in a boiler, peracetic acid; Approximately 500g of Hydrogen peroxide and 500g of Acetic Acid was added. The slurry was heated under low heat for 20 minutes. The boiler was removed from the fire and the fibers were rinsed thoroughly with water to remove residual chemicals and to neutralize the puree. The rinsed fibers were placed in a container and blended for 10 minutes into a puree. The puree was then blended further and poured into a stainless-steel tank with adequate water. The ratio of the puree with volume of water was 1 :5. Turbulence was introduced in the water to distribute the puree throughout the tank. The screen was then allowed to rest for about 1.5-2 minutes before being removed from the suspension tank, with slight tilting, to ensure that all the captured puree is uniformly distributed onto the screens. The screens were then inclined at initially 65° as the angle of elevation then later adjusted to 45° as the new angle of elevation in an open environment to allow the water to drain out and to dry, since the weather was conducive. The fibers are dried to reduce their moisture content. The sheet was removed from the screen and well stored in airtight polythene bag after it has completely dried for between 1-2 days at most, depending on atmospheric and / or room conditions.

[0143] 13.5kgs of PALF underwent the same preparation, pulping and rinsing processes as Batch 1. They were not bleached instead were beaten using a high-speed fabricated blender and screened.

[0144] Cottonized PALF

[0145] The first stage in pulping PALF is the preparation of the raw material. In this experiment, clean and dried cottonized PALF which are waste collected after brushing pineapple leaf fibers were chopped into smaller sizes using both scissors into uniform sizes.

[0146] Unbleached cottonized PALF

[0147] 13.5kgs of cottonized PALF underwent the same preparation, pulping and rinsing processes as Batch 1 of PALF. They were not bleached instead were beaten using a high-speed fabricated blender and screened.

[0148] Bleached cottonized PALF

[0149] 13.5kgs of cottonized PALF underwent the same preparation, pulping rinsing, bleaching and screening processes as Batch 1 of PALF.EXAMPLE 2 - Characterization of pulp

[0150] Samples of maize, pineapple, and sugarcane pulp were received from Nyungu. Commercial wood. The list of samples analyzed is described in Table 1.Table 1.

[0151] Pulp characterization was conducted on all samples to understand the properties of the pulp. Pulp characterization was done by measuring specific volume, pulp absorption capacity, and SEM. Each pulp sample was measured five measurements for specific volume and pulp absorption.

[0152] All the samples were received in pulp sheet form, necessitating defibration into fluff pulp form, suitable for pulp characterization and the airlaying process. Defibration is the process of breaking down pulp sheets into individual fibers. The impact of hammers breaks the pulp into smaller particles. The mesh screen assists in separating fibers, regulating fiber length and consistency, and removing impurities.

[0153] Screen mesh size with a hole diameter of 8 mm was consistently used for all pulp samples during defibration.

[0154] Defibration of pulp samples- trial observations

[0155] Wood fluff pulp and unbleached pineapple processed smoothly through the hammermill. Bleached pineapple experienced blockage in the screen mesh and frequent feeding issues, leading to about one-third of the sample being fed via bypass to the hammers. The remainder of samples were all defibrated using the bypass, feeding directly to the hammers.

[0156] A bypass diverts a portion of the fibers from the main process flow to prevent operational issues such as blockages.

[0157] The pulp sheets low thickness / low flexural rigidity caused tangling around the feed roller, meaning sheets required feeding directly to the hammers requiring the feed angle to be altered through use of the bypass.

[0158] Samples fed through a bypass yielded similar results to those fed through the main process flow as the sieve ensured sufficient hammering in both cases.

[0159] The hammering result for samples from sugarcane (bleached and unbleached) and maize (small particle and semi-bleached) resembled flakes rather than fiber fluff which may not be suitable for pulp characterization and air laying.

[0160] Semi-bleached maize sample contained a significant number of fines, with fine dust not completely captured.

