WO2021040629A1

WO2021040629A1 - Bulletproof plate

Info

Publication number: WO2021040629A1
Application number: PCT/TH2019/000035
Authority: WO
Inventors: Teerayut KITCHAROEN
Original assignee: Innovative Technology Challenge Company Limited
Priority date: 2019-08-23
Filing date: 2019-08-23
Publication date: 2021-03-04

Abstract

A bulletproof plate comprising polymer sheets (100) which are made from a thermoplastic, especially a thermoplastic polymer which has ultra-high molecular weight polyethylene (UHMWPE), and comprise a specific fiber orientation and are coated on the upper part (200) or the lower part (300) or both parts with graphene solution. During manufacture two or more are stacked and compression molded under heat and compressive force, the resulting bullet plate is cooled down thereafter before actual uses.

Description

Title of the invention

Bulletproof Plate

Field of the invention

The present invention relates to science and engineering in the field of chemical and material in relation to a bulletproof plate.

Background of the invention

Bulletproof vest is an essential apparatus to prevent a person from the impact either reduce or stop the force of a bullet in penetration through a body, since a bulletproof vest are made by adding an impact absorbing material layer such as metal, ceramic or high-density polyethylene inside the vest ; wherein when a bullet penetrates to said area, the impact force will be absorbed by the area of said materials, creating a dissipation of impact force around the area of said materials as well as causing the bullet head to be deform which making it unable to cause severe damage to the wearer; wherein the significant characteristic of a bulletproof vest is that it must be able to prevent penetration of a bullet into the body of wearer and it must be lightweight to make it comfortable for user. In the past, metal and steel have been used as a protection material for a bulletproof vest; however, it has some operational difficulty due to its weightiness that makes it uncomfortable to use, its lack of elasticity, and its high price. For a bulletproof vest with ceramic as a protection material, even if it is lighter than metal, due to the complex manufacturing process, inventors, therefore have developed a bulletproof vest with such protection material as polymer, especially thermoplastic polymer such as polyethylene. However, due to its high mechanical properties that allow easy structural changes when undergoing force or heat treatment since there Is no cross-link, its high level of strength, its high level of elasticity, its light weight, and its high resistance to impact; wherein the polymer sheets include other reinforcing materials or coating of materials or composite materials to enhance its usable properties, e.g. graphene that has high strength, wherein at the same level of thickness, graphene has higher strength than steel, yet it is highly elastic and can be easily twisted, rolled or folded without causing damage to the molecule. According to the international patent database, a disclosure of inventions in relation to ultra-high molecular weight polyethylene (UHMWPE) sheets that are stacked and adhered to each other by pressure and heat has been found as follows:

Chinese patent publication number CN204612597U of the invention titled “Annour mentions ultra-high molecular weight polyethylene sheets that are woven and adhered by pressure and heat

Chinese patent publication number CN102519311 A of the invention titled “A preparing method of ultra-high molecular weight polyethylene bullet-proof plate” mentions ultra-high molecular weight polyethylene fiber sheets that are stacked wherein there is a process for adhering them more than one time with a pressure of 5-10 Megapascal (MPa) at the temperature of 80-100 Celsius (°C) for 20-30 minutes and successfully adhered at pressure of 25-30 Megapascal (MPa) at the temperature of 100-140 Celsius (°C).

Canadian patent publication number CA2515868A1 of the invention titled “Multilayered polyethylene material and ballistic resistant articles manufactured therefrom” disclosed synthetic fiber sheets of ultra-high molecular weight polyethylene (UHMWPE) layered without any adhesives and connected by compressive force of 0.1-1 Megapascal (MPa) at temperature of 100- 150 Celsius (°C).

Some prior arts disclosed graphene-coated polyethylene sheets and coating process.

For instance, international patent publication number WO2014197082A2 of the invention titled "Gradient nanoparticle-carbon allolrope-polymer composite material" and

WO2012054472A2 of the invention titled “Gradient nanoparticle-carbon allotrope-polymer composite material" mentions coating of synthetic fiber sheets of ultra-high molecular weight polyethylene (UHMWPE) with carbon compounds and graphene.

Some prior arts mention a layer of polymer sheets comprising ultra-high molecular weight polyethylene (UHMWPE) and a layer comprising stack of graphene and manufacturing process by adhesion of compressive force and heat For instance, Canadian patent publication number CA2966512A1 of the invention titled -Soft ballistic resistant armor mentions a stack of composite sheets comprising ultra-high molecular weight polyethylene (UHMWPE) fibers that alternates with a layer of graphene, wherein the layer of graphene is coated with silicone sheets placing between each layer and then adheres by compressive force of 14-28 Megapascal (MPai at temperature of 93-150 Celsius (°C), becoming light sheets having a stack of composite sheets comprising ultra-high molecular weight polyethylene (UHMWPE) fibers that alternates with a layer of graphene.

