DE19757418A1 - Molded bodies of vegetable matter using tubular spadix material, for insulating, filling or packaging - Google Patents

Abstract

The vegetable material, to be used for insulation or filling or packaging, is a biomass of tubular spadix material growing above the ground with a retained aerating tissue structure. The vegetable material is in the form of leaves or leaf fragments with a maximum length of 15 cm and preferred maximum of 2-6 cm, and a particle volume of 0.01-15.0 cm<3> and preferred particle volume of 0.5-5.0 cm<3>. The leaf material is cut through longitudinally once or more, only at the outer skin, which is softened by steam or liquid processing. The material is formed using particles of different sizes and shapes. The outer skin and/or aerating tissue are impregnated by inserting dry particles into the aerating tissue by pressure or suction with an impregnating fluid, and mangling out the surplus. An Independent claim is included for an insulating material with included insulating particles and a bonding agent, pressed in at right angles to the leaf surfaces. Preferred Features: The pressure across the leaves is at a low level of maximum 2 bar and preferrably no grater than 1 bar. In a sandwich material structure, the layers differ from each other in terms of density, particle size or shape and/or the type or volume of the bonding agent. The fibers of the insulating material in the core layer are at right angles, horizontal or in a random alignment to the surface of the shaped material, and the outer layers are pressed against the center core. The outer layers are bonded to the core layer by a bonding agent, at a pressure of 1-10 bar and preferably 3-5 bar. The outer layers can be of different material from the tubular spadix material of the core, or they are of spadix matter compressed at different densities from the core. The outer layers, of a different material, can be of veneer wood, films, board materials, paper or cardboard, mortar, paint or textiles.

Description

The invention relates to insulating, filling or packaging materials and from them Moldings made from plant material.

Various plant materials are known to cause insulation fabrics, insulation boards or lightweight boards are processed can and then more or less good thermal and acoustic insulation have properties; otherwise they are with such men are afflicted that they are partly ecological and health-threatening synthetic insulation materials could not prevail on the market.

Some of them consist of raw materials that are only used to a limited extent are available and / or require long transport routes, such as cork,  Coconut fiber and reeds, some of the raw materials be prepared in a complex manner, such as B. in the manufacture of Fiberboard. Many insulation materials have due to the Gewe structure of the starting material and / or due to the origin positioning process only moderate insulation properties, e.g. B. wood wool lightweight panels, reed and straw panels. The called Deficiencies result in high consumer prices.

Furthermore, DE-C-812 729 describes a process for the production of components in the form of sawable blocks from organi fillers and mineral binders as well as water Glass known in which a larger volume of breakage pieces of tubular plants such as bulrush, rushes break, poppy-broke, pond-break or other swamp plants of reed-like appearance with a slight Amount of water glass solution is treated and silicified, after which the mass after complete drying with small amounts of mine ralische binder, especially cement, and clay intimately mixed and under high pressure (more than 5 bar) to about tenth part of the initial volume is compressed, the Cement is set during the pressing process.

Cavities and thus a certain insulating effect are this method mainly achieved by partially pressure-stable tubular plant materials are used. The fabric structure of the less pressure-resistant sheets, e.g. B. from Cattail, poppy seed flask, pond flask u. Like. is by the high pressure completely destroyed.

The invention was based on the object of renewable, domestic, vegetable raw materials insulation, fillers and packaging materials as well as to create molded articles made therefrom have a similar insulation value to that of synthetic insulation materials and their manufacture, use and disposal simply as well are harmless to health and the environment. Further the task was to find a material that was next to  its good insulation properties has a certain elasticity, so that it is also suitable as packaging material with insulating properties is.

The invention thus relates to an insulation, filling or packing material from plant material, which is characterized by that it is the above-ground biomass from cattails, whose Aerenchym structure is still largely preserved, contains or consists of it.

Cattails (botanical name: Typha) with their most common common species Thypha latifolia L. and Typha angustifolia L. are wild plants that can be cultivated in our climate high yield (20 to 40 t dry matter / ha annually) guarantee and enable environmentally friendly cultivation. They are easy to cultivate on wet areas, whereby the cultivation can be linked to water protection measures can. They are able to drain from sewage and surfaces water to bind the excess nutrients so that they are in Plant sewage treatment plants can be used. They can too for the use and stabilization of rewetted peat soils be used.

