WO2018163132A1

WO2018163132A1 - Pressed wood and polystyrene panels having a characteristic smell and production process thereof

Info

Publication number: WO2018163132A1
Application number: PCT/IB2018/051581
Authority: WO
Inventors: Alejandro SEPÚLVEDA VALLEJO; Elizabeth FLOREZ YEPES; Esteban Alberto CORREA BEDOYA
Original assignee: Universidad De Medellín
Priority date: 2017-03-09
Filing date: 2018-03-10
Publication date: 2018-09-13
Also published as: CO2017002348A1

Abstract

The invention relates to pressed panels having a composition of terpene:EPS:sawdust of 10%-40%:20%-50%:40%-70%, and wherein the sawdust has a density between 0.40 and 1.06 g/cm3 and a particle size between 0.850 and 4.750 mm. The panels have a pleasant characteristic smell and can be used after a conventional drying process between 25 and 100°C for a period of 8 to 10 days.

Description

WOOD AND ICOPOR PRESSED PANELS WITH ODOR

CHARACTERISTIC AND ITS MANUFACTURING PROCESS

FIELD OF THE INVENTION The present invention relates to pressed wood and expanded polystyrene (EPS) panels with terpene-type organic solvent useful in the manufacture of boards for furniture products.

SUMMARY

The present invention is directed to pressed panels having a terpene composition: EPS: Sawdust of 10% -40%: 20% -50%: 40% -70% and where the sawdust has a density between 0.40 and 1.06 g / cm ³ and its particle size is between 0.850 and 4.750 millimeters. The panels have a pleasant characteristic odor and can be used after a conventional drying process between 25 and 100 ° C for a period of 8 to 0 days.

STATE OF THE TECHNIQUE

One of the solid wastes that are generated in large quantities in the world is polystyrene in its expanded form. This material is usually used as packaging material as it provides protection for delicate products during transport. However, its reuse for packaging and transport processes is difficult since the shapes and sizes of icopor packaging respond to specific products and can hardly be adapted to new packaging of different products. For this reason, icopor has a very short life cycle as it is produced, used and disposed of quickly. Additionally, polystyrene is a polymer that takes many years to degrade to natural conditions, it has been estimated that it takes approximately 500 to 1000 years for degradation. Alternative ways have been thought of to reduce the environmental impact due to the accumulation of this polymer, for example, it has been used to create resin-based adhesives that contain organic solvents such as toluene, benzene and xylene, among others to take advantage of polystyrene such as part of the matter! resinous of said adhesives or as a polystyrene base to mix with pigments, dusts or any type of fibers to obtain agglomerates. This is the case, for example of the patent CO02117382 which reports a polystyrene resin that is obtained as a product of the recycling of expanded polystyrene, where the polymer is dissolved with gasoline and xylol.

Another way that has been proposed to take advantage of polystyrene is by mixing the particulate material of said polymer with raw materials from the construction sector, for example, mortar, concrete, concrete to create building blocks and structures. For example, patent CO07004953 which reports a process for the elaboration of panels for constructions based on recycled icopor, where solid waste from icopores from packaging, glasses and plates used is mixed with silicas or cements to produce lightweight concrete sheets . Polystyrene can also be mixed with cellulosic materials, where polystyrene is previously melted at high temperatures until it reaches adequate fluidity to form agglomerates, which is the case, for example, of US patent 2009/0176912 which refers to plastic compounds that include cellulosic fillers, such as sawdust, where the particle size varies between 5 meshes up to 100 meshes (4000-149 microns) and plastics, such as recycled polystyrene, are melted and mixed with the sawdust. The process is low cost where the cellulosic materials are mixed with the plastic waste in the molten state and mixing at least 30% of said molten plastic at a temperature and pressure higher than the melting temperature of the plastic and where at minus 70% of the plastic melts. The resulting product can be used as raw material for compression, extrusion, co-processes. extrusion and injection of molded structures, such as panels in which at least 70% of plastics melts and encapsulates the filler material. The encapsulated plastic filler can be used as a material for various services, such as chipboard agglomerates.

Wood agglomerates are a material for boards and are composed of wood particles of different sizes, joined together by some type of resin, glue or other material and subsequently pressed at a temperature and controlled pressure forming the boards. In most of the process, the wooden boards are obtained from sawdust (obtained from a source of wood), a binder and a solvent. Conventional wood chipboard boards use resins derived from formaldehyde as an adhesive or binder material. Such resins can emit chemicals that under certain conditions affect the health and well-being of end users, so conventional products must have a long storage time in adequate places to dissipate the gases of formaldehyde and other substances generated by the agglomerate. After its production.

