Title of Invention

"IMPROVED PROCEDURE FOR THE MANUFACTURE OF A LOW DENSITY PLASTIC SAND, THE PLASTIC SAND AND COMPOSITIONS"

Abstract

This invention refers to a low-density plastic sand based on recycled or virgin low-density polyethylene, to the obtainment and fabrication process, and to the compositions from by it, the plastic sand obtained through the fabrication process is obtained by using any kind of low-density polyethylene, as for example, disposable straws, glasses and plates, bags, bottles, etc., recovered from trash dumps as solid waste or from any other industrial source where available.

Full Text

IMPROVED PROCEDURE FOR THE MANUFACTURE OF A LOW-DENSITY PLASTIC SAND , THE PLASTIC SAND AND COMPOSITIONS. BACKGROUND OF THE INVENTION. This invention refers to a low-density plastic sand based on recycled low-density polyethylene and the compositions formed by it, the use of plastics in the world has flooded vital spaces, contaminating soil and the water stratum with a wide variety of waste, which because of their slow biodegradation, have forced us to search alternatives for the use of such materials, recycling and withdrawing them from open-air dumps where, because of effects of the environment (the sun, air, etc.), they let off gases and toxic fumes that aggravate the deterioration of soil and water strata, as well as the creation, accumulation and proliferation of bacteria and parasite animals; on the other hand, conventional sand as a basic material for mortar (sand, cement and water) is used in all constructions to join blocks and bricks , and the process followed in producing them also damages and contaminates the environment, in addition to the high transportation costs, which significantly increase housing and building costs. There are different methods of recycling low-density polyethylene, but none as the one contained in this invention; this fine sand is obtained or manufactured from all kinds of recycled low-density polyethylene plastics, that when smelted are transformed into fine sand that is 53% lighter than conventional sand and can be used as mortar or in bricks and concrete parts. DESCRIPTION OF THE INVENTION This invention refers to a low-density plastic sand based on recycled or virgin low-density polyethylene, to the process of obtainment and fabrication, and to the compositions formed by it, the plastic sand obtained through the fabrication process is obtained by using and kind of lowdensity polyethylene, as for example, drinking straws, glasses and disposable plates, bags, bottles, etc., recovered from trash dumps as solid waste, or from any other industrial source where it can be found. The raw material of the sand of this invention consists of all kinds of low-density polyethylene found in trash dumps as solid or industrial waste, when polyethylene is heated up to the smelting point or above it is transformed and a change surprisingly occurs, that is, it become less ramified and less dense, and therefore, more flexible; this rearrangement of reorientation of polymer chains in the low-density polyethylene is carried out through this procedure to produce the plastic sand, once the plastic which is low-density polyethylene is reunited, it is placed in a closed container, which is heated when applied direct fire, the container has a outlet conduct through which the gases produced from the smelting and part of combustion produced during this stage come out directly to the nozzles of the burner thereby eliminating those gases through combustion, avoiding contamination of the environment, this container also has a feeding means and a temperature regulator, the recommended interval temperature to carry out the smelting process and part of combustion of the plastic is approximately from 65°C to 90°C, preferably 70°C to 80°C during 3 to 20 minutes, preferably 3 to 5 minutes, it is important to not go beyond this range and not go above 100°C, because if this temperature is surpassed the raw material will be lost, that is, it begins to burn and becomes carbon, losing reorientation and the molecular rearrangement of the low-density polyethylene polymer, enormously affecting its qualities, that is, it is transformed into ashes in the form of gas, which are totally eliminated when reaching the burner, by carrying out this step with the polyethylene, the highly ramified chains that constitute the polymer are broken, reoriented and rearranged, forming new non-ramified chains with new properties, as for example, flexibility, that is, the plastic becomes less dense and more flexible, to this plastic material with new chains a predetermined amount of petroleum in solid form, known as curved tar from waste is added, in an amount varying approximately from 0.1% to 30%, preferably 2% in proportion to the weight of the raw material of smelted polyethylene, leaving the union of these materials at the same temperature during 10 to 35 minutes. The tar astoundingly favors the formation of a larger and more flexible polymeric molecule. Once having thoroughly mixed the plastic and the tar, the mixture is taken out of the container to be poured on a clean surface or in containers until it