The lanceolate leaves of the native species grow Typha angustifolia or latifolia as a bundle of leaves directly from the rhizome. The leaves have one crescent-shaped cross section. The cellular tissue of the outer skin is in the longitudinal axis closely bundled bundles of bast fiber and pure bast strands. The thin is braced Outer skin through an internal chamber system in the longitudinal direction arranged parallel and offset in the transverse direction neten partition walls. The longitudinal dividing walls consist of ge closed-cell tissue, the transverse septum (diaphragms) against it are permeable. They are predominantly similar to a network triangular and square mesh. Between the partitions there are air chambers (lacunae) that are in adult  Scroll a length of 3 to 4 mm and a width of 2 to Have 3 mm. The interior of the lacunae is fine with a thread Sponge tissue, the aerenchyma or aeration tissue filled, that takes up most of the sheet volume and the good ones Insulation properties.

The invention is based on the knowledge that insulating, filling or packaging materials with good insulating properties can be obtained if the aerenchymic structure of the cattail leaves is still largely preserved. The aerenchyma is an elastic tissue, the elasticity of which is irreversibly lost when the tube piston blades are subjected to a higher pressure, e.g. B. from more than 4 to 5 bar. This fact was not recognized by the inventor of DE-C-812 779, since when compressed under a pressure of about 5 atmospheres and more, a reduction in volume by a factor of 10 occurs. Microscope examinations of samples produced in this way showed that the chamber system and the pore structure of the aerenchyme were crushed by cattails. However, partial regeneration was also no longer possible, since the water glass and the hydraulic binder prevented expansion after the molded body had hardened. The specific weight of the test specimens was at least 1,100 kg / m ³ , which corresponded to the specific weight of the brick used today. A high insulation effect cannot be achieved with this. It is therefore not possible to speak of an actual insulating or insulating material, at most it is a lightweight construction element.

The fact that the inventor of DE-C-812 779 has the meaning has not recognized an intact aerenchymal structure also from the fact that in addition to cattails also other tubular Plants without a spongy aerenchyma, e.g. B. reeds, were used. Through the chosen process technology, esp especially due to the high pressures and the resulting Compression to about a tenth of the original volume  just destroyed those plant tissues that are particularly good would be suitable for the production of insulation materials.

The insulating, filling or packaging materials according to the invention are preferably in the form of sheets or sheet parts with a length of at most 15 cm, preferably from at most 2 to 6 cm. The particle volumes of the comminuted material are between approximately 0.01 and 15 cm ³ , preferably between approximately 0.5 and 5 cm ³ .

Since the leaves or leaf parts have a crescent-shaped cross section have, it has proven to be expedient to put the outer skin in To cut lengthways one or more times. Through this Measure is achieved in that the particles lie flat on one another lie so that the volume between the particles as possible becomes low. With this treatment, the aerenchyma does not damaged. Usually the Outer skin in that the leaf sections after chopping sent in the longitudinal direction through parallel knife disks be, in strips with a width of about 1 to 10 mm can be disassembled. With this measure one reaches before all relaxation and easier handling of the Materials. The sickle shape of the leaves is flattened; thereby the particles lie closer together and the danger of Cavitation between the leaf parts decreases. Can also lower pressures applied in the subsequent shaping become.

It is also favorable here that typhoid leaf mass is largely free of SiO ₂ and can therefore be broken down precisely to the desired shaped particles with sharp cutting tools without the cutting tools becoming prematurely blunt.

According to a special embodiment, the knife slice only the outer skin severed, taking the leaf parts remain connected to each other via the aerenchyma tissue. On  in this way the tension in the outer skin will also be sides, whereby larger, flat particles arise, so that the free space between the particles is reduced. In addition less aerenchymal tissue is exposed, which leads to the penetration binders in the pores in the following Production of moldings is reduced. Except through Knife discs can the leaves or the outer skin of the Sheets also through cutting rollers, sawmills and with the help be cut by rays of mass or light.

Another way to get the particle shape required Adjusting structure is that you can leaf parts through a steam or liquid treatment softens, so that too in this way the crescent-shaped cross section of the leaves is flattened.

Finally, there is the option of the lower ends the leaf bundle, like her, slightly glued, from the rhizome grow out, not to disassemble into single sheets, but the closed bundles by dividing them into suitable ones disassemble larger sheets of sheets.

The insulation, filler or packaging materials according to the invention can Mixture of particles of different sizes and shapes represent. The smaller particles fill the cavities between the larger particles, reducing the insulating effect is improved.

According to a further preferred embodiment, the outside skin and / or impregnated the aerenchyma. The impregnation can be done by incorporating a powdered impregnating agent or with an aqueous solution of the impregnating agent. The inner surface is either impregnated by penetration of the dry particles into the sponge structure of the aerenchyma or by compressing the elastic Leaf tissue and the subsequent relaxation in the imprint  kidney fluid. The aerenchym soaks in like a whole Sponge. A fire, putrefaction, pest or the like Protective treatment is therefore much more effective than that purely superficial finishing of closed-cell plants zen woven. The excess impregnation liquid will squeezed, whereupon the aerenchyma due to its elasticity goes back to the original form. To the imprint kidney treatment can, if desired, drying connect.

