BR102018002237A2 - PROCEDURE FOR OBTAINING LDPE - PP THERMOMOLDABLE BOARDS AND PRODUCTS OBTAINED. - Google Patents

Abstract

process of obtaining thermoforable pebd - pp plates and obtained products. refers to the process of obtaining (fig. 1) thermoforable plates (fig. 2) to be employed in the health sector for the manufacture of orthoses and prostheses; low cost of manufacture and operation when compared to the current state of the art; and using as a raw material the blends of pp copolymer (fig. 3 and 1) and recycled pebd grains (fig. 4 and 2), in ideal proportions, providing two plate variations: 25% pp copolymer and 75% recycled pebd (v1) and 50% pp copolymer and 50% recycled pebd (v2). The invention has an environmental appeal because it enables the collection and use of discarded polymeric material, as well as providing efficient, high quality products that meet the standards established by the medical research council. Moreover, the process has simple execution steps consisting basically of weighing (e7), mixing (e8), homogenization (e9) and calendering (e10) to obtain the thermoforable plates (figs 2 and 5).

Description

PROCESS OF OBTAINING LDPE - PP THERMOMOLDABLE PLATES AND PRODUCTS OBTAINED

BRIEF DESCRIPTION [001] The present patent application for an unprecedented “PROCESS OF OBTAINING PEBD THERMOMOLDABLE PLATES - PP AND OBTAINED PRODUCTS” deals with the process of obtaining thermoformable plates to be used in various sectors, including the health, in the manufacture of orthoses and prostheses; with low cost of manufacture and operation, when compared to the current state of the art; and that uses recyclable polymers as raw material, Low Density Polyethylene (LDPE) and Polypropene (PP).

FIELD OF APPLICATION [002] The present invention belongs to the section of human needs; the health field, more specifically medical science; because it is a process of obtaining thermoformable plates to be used in the manufacture of prostheses and orthoses.

CONVENTION [003] More and more plastic materials have been adopted in the health field. They are found in several ways and their use is the most varied, due to their characteristics of durability, compatibility and hygiene. Some of the uses of plastic materials in the health area are exemplified below: polypropylene (PP) fabrics are used, which are durable and disposable, for example in aprons, caps, masks; manufacture of syringes, which are disposable and inexpensive; manufacture of catheters and stents that are compatible with other materials and with the organism, in addition to being flexible, which provides greater comfort to the patient; manufacture of hearing aids and prostheses, either to correct deformities or to restore vision, since silicone corneas can restore vision with the same characteristics as a natural cornea. From this, it can be noted that there are numerous applications of plastic materials in the health area.

[004] Polypropylene (PP) is a synthetic material, widely used in health, which produces little tissue reaction and has good tensile strength, a resistance that is maintained for several years after its use in living organisms (Diogo-Filho et al., 2004).

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2/9 [005] In addition, it has low cost, high chemical and solvent resistance, high resistance to bending and impact fracture, good thermal stability; characteristics that contribute to its application in the health sector.

[006] Low Density Polyethylene (LDPE), under normal conditions, is non-toxic and can be used in contact with food and pharmaceutical products. LDPE has a unique combination of properties: toughness, high impact resistance, high flexibility, good processability, stability and remarkable electrical properties.

[007] Despite being highly resistant to water and some aqueous solutions, including at high temperatures, LDPE is slowly attacked by oxidizing agents; and its water permeability is low when compared to that of other polymers (Coutinho et al., 2003). Due to its characteristics, it is applied as films for industrial and agricultural packaging, films for liquid and solid food packaging, laminated and plasticized films for food, packaging for pharmaceutical and hospital products, toys and housewares, wire and cable coating, tubes and hoses (OPP Product Catalog, 2000).

[008] Physical rehabilitation processes, in general, involve the use of a set of practices, methods and techniques that aim to supply deficient organic functions, through material artifices (Agnelli et al., 2003), nowadays, more and more plastic materials have been used in these processes. Prostheses are resources that are intended to replace an absent anatomical part; orthoses, on the other hand, are devices to be added to a segment of the body and can be used for various functions, such as joint and bone corrections. Orthoses can be static, being used to immobilize or stabilize in a specific position; or dynamic, which allow controlled mobility of the joints and restoration of some movements.