[0161] Specific Volume and Pulp Absorbency

[0162] Method

[0163] Specific volume was measured according to SCAN-C 33 :80. The height of 3g pulp sample under 2.5kPa pressure was measured. The volume occupied was calculated by multiplying the height by the area covered by the sample. Specific volume was calculated by dividing the volume occupied by a dry sample by the weight of the dry pulp sample.

[0164] Fiber Absorbency was measured according to SCAN-C 33:80. A pulp sample of 3g was put in contact with water at a vertical position for 30s under a constant pressure of 2.5kPa. The water was then removed, and the sample was allowed to stand for 30 seconds under the same constant pressure of 2.5kPa. The fiber absorbency was calculated as the weight of liquid absorbed per unit weight of dry pulp sample.

[0165] Results

[0166] The absorbency and specific volume of pineapple and maize fibers were benchmarked against wood pulp fibers. Wood pulp fibers exhibit highest performance, followed by pineapple, maize and sugarcane respectively, for both metrics. Bleached fibers demonstrate better absorbency and specific volume compared to unbleached fibers among the tested samples. Semi bleached maize pulp gave better performance than bleached and small particle size maize pulps. The results are shown in FIG. 2A and FIG. 2B.

[0167] The wood pulp exhibited higher absorbency and specific volume than pineapple, maize and sugarcane pulps. Bleached pulp exhibited higher specific volume and absorbency than unbleached pulp of pineapple, maize, and sugarcane samples. Pineapple pulp exhibited higher specific volume and absorbency than maize pulp and maize pulp exhibited higher specific volume and absorbency than sugarcane pulp.

[0168] Fiber length and diameter

[0169] Method

[0170] Fiber length and diameter measurement was carried out as follows. The samples were separated into individual fibers. An optical microscope was used to capture images of individual fibers. The length and diameter of the individual fibers was measured and recorded. Forty fibers were measured to establish the fiber length and diameter distribution for each sample.

[0171] Results

[0172] Table 2 and FIG. 2C show the fiber diameter of the pulp samples. A high degree of consistency and uniformity in fiber diameters of samples NY-24 / 1 , NY-24 / 2, NY-24 / 3, NY-24 / 8,and NY-24 / 9, with small diameters was observed. The fiber distribution of NY-24 / 8 and NY- 24 / 9 loosely resembled the benchmark NY-24 / 1.

[0173] A high variability and less uniformity in the fiber diameter measurements of samples NY-24 / 4, NY-24 / 5, NY-24 / 6, NY-24 / 7 with large diameters was observed. This variability can be attributed to variations in processing conditions for the pulps, including differences in chemicals used and temperatures and inherent unique characteristics of the different fibers, such as chemical composition and fiber morphology.Table 2.

[0174] Table 3 and FIG. 2D show the fiber length of the pulp samples. A high degree of consistency in the fiber lengths of NY-24 / 1, NY-24 / 8 and NY-24 / 9 with short fibers was observed. A high variability and less uniformity in the length measurements of for NY-24 / 2, NY-4 / 3 with long fibers was observed. A moderate variability and uniformity in the length measurements of for NY-24 / 4, NY-24 / 5, NY-24 / 6, NY-24 / 7 was observed. The presence of long fibers in NY-24 / 2 and NY- 24 / 3 may pose potential issues during airlaying, as the process is designed for short fibers of less than 10 mm.

[0175] The results show similarities in fiber length and diameter distribution between small particle size and semi-bleached maize to wood pulp, characterized by thin and short-length fibers. The results further illustrate pineapple fibers exhibit thinner and longer fibers, while sugarcane and maize pulp feature coarser and medium-length fibers.Table 3.

