ES2595929B1 - Corn carozo board - Google Patents

Abstract

The board object of the invention consists of a board made from crushed, cut or whole corn kernel, mixed or not with thermosetting resins and applying a board manufacturing process similar to that used in medium density fibers.

Description

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DESCRIPTION

Corn carozo board.

Object of the invention.

The present invention relates to a board made of natural fibers, specifically using corn cob, crushed, cut, whole, with excellent properties as acoustic and thermal insulator, which can be used in construction, and which essentially provides characteristics of Novelty and notable advantages over other similar materials known and used for the same purposes according to the current state of the art, especially in regard to the absorption of sound waves.

Background of the invention.

The process of manufacturing composite boards from raw materials from wood and other natural raw materials is well known. Thus, different types of boards are currently manufactured, such as particleboard chipboard, commonly called "particle board" (PB), medium density fiberboard (MDF), chip oriented boards (OSB) , etc. All these types of board are commonly used in construction and especially in the manufacture of furniture and interior elements.

Each of the types of board mentioned above has, in turn, different classifications, both derived from variations in its physico-mechanical properties and modifications on the base product for different applications. Varieties of bare boards or boards are found on the market, to which their surface appearance has been improved by different coatings, the papers impregnated in melamine resins, natural wood veneers, PVC laminates, polyester decorative laminates, lacquers, varnishes being usual. , or textile coatings. Boards with special characteristics are also usually manufactured for specific applications. Thus, we have boards of low density, high density, water repellent, fire retardant, etc.

The differential characteristics of these boards come in some cases from differences in some phase of the manufacturing process, while in other cases

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they derive from differences in the raw materials used, or from the previous treatment carried out on them.

The good properties of the boards in general, as well as their lower cost, have led to the production and use of them having continued to increase in recent years, increasingly replacing solid wood.

At the present time there is a growing concern about the availability of wood for domestic and industrial applications, and the production of this type of boards has led to an increasingly important use of recycled material, mainly from the waste of the industrial industries. First transformation of wood. However, it is already beginning to notice even a shortage of waste of this type, which translates into an increase in prices and a greater difficulty for sustainable sourcing. This situation has caused that, in recent years, alternatives for the development of boards using other types of natural fibers, such as wheat and rice straw, have been studied.

There are agricultural and annual cycle plants whose residues may be susceptible of being used in the production of boards. This possibility is attractive both from an economic point of view and from an environmental point of view and from a social point of view. An economic, ecological and social sustainability is achieved, by achieving an agricultural waste as a raw material in the industry, being also a use that does not interfere with the food chain, not being usable for food or human or animal.

On the other hand, in the field of application of the boards there is a need to respond to increasingly demanding needs. Specifically, in the field of construction, the appearance of more restrictive regulations, which allow for better comfort conditions oblige the development of high-performance products, which at the same time have the characteristic of being environmentally friendly, that are recyclable, Versatile and low cost.

The combination of these needs has meant that in this invention several of the current challenges of the board manufacturing sector, the agricultural sector, and the construction sector, and the environmental moments have been combined, focusing our interest in the mazo stone, as an ideal element to respond and solve them. On the one hand, the need for natural fibers for the manufacture of boards, protecting and preserving the current forest mass; on the other, contributing a value to an agricultural residue, difficult to manage; and, finally, getting a natural, ecological, sustainable product, with an extraordinary capacity for acoustic absorption and thermal insulation,

directly applicable in the field of construction with multiple and important advantages over the materials used today.

Description of the invention.

5 The board object of the invention consists of a board manufactured from crushed, cut or whole corn cob, mixed or not with thermosetting resins and applying a board manufacturing process similar to that used in medium density fibers.

Specifically, the present invention relates to the use of corn cob 10 as raw material to be used for the manufacture of boards or panels, but not limited to medium density and chipboard fiber boards, and using UF resins, MUF resins, isocyanates or other binders, or without binders, and pressed into boards or panels. The present invention has a certain basis in the investigation that corn cob has an excellent ability to be agglomerated, either with small amounts of resin, or even without binders, resulting in a product in the form of a board or panel with some excellent physical-mechanical properties, acoustic absorption and thermal insulation, of great value for its application in construction.

As an additional invention, boards or panels of corn cob 20 have been made alone and mixed with other binder fibers, obtained by mechanical refining, either composing the base material, either as a mixture of materials, or by making panels of alternate well-differentiated layers, each composed of a type of material.