[009] When choosing a material for the manufacture of orthoses and prostheses, some aspects of the material must be considered, such as: weight, resistance to deformation, resistance to wear, corrosion, toxicity and aesthetics. Polymeric materials have the characteristics that make them useful in the construction of structures and

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3/9 devices, since they are generally light, flexible and have good resistance to corrosion (Padilha, 1997).

[010] In this sense, the proposal of the present patent application, refers to a process of obtaining thermoformable plates produced from an ideal mixture of LDPE and PP, which are plastic materials, light, recyclable and of low cost, that present desirable characteristics to be used in the production of orthoses and prostheses for the health area. The invention to be described, in addition to its high efficiency and quality, solves problems present in the current state of the art, with regard to the availability of a low cost, high efficiency, environmental appeal process that provides a product to be used. used in the health field with the necessary characteristics and quality.

BACKGROUND OF THE INVENTION [011] In the current state of the art, some priorities are present that describe orthoses / prostheses produced from polymer composites. However, none of the previous findings anticipates what is proposed in this patent application.

[012] The previous PI 0406109-8, entitled Orthosis based on composite polymer and fiberglass and its manufacturing process describes an orthosis developed for recovery and treatment of people who have functional impairment of their members, as well as the productive process of said orthosis, which, unlike those currently known, makes it possible to obtain a part that simultaneously combines the properties of lightness, transparency and high mechanical resistance. As the orthotic device is made of plaster mold, which is shaped in the patient's limb to be a negative of the orthotic device, which then receives the finish of the internal surface. After the plaster curing process takes place, it receives five layers of polyvinyl alcohol release agent (diluted to 40% by mass of water), commercially known as PVA1. Then, a mixture of the resin is made with hydrogen peroxide which is applied to the mold alternating the layers of this mixture with layers of fiberglass. The orthosis has a main body (1) with holes (3) through which clips (2) of silicone with velcro pass, or simply, strips of velcro. Per

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4/9 more than the previous one describes the process of obtaining orthoses that uses a polymer as raw material, it is different from the copolymers used in the proposal of the present invention, which proposes a mixture of two fully recyclable and thermoformable copolymers, the that allows versatility to the product, in addition to the mechanical properties required in the field of application.

[013] Priority PI9205488-9, entitled Curable and moldable polymer / monomer system, biocompatible conformable composition, process for forming a biocompatible moldable and curable mass, process for forming a part of a human or animal body, process for forming an audiologic ear mold or ear piece, elastomer, ear mold or ear piece, and prosthesis describes a biocompatible moldable curable polymer / monomer system capable of curing at room temperatures to provide an elastomer product while producing a lower exotherm than previously used systems. [014] The system comprises (a) an alkyl acrylate or methacrylate homopolymer or copolymer, (b) a monomer mixture of an upper alkyl acrylate or methacrylate combined with one or more of acrylic acid, methacrylic acid and its lower alkyl esters and (c) a plasticizer. Crosslinking agents, anti-stick agents and activators or photoinitiators are preferably included. Particular uses include the preparation of masses for use in the production of ear molds and ear pieces or in the manufacture of prostheses. As much as the previous one describes an efficient system for the manufacture of prostheses, which contains polymers in its composition; it does not use the same polymers described in the present invention, so it does not solve the technical problem solved by the proposal described in the present application.

[015] As much as the previous ones presented describe materials to be used in the production of prostheses and orthoses that have polymers in their composition, they still describe the use of other materials associated with them, differently from the invention described in the present application, which of the mixture in ideal proportion of the copolymers used, Low Density Polyethylene (LDPE) and Polypropene (PP), makes it possible to obtain thermoformable plates that have the

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5/9 mechanical characteristics necessary for its use in the health sector, in the manufacture of prostheses and orthoses. Thus, the present invention fully meets the demands of the market, solving one of the problems present in the state of the art, with regard to the provision of a process for obtaining thermoformable plates, to be used in the manufacture of orthoses and prostheses, simpler and cheap, when compared to those present in the current state of the art and which still has environmental appeal, for using abundant raw materials, easily accessible and fully recyclable.