The invention also relates to molded articles, in particular Insulation elements that have a bonded insulation material as he protrudes is described contains. In the molded body, the insulation fabric in different sizes or shapes. The larger Outer particles ensure structural integrity and a low density of the moldings. The smaller particles be act the material closure of the molding compound, so that no larger There are cavities that could impair the insulation values.

The moldings according to the invention contain, in addition to the insulation Material particles preferably a binder, with a coarse ger pressure across the sheet direction (grain direction) for connection the insulation particle is sufficient. The maximum is applied Dete pressure across the blade direction about 2 bar, preferably maximum 1 bar, since the aerenchyma, as already said, at higher Pressing is irreversibly destroyed. Generally enough pressures from 0.2 to 1 bar, preferably pressures from 0.4 to 0.6 bar can be used. The pressures are hanging too on the desired density of the insulation particles.

In contrast, higher pressures can be applied in the direction of the blade axis be used without destroying the aerenchyma. In the The direction of the insulation is much more stable than across the sheet direction. The stability of up to 3 m high leaves relies on the combination of the preload Cover layers in the direction of the plate axis and the elastic  Filling the core layer with a foam fabric that is in chambers is divided along the plate axis. This fact charak terizes these static properties and thus the mechanical resilience. Cattail leaves are what yours static system concerns, so to speak "tires" with the Special feature of a high pressure stability of about 20 bar in Direction of the leaf axis and reversible elastic behavior across it in the range from 0 to about 3 bar.

This will be discussed below in connection with insulation boards made further details.

Organic or inorganic binders can be used as binders. The inorganic binders include, for example, water glass, sulfite waste liquor, gypsum, clay, lime-quartz sand mixtures or hydraulic binders such as cement, in particular Sorel cement (magnesia cement), which is obtained by stirring fired magnesium oxide with a MgCl ₂ or MgSO ₄ solution. These inorganic binders can be used at low pressures across the direction of the leaf so that the aerenchymal structure is not destroyed.

The organic binders are either in water or in dispersed or dissolved in an organic solvent, wherein the use of aqueous binders for reasons of order world protection is preferred. Small amounts of bin are sufficient medium, especially if the sickle-shaped leaf structure flattened by one of the treatments indicated above has been. Examples of binders are glue, paste, art resin adhesive, hot melt adhesive, casein glue, gum arabic, latex and rubber glue, acrylic dispersion glue etc.

The invention also includes moldings with a sandwich structure structure, the individual layers of which differ in terms of degree of compaction, Particle size or shape and / or by type or quantity  of the binder from each other. Generally be the moldings with a sandwich structure are made of one or two more compact top layer (s) and one core layer with lower density.

The fibers of the insulation particles in the core layer are lower right to the surface of the molding, parallel to it or randomly aligned, depending on the requirements of the statics of the Molded body; the top layer (s) is (are) on the surface pressed onto the core layer. The cover layer (s) is (are) in the generally bonded to the core layer with a binder den and is (are) at a pressure of about 1 to 10 bar, preferably from about 3 to 5 bar, on the core layer pressed on.

The individual layers, especially the top layer (s) of the Sandwich structure, can also be made of other materials than from bulrush or from compressed bulrush particles exist. Other materials for the top layer (s) are, for example, wood veneers, foils, board materials, Paper or cardboard, mortar, paint or textile materials.

The invention is illustrated by the following examples tert.

example 1 Production of an insulation material

Typha leaves are cut lengthways with a cutting roller Cut strips about 3 mm wide. The Strips are then cut with a cross cutter Cut particles with a length of about 3 to 5 mm. After both cutting operations, the aerenchyma is still intact.  

The particles are fine in a drum mixer ground mixture of ammonium sulfate (14% by weight, based on the organic material) as flame retardant and sodium borate (0.1% by weight, based on organic material) as anti-rot and anti-fungal agent, mixed until the powder shaped mixture completely from the aerenchyma of the leaf par article is included.

The impregnated material has a bulk density of approximately 40 kg / m ³ and a specific thermal conductivity (λ) of approximately 0.035 watts / (km).

The particles are in as a blowing or bulk insulation Cavities of constructions interconnected on both sides or in Hollow bricks are used, the injection pressure being sufficient for the mass of the particles no longer accumulates when shaken mensack because the particles have good permanently elastic properties to have. The particles also have good flow properties.

