AT526772A4 - Wood fibreboard and method for producing a wood fibreboard - Google Patents

Abstract

The invention relates to a resource-saving wood fiber board with coffee grounds, in which the wood fibers and the coffee grounds are bonded with a urea-formaldehyde resin. The coffee grounds are waste products that accrue during the production of coffee using a portafilter or during the production of instant coffee. If a solids content of coffee grounds between 20% and 45% is used, the technical properties of the board according to the invention are in the range of MDF standards when manufactured industrially.

Description

and a process for their production.

The resource “wood” has become valuable worldwide and especially in Europe due to climate change, as many trees are under massive threat due to heat and drought. Pests are also spreading extremely quickly, so that the forests have to be cleared, but the subsequent reforestation takes decades. In terms of the CO2 balance, wood should also be as low as possible.

be used sparingly.

On the other hand, there is an extremely wide range of applications for wood fibre boards with a wide variety of requirements for technical properties, especially mechanical strength. Examples include the use of wood fibre boards in the construction and furniture industry, the funeral industry and

Automotive industry.

In order to save resources, Poo Chow suggested in his 1976 publication “The Use of Crop Residues for Boardmaking”, Environmental Conservation, Vol. 3, No.l, Spring 1976, pages 59-62, that typical waste products from US agriculture, such as peanut shells, be mixed with another waste product, including coffee grounds, glued together with a urea resin (UF glue) and pressed into a board. In a series of experiments, maple shavings from a furniture factory were also added and a chipboard was produced, which, however, was not suitable for use as a load-bearing element in buildings due to its low bending elasticity.

unsuitable for the construction industry.

WO-A2-2018/078391 discloses a process in which agricultural waste products, namely straw fibers, are pressed into panels. Another waste product, namely coffee grounds, is used as an additive. In addition, the teaching according to WO-A2-2018/078391 is based on the task of avoiding formaldehyde-containing adhesive resins.

and instead use pMDI (polymeric

detrimental.

The object of the present invention is to provide a wood fibre board which requires less of the natural resource wood and yet has satisfactory product properties, some of which even meet relevant standards, and in conventional

production facilities can be manufactured.

This task is solved with a wood fibre board with the

Features of claim 1.

This task is further solved with a method with

the features of claim 16.

Preferred embodiments of the invention are the subject of

Subclaims,.

The invention essentially consists in the fact that the wood fibre board contains, in addition to wood fibres as a solid component

also contains coffee grounds as a solid component.

Experiments (see below) have shown that a

°

Coffee grounds content of up to 80% by weight acceptable

strength values. The solid content of the

°

The plate according to the invention can accordingly contain up to 80 wt.% and

°

accordingly contain 20 wt.% or more of wood fibres.

In particular, the invention contains a proportion of coffee grounds

°

preferred, which is between 20 wt.% and 45 wt.%, because

standards of a pure wood fibre board.

According to the invention, coffee grounds are preferably used, which are a waste product or residue from coffee preparation or coffee production.

Coffee grounds resulting from the production of instant coffee typically have an average particle size of 125

by 2000.

Coffee grounds that accrue during the production of coffee beverages using a portafilter have an average

Particle size from 125 um to 2000 um.

Both types of coffee grounds can be used equally in the invention and have the advantage that they are available worldwide in very large quantities and are suitable for the present invention.

have essentially equally good product properties.

The use of urea-formaldehyde resin as a binder should of course be carried out in the smallest possible quantities, whereby according to the invention the amount of urea-formaldehyde resin

°

at least 8 wt.%, preferably in a range of ©

10 wt.% to 12 wt.%, based on 100 wt.% of the

Sum of wood fibers and coffee grounds.

This means that, for example, if the proportion is 80% by weight of coffee grounds and 20% by weight of wood fibers, these proportions together make up 100% of the solids content. If, for example, 10% by weight of urea-formaldehyde resin is added, this means that the 100% by weight of the finished board is made up of 90% by weight of solids (coffee grounds and wood fibers) and 10% by weight of

Urea-formaldehyde resin.

With such a proportion of binder, a very even distribution of the binder and good homogeneity of the glue distribution in the board and thus a very even strength structure can be achieved. Since the laboratory-scale tests have shown that a proportion of

10 wt.% to 12 wt.% of urea-formaldehyde resin too much

will lead to satisfactory results.

The density of the wood fiber board according to the invention is in the range from 500 kg/m? to 1,000 kg/m?, preferably in the range from 550 kg/m? to 950 kg/m*. Boards with a density in these ranges are boards used in many areas of application, in which the board according to the invention also achieves the good technical properties explained in detail below.

can.