In this sense, it is clear that in the state of the art there is still a need to provide agglomerated wood panels with desirable characteristics of strength, traction, durability, and that incorporate waste of EPS (expanded polystyrene) to give way to alternative raw materials and It contributes to the reduction of the negative environmental impact generated by this plastic derivative. Detailed description of the figures

Figure 1 shows resulting panels after following the procedure outlined in the present invention. The panels are made of wood with different particle sizes.

Figure 2 shows a penetration hardness test on the panel face. Figure 3 shows a test of resistance to the removal of a nail. Detailed description of the invention

The present invention is directed to panels comprising expanded polystyrene (EPS) residues dissolved in a biodegradable natural extraction organic solvent. Said mixture forms a binder that makes it possible to manufacture, using conventional methods, chipboard boards, avoiding the use of urea-formaldehyde.

The panel according to the invention comprises terpenoid: EPS: Sawdust in proportions that are between 10% -40%: 20% -50%: 40% -70%

Where terpene is an organic solvent extracted from organic waste. The extraction of these solvents is done by conventional techniques, for example, by steam dragging, etc.

Preferred organic solvents that are part of the panel according to the present invention include terpenes with a carbon number between four and eighteen or mixtures thereof. The invention may include but is not limited to monoterpenes and sesquiterpenes or mixtures thereof.

Among the monoterpenes that can be used in the invention, for example, are but are not limited to nerol, geraniol, citronelal, limonene, car-3-ene, phenylethyl alcohol, fenchona, thuyona, alpha-pinene, camphor, range- thuyaplicin and nepatalactone or mixtures thereof.

Among the sesquiterpenes that can be used in the invention, for example, are but are not limited to farsenoi, neroididol, gamma-bisabolene, alpha-cadinen, beta-selinen, karyophylene, carato !, absc acid In a preferred embodiment of the invention, the organic solvent is limonene that is extracted from the oil of citrus peels and that provides the smell characteristic of these fruits. This compound belongs to the group of dipterpenes, specifically to limonoids. In one embodiment of the present invention, the optical isomers of this substance can be included, ie R-limonene and S-limonene or mixture thereof.

The expanded icopor or polystyrene that participates in the panel of the present invention and that dissolves in the terpene, is recycled polystyrene which undergoes a pre-cleaning process depending on the nature of the icopor used. Then, a step of reduction and homogenization of particle size can be done to facilitate dissolution of icopor in the biodegradable organic solvent. The polystyrene can also be expanded polystyrene that has not been used (virgin, new), recycled or clean and where the wood is wood dust (sawdust), fiber, that is, filaments of natural or artificial origin and of varying lengths from centimeters up to micrometers, for example, between 1 cm and 1 micrometer or mixtures thereof.

In another aspect, the present invention is also directed to a process for the manufacture of wood panels characterized in that it comprises the steps of a. Contact the expanded polystyrene with the biodegradable organic solvent in a container. Stir the mixture at an angular speed between 20 and 100 rpm for a time between 8 and 15 minutes.

b. Increase the speed between 120 and 180 rpm for a period between 2 and 10 minutes.

C. Increase the speed between 200 and 300 rpm for 30 seconds and 2 minutes. d. Add the wood to the mixture obtained in the previous step.

and. Mix for a period between 2 to 10 minutes at an angular speed between 20 and 100 rpm until a homogeneously integrated material is generated.

F. Form the pressed panel into a mold and compress using an approximate pressure between 5 and 15 MPa for a period between 3 and 7 minutes, g. Dry the product by oven for 12 to 48 hours at a temperature between 80 ° C 1010 ° C and then dry the product at a temperature between 30 and 60 ° C for 48 to 30 hours, then dry at room temperature for 12 to 48 hours .

The final product obtained is characterized in that it comprises a final terpene composition: EPS: Sawdust of 5% -20%: 40% -60%: 20% -40% and where the sawdust has a density between 0.40 and 1.06 g / cm ³ and its particle size is between 0.850 and 4.750 millimeters. The panels have characteristic smell.

In addition, as shown in the following comparative example, the product has been subjected to tests of resistance to compression, humidity, density, hardness and nail extraction according to Colombian regulations (NTC) and international regulations (AST) where Results showed that the product, in most cases, behaves similarly to those existing in the local market, but being a product from EPS and natural organic solvents, it becomes an environmentally friendly product and economical in terms of production costs and with the additional advantage that the panels can be used right after their manufacture in the manufacture of boards, chairs, desks, etc., without the need to be stored, since the solvent that remains in The panels are not harmful to health and on the contrary, it provides a pleasant citrus smell, which makes the panel of the present invention have differentiated organoleptic properties ras (smell), property that is absent in conventional products. In fact, the product of the present invention does not require odor dissipation times after its production, since, as indicated above, the new product has improved organoleptic characteristics and its components do not pose any danger to users. In this sense, the present invention provides a product in which the use of formaldehyde resins as a binder is eliminated as waste material and a naturally occurring organic solvent (terpenes) are used to agglomerate the wood. Example 1 :