OBJECTIVE OF THE INVENTION [016] The present invention aims to offer the market a product made with recycled polymers, of low cost and that has sufficient conformation characteristics for the elaboration of structural components that make up orthoses and prostheses, in the most varied applications for humans and animals; and that, due to its low cost, it still allows the reduction of the final cost of the product, favoring the reach in the most varied economic and social layers.

THE INVENTION [017] The present patent application refers to the process of obtaining thermoformable plates to be used in the health sector, for the manufacture of orthoses and prostheses; with low cost of manufacture and operation, when compared to the current state of the art; and which uses recyclable polymers as a raw material, Low Density Polyethylene (LDPE) and Polypropene (PP), in ideal proportions. The invention has an environmental appeal for making it possible to collect and use discarded polymeric material, in addition to providing efficient, high-quality products that meet the standards established by the Medical Research Councilé.

ADVANTAGES OF THE INVENTION [018] In summary, the present invention has as main advantages:

V Have a process for obtaining thermoformable plates with simple steps of execution and low cost, when compared with the techniques available on the market today;

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V Have a process for obtaining thermoformable plates that uses abundant, low-cost and fully recyclable raw materials;

V Have a process for obtaining thermoformable plates that allows the collection of discarded polymeric material;

V Have versatile thermoformable plates, which have the possibility of being modeled, as needed;

V Have thermoformable plates that present resistance to flexion, above the normal force against resistance (Grade 5 of FM), as established by the Medical Research Council (1981);

V Have thermoformable plates with the possibility of stabilizing the wrist in the neutral position, where flexions or wrist extensions are not required (below Grade 3 of FM).

DESCRIPTION OF THE FIGURES [019] The invention will be described in a preferred embodiment, thus, for better understanding, references will be made to the flowchart and figures:

V Figure 1: Flowchart of the process for obtaining thermoformable plates;

V Figure 2: LDPE - PP thermoformable plate;

V Figure 3: PP copolymer grains;

V Figure 4: Grains of recycled LDPE.

DETAILED DESCRIPTION OF THE INVENTION [020] The raw materials used to obtain the thermoformable plates (Fig.1) are blends of PP copolymer, obtained in grains (Fig. 3 and 1), obtained commercially and called Aramco PP CP55N; and grains of recycled LDPE (Fig. 4 and 2), previously obtained.

[021] The recycled LDPE grains (Fig. 4 and 2) used in the present invention are obtained from a mixture of various LDPE scraps, reprocessed and transformed into grains. Therefore, pure LDPE, obtained from a specific industrial chemical process, is not used. It is a material already conformed in previous processes, which comprised packaging and several other products, and which after being discarded, were reused. The reuse process consists of recycling the LDPE,

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7/9 through collection (E1), separation (E2), washing (E3), crushing into flakes (E4), reheating (E5) and extrusion (E6) to be transformed into recycled LDPE grains (Figs 4 and 2) . The material is of different origin, part of which is scrap from the factory production line itself. In summary, it is an LDPE that has already undergone heating and reheating.

[022] To obtain (Thermoformable Plates (Fig.1)), initially the PP copolymer blends (Fig. 3 and 1) and the recycled LDPE grains (Fig. 4 and 2) are weighed (E7 ), on a precision scale from the manufacturer Mars, model AY220, according to the following table:

Variation PP copolymer (1) Recycled LDPE (2) 25-75% 25% 75.0041 75% 225.0015 50-50% 50% 150.0126 50% 150,019

Table 1: Weighing in grams of the sample of polymers used.

[023] After weighing the raw materials, they are mixed (E8), in the proportions of the two plate variations, which present the same components and are obtained from the same process, however, using raw material proportions different: 25% PP Copolymer and 75% Recycled LDPE (V1) and 50% PP Copolymer and 50% Recycled LDPE (V2).