Further features and advantages of the invention will become apparent from the following description of preferred embodiments of the invention, which do not limit the scope of protection,

Reference to the attached drawings. It shows:

Fig. 1 an exemplary process diagram,

Fig. 2 a diagram with the density of all manufactured and examined fibreboards,

Fig. 3 a diagram showing the bending strength of all manufactured and tested fibreboards,

Fig. 4 a diagram showing the elastic modulus of all manufactured and tested fibreboards,

Fig. 5 is a diagram showing the transverse tensile strength of all fibreboards produced and tested, and

Fig. 6 a diagram showing the increase in length, thickness and mass after 24 hours of water storage of all manufactured and

examined fiberboards.

In the following, the invention is explained in more detail using an exemplary and non-limiting working procedure for producing a wood fiber board according to the invention.

explained.

If the following figures are given in percentages, they are

always by weight%.

As already mentioned, coffee grounds are waste products or residues that arise during the production of coffee beverages using a portafilter.

Coffee grounds type is abbreviated as ST in the following.

Another waste product used in the invention is coffee grounds, which are produced during the production of instant powder for soluble coffee. This type of coffee grounds is abbreviated to INSTA below. The average particle size is usually between 125 µm and 2000 µm.

The proportions of portafilter coffee and instant coffee used for both coffee varieties ranged from 20% to 45% in 5% increments and additionally at 55%, 65% and 75% for the

Portafilter variant.

As is usual in the industrial production of fibreboard, a common urea-formaldehyde resin was mixed with

different binder proportions (10 % and 12 %)

used.

A urea-formaldehyde resin (UF) was deliberately chosen because it is very reactive and therefore binds well and quickly. Furthermore, the resin can be worked onto the wood fibres in conventional systems without the need for additional

technical measures must be taken.

The wood fibres used were MDF quality, as is also standard in industry. The fibres were preferably softwood fibres, for example spruce fibres or a mixture of spruce and

Jaw.

However, it is also possible to use recycled fibers from wood fiber materials. In the event that recycling causes damage to the fibers, such as shortening of the

fiber length, which for the respective application

mechanical properties.

The wood fibre boards with coffee grounds according to the invention were produced with a target density of 550 kg/m? and 650 kg/m? and with a coffee grounds content of between 20% and 45% (in 5% increments). The binder content was 10% and

12%.

In addition, plates containing instant coffee grounds of 20

%, 35 % and 45 %, a binder content of 10 % and a

density of 950 kg/m?

In another series of tests, portafilter coffee grounds proportions of 55%, 65% and 75% were used for

Portafilter coffee plates with 650 kg/m? are used.

Finally, for comparison, corresponding reference plates without coffee addition (each with the designation REFLAB and

further details).

After production, the pressed panels were conditioned for at least 7 days in a standard climate at 20 °C and 65 % relative humidity. The panels were then cut to size using a circular saw and tested for their bending strength, their bending elastic modulus (EN 310), their transverse tensile strength (EN 319) and thickness swelling after 24 hours of water storage (EN 317) and the data

evaluated and interpreted.

The manufacturing steps for implementing the general working instructions are described below, whereby only for the purpose of illustration - the

Process diagram according to Fig. 1.

In Fig. 1, a wood fibre board 1 with coffee grounds, the wood fibres 2, the coffee grounds 3, measuring devices 4 for measuring the moisture content using the drying method, measuring devices 5 for weighing the glued wood fibre

Coffee grounds mixture, storage container 6 for the dried

7734

hydraulic hot press 15 is shown.

The parameters described in the manufacturing process were independent of the desired density and were identical for ultra-light MDF, light MDF and MDF boards with higher densities. The manufacturing of the boards differed essentially only in the total board mass, which per

was weighed in a defined volume.

In a first step, the moisture content of both the wood fibers and the coffee grounds types (portafilter coffee grounds and instant coffee grounds) was determined using the drying method. A few grams of samples were taken from the respective materials, weighed and then the samples were stored at a drying temperature of 103 °C until the weight was constant. The moisture content was then determined based on the difference between the moist and the dried sample. All ratios in the board composition were

based on the dried mass or the dry solids content.

Based on the dried mass, the desired ratios between wood fibers and coffee grounds as well as the respective resin content were calculated and then related to the actual, moist mass (determined moisture content). Since material can be "lost" during the production process on a laboratory scale due to the gluing process,

A 10% safety surcharge was added to all components

(additional weight) is used for gluing.