Among the advantages of the developed product are:

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It reduces the consumption of solid wood, reducing the pressure on the exploitation of forests.

Availability of cornfield as agricultural waste from annual crops.

Recovery of a waste, solving the additional problem of ecological elimination by recycling of an agricultural waste

Available in sufficient quantities for the possible manufacturing demand due to the abundance of this crop and economical because it is a waste product, which implies an ecological and sustainable industrial process.

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• Good physico-mechanical characteristics of boards or panels.

• Good machining characteristics.

• Excellent aesthetic appearance that would allow its use without coatings, which again means economic savings and a decrease in the use of potentially aggressive paints and varnishes against the environment.

• Good dimensional stability.

• Excellent acoustic absorption properties, well above the materials currently used in construction.

• In this invention, several processes / methods have been designed to produce boards from corn cob. They are described below, without limiting their scope of application. The first one includes the following steps:

> Selection, cutting, crushing and depuration of corn cob.

> Selection of the pits, pieces of stone or particles of stone depending on their granulometry and the needs for the manufacture of the boards

> Conditioning of the elements of the previous point to begin the mixing process (moisture homogenization, ...).

> Mix of the previously mentioned elements with UF or MUF resins, isocyanates, ...

> Panel preforming by applying cold pressure when necessary.

> Pressing the mixture by applying hot pressure (one or several cycles) at the same or different temperatures and times of pressing and curing.

The cornfield can be cut and ground with hammer mills or blades using different sieves to make the selection of grain sizes. The conditioning of the particles is necessary to achieve homogeneous moisture in the material. Good results have been achieved with humidity in the environment of 8% -16%. A cold pressing process is carried out prior to hot pressing, removing part of the air in the mixture, increasing its density and favoring densification in the hot pressing phase.

• The second method / procedure includes the following steps:

> Selection, cutting, crushing and purification of corn cob.

> Selection of the pits, pieces of pits or particles of piles depending on their granulometry and the needs for the manufacture of the boards

> Conditioning of the elements of the previous point to begin the mixing process (moisture homogenization, ...).

> Mixture of the aforementioned carozo elements with vegetable fibers obtained through a mechanical defibration process or other procedure. Fibers of other origins and even synthetic ones could also be used.

> Addition of UF or MUF resins, isocyanates, ... to the carozo-fiber mixture.

> Panel preforming by applying cold pressure when necessary

> Pressing the mixture by applying hot pressure (one or several cycles) at the same or different temperatures and times of pressing and curing.

The cornfield can be cut and ground with hammer mills or blades using different sieves to make the selection of granulometnas. The conditioning of the particles is necessary to achieve homogeneous moisture in the material. The fiber has been obtained from wood (pine, 20 eucalyptus, poplar, etc.) through a mechanical defibration process, but the use of other types of fiber with different origins and even the use of a percentage of fiber is not ruled out. Synthetic The mixture of materials comprises different proportions of the components, using approximately 80% corn cob and 20% fiber in the tests carried out to date. A cold pressing process is carried out prior to hot pressing, removing part of the air in the mixture, increasing its density and favoring densification in the hot pressing phase.

• The third method / procedure includes the following steps:

> Selection, cutting, crushing and purification of corn cob.

30> Selection of the carozos, pieces of carozo or particles of carozo in

function of its granulometry and the needs for the manufacture of the boards

> Conditioning of the elements of the previous point to start

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the mixing process (humidity homogenization, ...).

> Mixture of the elements of carozo previously mentioned to different granulometri'as and, if it is the case, with vegetal fibers obtained by means of a process of mechanical defibration or another procedure. Too

5 fibers from other and even synthetic origins could be used.

> Addition of UF or MUF resins, isocyanates, ... to the carob binder with different granulometri'as or to the mixture with other binders if it is the case.

> Formation of layers of material of different granulometna and different

10 fibers if necessary, making a "sandwich" board, with faces

exteriors composed of material with granulometna inferior to the inner layer.

> Panel preforming by applying cold pressure when necessary.

15> Pressing the mixture by applying hot pressure (one or several cycles)

at the same or different temperatures and times of pressing and curing.