In the flame test, the material almost meets the requirements of Fire class B I.

The insulation material particles produced according to Example 1 can also be used as packaging materials for dishes and machine parts, in which case the impregnation can be omitted. However, larger particles with a volume of approximately 5 to 20 cm ³ are preferably used as packaging materials. When used as packaging material, the material can be composted at the recipient.

Example 2 Production of an insulation board

A mixture of cut typha sheets with three different particle sizes is used to produce an insulation board that is suitable for thermal and impact sound insulation:
40% large particles from only cross-cut leaf bundles cut from the lower end of the typha leaves (length 3 to 5 cm, volume about 20 cm ³ );
40% medium-sized particles which were obtained by dividing the typha leaves into strips of about 1 cm with cutting rollers and then dividing them transversely into sections of about 1 cm in length (particle volume about 5 cm ³ );
20% small particles, which were obtained by division into strips about 0.3 cm wide and about 0.3 cm long (particle volume about 0.5 cm ³ ).

By using a mixture of different parties the remaining voids between the larger particles filled with the smaller particles, which makes the plate more compact and harder.

This batch is mixed with the finest in a drum mixer ground ammonium sulfate / sodium borate mixture from Example 1 dry in the weight ratios specified there blended until the powdery material completely from Aerenchyma of the leaf particles is taken up.

The batch pretreated in this way is placed in a gluing drum with about 35% by weight of a latex adhesive emulsified in water (Solids concentration 30%) mixed. The mixture is in  perforated shapes with the dimensions 2 × 1 m shaken and with a pressure of 0.25 bar to a layer thickness of about 6 cm pressed and dried by blowing through preheated air net. The core layer is obtained in this way.

The cover layers are obtained as follows.

From the upper third of a leaf of typha plants with a clot Lower aerenchymal volume than in the lower part with cutting Roll cut approximately 2.5 mm wide longitudinal strips from which then cut pieces about 10 cm long. The treatment treatment of these pieces with ammonium sulfate, sodium borate and latex glue is made like the core layer.

The batch of leaves will graze with a thorn roller randomly ejected to an approximately 4 cm high fleece, with Warm air pre-dried and then between pairs of rollers, hole bands or perforated rigid plate shapes under one pressure from about 10 bar to plates with a thickness of about 3 mm pressed.

After curing, the cover layers are re-coated on both sides the contact adhesive process (spraying the latex on the upper surfaces), drying and pressing at a pressure of approx 10 bar glued to the core layer, formatted and to the four faces, each with two grooves and two tongues verse hen. On the end faces pretreated in this way are applied accordingly preformed top layer strips glued on.

The insulation board produced in this way has been stored at norma air humidity has a specific thermal conductivity (λ) of 0.040 watts / (K.m). It meets the standards for fire resistance according to B II; it is resistant to rotting and can be used as Impact sound insulation board can be used. Both the core layer as well as the top layers are isotropic, i. that is, there are none preferred processing direction.  

Example 3 Making a sandwich plate

A sandwich panel that is suitable for thermal and acoustic insulation and that has high compressive strength and bending stiffness is produced as follows:
To produce the core layer, the U-shaped frame (width 2 m, height 1.20 m, depth 60 cm), the lower thirds of the cattail leaf glued with Sorel cement adhesive are quickly and parallel aligned as a bundle of leaves (length approx. 60 cm) ( because of the short setting time of the Sorelzemen tes); When the frame is filled, the parallel aligned sheet strips are compressed from above with a flat plate under a pressure of approximately 0.25 bar to a height of 1.0 m, essentially only the free space between the sheet strips disappears, while the chyme volume is not significantly reduced. The package obtained is allowed to harden and plates with a thickness of about 7 cm are cut perpendicular to the leaf axes. The ratio between binder and sheet mass (in each case based on the dry matter) is about 2: 1.

The plates obtained are first (if necessary after formatting or assembly to larger structures) on a flat pressure brought firm base. Then, one by one, the deck layers from the randomly arranged particles of example 2 applied, but instead of with the latex adhesive with the previously mentioned Sorel cement binders (Weight ratio of binder to sheet mass = 5: 1, in each case based on dry matter). The top layer is covered with a Pressure of about 5 bar pressed onto the core layer.

After curing, the second top layer is in the same Way applied to the back of the core layer.  

The plate obtained by the above-described method has a density of about 180 kg / m ³ , a specific thermal conductivity (λ) of 0.045 watt / (km), a compressive strength of about 5000 kg / m ² and a bending stiffness which is approximately that of one 20 mm thick softwood boards corresponds.

The plate is sufficient without additional fire protection equipment means the regulations for fire protection according to the Class B II, because the Sorel cement acts as a fire protection agent. Protection against rotting is also sufficient.