[0176] FIG. 2E is a table summarizing the pulp characterization results. Samples have been traffic light coded based on the results of pulp characterization. Specific volume and pulp absorbency have been ranked from best performing (9) to worst performing (1) and categorized into red / amber / green according to their rank. Fiber length and diameter were scored based on their similarity to commercial pulp sample, where high consistency samples have been scored green, moderate variability scored amber and low consistency samples scored red.EXAMPLE 3 - Prototype CoresAir lay process

[0177] Issues were observed regarding the presence of many long fibers getting trapped in the drum leading to inefficient running of the air laying process. The unbleached and bleached pineapple fibers exhibited significant variability in fiber lengths, with interquartile ranges extending above the optimal 10 mm length and outliers reaching up to 40 mm and 30 mm, as shown in Example 1.

[0178] Long fibers can tangle more easily, blocking the drum from releasing the fibers onto the conveyor belt and reducing the efficiency of the airlaying process. Maize samples with shorter and more consistent fiber lengths had flakes of varying diameters, making it difficult for them to escape from the drum to the conveyor belt.

[0179] To improve the airlaying process, the opening or preprocessing passages for the fibers were increased so that the longer fibers were filtered out and only the shorter fibers remained for airlaying.

[0180] 5 pad core prototypes were made of 100% of wood, bleached and unbleached pineapple and bleached and unbleached maize pulps. All pulps were successfully bonded within a core structure using heat at 180°C and pressure. Maize core samples experienced shedding because there was little bonding amongst the fibers within the core. The prototypes show grooves on their surface which are the bonding points (FIG. 3). All the pad cores were tested against absorbency, retention, strikethrough and wetback tests.

[0181] Absorbency and retention

[0182] Method

[0183] LAC was measured according to the EDANA standard (NWSP 010.1. R0 (20)). A 10 cm x 10 cm sample was prepared. The sample was immersed in saline for 30 seconds. The sample was allowed to drain for 2 minutes and the weight of the sample was measured. LAC was determined as the difference between the wet and dry weights of the sample (i.e. weight of fluid remaining in sample) expressed as a percentage of original sample weight (g / g).

[0184] Retention was measured using the following method as an adaption to NWSP 010. 1. R0 (20). After draining, a weight of 2560 g was placed on the sample for 30 seconds. The sample was weighed to determine the amount of liquid retained within the material. Liquid Retention Capacity is the difference between the final (post compression) weight and the drained (pre compression) sample weight expressed as a percentage of original sample weight (g / g). Liquid retention can also be expressed as a percentage of absorbed fluid (LRC / LAC).

[0185] Results

[0186] Wood pulp exhibited the highest absorptive capacity whilst the bleached pineapple exhibited the highest retention capacity. Unbleached pineapple and unbleached maize exhibited a good balance of absorbance and retention capacity. Bleached pulps were expected to absorb more than the unbleached pulps (as was the case in pulp characterization), this may be due to removal of the certain fibers during the airlaying process - the bleached pineapple absorbency results were particularly low. Bleached samples were able to retain a higher percentage of the fluid absorbed, showing the bleaching process helps to absorb fluid into the fiber structure rather than maintain within the fabric pore structure.

[0187] Strikethrough (STT) and wetback

[0188] Method

[0189] Strikethrough and rewet properties of the pad core were evaluated according to EDANA standards. A sample was cut into a 10 cm x 10 cm. 3 x 5 ml of saline solution was applied to the prepared sample in consecutive intervals of 60 seconds each. STT was recorded as the time taken for the liquid to pass through the sample.

[0190] Wetback After Repeated Strike-Through Time

[0191] A 4000 g weight was lowered onto the sample for 30 seconds. A special filter paper was used to measure the amount of liquid that passes back through the sample into the filter paper due to the applied load. The wetback was calculated as the difference between dry and wet filter paper weight in g.

[0192] Results

[0193] FIG. 5A and FIG. 5B show the strikethrough time and wetback of prototype pad cores.

[0194] Unbleached maize had the best performance of the agricultural waste pulp samples in both strikethrough time and wetback, making it the most efficient material for quick absorption and minimal rewet.

