DE102007013662A1 - plant containers - Google Patents

Abstract

Plant containers, containing organic fiber material, such as mechanical and / or thermomechanical digested wood fibers or peat with an addition of 1 to 50% by volume adhesively or cohesively bound to the fiber material technical lignin and optionally other additives, such as compressed stock or peat.

Description

The The invention relates to novel plant containers containing organic Fiber material and lignin and the production of such plant containers.

State of the art

In Germany, about 9 million m ^{3 of} peat (70% black and 30% white peat) are mined each year, of which 85% are used for horticultural purposes (VOGTMANN 2005). On the assumption of constant mining, the resources of Weißtorf would last for another 25 years and the deposits of black peat would be exhausted in about 40 years.

Since 1995, a natural wood fiber material has been produced by Toresa ^® Deutschland GmbH as a peat substitute in Germany ( European Patent 0472684 ). For the production of plant substrate made of wood, the logs must first be crushed. The digestion of the wood takes place in the Retruderverfahren. In the retriever there are two parallel running screws whose conveying direction runs opposite to the last end of the screw in the same direction of rotation of the screw. By reversing the conveying direction creates a high frictional pressure, which causes the fraying of wood chips. In this grinding process, temperatures rise to over 100 ° C, ie the material is germ-free after digestion. The fiber length distribution of this material is composed as follows: TABLE 1 Fiber length distribution of the wood fibers digested in the Retruder process. Fiber length distribution > 8 mm approx. 2% by weight 5-8 mm approx. 7 wt.% 2-5 mm approx. 22 wt.% <2 mm approx. 69 wt.%

Another method of producing wood fibers is Thermo-Mechanical Pulping (TMP). Here, the wood is first digested in a defibrator at 164 ° C and a pressure of 7 to 8 bar. In the actual main digestion, the wood is ground at a pressure of 6.8 bar between a fixed and a rotating disc and thereby shot. The fiber length distribution is shown in Table 2. Table 2: Fiber length distribution of the wood fibers digested in the TMP process. Fiber length distribution > 2 mm approx. 1 wt.% 2-0.5 mm approx. 36 wt.% 0.5-0.1 mm approx. 45 wt.% <0.1 mm approx. 18 wt.%

One Disadvantage of the peat substitute made of wood fibers consists in the relative low water absorption capacity. Surprisingly let yourself the water absorption capacity of wood fibers through the addition of lignins. For this one uses technical Lignine u.a. in the form of sodium, calcium, Ammonium and magnesium lignosulfonate, Organocell lignin and Kraft Lignin. These substances are a mass product, which is produced annually in a lot of about 50 million t (20 million t lignosulfonates and 30 million kraft lignin) as Waste or by-product of pulp industry occurs.

• 1. Sulfat Verfahren
• 2. Sulfit Verfahren
• 3. Organocell Verfahren
• 4. Organosolv Verfahren
• 5. Acetosolv Verfahren

Technical lignins are mainly produced in the following five production processes:

• 1. sulphate process
• 2. sulphite process
• 3. Organocell method
• 4. Organosolv method
• 5. Acetosolv method

The use of these technical lignins together with wood fibers in substrates for the cultivation of plants has the following advantages:
The technical lignin has a broad molecular weight distribution, eg lignosulfonates of 1,000 to 1,000,000 daltons MW (Hüttermann 1977; Hüttermann et al. 1977 ). Lignin is a substance that can be absorbed by plants and promotes growth;
After drying of the substrate or press pot, the substrate can be rewetted well;
The substrates have better dimensional stability, increased strength and water absorption is greatly accelerated.

Container made of wood fibers

In recently, Time was already trying to produce plant containers made of wood fibers. The disadvantage of these containers, however, is that they too had to be covered with a foil and a certain amount contained in shredded polyethylene. Without wrapping are such plant containers only conditionally stable.

The Object of the present invention is therefore to provide a Substrate for the cultivation of green plants, which is dimensionally stable and for this reason at the same time as a plant container can be used, which has a good water absorption capacity or wettability and has a good rewettability and in any Shape and size made can be.

Is solved this task by a plant container, the organic fiber material, which mechanically and / or thermomechanically digested wood fibers or peat with an addition of 1 to 50% by volume of adhesive or cohesive technical lignin bound to the fiber material and optionally further Additives, such as compressed stock or peat contains.

Of the Plant container can be a shaped body in the form of cubes, Be cuboids, round or square pyramidal sections.