The mixing of wood fibres and coffee grounds, as well as their gluing, took place in a gluing drum with a diameter of 100 cm, a depth of 45 cm and a rotation speed of 80 rpm. For this purpose,

the two solids are tipped unmixed into the drum. The

which depended on the amount of glue.

°

2% ammonium sulfate was added to the UF glue as a hardener. The glue was then applied using a pneumatic glue gun that was inserted centrally into the gluing drum. The feed pressure and the feed volume were selected so that a fine adhesive mist was formed in the gluing drum without large droplets forming, in order to achieve the most homogeneous possible glue distribution on the fibers. The glued fiber/coffee grounds mixture was then removed from the drum and the final

Mass (without safety margin) weighed.

The weighed glued fiber/coffee grounds material was spread by hand as homogeneously as possible into a 250 x 250 mm plate cake frame and pre-compacted in the frame using a hydraulic cold press from a fiber cake height of several centimeters to a fiber cake height of approximately 5 cm. This pre-compacting step in the frame is important because if the pre-compacting is insufficient, the fiber cake expands within the plate plane during hot pressing, so that the

Target density cannot be achieved.

After pre-compaction, the frame was removed and 9 mm steel spacers were positioned next to the fibre cake on the press plate, after which hot pressing was carried out. The hot pressing was carried out at 200 °C pressing surface temperature with a pressing factor of 10 sec/mm (90 seconds pressing time), whereby the press was operated up to the spacers with a maximum pressure

of 3 MPa had to be closed.

After completion of the pressing process, the plates were placed vertically to allow even cooling and then placed in the

Stored under standard conditions at 20 °C and 65 % relative humidity.

tested plate variants are listed.

Table 1: Overview of laboratory-scale

Fiberboard We ee Coffee grounds type | Bulk density a DESCRIPTION: 0% 100 % X 550 kg/m} 10 % REFLAB-550-UF10 20 % 80 % Portafilter 550 kg/m} 10 % ST20-550-UF10 25 % 75 % Portafilter 550 kg/m? 10 % ST25-550-UF10 30 % 70 % Portafilter 550 kg/m} 10 % ST30-550-UF10 35 % 65 % Portafilter 550 kg/m} 10 % ST35-550-UF10 40 % 60 % Portafilter 550 kg/m} 10 % ST40-550-UF10 45 % 55 % Portafilter 550 kg/m} 10 % ST45-550-UF10 0% 100 % X 650 kg/m} 10 % REFLAB-650-UF10 20 % 80 % Portafilter 650 kg/m} 10 % ST20-650-UF10 25 % 75 % Portafilter 650 kg/m} 10 % ST25-650-UF10 30% 70% Portafilter 650 kg/m} 10% ST30-650-UF10 35% 65% Portafilter 650 kg/m} 10% ST35-650-UF10 40% 60% Portafilter 650 kg/m} 10% ST40-650-UF10 45% 55% Portafilter 650 kg/m} 10% ST45-650-UF10 0% 100% X 650 kg/m} 10% REFLAB2-650-UF-10 55% 45% Portafilter 650 kg/m} 10% ST55-650-UF-10 65% 35% Portafilter 650 kg/m} 10% ST65-650-UF-10 75% 25% Portafilter 650 kg/m} 10% ST75-650-UF-10 0% 100% X 950 kg/m} 10% REFLAB-950-UF-10 20% 830% Instant 950 kg/m} 10% INSTA20-950-UF-10 35% 65% Instant 950 kg/m} 10% INSTA35-950-UF-10 45% 55% Instant 950 kg/m} 10% INSTA45-950-UF-10 0% 100% X 550 kg/m} 12% REFLAB-550-UF12 20% 830% Portafilter 550 kg/m? 12% ST20-550-UF12 25% 75% portafilter 550 kg/m? 12% ST25-550-UF12 30% 70% portafilter 550 kg/m} 12% ST30-550-UF12 35% 65% portafilter 550 kg/m} 12% ST35-550-UF12 40% 60% portafilter 550 kg/m? 12% ST40-550-UF12 45% 55% portafilter 550 kg/m? 12 % ST45-550-UF12 0% 100 % X 650 kg/m} 12 % REFLAB-650-UF12 20 % 830 % Portafilter 650 kg/m} 12 % ST20-650-UF12 25 % 75 % Portafilter 650 kg/m} 12 % ST25-650-UF12 30 % 70 % Portafilter 650 kg/m} 12 % ST30-650-UF12 35 % 65 % Portafilter 650 kg/m} 12 % ST35-650-UF12 40 % 60 % Portafilter 650 kg/m} 12 % ST40-650-UF12 45 % 55 % Portafilter 650 kg/m} 12 % ST45-650-UF12 20% 80% Instant 650 kg/m} 12% INSTA20-650-UF12 25% 75% Instant 650 kg/m} 12% INSTA25-650-UF12