The cornfield can be cut and ground with hammer mills or blades using different sieves to make the selection of granulometnas. The conditioning of the particles is necessary to achieve homogeneous moisture in the material. The fiber has been obtained from wood (pine, eucalyptus, poplar, etc.) through a mechanical defibration process, but the use of other types of fiber with different origins and even the use of a percentage of synthetic fiber is not ruled out. . The mixture of materials comprises different grains and proportions of the components. A cold pressing process is carried out prior to hot pressing, removing part of the air in the mixture, increasing its density and favoring densification in the hot pressing phase. The layers of material are composed of particles of carozo and other binder fibers, where appropriate, of different granulometri'as, with the lower layers of the boards having those of lower granulometna.

30 Below are examples that demonstrate the invention, without limiting its scope of application.

Description of the figures

Figures 1, 2, 3 and 4 represent different board configurations depending on the different alternatives available for manufacturing. In detail 1 of the figure

you can see the structure of the board using particles and pieces of cornfield of different granulometri'as. The detail of figure 2 allows us to observe the arrangement of the corn particles mixed with fibers.

Figure 3 represents the board made of layers of different granulometers 5 alone or mixed with other fibers or particles. Layers 1, 2, 3 and 4 of the detail correspond to different materials or mixtures.

In Figure 4, the material is arranged in Sandwich layers, alternating the different materials or mixtures (1 and 2).

10 Production of the reference boards:

Reference boards have been investigated and formed in the laboratory by conventional techniques, using particles and pieces of cornfield from different granulometers, obtained by crushing the cobblestones in an electric mill and then filtering them in a sieve column 15 that separated it according to the size of the particles and at the same time purifies the material eliminating impurities. In some tests the particles and chunks of the stonework mixed with wood fiber have been used, which was obtained through a mechanical defibration process based on pine and eucalyptus wood. In these experiences, the thicknesses sought in the boards were between 10 mm and 18 mm, 20 and three types of binders were used: UF resins, MUF resins and MDI. The first resins were used at levels of the order of 12% in their catalyzed form on a dry basis, and the MDI was used at a level of 3% also on a dry basis. The humidity of the material ranged from 10% to 15%. The prey temperatures were between 160 QC and 200 9C. Depending on the type of board to be manufactured and the characteristics, granulometries and humidity of the base materials, excellent results were achieved by applying from one to four pressing cycles. The pressures varied from 8 kg / cm2 to 40 kg / cm2, depending on the characteristics of the mixture and the pressing cycle. The cold pressing process was carried out with pressures between 5 kg / cm2 and 20 kg / cm2.

30 In each case, several replicas of the panels were produced, determining their physical-mechanical properties by several procedures, including Nuclear Magnetic Resonance and especially analyzing their specific density with X-rays and their absorption characteristics with impedance tubes.

Claims (5)

5 10 fifteen twenty 25 30 ES 2 595 929 A1 1. Board of cornfield characterized in that it contains crushed, cut or whole cornmeal, mixed or not with thermosetting resins such as UF, MUF, isocyanate or natural resins or mixtures thereof. 2. Manufacturing process of corn cobble board characterized in that it is manufactured essentially from the cobblestones or corncobs, and may contain other elements, according to the following steps: • Obtain the particles, pieces of carozo or whole corn kernel by processing it by cutting or cutting by grinding, separating and selecting different granulometers at the same time that the samples are purified eliminating impurities. • Subject the particles to a moisture homogenization process. • Mix with a binding agent (UF resins, MUF, isocyanates or natural resins or their mixtures) the materials that will make up the board, only corn cob cob or mixed with other fibers or plant particles, or other non-vegetable origin, including Synthetic • Arrange the material in the position where the board will be formed. • Subject the assembly to a cold pressing process and subsequently to a hot pressing process, with different pressures, temperatures and pressing and curing times, so that the bonding agent reacts. 3. Process for manufacturing a maize pie board, according to claim 2, characterized in that a mixture of fibers or particles obtained by a mechanical defibration process or another similar process for the same purpose is added to the mixture of carozo-resin. , fibers or particles of another origin, including the synthetic one, can also be used in the mixture. 4. Process for manufacturing the maize slab board according to claims 2 and 3, characterized by arranging the maize slab particles in several layers of different granulometers, alone or mixed with other fibers or particles. 5. Process for manufacturing the corn slat board according to claims 2, 3 and 4, characterized in that its structure is formed by layers of "sandwich" board.