crystallizes at room temperature, once it crystallizes, the substrate formed, which is brittle and therefore forms different sizes of grain, is lifted from the surface or containers and sieved, passing it through sieves of different sizes, which allows to obtain control of the diameter of the grain according to the requirements or intended use. The size of the crystal or grain may be vary very fine to one inch, larger grains that remain in the sieve are collected to be further passed through a mill, reducing their diameter to be further sieved. If the plastic sand thus obtained must be transported from one place to another, we recommend providing it a little dampness to avoid losing it because of its extreme lightness. The following is a description of the procedure followed to manufacture or fabricate plastic sand with this invention, that comprises the following steps: A) Collect raw material consisting of all kinds of lowdensity polyethylene found in trash dumps as solid or industrial waste; B) once having collected the plastic consisting of low-density polyethylene, it is placed in a closed container that is heated by applying direct fire, the container has a outlet conduct through which the gases released from smelting and part of combustion produced during this stage come out directly to the nozzles of the burner thereby eliminating those gases through combustion, avoiding contamination of the environment, this container also has feeding means and a temperature regulator, the recommended interval temperature for the smelting process and part of combustion of the plastic is approximately 65°C to 90°C, preferably 70°C to 80°C during 3 to 20 minutes, preferably 3 to 5 minutes, it is important to not go beyond this range and not reach above 100°C, because if this temperature is surpassed the raw material will be lost, that is, it begins to burn and form carbon, losing reorientation and the molecular rearrangement of the low-density polyethylene polymer, which enormously affects its qualities, that is, it is transformed into ashes in the form of gas, which are totally eliminated when reaching the burner C) a predetermined amount of solid petroleum known as curved tar obtained from waste is added, this amount varies approximately 1% to 30%, preferably 2% in proportion to the weight of the raw material of smelted polyethylene, and leaving the union of these materials at the same temperature for 10 to 35 minutes; D) once the plastic and the tar are perfectly mixed, the mixture of these materials is taken out of the container to be poured on a clean surface or in containers until it crystallized at room temperature; F) once having crystallized, the substrate formed, which is brittle and therefore forms different sizes of grain, is lifted from the surface or containers and is sieved, passing it through sieves of different sizes, which allows to obtain control in the diameter of the grain according to the requirements or intended use; G) The size of the crystal or grain may be from very fine to one inch, larger grains that remain in the sieve are collected to further be passed through a mill and reduce their diameter, to be later sieved according to F) above. The properties and characteristics of the plastic sand obtained through this manufacture or fabrication procedure are obtained in the laboratory, with the results and various tests mentioned below. "Granulometry of the sand" The plastic sand was submitted to the granulometry test to determine its fineness standard; and in addition, to know the following elements: 1. Volumetric Weight 2 . Density 3. Absorption 4. Loss through Washing 5. Colorimetry First granulometry test For the granulometry of the plastic sand, a 500 gr. sample was taken, that was passed through meshes numbers 8, 14, 36, 48 and 100, the powder was collected, with the following results: (Table Removed) Fineness standard For specification of the fineness standard of the plastic sand, inside meshes numbers 8, 14, 28, 48 and 100. Mesh •# 100 Mesh •# 100 Fineness Standard = 1/100 £ referred accumulative percents Mesh •# 4 Fineness Standard = 218/100 Fineness Standard = 2.18 (fine plastic sand). This plastic sand may already be classified by its fineness standard, based on designation 4 by the A.S.T.M, according to the following table. Class Thick sand Fine sand Very fine sand Fineness standard 2.50 to 3.50 1.50 to 2.50 0.50 to 1.50 Weight of sample in grs. 400 to 800 200 to 400 100 to 200 As the result of the fineness standard was 2.18, it ranges within classification 1.50 to 2.50, and results in a class of fine plastic sand. Second granulometry test and determination of the fineness standard (Table Removed)Fineness standard For specification of the fineness standard of the plastic sand, inside meshes numbers 8, 14, 28, 48 and 100. Mesh •# 100 Mesh •# 100 Fineness Standard = 1/100 £ referred accumulative percents Mesh •# 4 Fineness Standard = (2.49+3.09+23.04+24.43+27.96)7100 Fineness Standard = 81.01/100 Fineness Standard =0.81 (very fine plastic sand). This plastic sand may already be classified by its fineness standard, based on designation 4 by the A.S.T.M, according to the