30% 70% Instant 650 kg/m} 12% INSTA30-650-UF12

35% 65% Instant 650 kg/m} 12% INSTA35-650-UF12

40% 60% Instant 650 kg/m} 12% INSTA40-650-UF12

45 % 55 % Instant 650 kg/m} 12 % INSTA45-650-UF12 Total panels produced 126

For the determination of the transverse tensile strength and the water storage, samples of 50 x 50 mm were prepared using a circular saw, and for the bending tests, samples of 230 x 50 mm were prepared using a circular saw. Before the tests, the

The bulk densities of individual samples were determined. Bulk density

The density was determined after conditioning in standard climate (20 °C and 65 % relative humidity) on three

50 x 50 mm samples per plate.

The diagram in Fig. 2 shows the density of all investigated

Fiberboard.

As can be seen from Fig. 2, all desired density ranges were easily achieved. Very small density fluctuations can be observed in all three density groups, which indicates a homogeneous scattering and distribution of the fibers and particles. Thus, no significant connection can be determined between density and coffee grounds content or binder content. This means that the density of the board does not change significantly, even if the proportion of coffee grounds or binder content is varied. This effect is due, among other things, to the fact that in the first process step the moisture content is determined using the drying method for both the wood fibers and the types of coffee grounds (portafilter coffee grounds and instant coffee), and that the desired ratios between wood fibers and coffee grounds as well as the respective glue content are calculated on the basis of the drying mass and then added to the actual moist mass.

(determined moisture content).

Of course, the homogeneous production of the fibre cake

and its pre-compaction has an influence on the bulk density.

Bending strength and flexural modulus

The bending strength and the bending elastic modulus provide information about the influence of the wood fiber content used, since fibers generally have a positive effect on the bending properties of materials due to their geometry. Three bending tests were carried out on the panels in accordance with EN 310, and the bending strength and the bending elastic modulus were determined using the crossbar (Zwick and Roell ZzZ20 universal testing machine). A statistical mean value comparison was then carried out (PostHoc Scheffe, p=0.05).

For this purpose, the samples were positioned in a 3-point bending test setup, with the support distance being 20

times the plate thickness (approx. 180 mm support distance).

The loading speed was adjusted so that the

Breaking force was reached within 60 + 30 sec.

Fig. 3 shows a diagram with the bending strength according to EN 310 of all produced fibreboards.

As can be seen from Fig. 3, the influence of the bulk density is evident in the bending strength, and the coffee grounds content in the panels also becomes apparent in the strength values above a certain amount. Not surprisingly, the panels in the group with 550 kg/m? show a lower strength compared to the group with 650 kg/m? or

950 kg/m}. There are no statistically significant differences between the plates with coffee content and the reference plates without coffee (each with the designation REFLAB and further information).

significant differences.

In the case of the panels with 650 kg/m? with 10 % binder content, differences can be seen between individual variants, but not between the two pure MDF reference fibreboards, which is why a comparison between the screen carrier panels with 55 % or more

Portafilter coffee grounds content and those with 45% or less

Portafilter coffee grounds content is permissible. If we consider the

° °

Group of 20% to 45% portafilter coffee grounds content, no difference between the individual plate types within the group can be assumed. Only when the values from 55 $% onwards are taken into account can a certain trend with decreasing bending strength as the coffee grounds content increases can be assumed. The plates only show a noticeable difference from 55 $% coffee grounds content and above.

the reference plates.

It can therefore be stated that the bending strength at a density of 550 kg/m? or 650 kg/m? and a binder content of 10% or 12% does not change significantly by adding coffee grounds up to 45% and results in surprisingly good values. Depending on the intended use and the required bending strength, taking into account the object of the invention to reduce the use of wood for the production of wood fiber boards and to enable an effective further use of coffee grounds, a

°

A proportion of coffee grounds of up to 80% can be considered.

In the case of the instant coffee plates with a density of 950 kg/m2, the plates differ noticeably from the reference plates from as little as 20% coffee grounds content. However, higher bending strength values can be achieved here than with the plates with a lower density, and plates with a density of 950 kg/m2 are therefore within the scope of the invention.

also preferred.