Chinese patent publication number CN107471791 A of the invention titled "A graphene- reinforced composite ballistic plate and preparation method thereof- mentions synthetic fiber sheets of ultra-high molecular weight polyethylene (UHMWPE) that are stacked with graphene olefin sheets, wherein they are adhered at compressive force of 16-25 Megapascal (MPa) at temperature of 70-130 Celsius (°C) for 30 minutes.

According to background of the invention, it is clearly seen that there is a development of polymer sheets, especially ultra-high molecular weight polyethylene (UHMWPE), to increase its strength for further utilization; wherein there is a mention of graphene for coating polymer sheets to increase its strength as well as adhesion by chemicals or heat and pressure at different conditions; wherein the present invention will disclose polymer sheets, especially ultra-high molecular weight polyethylene (UHMWPE), that are coated or printed with proper concentration of graphene solution with a specific form of fiber orientation of the present invention, and that are stacked in preparation for compression molding by specified heat and pressure. Products that are tested that they are better in absorbing impact force from a bullet than ultra-high molecular weight polyethylene (UHMWPE) without graphene solution coating or printing can be applied in the production of soft bulletproof vest, hard bulletproof plate, and bulletproof helmet.

Summary of the invention

The present invention relates to a bulletproof plate comprising polymer sheets, especially thermoplastic polymer such as ultra-high molecular weight polyethylene (UHMWPE), by which either upper part or the lower part, at least one part or both parts in combination, is coated with graphene solution, and at least two sheets of said polymer sheets are stacked and then compressed by heat and compressive force and the products should be cooling down before using.

The purpose of the present invention is to provide a bulletproof plate obtaining from a stack of polymer sheets coated with graphene solution that has high strength in its property and taken to compression molding. The resulting bulletproof plate product has high strength, high elasticity, and high resistance to impact force and it is appropriate to use as hard bulletproof plate or protection material in the production of bulletproof vest, soft bulletproof vest, and bulletproof helmet.

Brief description of the drawings Figure 1 illustrates polymer sheets coated with graphene solution according to this invention.

Figure 2 illustrates a stacks of polymer sheets that are coated with graphene solution and taken to compression molding according to this invention.

Figure 3 illustrates a tested results of graphene coating thickness of sample polymer sheets by which fiber orientation is set to be placed vertically and horizontally at 0/90 degree (UHMWPE- A) wherein the test is repeated 5 times.

Figure 4 illustrates a tested results of graphene coating thickness of polymer sheets sample by which the fiber orientation is set to be placed vertically, horizontally, and diagonally at 0/90/±45 degree (UHMWPE-B) wherein the test is repeated 5 times.

Figure 5 illustrates a graph comparing tensile strength of ultra-high molecular weight polyethylene (UHMWPE) sheets and ultra-high molecular weight polyethylene (UHMWPE) sheets that are coated with graphene solution.

Detailed description of the invention

According to figure 1, bulletproof plate comprises polymer sheets 100 by which the upper part 200 or the lower part 300, at least one part or both parts in combination, is coated with graphene solution of 0.5-5.0% by weight, wherein the polymer sheets 100 are thermoplastic which can be chosen from one or more of polystyrene or polyethylene or polypropylene or polyvinyl chloride or nylon or polyamide.

Polymer sheets 100 are preferably polyethylene or it is most preferred to be ultra-high molecular weight polyethylene (UHMWPE).

Process for coating graphene solution on polymer sheets 100 comprising the following steps:

A. Preparation of graphene solution of 05-5.0% by weight.

B. Coating graphene solution of 0.5-50% by weight on polymer sheets by which the upper part 200 or the lower part 300, at least one part or both parts in combination, is coated by screen printing technique or a screen printer.

C. Letting graphene solution coated polymer sheets dry at room temperature, Preferably, letting the said sheets to dry at room temperature for at least 3 days.

Then, taking the dried graphene solution coated polymer sheets to undergo compression molding process, wherein the process comprises the following steps:

1) Stacking polymer sheets 100 at least two sheets or number of sheets required for actual use.

2) Taking the stacked polymer sheets 100 to undergo transfer molding process by transfer molding machine, using heat and compressive force for 10 to 20 minutes.

For compression molding, temperature of the lower mold or the upper mold, at least one or both in combination is between 135-148 Celsius (°C) and compressive force is between 5 to 10

Megapascal (MPa).