The Production of the plant containers according to the invention can be done in a wet process (suspension process) since will be described below.

in the Suspension process is made of 100% wood fiber material a fleece made, the final divided into pots becomes. The wood fibers should have a size of 8 mm to 0.1 mm, preferably from 7 mm to 0.3 mm, optimum from 5 mm to 0.3 mm. to Fleece formation is a certain amount of wood fibers, depending on from the desired Fleece size and residual moisture of wood fibers, in a container of water filled. Of the Solids content in the suspension should be <10%, better still <5%. To this suspension From fiber material and water is lignin in liquid or powdery form added. The proportion of lignin should be between 1% and 50%, better between 5% and 30%. Directly into the suspension can also fertilizer if necessary be added. commercial Nitrogen, phosphorus and potassium fertilizers (NPK fertilizers) can be used e.g. in powder form without impairment the web formation can be integrated into the process. This suspension is done with the help of a stirrer mixed well and then in a container, at the sieve-shaped Ground a vacuum can be applied, poured.

By the application of the vacuum removes the water from the suspension, so that the fibers merge slowly and evenly into a fleece can matt. An additional Pressing the wood fibers to a plate is in this process unnecessary. The extracted wastewater of the suspension contains depending on Added amount of lignin, certain amounts of lignin. This wastewater can be used again for web formation.

• • Ofentrockung
• • Mikrowellentrockung

The fleece body contains depending on the level of negative pressure during web formation, as well as fleece height a certain residual moisture. This varies between 100% to 600% based on the dry mass of the fleece. The wet fleece can be removed from the water in various drying processes. These methods are:

• • oven drying
• • Microwave drying

When oven drying, the fleece must be dried for several hours, depending on the moisture and size of the fiber body and the performance of the oven. The drying in microwaves depends on the same parameters, but runs much faster due to the much higher performance. The drying in the microwave took at a power of 500 watts for a nonwoven plate with the dimensions 19 cm × 19 cm × 5 cm depending on the initial moisture content 20 to 90 minutes. For more powerful industrial microwaves the drying takes only a few minutes. The drying process in the microwave is approximately linear.

To During drying, the wood fiber fleece is divided into the desired plant container size and drilled a hole in the middle of each body. In this planting hole can now either one or more seeds or a cutting planted become. At a very low final moisture in the plant containers catch the seeds without an extra Moire not to germinate. This in turn means that completely for the cultivation finished plant containers delivered to the respective companies could become, so that they only need to pour the containers to with the cultivation to start.

The Moisture in the dried plant containers is for plant growth first too low. Consequently started within a trial period of 14 days no seeds to germinate. This in turn means for the practical Application that produces the plant container complete with plant seeds and could be delivered. The growth is only through the moistening of the plant container induced. The plant containers were easily removed from the roots of the plants (eg: Triebkopfsalat) by rooting. To reduce evaporation can the plant containers with commercial, biodegradable films are provided. Damage the Plants could during of cultivation can not be determined.

• • eine Ummantelung der Container mit Folie ist nicht zwingend notwendig
• • das Lignin ist ein Holzeigener Stoff und somit bezüglich der Umweltverträglichkeit vollkommen unbedenklich
• • das Lignin erhöht die Wasseraufnahmekapazität der Container
• • die Container können kompostiert werden

Further advantages of these containers over the already known containers made of wood fibers are:

• • It is not absolutely necessary to wrap the containers with foil
• • The lignin is a wood-based substance and therefore completely harmless in terms of environmental compatibility
• • the lignin increases the water absorption capacity of the containers
• • the containers can be composted

plant containers can in addition to the wet process also be prepared by dry process. To produce the plant container according to this method, the Wood fiber material, depending on the composition, if necessary first screened, so that rougher Wood fibers or pieces (> 0.7 cm) away become. The screened material is then sprayed with lignin. These impregnated Fibers are then treated with conventional press pot substrate (Mixture of black peat and white peat), depending on the desired Volume fraction, mixed and filled in the Erdtopfmaschine. to better stability the plant container must be slightly moistened with water become. It is important to ensure that by excessive humidification the binding ability of the Erdtopfsubstrats is greatly reduced.

To can press the pots directly from the conveyor belt the earth pot machine in boxes be packaged and planted.

Example 1: Production of plant containers in the suspension process (wet process)

To produce the plant containers wood fibers were used, which after the im EP 0 472 684 were prepared and had the fiber length distribution shown in Table 1. For this purpose, 350 g of wood fibers with a humidity of 43% were placed in a container filled with 3.6 l of water. The solids content in the suspension was thus 5%.