It has been shown that the binder content in the variants investigated (10 % and 12 %) does not have a significant

influences the bending strength.

Fig. 4 shows a diagram with the elastic modulus according to EN

310 of all fiberboards produced can be seen.

A similar picture to that of the flexural strength can be seen in Fig. 4 for the elastic modulus. Here, too, a clear difference can be seen between the two bulk density groups, with tendencies between the coffee proportions

can only be seen in the 650 kg/m? plates. Here

Both coffee varieties show a tendency, but not a statistically significant decrease in the elastic modulus with increasing coffee grounds content. Here too, the conditions for the plates with a gross density of 950 kg/m? are almost identical to those for the bending strength. The only notable exception here are the values for instant coffee, which show lower values than the

Reference laboratory plate.

It can also be stated that the elastic modulus is determined at a density of 550 kg/m? or 650 kg/m? and a binder content of 10 % or 12 % by

Coffee grounds addition up to 45 % does not change significantly and

surprisingly good values.

Transverse tensile strength

The transverse tensile strength of board materials provides insight into the homogeneity of the glue distribution within the board and the fiber distribution (scattering) before pressing. Since the test is carried out in parallel with the fiber orientation of the board, positive factors for the mechanics of a board such as

For example, the fibre length is of lesser importance here.

For the investigations, three samples per plate were tested according to EN 319 and then a statistical comparison of the mean values (PostHoc Scheffe, p=0.05) was carried out. For the investigation, the 50 x 50 mm samples were glued to aluminum transverse tensile yokes using hot melt adhesive (Henkel Technomelt Supra 325 HT). The offset between the two yokes was 90° in order to avoid any torque during the tensile test and thus to ensure a

To avoid cracking.

Fig. 5 shows a diagram with the transverse tensile strength according to EN

319 of all fibreboards produced.

Fig. 5 shows the absolute values of the measured transverse tensile strength, whereby differences between the

both density ranges and the higher

bulk density has the highest transverse tensile strengths. In general, portafilter coffee shows a very high scatter of values, although it should be noted that no statistical difference can be determined between the two reference plate variants with 650 kg/m? and 10% binder. Even if individual plate variants show statistically significant differences to their plates with a similar coffee content, overall there is no significant difference to the reference plates. An example of this is the portafilter plates with 10% binder, where the plate with 45% coffee differs from the variant with 35%, but not from the variants with 40%, 30% or 20% coffee content. The situation is similar with the portafilter plates with 12% binder content. It is interesting to note that the scatter of the portafilter plates decreases with increasing coffee grounds content and the plates with 55%, 65%

°

and 75% portafilter portion differ from the values with 40% and 45% coffee portion, but not from the plates with 35 $ and 25%, and thus not in total from the total

Group.

With the instant coffee plates, there is a tendency for the strength to decrease with increasing coffee content, but here too, due to the scatter, one cannot speak of a statistically significant difference between the plates. Based on the results obtained, no difference can be seen.

between 10 % and 12 % binder content in the

Portafilter plates visible.

Since all plates were manufactured using the same means, the variation of the portafilter plates at 650 kg/m? bulk density can probably be attributed to the portafilter material. In comparison to instant coffee grounds, a higher degree of agglomeration was subjectively found in the portafilter grounds during processing during gluing in the gluing drum. This could have led to partially more varied coffee grounds proportions in the plates and thus also explain the variation. Even if values for individual variants are higher here,

appear, they are still in relation to the reference

within the scatter range and no significant difference can be assumed based on the available values. The values determined can therefore be interpreted in such a way that at 650 kg/m? for instant coffee with higher coffee contents of over 35% there was a reduction and for (the smaller sample of) portafilter plates there was no noticeable reduction in the transverse tensile strength. In general it should be noted that with varying mixing ratios of the plates the total volume of coffee grounds and wood fibers to be glued also varies greatly between the individual plate types. A plate with 20% coffee content, for example, has a much higher volume when glued than a mixture with 45% coffee grounds or higher. This means that the gluing drum is filled much more with low coffee grounds contents than with mixtures with high coffee grounds contents. This can significantly affect the distribution of the glue on the fibres and coffee grounds, which is why it cannot be ruled out that the gluing process used with higher coffee grounds content will result in better or more homogeneous gluing.

could be achieved.

Overall, it can be stated that wood fibre boards with a coffee grounds content of up to 80%, in particular from 20% to 45%, have surprisingly good values for both bending strength and bending elasticity modulus, as well as for transverse tensile strength, when bonded with a urea-formaldehyde resin, and this in a density range of 550 kg/m3 to 950 kg/m3.