[0195] Bleached pineapple had the highest strikethough time and wetback making it is less effective in absorption speed and liquid retention - this is in line with the poor absorbency previously seen.

[0196] An increase in STT at the second and third intervals is expected as seen in the wood pulp. This difference in behavior of disclosed pulps could be due to variations in fibers structure, causing the structure to open up after initial insult and allowing ease of flow.

[0197] Strikethrough time results were higher than commercial wood pulp samples traditionally used in ecological menstrual pads, however this property can be increased by use of an acquisition distribution layer.

[0198] FIG. 5C provides a summary of the wetback, strikethrough time, absorbency and retention results. Wetback, strikethrough time, absorbency and retention were ranked from best performing (5) to worst performing (1) and categorized into red / amber / green according to their rank. Processing characteristics were subjectively scored (out of 5) to allow for comparison between samples.

[0199] Wood pulp exhibited higher core absorbency and strikethrough but has lower core retention than the disclosed samples. Unbleached pineapple and bleached pineapple have higher core retention, with bleached pineapple showing the highest core retention but significantly poorer strikethrough and wetback values. Unbleached maize and bleached maize exhibited moderate performance in core absorbency and core retention, with unbleached maize having the best wetback performance. There is minimal evidence at this stage to warrant omitting samples from further work as all show possible promise to act as a core material alongside further development of the pad structure. In use absorbency performance is attributed to low strikethrough time, high core absorbency, high pulp absorbency and high pulp specific volume - unbleached pineapple and bleached and unbleached maize seems to be performing best in these properties. In use low leak performance is attributed to low wetback, high core retention, high pulp absorbency, bleached pineapple, and bleached and unbleached maize seem to be performing best in these properties.

[0200] Blending pulps for core

[0201] Blending provides opportunity for fibers with good absorption properties (high specific volume, high absorbency, low strikethrough time) to be mixed with fibers with good retention properties (high retention, low wetback) for optimal in use performance. Four blends were produced as shown in Table 4.

[0202] Table .

[0203] Blended fibers samples, airlaid using Danweb were tested for specific volume and absorbency. The results are shown in FIG. 6A and FIG. 6B. Unbleached pineapple / bleached pineapple and unbleached pineapple / unbleached maize blends exhibited the highest specific volume and absorbency when compared to the bleached pineapple / unbleached maize and bleached pineapple / bleached maize blends. The results of these 2 blends are comparable to the results of defibrated pulp samples of unbleached pineapple, small particle maize and bleached maize samples. The porous structure of the maize can be increased by blending with pineapple which in turn also increases the absorbency.

[0204] FIG. 6C shows the properties of the blended pulp and unblended pulp.

[0205] Unbleached pineapple / bleached pineapple (NY-24 / 11) and 50% unbleached pineapple, 50% unbleached maize (NY-24 / 10) were selected to make prototype core using the method described above.

[0206] Liquid Absorptive capacity (LAC) and Retention Capacity (LRC) were measured using the methods previously described. As shown in FIG. 7B, NY-24 / 11 (Bleached pineapple / unbleached pineapple), NY- 24 / 10 (unbleached maize / unbleached pineapple) and 24 / 8 (small particle size maize) cores exhibited liquid absorption capacity above 850%.

[0207] As shown in FIG. 7C, all disclosed cores have better liquid retention capacity than wood pulp due to the high porosity of the core structure. Repeat tests for bleached pineapple show low absorbency and high retention, perhaps due to low porosity of the core structure.

[0208] Strikethrough and wetback were measured using the methods previously described. As shown in FIG. 7D, NY24 / 10 has faster strikethrough times than Natracare but slower than wood pulp. NY24 / 11 shows comparable strikethrough times to Natracare, although it is slower than wood pulp. As shown in FIG. 7E, all disclosed samples exhibited higher wetback than wood pulp, however, NY-24 / 8, NY-24 / 9, and NY-24 / 10 have wetback values comparable to Natracare. Bleached pineapple exhibited both higher wetback and strikethrough times in comparison to all other samples tested.