following table. (Table Removed)As the result of the fineness standard was 0.81, it ranges within classification 0.50 to 1.50, and results in a class of fine plastic sand. Volumetric weight of the plastic sand The volumetric weight of a material varies according to the compacting condition of the sample, as well as the dampness it contains. According to the applicable regulatory requirements, except for special cases, the material is always used in a saturated and superficially dry manner to determine the volumetric weight, without compacting. In this case, a cubic deposit made of thick nondeformable wood was used, with a 5-liter capacity. This known weight deposit (empty weight) was filled with a scoop, it was softly sieved inside the cube with a molder' s spoon at a height of not more than 2 inches from the upper edge, and then levels and weighed, obtaining the following result for the plastic sand: W.V. = (total weight - empty weight)/volume W.V. = (4.566 kg. - 2.320 kg.) 5/ Its. W.V.4 9 9 kg./m Density of the plastic sand To determine the density of the plastic sand, the Lechateelier or Chapman flask was used, where water was placed up to the O.C.C. mark, then 50 gr of saturated and superficially dry plastic sand were deposited in the flask always continuing to agitate it, with revolving movements, to eliminate the air bubbles. The flask was left to rest until the bubbles rose and disappeared, to be able to apply a new reading, which correctly gave the volume dislodged by the 50 gr of plastic sand placed, and resulted in the following: Density = Weight / Volume = 50 gr/ 23.8 C.C. =2.1 Absorption of the sand After performing the test on the saturated and superficially dry sand, a sample is taken with an exact weight of 500 gr and placed on a tray to be left to totally dry at a temperature of 60°C. It is then placed in a clean porcelain and placed to cool in a dryer for 20 minutes, after which it is weighed again. The difference between both weights reported the absorption of water, which is indicated in the percentage of water with respect to the dry weight, in our case, the absorption based on the weight of the dry material was: Absorption = (500 - 497.8) / 497.8)*100 = 0.441% This test, together with the density test, provide corrective data in order to obtain a quality control in producing the concrete. Saturated and superficially dry plastic sand Plastic sand has a dark color, and in order to obtain a saturated and superficially dry sand, 50 gr of this material to be saturated were placed in water during 24 hours, after which the highest amount possible of water was removed through known methods, being careful that powder is not washed away. The material then begins to slowly dry on a furnace. To avoid altering the process, temperatures below 110°C are recommended, always continuously removing the plastic sand until all the free water disappears, and then continue with the drying process caused by the sun or wind, until the plastic sand no longer forms lumps when squeezed in one's hand or when pressing a handful between both palms of the hands. This behavior showed that the material was very near the condition being looked for, and therefore, the test was applied with a cone made of sheet. The cone was totally filled with plastic sand and was pounded, pressed 25 times on the free surface of a tamper with a circular section that has an area with a one inch diameter (2.54 c.m) and a 12 ounce weight. The mold was filled up to its capacity with plastic sand, which was carefully withdrawn from it, with the result that the sand took the shape of the mold. This proved that it still had superficial dampness that gave it an apparent cohesion. The tests of the cone were continued two more times until the moment when the material obtained the desired condition, having taken its natural resting angle. Loss through washing This test was performed to know the amount of silt the sand might have, as on some occasions the sand it is not featured in the sand on the trays and is placed directly on the ground, which might influence in increasing contractions of the concrete and in reducing its resistance. A sample of entirely dry plastic sand with a dry weight of 600 grams was taken and placed in mesh #200 and washing was begun, until running water that passed through mesh came out totally clean. The washed plastic sand was collected and dried again on the stove, always taking care that the organic particles which it might contain did not get burned. Once the plastic was dried, it was weighed again and the difference with the original weight gives the weight of the power contained in the sand, which was expressed in percentage with respect to the original weight, providing the following data: Loss through washing = /500 gr of the sample - 487.5/500,)* 100 = 2.5%. According to standards, the sands accepted must have a loss below 5%, in this case the result was 2.5%. This result was because the material used is polyethylene (drinking straws, disposable plates and plastic bags). Test to determine dampness in fine sand To begin this test, the porcelain capsule was first washed with the intention of eliminating