This applies to both instant coffee grounds and

Portafilter coffee grounds.

Thickness swelling after 24 hours of water storage

For water storage, three samples per plate were placed in a water bath (water temperature approx. 20 °C) and

Metal sieve fixed below the water surface.

The lengths, thicknesses and mass increase of 50 x 50 mm samples were determined after 24 hours of water storage. For this purpose, the samples were only slightly

dabbed and measured.

Fig. 6 shows a representation of the length, thickness and

Mass increase after 24 h water storage according to EN 317

Fig. 6 again shows a difference between the two bulk density ranges. The most obvious difference is in the mass increase, with the panels with the lower binder content tending to increase in mass more and with higher coffee content, sometimes significantly higher mass increases can be seen compared to the reference. The 550 kg/m2 panels also show a significantly higher increase in thickness swelling than the 650 kg/m2 panels. The lowest values were shown by the panels with instant coffee and a bulk density of 950 kg/m2, with statistically significantly higher increases being seen with increasing coffee grounds content. The panels with 35% and 45% coffee grounds content show statistically significant increases in mass increase and with 45% coffee grounds content show statistically significant increases in thickness increase.

higher values than the reference plates without coffee grounds.

For the portafilter plates with a density of 650 kg/m}

°

and a binder content of 10%, statistically significant differences to the reference panels can only be identified in the mass increase of the panel variant with 75%. All other variants do not differ significantly from one another in terms of mass increase or thickness swelling, although a trend with increasing values as the coffee grounds content increases can be identified for the panels with coffee grounds content of >45 $. There are also no statistically significant differences between the

different coffee grounds proportions can be detected.

Interestingly, even with water storage, no °

Difference between the two binder proportions of 10 %

and 12%.

With regard to the different properties after water storage, it should be added that the fact that some of the tested panels tend to have poorer properties does not in any way indicate that their use is not advisable, because, as with mechanical strength, it depends on the intended use of the panels whether a particular composition of an inventive

Wood fiberboard is suitable or not.

Evaluation of the measurement results

All in the course of the general working instructions for

The findings obtained from the implementation of the invention refer to a wood fiber board made with coffee grounds in the laboratory. However, due to the good measurement results, an up-scaling to an industrial scale is realistic. This is particularly the case if the

Plate is used in dry areas.

Table 2: Requirements for general purpose panels for

Use in dry areas according to EN 622-5

TYPE: MDE Nominal thickness ranges [mm] Property | Peer "Unit | 1.8 [>2.5] >4 | >6 ] >9 ] >12 ] >19 | >30 experience up to | up to | up to | up to | up to | up to | >45 2.5 4 6 9 12 19 30 45 Thickness EN 317 % 45 35 30 17 15 12 10 8 6 Transverse tensile EN 319 N/mm? | 0.65 | 0.65 | 0.65 | 0.60 | 0.55 | 0.55 | 0.50 | 0.50 Bleger EN 310 N/mm? 23 23 23 23 22 20 18 17 15 Bending strength Elasticity EN 310 N/mm? — - | 2700 | 2700 | 2500 | 2200 | 2100 | 1900 modulus Type: Light: MDF Nominal thickness ranges [mm] - Test - Property procedure Unit >6 >9 >12 >19 >30 up to up to up to up to >45 9 12 19 30 45 Thickness swelling | x 317 % 20 16 14 12 11 11 24h Transverse tensile EN 319 N/mm? | 0.45 | 0.45 | 0.45 | 0.45 | 0.40 0.40 strength

Bending

1 N 2 2 2 1 1 14 14 Strength EN 310 /mm 0 0 8 5 Bending modulus EN 310 N/mm? 1700 | 1700 | 1600 | 1500 | 1400 1200 Ultralight: MDF. Nominal thickness ranges [mm] _ Test _ _ Property procedure Unit >9 >12 519 >30 to to to 30 to >45 12 19 45 Thickness swelling | N 317 % 18 14 13 12 12 24 h Transverse tensile strength EN 319 N/mm? |0.15|0.15| 0.15 | 0.13 0.13 Bending strength 2 1 1 strength EN 310 N/mm 7.7 6.9 6 5. 5. Bending elasticity EN 310 N/mm? 600 560 510 470 470 modulus

Table 2 lists the minimum requirements according to EN 622-5 for industrially manufactured MDF boards for the furniture sector. Experience has shown that laboratory-produced fibreboards are 50% to 66% below the strength values of comparable industrial fibreboards, which is why the reference board produced in the laboratory with a density of

550 kg/m? and 650 kg/m? without coffee content would not currently meet the requirements of EN 622-5. The panels with a density of 950 kg/m* achieve higher bending strength and bending elastic moduli than specified in EN 622-5, but remain below the transverse tensile strength

below the minimum requirements.