[0209] FIG. 7F provides a table with a summary of the pulps and blended pulps. Wood pulp exhibited better core strikethrough, wetback and absorbency properties than all the disclosed sample cores. This may be due to fineness of fiber and resulting pores within the structure. All disclosed pulp cores exhibited better liquid retention than wood pulp - however this did not result in better wetback properties.

[0210] Among the disclosed pulps, NY24-8 - small particle size maize exhibited good liquid retention and moderate strike-through time, wetback, and absorbency. NY24-10 - 50% unbleached pineapple / 50% unbleached maize exhibited quick strikethrough, low wetback, and good retention. NY24-11 - 50% bleached pineapple / 50% unbleached pineapple exhibited has high retention, but slower strikethrough and higher wetback. The cores made from NY-24 / 8, NY- 24 / 10, and NY-24 / 11 have comparable test results to the Natracare pad, indicating an opportunity to develop Nyungu fibers into a pad.

[0211] FIG. 7G is a summary of wood pulp and all the disclosed pulps. Maize fibers (both unbleached maize and small particle maize) enable a good pore structure to be formed, providing good fluid management properties within a core structure, however experience shedding and discoloration upon heating which may impact processing and aesthetic properties. Pineapple fibers provide more bulk and resilience to the core structure, allowing for more cohesion on air laying, and maintenance of the pores created, however many fibers are lost in the air laying process and translation to fluid management of the core structure was not always seen. Blending of pulps allows for creation of a pore structures to enhance fluid management of the cores, where pineapple fibers provide the cohesion in the structure and maize fibers enhance the pore structure provided. The bleaching process enhanced pulp properties enabling larger pores to be created and better absorbency of the pulp, however this was not translated to the core structure where reduced fluid management was seen in both pineapple and maize.

Claims

CLAIMSWhat is claimed is:

1. A biodegradable absorbent material comprising pulp extracted from at least one of rice husk, sugar cane, hemp, powdered maize husk, cottonized pineapple leaf fibers, or combinations thereof.

2. A biodegradable absorbent material comprising pulp extracted from at least one of rice husk, sugar cane, maize husk, pineapple leaves, or combinations thereof, wherein the pineapple pulp, maize pulp, and sugarcane pulp is bleached, semi-bleached, or unbleached.

3. The biodegradable absorbent material of claim 2, wherein the material is highly absorbent.

4. The biodegradable absorbent material of claim 2 or 3, wherein the biodegradable absorbent material comprises pulp extracted from pineapple leaves, maize husk, hemp, powdered maize husk, cottonized pineapple leaf fibers, and sugarcane.

5. The biodegradable absorbent material claim 4, wherein: the pulp extracted from maize husk is maize pulp; the pulp extracted from powdered maize husk is maize pulp; the pulp extracted from hemp is hemp pulp; the pulp extracted from cottonized pineapple leaf fibers is cottonized pineapple pulp; the pulp extracted from pineapple leaves are pineapple pulp; and the pulp extracted from sugarcane are sugarcane pulp.

6. The biodegradable absorbent material of claim 5, wherein the pineapple pulp, maize pulp, hemp pulp, powdered maize husk pulp, cottonized pineapple leaf fibers pulp and sugarcane pulp is bleached, unbleached, or semi-bleached.

7. A menstrual pad comprising a core and a core wrap; wherein the core comprises a biodegradable absorbent material comprising pulp extracted from at least one of rice husk, sugarcane, maize husk, pineapple leaves, hemp pulp, powdered maize husk pulp, cottonized pineapple leaf fibers pulp, or combinations thereof.

8. The menstrual pad of claim 7, wherein the biodegradable absorbent material comprises pulp extracted from pineapple leaves, maize husk, sugarcane, hemp, powdered maize husk, cottonized pineapple leaf fibers, or a combination thereof.