impurities, it was then placed on the stove for 10 minutes at 100°C, it was taken out and placed on a glass dryer for about 15 minutes. The scale was gauged and the empty capsule was weighed, immediately after the sample was placed in the porcelain was weighed (the sample weighed 34.3 grams), it was placed on the stove at 60°C for approximately 2 hours, the sample was withdrawn and placed on the dryer for approximately 20 minutes. The final result was 69.9 grams; consequently, the dampness content was 0.1 grams. Colorimetry The colorimetry test provides an index of the content or organic matter or other elements in the plastic sand, that may be less or above what a so-called "normal color" is. The test was performed in a 250 ml capacity suckingbottle, where approximately 125 ml of plastic sand were placed per test. A 3% solution of caustic soda (NaOH) was added (one liter of water with 30 gr of caustic soda (NaOH) up to the 200 ml mark, level that together with additions of solution must be kept in the flask after having been vigorously shaken. It was left to rest for 24 hours, after which the color of the solution in the bottle is compared with the normal colored glass. Data obtained from this test correspond to a minimum of organic matter, because the polyethylene used in preparing the plastic sand is obtained from waste. The analysis of the result of determining ashes at a 975° temperature shows us a low percentage, because the sample had a 25% of impurity in weight, the reason why the final percentage of the elements analyzed was as follows: (Table Removed)The plastic sand obtained is an alternative construction material, of low cost, fire-proof, insulating, thermal, easy to handle, lighter than conventional sand, compatible with conventional sand, in addition to a high resistance to compression stress and can be used in walls and slabs together with other materials without affecting their qualities, as aggregate when used in mortars and concrete in at least 30%, by being lighter, less dense and even so, preserves its volume with that of normal sand, plastic sand preserves a minimum of dampness, which provides consistency, avoiding that its lightness not be as volatile, avoiding complications when placing the material together and transporting it. Among its chemical qualities, plastic sand contains a high resistance to fire, of approximately 80 to 100°C, and begins to melt at one fourth of its amount at 200°C without changing its structure, characteristic which it shares with the material with which it is combined, either mortar or in bricks, providing higher resistance to fire, water, dampness and wear, extending its useful life 10 times more than conventional materials. One of the main characteristics of this product is that, being very similar to normal sand, it has many uses in the field of construction, because of its origin from recycled polyethylene it reduces the costs in any construction or edification. The following are some of its qualities: 30% cheaper than conventional sand No specialized material is required in order to produce it Does not require skilled hand labor It reduces the cost of structures up to 50% - Among the physical qualities, the size of the grain runs from fine up to % inch (1.9 cm) Its volumetric weight is 449 Kg/m3 Among its qualities, it is resistant to fire from 80 to 100°C without modifying its structure, it begins to melt in one fourth part at 210°C EXAMPLES Example 1 The following composition of plastic sand is prepared with the procedure described above, the plastic sand includes 2% of waste tar, in proportion to the weight of the lowdensity polyethylene plastic material of 5, 4, 12, 200 and 1000 grams, letting the elements join together at the same temperature for 10 minutes, by using plastic sand in mortars (normally water, sand, cement), one must have the following specification: 50% natural sand and 50% plastic sand, in addition to water and cement; if it will be used in parks and gardens, it is important to make a detailed analysis with experts in the field to be able to mix it as follows, 55% normal sand and 45% plastic sand. Example 2 The same procedure as in the previous example, but using a composition of plastic sand that includes polyethylene, that may vary between 55, 10, 30, 200 or 500 kilograms with 2% curved tar obtained from waste; with this plastic sand obtained, several kinds of bricks are produced, that include Table 1 below provides comparative examples of stress on compression of different kinds of bricks produced with plastic sand obtained through this invention. (Table Removed)Note: Stress obtained through compression tests. Attached is a report describing materials used to produce the bricks (samples). Some of these materials correspond to patent applications being filed simultaneously to this patent application. SAMPLE (No) MATERIALS USED IN THE BRICK: 1.- Wood shavings, granulated styrene, sand and type I cement. 2.- Plastic, granulated styrene, clay, sand and type I cement. 3.- Plastic sand, granulated styrene, wood shavings and type I cement. 4.- Silica, granulated styrene and sawdust. 5.- Newspaper, cardboard, clay, sand, wood shavings and type I cement. 