Basically, it can be said that when producing laboratory fiberboards, there are always compromises in terms of board properties compared to industrially produced boards. This is due to the gluing, the manual spreading and the time between glue application and hot pressing. However, the low density scatter suggests a homogeneous distribution and high-quality and well-glued boards for laboratory conditions. The influence of the density was significantly greater in relation to the glue content. The strength and the

Water storage was essentially only possible at the bulk densities

a consistently significant difference was observed. The mean values and standard deviations of all tested plates

are summarized in Table 3.

Table 3: Mean values (MW) including standard deviation (STDEV)

of all examined plate variants

RELAB-550-UF ST20-550-UF ST25-550-UF ST30-550-UF ST35-550-UF ST40-550-UF ST45-550-UF

REFLAB-950-UFINSTA20-950-UFINSTA35-950-UFINSTA45-950-UF-

RELAB-550-UF12 ST20-550-UF12 ST25-550-UF12 ST30-550-UF12 ST35-550-UF12 ST40-550-UF12 ST45-550-UF12

INSTA20-650-UF12 INSTA25-650-UF12 INSTA30-650-UF12 INSTA35-650-UF12 INSTA40-650-UF12 INSTA45-650-UF12

Based on the results of the tests carried out, it can be stated that although not all panels met the minimum requirements of EN 622-5,

However, at least in most cases with the variant

Portafilters with a density of 650 kg/m? and a binder content of 10% up to a coffee grounds content of 45% showed no statistically significant differences following a trend compared to the reference plates produced in the laboratory

without any coffee components.

If one assumes that plates with coffee grounds can be produced in the course of industrial production with higher mechanical parameters and that they have similar relationships to those in the present patent application, a greater drop in mechanical parameters or a greater increase in mass and thickness after 24 hours of water storage would only be expected if >45% of coffee grounds were added. If one compares the two coffee grounds variants, the slightly lower scatter of the instant coffee plates is noticeable.

on.

Summary findings:

In summary, it can be said that the properties of the board according to the invention, in particular its MDF quality, are influenced by the following material or process parameters

becomes:

- Particle size of coffee grounds: Smaller particles are better embedded between the fibers than larger particles.

- Fiber length: Longer wood fibers are more flexible than shorter wood fibers. This must be taken into account when using shorter wood fibers, such as those obtained through recycling.

- Drying method: The starting products wood fibers and coffee grounds are dried to a constant weight. This creates a free-flowing bulk material that can be easily stored and processed further. Furthermore, the proportions of wood fibers and coffee grounds as well as the resin content can be calculated precisely for the further process.

- Resin application: A homogeneous resin application is achieved when the resin is continuously applied to the preferably evenly

moving starting products. This makes it

°

It is also possible to reduce the resin content to $8. In industrial production of the plate according to the invention, resin application can be carried out using a blowline process.

- Pre-compaction: The homogeneous distribution of coffee grounds and wood fibers is significantly influenced after the resin application if a type of board blank is produced that has been pre-compacted by cold pressing,

- Target density: The target density of the plates is determined by a pressing diagram with the parameters pressure and temperature

reached.

Taking these material and process parameters into account, it is the routine work of a specialist in the field of wood fibre board production to up-scaling

for industrial scale.

Thus, the resource-saving wood fiber board with coffee grounds according to the invention can also be produced sustainably and successfully on an industrial scale. This means that not only large-scale technical parameters, but also requirements for environmental compatibility and climate neutrality are met. Since MDF boards are primarily made from spruce wood, this raw material can be saved, especially since spruce is particularly at risk as a result of climate change (“spruce dieback”). It must also be taken into account that waste disposal is a problem due to the ever-increasing consumption of coffee worldwide. This is because huge amounts of coffee grounds would have to be burned, for example, which

admittedly has a negative impact on the CO2 balance.

The resource-saving wood fibre board according to the invention can be provided in MDF and HDF quality, so that areas of application include the construction and furniture industry (including the provision of coffins) and the

automotive industry.