A three-layer pressed panel was manufactured as follows:

Layer 1 and 3 respectively: a) 23.8% solvent, in this case Limonene was used.

b) 30.7% of expanded, clean and homogeneous particle size polystyrene.

c) 45.5% of wood whose particle size is between 0.850

millimeters

Layer 2

a) 23.8% of solvent, in this case Limonene was used.

b) 30.7% of expanded, clean and homogeneous particle size polystyrene.

c) 45.5% of wood whose particle size is between 1.18 and 4.75 millimeters.

In the industrial blender, the EPS and organic solvent are poured. Mix for 0 minutes at an angular speed of 60 rpm. The resulting mixture is homogeneous. Once the material is unified, the speed is increased to 124 rpm for 4 minutes, once that time has elapsed, the speed is increased again to 255 rpm for 1 minute. The mixer is stopped and wood (fine particles for layer 1 and 3 or coarse particles for layer 2) is poured into the mixture obtained from terpene and EPS. Then, the wood-terpene-EPS is mixed for 4 minutes at a speed of 60 rpm generating a homogeneously integrated material. Once the mixture with fine particles and the mixture with thick particles is obtained, the pressed panel is formed. In a mold a mixing layer with fine particles is arranged, then a mixing layer with thick particles and finally a mixing layer with fine particles. The mold is closed and the panel is compressed by applying approximately 70 kilograms per square centimeter (kg / cm ² ). Once the desired pressure is reached, it is sustained for 5 minutes. The panel is unmold, weighed and baked for 24 hours at 8Q ^e C and then 120 hours at 50 ° C and finally, 48 hours at room temperature. The thickness and density of the panels vary depending on the number of layers arranged in the mold.

The resulting panel shown in Figure 1, was subjected to tests of compressive strength, hardness on the face, resistance to nail removal, moisture, density and swelling (maximum 24 hours of immersion), according to the Colombian regulations NTC 2261 and international regulations ASTM D1037. Table 1 shows the values obtained for each test and the dimensions of! panel obtained. Table 2 shows values reported by companies that sell these types of boards.

Table 1 :

Table 2:

Thickness 15 mm

Density 0.61 g cnrr ³

10% humidity

Swelling 14% (max. 24 hours)

Hardness 3 kN

200 N nail resistance According to the results of Table 1 and 2, it can be concluded that the board manufactured according to the quantities, procedure and characteristics of the materials revindicated in the present invention, has characteristics comparable to that of the commercial boards of the region. In addition, the mechanical properties evaluated are comparable with such boards. The foregoing implies that the present invention has sufficient potential to be used in the production of furniture products with desirable physical characteristics and based on organic solvents friendly to the environment and users, for various industrial sectors

Claims

1. A pressed wood panel characterized in that it comprises expanded polystyrene with terpene-type organic solvent and where the expanded polystyrene comes from virgin, recycled or clean material and where the wood is wood dust (sawdust), fiber or mixtures thereof .

2. The pressed wood panel according to claim 1, characterized in that the initial terpene composition: EPS: Sawdust is between 10% -40%: 20% -50%: 40% -70% and wherein the sawdust It has a density between 0.40 and 1.06 g / cm ³ and its particle size is between 0.850 and 4.750 mm. The panels have a pleasant characteristic odor and can be used after a conventional drying process between 25 and 100 ° C for a period of 8 to 10 days.

3. The pane! wood pressing according to claim 1 or 2, characterized in that the wood has a particle size between 0.850 and 1.18 millimeters.

4. The pressed wood panel according to claim 1 or 2, characterized in that for wood it has a particle size between 1.18 and 4.75 millimeters.

5. A process for the manufacture of wood panels characterized in that it comprises the stages of: a. Contact the expanded polystyrene with the biodegradable organic solvent in a container. Stir the mixture at an angular speed between 20 and 100 rpm for a time between 8 and 15 minutes. b. Increase the speed between 120 and 180 rpm for a period between 2 and 10 minutes.

C. Increase the speed between 200 and 300 rpm for 30 seconds and 2 minutes.

d. Add the wood to the mixture obtained in the previous step.

F. Form the pressed panel in a mold and compress using a pressure between 5 and 10MPa for a period between 3 and 7 minutes. g. Dry the product by oven for 12 to 48 hours at a temperature between 80 ° C 10 ° C and then dry the product at a temperature between 30 and 60 ° C for 48 to 130 hours, then dry at room temperature for 12 to 48 hours.