Example 4 Making a sandwich plate

According to the procedure given in example 3, core layers, but with an organic Binder (latex adhesive, 20 wt .-% of the sheet mass, each based on dry matter). The core layers produced in this way of 40 mm thickness are mixed with an aqueous solution of Ammonium sulfate and sodium borate (weight ratio as in Example 1) impregnated by this solution on both sides the plate-shaped core layer is sprayed on. After this The core layer is dried under a pressure of about 5 bar and with the use of polyurethane glue top layers glued from plywood with a thickness of about 6 mm.

The sandwich panel obtained has a good thermal conductivity (λ) of 0.045 watts / (km) and the good sound insulation properties of an 8 cm thick mineral fiber insulation panel of around 300 kg / m ³ , especially a very high bending stiffness a 45 mm thick softwood board (quality class II) with low weight (approx. 120 kg / m ³ ). The plate is suitable, for example, for the production of door leaves, wall elements, table tops and the like.

Example 5 Production of an insulation board

Layers are produced like those in Example 2 wrote top layers, with the difference that they are not compressed with 10 bar to 3 cm, but with 1 bar to 8 cm become. Four of this material are made using contact adhesive technology Add layers to a plate. This is particularly suitable for the insulation of impact sound.

Example 6 Production of a shaped stone

A shaped block in the form of a hollow brick is used of the non-impregnated insulation particles from Example 1 Mixing with an aqueous clay suspension prepared (Ge Weight ratio of insulation material particles: clay, each based on Dry matter = 1: 5; Concentration of the clay suspension 40% by weight).

Hollow blocks are made from the mixture by extrusion the dimensions 49 × 24 × 10.8 cm with a wall thickness of about 6 cm, which are then dried.

By using clay as a binder in a larger Amount deteriorate the thermal conductivity create something (λ = 0.055 Watt / (K.m), but the Form stone a surprisingly high compressive strength.

The cavities in the molded block can be covered with the insulation particles from example 1.

Claims (15)

1. Insulating, filling or packaging material made of plant material, characterized in that it piston the above-ground biomass of pipe, the aerenchymic structure of which is largely preserved, contains or consists thereof. 2. Insulating, filling or packaging material according to claim 1 in the form of sheets or sheet parts with a length of at most 15 cm, preferably of at most 2 to 6 cm and a particle volume of about 0.01 to 15 cm ³ , preferably of about 0 , 5 to 5 cm ³ . 3. Insulating, filling or packaging material according to claim 1 or 2, characterized in that the leaves or leaf parts in Longitudinal direction continuously or only in the area of their outer skin are severed one or more times. 4. insulation, filler or packaging material according to claim 1 or 2, characterized in that the outer skin by a steam or fluid treatment is softened. 5. Insulating, filling or packaging material according to one of claims 1 to 4, characterized in that it is a mixture of Represents particles of different sizes and shapes. 6. Insulating, filling or packaging material according to one of claims 1 to 5, characterized in that the outer skin and / or the Aerenchym are impregnated. 7. insulation, filler or packaging material according to claim 6, characterized characterized in that the impregnation by storing Dry particles in the aerenchyma or by pressing sucking an impregnation liquid and pressing the over liquid impregnation liquid has been carried out.   8. Shaped body, in particular insulating element, containing one bonded insulation material according to one of claims 1 to 7. 9. Shaped body according to claim 8, characterized in that the insulation particles using a binder a small pressure across the sheet direction has been pressed are. 10. Shaped body according to claim 8 or 9, characterized net that he applied pressure across the leaf a maximum of 2 bar, preferably a maximum of 1 bar has been. 11. Shaped body according to one of claims 8 to 10 with a Sandwich structure, the individual layers of which are related Degree of compaction, particle size or shape and / or by distinguish the type or amount of binder from each other. 12. Shaped body according to claim 11, characterized in that the fibers of the insulation particles in the core layer vertically, horizontal or irregular to the surface of the molded body are directed and the cover layer (s) on the surface of the Core layer is pressed on. 13. Shaped body according to claim 12, characterized in that the top layer (s) with a binder with the core layer is connected and with a pressure of about 1 to 10 bar, preferably from about 3 to 5 bar, on the core layer is (are) pressed on. 14. Shaped body according to one of claims 11 to 13, characterized characterized in that the top layer (s) of the sandwich structure from materials other than cattails or from difference heavily compressed cattail leaf mass particles consist.   15. Shaped body according to claim 14, characterized in that the other materials made of veneer wood, foils, panels fabrics, paper or cardboard, mortar, paint or textile mate rialien exist.