3) Letting compressed polymer sheets 100 cool down, wherein the products are in the condition when compressive force is between 5 to 10 Megapascal (MPa), wherein there is a cooling until temperature of products is from 75 to 80 Celsius (°C).

It becomes a bulletproof plate as shown in figure 2, wherein polymer sheets 100 are coated at the upper part 200 and lower part 300 with graphene solution, wherein the lower part of upper polymer sheets overlaps the upper part of lower polymer sheets. One or more embodiment of the present invention will be described in detail with reference to examples of bulletproof plate prepared by the present invention. However, these prepared examples of bulletproof plate are not intended to limit the scope of one or more embodiment of the present invention. The following examples are provided to show certain embodiments of invention in terms of function. It will be understood by those skilled in the art that the present invention extends beyond the specifically disclosed examples.

Process for coating graphene solution on polymer sheets 100 comprises the following steps·.

A. Preparation of graphene solution of 0.5-5.0% by weight.

B. Coating graphene solution of 0.5-5.0% by weight on polymer sheets, wherein it is coated over the upper part 200 and the lower part 300 by screen printing technique or screen printer, wherein the characteristic of polymer sheets is that fibers of the polymer sheets are placed vertically and horizontally at 0-90 degree or placed vertically, horizontally, and diagonally at 0/90+45 degree.

C. Letting the graphene solution coated polymer sheets 100 dry at room temperature. Preferably, letting the said sheets dry at room temperature for at least 3 days.

Example 2

Process for compression molding of bulletproof plate comprises the following steps:

1) Stacking polymer sheets (100) with 10 to 125 sheets.

2) Taking stacked polymer sheets (100) from 1) to undergo compression molding by transfer molding machine, wherein temperature of lower mold and temperature of upper mold is between 135-148 Celsius (°C) and compressive force is between 5 to 10 Megapascal (MPa) for 10 to 20 minutes.

3) Letting compressed polymer sheets 100 dry, wherein the products are in the condition when compressive force is between 5 to 10 Megapascal (MPa), wherein there is a cooling until temperature of products is between 75 to 80 Celsius fC). Example 3

Thickness measurement of graphene solution coating that coats on polymer sheets 100, wherein UHMWPE-A refers to polymer sheets by which its fibers are placed vertically and horizontally at 0/90 degree and UHMWPE-B refers to polymer sheets by which its fibers are placed vertically, horizontally and diagonally at 0/90/±45 degree.

According to figure 3, it shows the average thickness of graphene solution coating on polymer sheets by which its fibers are placed vertically and horizontally at 0-90 degree

(UHMWPE-A) which is repeatedly tested 5 times (No.l -No.5); and according to figure 4, it shows the average thickness of graphene solution coating on polymer sheets by which its fibers are placed vertically, horizontally and diagonally at 0/90/+45 degree (UHMWPE-B) which is repeatedly tested 5 times (No.l -No.5). It is found that graphene solution coating on polymer sheets by specific technique of screen printing according to the present invention can accurately control graphene coating thickness and can provide graphene coating that has 1-100 micrometer

(pm) thickness.

Example of graphene coating thickness of example of polymer sheets by which its fiber orientation is set to be placed vertically and horizontally at 0/90 degree (UHMWPE-A) No.3 and polymer sheets by which its fiber orientation is set to be placed vertically, horizontally, and diagonally at 0/90/±45 degree (UHMWPE-B) No.4 is shown in table 1.

Table 1 shows graphene coating thickness of example of polymer sheets by which its fiber orientation is set to be placed vertically and horizontally at 0/90 degree (UHMWPE-A) No.3 and polymer sheets by which its fiber orientation is set to be placed vertically, horizontally and diagonally at 0/90/±45 degree (UHMWPE-B)No.4.

Example 4

Tensile strength test results of ultra-high molecular weight polyethylene (UHMWPE) sheets and ultra-high molecular weight polyethylene (UHMWPE) sheets that are coated with graphene solution in accordance with ASTM D3039/3039M-17 are shown in table 2, table 3, and figure 5.

Table 2 is a table of strength test results of ultra-high molecular weight polyethylene (UHMWPE) sheets.

Table 2 is a table of strength test results of ultra-high molecular weight polyethylene (UHMWPE) sheets that are coated with graphene solution.

When comparing test results, it is found that ultra-high molecular weight polyethylene (UHMWPE) sheets that are coated with graphene solution has increasing tensile modulus of 9% and increasing max load of 24% and increasing tensile strength of 26%.