Based on the dry mass of wood fiber, 20% lignin _{atro was added} to the suspension. The lignosulfonate had a residual moisture content of 6.8%. Partially continued to be added to the suspension was the following fertilizer at a concentration of 2 g / l H ₂ O:
Flory 3 Green 15-10-15 (+2) '' with 15% nitrogen (N), 10% phosphorus (P), 15% potassium (K) and 2% magnesium (Mg; trace elements).

The Suspension was mixed by means of a stirrer and into a container poured with sieve bottom. The liquid was sucked off by an applied vacuum, leaving a slow and even distribution ensured of the solid was. The sewage would a container caught and could be used again.

The drying of the wood fiber body was carried out in a microwave apparatus with a power of 500 watts. This resulted in the 1 illustrated drying process.

In conclusion was the fleece by means of a circular saw in the desired Cut pot sizes and with the help of a drill a planting hole drilled in the middle.

Example 2

The production of the plant containers was carried out as in Example 1. The addition of different amounts of lignosulfonate to the plant substrate water absorption could be increased. For this example 1 was varied as follows:
5%, 10%, 15%, 25% and 30% lignosulfonate were added to the suspension instead of the 20% lignosulfonate. The further process steps were identical to those in Example 1. Subsequently, the plant containers were measured with the help of a caliper and determined the dry weight. A bowl was filled with water, the filling height of half of the plant container height corresponded. Another bowl of water along with a grid screen on it served as a drip. The plant container was immersed in the water bath and held so that it is in contact with the water up to half its height. After 20 seconds, the container was removed from the liquid and placed on the device for dripping. After no more dripping water, the weight was determined. Then, the plant container was dipped into the water bath for another 20 seconds, without the amount of water was replenished before and weighed after draining. This process was repeated until the end of the 180th second.

mit:

WK

= Wasserkapazität [%]

p_feucht

= feuchte Probe [g]

p_atro

= trockene Probe [g]

The water capacity was calculated using the formula:

With:

WK

= Water capacity [%]

p _wet

= wet sample [g]

p _atro

= dry sample [g]

With The same formula was used for the maximum water capacity of the plant containers certainly. Therefor the containers were stored completely in water for 24 hours and weighed after draining.

It showed that the maximum water absorption capacity at all Plant containers was relatively the same, whereas the water absorption capacity depending from the amount of lignin wavered.

The amount of technical lignin added to the suspension does not completely adhere to the fibers. Some of the lignin is not bound and enters the wastewater of the suspension. The following amounts of lignin have remained in the plant containers for the different amounts added. Table 3: Addition levels and bound amount of technical lignin in the suspension process. Addition amount of lignin sulfonate [% based on atro fiber] in the suspension Amount of bound lignin [% relative to atro fiber] in the plant container 0 0 5 0.6 10 1.4 15 2.4 20 7.3 25 10.7 30 13.2

As in Table 3 are at an addition of 25% or 30% more than 40% of the added technical lignin during the Suspension has been bound to the fibers. This in turn has influence on the water absorption capacity the wood fibers.

In the 2 it can be seen that the water absorption capacity is greatly increased by the addition of varying amounts of lignosulfonate. With the addition of 25% lignosulfonate or a proportion of 10.7% bound lignosulfonate on the wood fiber based on the dry weight of the Fa The water absorption capacity is approximately 250% after 180 seconds.

Example 3

to further assurance of the test results were 50 in the suspension process Plant containers prepared according to Example 1 with rooted chrysanthemum cuttings planted. The containers left to water yourself very well and there were no problems during of the culture. The re-watering the container after provoked dehydration was good.

Example 4: Production of plant containers in a mixing process

It were plant containers pressed with a soil pot machine with wood fiber, as used in Example 1 prepared. For this were the coarser ones (> 0.7 cm) wood fibers removed first with the help of a sieve. Following was the wood fiber material wetted in a mixer with lignosulfonate. Sieved to 10 kg Wood fiber material with a residual moisture of 50% was 568 g of lignosulfonate given with a residual moisture of 12%. The degree of wetting was thus 10%. The lignosulfonate powder became 543 g of water to a 45% solution dilute and applied.