9. The menstrual pad of claim 8, wherein: the pulp extracted from maize husks is maize pulp; the pulp extracted from powdered maize husk is maize pulp the pulp extracted from hemp is hemp pulp; the pulp extracted from cottonized pineapple leaf fibers is cottonized pineapple pulp; the pulp extracted from pineapple leaves are pineapple pulp; and the pulp extracted from sugarcane are sugarcane pulp.

10. The menstrual pad of claim 9, wherein the maize pulp, pineapple pulp, hemp pulp, powdered maize husk pulp, cottonized pineapple leaf fibers pulp, or sugarcane pulp have a specific volume from about 10 cm3 / g to about 20 cm3 / g.

11. The menstrual pad of claim 9, wherein the maize pulp, pineapple pulp, hemp pulp, powdered maize husk pulp, cottonized pineapple leaf fibers pulp, or sugarcane pulp have an absorbency of about 6.0 g / g to about 11 g / g.

12. The menstrual pad of claim 9, wherein the maize pulp, pineapple pulp, or sugarcane pulp have a fiber diameter of about 3 pm to about 170 pm.

13. The menstrual pad of claim 9, wherein the maize pulp, pineapple pulp, hemp pulp, powdered maize husk pulp, cottonized pineapple leaf fibers pulp, hemp pulp, powdered maize husk pulp, cottonized pineapple leaf fibers pulp, or sugarcane pulp have a length of from about 0.5 mm to about 20 mm.

14. The menstrual pad of claim 9, wherein the pineapple pulp, maize pulp, hemp pulp, powdered maize husk pulp, cottonized pineapple leaf fibers pulp, and sugarcane pulp is bleached, unbleached, or semi-bleached.

15. The menstrual pad of claim 7, wherein the core has an areal density of from about 220 g / m2to about 300 g / m2.

16. The menstrual pad of claim 7, wherein the core wrap comprises a cotton fabric.

17. The menstrual pad of claim 16, wherein the cotton fabric is a spunlace cotton fabric.

18. The menstrual pad of claim 17, wherein the spunlace cotton fabric has an areal density of about 30 g / m2to about 40 g / m2.

19. The menstrual pad of claim 7, wherein the core is airlaid with areal density of from about 200 g / m2to about 300 g / m2.

20. The menstrual pad of claim 7, wherein the core comprises one or more distribution grooves.

21. The menstrual pad of claim 7, wherein the core comprises one or more channels.

22. The menstrual pad of claim 7, wherein the core has a Liquid Absorptive Capacity (LAC) of from about 400% g / g to about 1000 % g / g.

23. The menstrual pad of claim 7, wherein the core has a Liquid Retention Capacity (LRC) of from about 400% g / g to about 1000 % g / g.

24. The menstrual pad of claim 7, wherein the core has a liquid strikethrough tie of about 1 second to about 10 seconds.

25. The menstrual pad of claim 7, wherein the core has a wetback of about 1 .00 g to about 4.00 g-26. A method of making the absorbent and biodegradable material of any one of claims 1 to 6.