Claims (1)

Patent claims: Wood fibre board with a solid content of wood fibres bonded with a urea-formaldehyde resin, characterized in that the wood fibre board contains coffee grounds and that the solid content of coffee grounds ° is not more than 80% by weight. Wood fibre board according to claim 1, characterized in that the solid content of coffee grounds is between 20 wt.% and 45 wt.%. Wood fibre board according to claim 1 or 2, characterized in that the coffee grounds are a waste product which arises during the production of coffee beverages using a portafilter. Wood fibre board according to claim 3, characterized in that the coffee grounds have an average particle size between 125 um and 2000 um. Wood fibre board according to claim 1 or 2, characterized in that the coffee grounds are a waste product which is generated during the production of instant coffee. Wood fiber board according to claim 5, characterized in that the average particle size is between 125 µm and 2000 µm. Wood fibre board according to one of claims 1 to 6, characterized in that the wood fibres are softwood fibres and/or recycled wood fibres. Wood fibre board according to one of claims 1 to 7, characterized in that the amount of urea-formaldehyde ° resin is at least 8 wt.%, preferably in a ° ° Range of 10 wt.% to 12 wt.%, based on 100 ° % by weight of the sum of wood fibres and coffee grounds. Wood fibreboard according to one of claims 1 to 8, characterized in that its density is in the range of 500 kg/m? up to 1,000 kg/m*, preferably up to 950 kg/m}. 11. 12. 13. 14, 23 Wood fibre board according to claim 3, characterized in that they have a solids content of 20 wt.% to 45 wt.% ° of portafilter coffee grounds and a proportion of 10 wt.% to ° 12 wt.%, based on 100 wt.% of the sum of wood fibres and coffee grounds, of urea-formaldehyde resin, and that the bulk density of the wood fibre board is 500 kg/m? to 600 kg/m*, in particular 550 kg/m}. Wood fibre board according to claim 5, characterized in ° that they have a solids content of 20 wt.% to 45 wt.% ° of instant coffee grounds and a proportion of 10 wt.% to 12 ° % by weight, based on 100 % by weight of the sum of wood fibres and coffee grounds, of urea-formaldehyde resin, and the bulk density of the wood fibre board is 500 kg/m} to 600 kg/m*, in particular 550 kg/m?. Wood fibre board according to claim 3, characterized in ° that they have a solids content of 20 wt.% to 45 wt.% ° of portafilter coffee grounds and a proportion of 10 wt.% to 12 wt.%, based on 100 wt.% of the sum of wood fibres and coffee grounds, of urea-formaldehyde resin, and that the density of the wood fibre board is 600 kg/m? to 700 kg/m, in particular 650 kg/m}. Wood fibre board according to claim 5, characterized in ° that they have a solids content of 20 wt.% to 45 wt.% ° of instant coffee grounds and a proportion of 10 wt.% to 12 wt.%, based on 100 wt.% of the sum of wood fibres and coffee grounds, of urea-formaldehyde resin, and that the bulk density of the wood fibre board is 600 kg/m? to 700 kg/m, in particular 650 kg/m}. Wood fibre board according to claim 3, characterized in ° that they have a solids content of 20 wt.% to 45 wt.% ° of portafilter coffee grounds and a proportion of 10 wt.% to 12 wt.%, based on 100 wt.% of the sum of wood fibres and coffee grounds, of urea-formaldehyde resin, and that the bulk density of the wood fibre board has a value of 900 kg/m3 to 1,000 kg/m3, in particular 950 kg/m3, having. 24 / 34 16. 17. 18. 24 Wood fibre board according to claim 5, characterized in that it has a solids content of 20 wt.% to 45 wt.% of instant coffee grounds and a content of 10 wt.% to 12 wt.%, based on 100 wt.% of the sum of wood fibres and coffee grounds, of urea-formaldehyde resin, and the bulk density of the wood fibre board has a value of 900 kg/m} to 1,000 kg/m?, in particular 950 kg/m}. Method for producing a plate according to one of the Claims 1 to 15 comprising the following steps: a) Drying of the raw materials from wood fibres and Coffee grounds until constant weight, b) Calculate the desired ratios between wood fibres and coffee grounds as well as the proportion of Urea-formaldehyde resin, c) Continuous application of urea-formaldehyde Resin on the dried wood fiber-coffee grounds mixture d) homogeneous spreading to produce a plate blank e) Pre-compaction of the plate blank by cold pressing and f) Manufacturing the wood fibre board with coffee grounds by Pressing at increased pressure and temperature. Process according to claim 16, characterized in that the drying of the starting products from wood fibers and Coffee grounds are dried using the kiln method. Method according to claim 16 or 17, characterized in that the urea-formaldehyde resin is continuously applied as a fine mist onto the dried wood fiber coffee grounds mixture is applied.