[024] Then, the mixture obtained (3) is homogenized (E9). For this purpose, an MH plastic homogenizer is used, as used in the test, which through a thermokinetic process, where the melting temperatures used are: between 115 and 120 ^o C for recycled LDPE, and between 160 and 180 ^o C for the PP copolymer. The control of the homogenization step (E9), using the MH plastic homogenizer is done manually, using a timer; homogenization time varies according to the proportion of each raw material present in the mixture (3). Thus, the step needs to be interrupted a few times in order to verify the softening situation of the polymer inside the chamber. The exchange rates between the first speed and the second speed of the equipment is performed as the amperage increases equipment for 40 to 50 Amperes and is also perceived the change in sound from the operation of the equipment, since the noise emitted decreases with the

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8/9 increased amperage, also being a signal for speed increase. The mixtures (3), in both proportions, are homogenized twice, taking care to avoid burning the samples. Although care must be taken with the samples, there is a characteristic of subjectivity in the operation of the MH Plastic Homogenizer equipment, as parameters such as sample temperature during the procedure and equipment speed are not possible to be controlled, as they do not exist. markers and calibration equipment built into the operating panel. Therefore, the visual and auditory verification of the MH Plastics homogenizer was described during the process.

[025] After the homogenization step (E9), the homogenized mixtures (4) pass through the calendering step (E10), so that the material is formed into sheets. For this purpose, the Calandra Camargo Cilindro Micro 300 was used, which has two cylinders. After the calendering step (E10), thermoformable plates (Fig. 2 and 5), in the variations 25% PP Copolymer and 75% Recycled LDPE (V1) and 50% PP Copolymer and 50% Recycled LDPE (V2), are obtained and are ready to be remodeled according to their purpose, for example, production of orthoses and prostheses.

[026] The following tables reveal technical characteristics achieved by the thermoformable plates (Fig. 2 and 5) obtained from the described process (Fig. 1).

Sample 100% LDPE Sample 75% LDPE - 25% PP Sample 50% LDPE- 50% PP (V2) Sample 25% LDPE- 75% PP (V1) Flow stress (Mpa) 9.885 ± 0.8 15.12 ± 0.4 21.00 ± 1.4 26.57 ± 0.8 Voltage of Maximum force (Mpa) 11.51 ± 2.0 17.67 ± 1.3 22.61 ± 1.4 27.64 ± 1.5 Module of Elasticity (Mpa) 147.4 ± 13.2 261.3 ± 4.2 311.6 ± 12.0 359.6 ± 12.9

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Table 2: Grouping data from tensile tests

Sample 100% LDPE Sample 75% LDPE - 25% PP Sample 50% LDPE- 50% PP (V2) Sample 25% LDPE- 75% PP (V1) Flow stress (Mpa) 84.32 ± 8.05 66.18 ± 18.21 107.8 ± 24.03 158.0 ± 1.84 Voltage of Maximum force (Mpa) 23.12 ± 1.73 18.82 ± 5.29 29.87 ± 7.49 43.20 ± 1.61 Module of Elasticity (Mpa) 893.1 ± 97.82 1029 ± 64.89 1495 ± 70.67 1655 ± 28.56 Table 3: Grouping of data d bending tests

[027] From the foregoing, it is observed that the present invention fully meets the demands of the market, solving one of the problems present in the state of the art, with regard to the provision of a process for obtaining thermoformable plates, to be used in the manufacture of orthoses and prostheses, simpler and cheaper, when compared to those present in the current state of the art and which still has environmental appeal, for using abundant raw materials, easily accessible and fully recyclable, thus, the described invention is worthy of the patent privilege of invention.

Claims (3)

1) PROCESS OF OBTAINING PEBD THERMOMOLDABLE PLATES - PP characterized by starting with the PP copolymer blends and the recycled LDPE grains being weighed (E7) and being mixed (E8), in a proportion that varies according to the thermoformable plate to be obtained, which can be 25% PP copolymer (1) and 75% recycled LDPE (2) or 50% PP copolymer (1) and 50% recycled LDPE; then, the mixture obtained (3) will be homogenized (E9), twice, in an MH plastic homogenizer; and the homogenized mixture (4) passes through the calendering (E10) to form the material and thus the thermoformable plates (V1 and V2) are obtained. 2) PEBD - PP THERMOMOLDABLE PLATE, according to claim 1, the variation 25% PP Copolymer and 75% Recycled LDPE (V1) is characterized by being composed of PP and recycled LDPE copolymer, in a proportion of 25: 75%. 3) PEBD - PP THERMOMOLDABLE PLATE, according to claim 1, the variation 50% PP Copolymer and 50% Recycled LDPE (V2) is characterized by being composed of PP copolymer and recycled LDPE, in a proportion of 50: 50%.