27. A method of making a menstrual pad of any one of claims 7 to 25.

28. A method of making an unbleached pulp from a biological source, the method comprising: preconditioning the biological source to form preconditioned biological source; adding water a specified amount of water, the preconditioned biological source, and a basic solution to a boiler, wherein water is added at a specified volume ensuring a specified ratio of the preconditioned biological source to water; heating the basic solution, the preconditioned biological source, water, and the boiler for a specified time to form a mixture of individual fibers of the biological source and lignin;removing the mixture of individual fibers of the biological source and lignin from the boiler and cooling the mixture of individual fibers of the biological source and lignin to form a cooled mixture of individual fibers of the biological source and lignin; rinsing the mixture of individual fibers of the biological source and lignin to separate the individual fibers of the biological source and the lignin by passing the mixture through one or more screens, wherein the rinsing is continued until the pH of the mixture is between about 6.5 to about 7.5; pureeing the individual fibers of the biological source to form an unbleached pulp puree; rinsing the unbleached pulp puree by placing the bleached pulp puree in a tank comprising water and one or more screens, wherein the ratio of the unbleached pulp puree to water is specified, and wherein the tank comprises a screen at an angle; and drying the unbleached pulp for a specified time forming a sheet of the unbleached pulp; wherein drying is performed in an oven or in the sun for a specified time; wherein the biological source is sugarcane, maize husk, pineapple leaves, hemp, powdered maize husk, cottonized pineapple leaf fibers or a combination thereof.

29. The method of claim 28, wherein the biological source is maize husk.

30. The method of claim 28, wherein the biological source is pineapple leaves.

31. The method of claim 28, wherein the biological source is cottonized pineapple leaf fibers.

32. The method of claim 28, wherein the biological source is sugarcane.

33. A method of making a bleached pulp from a biological source, the method comprising: preconditioning the biological source to form preconditioned biological source; adding water a specified amount of water, the preconditioned biological source, and a basic solution to a boiler, wherein water is added at a specified volume ensuring a specified ratio of the preconditioned biological source to water; heating the basic solution, the preconditioned biological source, water, and the boiler for a specified time to form a mixture of individual fibers of the biological source and lignin; removing the mixture of individual fibers of the biological source and lignin from the boiler and cooling the mixture of individual fibers of the biological source and lignin to form a cooled mixture of individual fibers of the biological source and lignin;rinsing the mixture of individual fibers of the biological source and lignin to separate the individual fibers of the biological source and the lignin by passing the mixture through one or more screens, wherein the rinsing is continued until the pH of the mixture is between about 6.5 to about 7.5; bleaching the individual fibers of the biological source using a hydrogen peroxide solution and an acetic acid solution to form a bleached pulp; adding a sodium hydroxide solution to neutralize the bleaching after the formation of the bleached pulp; pureeing the bleached pulp to form a bleached pulp puree; and rinsing the bleached pulp puree by placing the bleached pulp puree in a tank comprising water and one or more screens, wherein the ratio of the bleached pulp puree to water is specified, and wherein the tank comprises a screen at an angle; and drying the bleached pulp for a specified time forming a sheet of the bleached pulp; wherein drying is performed in an oven or in the sun for a specified time; wherein the biological source is sugarcane, maize husk, pineapple leaves, hemp, powdered maize husk, cottonized pineapple leaf fibers or a combination thereof.

34. The method of claim 33, wherein the biological source is maize husk.

35. The method of claim 33, wherein the biological source is pineapple leaves.

36. The method of claim 33, wherein the biological source is cottonized pineapple leaf fibers.

37. The method of claim 33, wherein the biological source is sugarcane.

38. A method of extracting fibers from a biomass to make paper, the method comprising: cutting or grinding the biomass to form a plurality of cut or ground biomass; adding the plurality of cut or ground biomass to an alkaline solution in a heating device for a first specified time to form pretreated biomass; filtering the pretreated biomass by passing the pretreated biomass through a screen to form filtered biomass; washing the filtered biomass with distilled or fresh water to remove residual alkaline solution resulting in hemi-cellulose-free biomass; drying the cellulose-free biomass in a heating device at a second specified temperature to form a dried cellulose-free biomass;bleaching the dried hemi-cellulose-free biomass by combining the dried hemi-cellulose- free biomass with an acidic and basic solution at a third specified temperature forming a residue; treating the residue by filtering and rinsing with distilled water to form a purified residue; adding the purified residue and water with a specified ratio of the purified residue to water in a tank to form a liquid suspension; and passing the liquid suspension through a second screen to make the paper.

39. The method of claim 34, wherein the extracted fibers are highly absorbent and / or biodegradable.