• • größeres Porenvolumen => bessere Wurzelbildung
• • bessere Wiederbenetzung der Töpfe
• • leichte Fungizide Wirkung des Lignins

The wetted wood fiber in the press pot has the following advantages:

• • larger pore volume => better rooting
• • better rewet the pots
• • mild fungicidal action of lignin

Before compression, the substrates listed in Table 3 were mixed by hand with the aid of a blade and moistened with water for better adhesion. The following substrate variants were used for the production of pressed plant containers: Table 4: Substrate compositions for the production of pressed plant containers. substratum composition relationship 1 • Mixture of black peat and white peat, where the proportion of black peat is> 90% 60% vol. • Spray wood fiber (Toresa ^® R) with lignin sulphonate 40% vol. 2 • Mixture of black peat and white peat, where the proportion of black peat is> 90% 80% vol. • Spray wood fiber (Toresa ^® R) with lignin sulphonate 20% vol.

The Production of the plant container with wood fiber worked with the Erdtopfmaschine without problems. The pots had sufficient Firmness or sufficient fiber peat binding on and could, without that they were broken, stacked in boxes. The pots out Substrate variant 2 (80% by volume black and white peat mix, 20% wood fiber) were stronger than those from variant 1 (60% by volume of black and white peat mix; 40% vol. Wood fiber).

A further increase in the strength properties can be achieved by increasing the Black peat share in the black peat / white peat mix are achieved, since this improves the adhesive properties of the peat mixture.

literature

• HÜTTER MAN A. (1977): Gel chromatography of Na lignosulfonates on Sepharose CL 6B. Wood Research 31, 45-50
• HÜTTER MAN A., GEBAUER, M., VOLGER, C. AND RÖSGER, C. (1977): Polymerization and degradation of lignosulfonate by Fomes annosus. wood research 31, 83-89
• MOMBÄCHER, R. (1988): Holz Lexikon Volume 1 A-M. DRW publishing house: 195
• VOGTMANN, H. (2005): Preventing climate change - regional Close nutrient cycles. Federal Bureau for nature conservation. EKO-PLANT symposium on 13 October 2005 at Burg Ludwigstein. http://www.bfn.de/09/0903.htm Date: 13.12.2005

Claims (11)

Plant container containing organic fiber material, such as mechanically and / or thermomechanically digested wood fibers or peat with an addition of 1 to 50% by volume of adhesive or cohesive technical lignin bound to the fiber material and optionally further Additives, such as compressed stock or peat. Plant container according to claim 1, characterized that they are as shaped bodies in the form of cubes, Ashlar, round or square pyramidal sections are present. Plant container according to claim 1, characterized that the fiber material is made of wood fibers with the following fiber length distribution consists of> 8 mm to <2 mm, and> 2 mm to <0.1 mm. Plant container according to claim 1, characterized in that the technical lignin is Na, Ca, NH ₄ and / or Mg lignin sulfonate, organocell lignin or kraft lignin. A refuse container according to claim 1 or 2, characterized that they have a height from 0.5 to 50 cm. Plant container according to claim 5, characterized that they have a height from 1 to 30 cm. Plant container according to one or more of claims 1 to 6, characterized in that they contain 50 to 90 vol .-% peat. Plant container according to claim 7, characterized that they contain 60 to 80 vol .-% peat. Plant container according to claim 7 or 8, characterized that the peat is a mixture of black peat and white peat. Process for the preparation of plant containers the claims 1 to 9, characterized in that 350 g of wood fibers with a Initial moisture content of 5 to 100 vol .-% in 3.6 liters of water introduced be mixed with 1 to 30% lignosulfonate (based on atro fiber) be up to 20 g of a conventional Nitrogen, phosphorus and potassium fertilizers (NPK fertilizer) are added, the Mix by stirring is mixed and the liquid aspirated by an applied vacuum, the obtained wood fiber body 160 to 180 ° C 6 to 8 hours in a drying oven or 1 to 90 minutes in one Microwave is dried. Process for the production of pressed plant containers according to the claims 1 to 9, characterized in that sieved to 10 kg wood fiber material with a residual moisture of 1% to 50%, 568 g of lignosulfonate be given with a residual moisture of 1% to 20%. The lignosulfonate powder with water to a viscous solution dilute and applied to the wood fibers. The wood fibers are with a Schwarztorf- / Weißtorfgemisch in a relationship from 90 vol.% black peat / white peat mix to 10% by volume of wood fibers up to 50% by volume of black peat / white peat mix mixed to 50 vol .-% wood fibers and in a Erdpresttopfmaschine pressed to plant containers.