6.- Styrene, gasoline, clay and sand. 7.- Granulated styrene, clay, wood shavings and type I cement. 8.- Newspaper. 9.- Soot, clay, sand, plastic sand, type I cement. 10.- Sugarcane molasses, plastic sand, clay, sand and type I cement. 11.- Sawdust, small white seashells and white cement. This invention must not be considered limited to the particular examples described above, but must be understood to cover all aspects of the invention clearly as observed in the attached claims. Several modifications, equivalent processes, as well as numerous compositions and procedures to which this invention may be applicable and shall be clear and easy for experts in the art on which this invention focuses, with respect to the time when reviewing the specification. I put on record that to this date, the best method known by the applicant in order to put into practice the abovementioned invention, is the one that results clear from this de-scription of the invention. Having described the above invention, the content of the following claims are claimed as property: CLAIMS 1.- A manufacturing or fabrication procedure of plastic sand based on recycled low-density polyethylene plastic, featured for containing the following steps: A) Collect raw material consisting of all kinds of lowdensity polyethylene found in trash dumps as solid or industrial waste; B) once having collected the plastic consisting of low-density polyethylene, it is placed in a closed container that is heated when applied direct fire, the container has a outlet conduct through which the smelted gases and part of combustion produced during this stage come out directly to the nozzles of the burner, thereby eliminating those gases through combustion, avoiding contamination of the environment, this container also has feeding means and a temperature regulator, the recommended interval temperature for the smelting process and part of combustion of the plastic is approximately 65°C to 90°C, preferably 70°C and 80°C during a time period of 3 to 20 minutes, preferably 3 to 5 minutes, C) add a predetermined amount of solid petroleum known as curved tar from waste, the amount varies from approximately 0.1% to 30%, preferably 2% in proportion to the weight of the raw material of smelted polyethylene, and leave these materials to mix at the same temperature for 10 to 35 minutes; D) once the plastic and the tar have been perfectly mixed, the mixture is withdrawn from the container to be poured on a clean surface or in containers until it crystallizes at room temperature; F) once having crystallized, the substrate formed, which is brittle and therefore forms different sizes of grain, is removed from the surface or containers and is sieved, passing it through sieves of different sizes, which allows to obtain control of the diameter of the grain according to the requirements or intended use; G) The size of the crystal or grain may be from very fine to one inch, larger grains remaining in the sieve are collected to further be passed through a mill and be reduced in diameter, to be later sieved according to step F) above. 2, The method according to claim 1, featured because the low-density polyethylene used is selected from any kind, as for example, disposable straws and glasses, bags, bottles, etc., collected from trash dumps as solid waste or from any other industrial source. 3. The method according to claim 1, featured because in step B) , when heating the polyethylene one is able to break the highly ramified chains that constitute the polymer, provoking their reorientation and rearrangement, forming new non-ramified chains with new properties. 4. The method according to claim 1, featured because in step C) , the tar added contributes to the formation of a larger and more flexible polymeric molecule. 5. A plastic sand based on recycled plastic featured because it contains recycled low-density polyethylene and petroleum in solid form from 0.1% up to 30%, preferably t%, all of which must be adjusted to 100%. 6. A plastic sand according to claim 5, featured because the solid petroleum is selected from curved waste tar. 7. A plastic sand according to claim 5, featured because the low-density polyethylene is selected from all kind of low-density polyethylene, for example, straws, disposable glasses, bags, bottles, etc., collected from trash dumps as solid waste or from any other industrial source. 8. The use of plastic sand in claim 5 obtained from the process of claim 1 to manufacture bricks, mortar, concrete, and in construction.

Documents:

1759-delnp-2007-Abstract-(10-07-2013).pdf

1759-delnp-2007-abstract.pdf

1759-delnp-2007-Claims-(10-07-2013).pdf

1759-delnp-2007-claims.pdf

1759-delnp-2007-Correspondence Others-(01-09-2008).pdf

1759-delnp-2007-Correspondence-Others-(10-07-2013).pdf

1759-delnp-2007-correspondence-others.pdf

1759-delnp-2007-description (complete).pdf

1759-delnp-2007-form-1.pdf

1759-delnp-2007-Form-18-(01-09-2008).pdf

1759-delnp-2007-form-2.pdf

1759-delnp-2007-Form-3-(10-07-2013).pdf

1759-delnp-2007-form-3.pdf

1759-delnp-2007-form-5.pdf

1759-delnp-2007-pct-210.pdf

1759-delnp-2007-pct-notification.pdf