Example 5

Shooting test by stacking ultra-high molecular weight polyethylene (UHMWPE) sheets and ultra-high molecular weight polyethylene (UHMWPE) sheets that are coated with graphene solution for 40 sheets each in anti -dispersion bag, one type for each bag, and performing shooting test by gun and bullet .357 SIG, bullet weight is 125 gr, at shooting distance of 5 meters, and measuring sinking distance of clay for a comparison wherein test results are shown in table 4.

Table 4 is a table of shooting test results by gun and bullet .357 SIG, bullet weight is 125 gr, at shooting distance of 5 meters.

N f N b f W i h Si ki di f l

Shooting test results of ultra-high molecular weight polyethylene (UHMWPE) sheets found that clay imprint at the area of 4^th time-shooting, there is a crack behind anti-cut bag; and penetrating level is 50%.

Example 6

Shooting test by taking ultra-high molecular weight polyethylene (UHMWPE) sheets and ultra-high molecular weight polyethylene (UHMWPE) sheets that are coated with graphene solution for 25 sheets each and ultra-high molecular weight polyethylene (UHMWPE) sheets and ultra-high molecular weight polyethylene (UHMWPE) sheets that are coated with graphene solution for 15 sheets each to perform shooting test by gun CLOCK 9 MM, bullet weight is 135 gr, at shooting distance of 5 meters are shown in table 6.

Table 4 is a table of shooting test results by CLOCK 9 MM, bullet weight is 135 gr, at shooting distance of 5 meters.

Shooting test results of ultra-high molecular weight polyethylene (UHMWPE) sheets found that the workpiece is damaged and there are more penetrated layers than ultra-high molecular weight polyethylene (UHMWPE) coated with graphene solution, In many possible aspects of invention wherein the principle of disclosed invention might be used, disclosed embodiment of the invention is only preferred example of invention and it should not limit the scope of the invention.

Best mode of the invention

The best method of invention is as described in detailed description of the invention.

Claims

1. A bulletproof plate comprises polymer sheets (100) by which the upper part (200) or lower part (300), in at least one part or both parts is coated with graphene solution of 0.5-5.0% by weight.

2. The bulletproof plate according to claim 1 wherein the polymer sheets (100) is thermoplastic.

3. The bulletproof plate according to claim 1 wherein the polymer sheets (100) is thermoplastic which can be chosen from thermoplastic by which the fiber orientation is set to be placed vertically and horizontally at 0/90 degree or thermoplastic by which the fiber orientation is set to be placed vertically, horizontally, and diagonally at 0/90±45 degree.

4. The bulletproof plate according to claim 1 wherein the polymer sheets (100) can be chosen from thermoplastic in file group of any one or more than one of polystyrene or polyethylene or polypropylene or polyvinyl chloride or nylon or polyamide,

5. The bulletproof plate according to claim 1 wherein the polymer sheets (100) is preferably polyethylene.

6. The bulletproof plate according to claim 1 wherein the polymer sheets (100) is preferably an ultra-high molecular weight polyethylene (UHMWPE).

7. The bulletproof plate according to claim 1 wherein the polymer sheets (100) is coated on the upper part (200) or the lower part (300), at least one part or both parts in combination, with graphene solution of 0.5-5.0% by weight and let dry at room temperature.

8. The bulletproof plate according to claim 1 or 5 wherein the polymer sheets (100) is coated on the upper part (200) or the lower part (300), at least one part or both parts in combination, with graphene solution of 0.5-5.0% by weight and let dry at room temperature. Preferably, it is set to be let dry at room temperature for at least 3 days.

9. The bulletproof plate according to claim I wherein the polymer sheets (100) are stacked with at least 2 sheets.

10. The bulletproof plate according to claim 1 or 7 wherein the polymer sheets (100) undergo compression molding process which comprises the following steps: a. Stacking polymer sheets ( 100) at least two sheets b. Taking products from a. to compressed by heat or compressive force for 10 to 20 minutes c. Letting the products from b. cool down

11. The bulletproof plate according to claim 1 or 8 wherein the polymer sheets (100) undergo compression molding by transfer molding process.

12. The bulletproof plate according to claim 1 or 8 wherein the polymer sheets (100) undergo compression molding wherein the lower mold temperature or the upper mold temperature at least one or both in combination is between 135-148 Celsius.

13. The bulletproof plate according to claim 1 or 8 wherein the polymer sheets (100) undergo compression molding with compressive force of 5 to 10 Megapascal (MPa).

14. The bulletproof plate according to claim 1 or 8 wherein the polymer sheets (100) is let to cool down under compressive force of 5 to 10 Megapascal (MPa).

15. The bulletproof plate according to claim 1 or 8 wherein the polymer sheets (100) is let to cool down until temperature of products is between 75 to 80 Celsius (°C).