Composition of fibrous material

Abstract

The present invention relates to a fibrous material composition having a predefined fraction of fresh fibres and/or waste paper with a further fraction of sweet grass, sedge, seagrass and/or algae fibres and adjuvants and water, where the weight fraction of sweet grass, sedge, seagrass and/or algae fibres is greater than 1 and less than 100 wt. % of the total material mass, in each case calculated as oven-dry material fraction. The invention further relates to a method for producing the fibrous material mixture and its use for producing fibrous-material-containing products.

Claims

1. A method for producing a fibrous material composition comprising the steps: a) harvesting at least one of sweet grass, sedge, seagrass and algae; b) cutting the at least one of sweet grass, sedge, seagrass and algae to a predefined length between 10 mm and 1 mm; c) after cutting, fibrillating grinding of the at least one of sweet grass, sedge, seagrass, and algae; d) after fibrillating grinding, at least partially pelleting the at least one of sweet grass, sedge, seagrass and algae individually or in combination; e) after at least partially pelleting, suspending the at least one of sweet grass, sedge, seagrass and algae in water; and f) adding predefined fractions of at least one of fresh fibres, waste paper and adjuvants to the suspension.

2. The method according to claim 1 wherein at least one of the sweet grass, sedge, seagrass and algae are at least partially dried individually or in combination.

3. The method according to claim 1 wherein the at least one of sweet grass, sedge, seagrass and algae is ground at least one of before and after the addition of fresh fibres and/or waste paper.

4. The method according to claim 1 further including at least one of bleaching, sorting, dispersing and homogenizing at least one component of the fibrous material composition.

5. The method according to claim 1 wherein the fibrous material composition is adjusted to a predefined material consistency before the further processing.

6. The method according to claim 1 wherein before cutting to a predefined length, the at least one of sweet grass, sedge, seagrass and algae is cleaned mechanically.

7. The method of claim 1 further including using the fibrous material composition to produce at least one of paper, board, card, print substrates, isolating or insulating material, fibre boards, filler material, and combinations thereof.

8. The method of claim 1 wherein at least one of the seagrasses and the algae are harvested and are selected from a group which includes seagrasses zostera and species zostera angustifolia hornem.rchb., zostera asiatica miki, zostera caespitosa miki, zostera capensis setch., zostera capricorni asch., zostera caulescens miki, zostera japonica asch. & graebn., common seagrass zostera marina l., zostera mucronata hartog, zostera muelleri lrmisch ex asch., dwarf eel-grass zostera noltii hornem., zostera novazelandica setch., zostera tasmanica m.martens ex asch., heterozostera and phyllospadix, Neptune grasses posidonia from the family posidoniaceae, cymodocea, halodule, syringodium and thalassodendron from the family cymodoceaceae and enhalus acoroides, halophila and thalassia from the family of the tape grass family hydrocharitaceae , subfamily halophiloideae, or glaucophyta, haptophyta, brown algae phaeophyta , red algae Rhodophyta , green algae chlorophyta , heterokontophyta, excavata, stramenopile, haptophyta, chlorarachniophyta and heterokontophyta, alveolata, biliphyta and combinations thereof.

9. The method according to claim 1, wherein at least one of the fresh fibres and the waste paper are selected from a group containing long fibre pulp, short fibre pulp, chemically delignified fibrous materials, sulphate pulp, sulphite pulp, pulps from the soda process or organocell process, cotton pulp, mechanical pulp, thermo mechanical pulp, groundwood pulp, chemo thermo mechanical pulp, waste paper, bleached cellulose, and combinations thereof.

10. The method according to claim 1 wherein at least one of the sweet grass and sedge fibres are selected from a group of grasses which includes spike grasses, meadow grasses and spiked meadow grasses as well as sedges of the genera poaceae, and cyperaceae, zea mays - maize, meadow grass, sport and utility grass, sedges of the species carex, and combinations thereof.

11. The method according to claim 1 wherein adding the predefined fractions includes mechanically preparing grass fibers.

12. The method according to claim 1 wherein a fibre component of the fibrous material composition is chemically brightened.

13. The method according to claim 1 wherein a fibre component of the fibrous material composition is bleached.

14. The method according to claim 1 wherein the adjuvants are selected from a group which includes retention agents, dewatering adjuvants, retention agent dual systems or microparticle systems, wet and dry strength agents, fillers, pigments, and combinations thereof.

15. The method according to claim 1 wherein the weight fraction of grass fibres is greater than 10%.

16. The method according to claim 1 wherein the at least one of sweet grass, sedge, seagrass and algae is ground in a fibrillating manner before or after the addition of at least one of fresh fibres and waste paper.

17. A method for producing a fibrous material composition comprising the steps: a) harvesting at least one of sweet grass, sedge, seagrass, and algae; b) cleaning the at least one of sweet grass, sedge, seagrass, and algae, individually or in combination, by at least one of (i) mechanically cleaning and (ii) washing with at least one of air and water; c) cutting the at least one of sweet grass, sedge, seagrass, and algae to a predefined length between between 10 mm and 1 mm; d) after cutting, fibrillating grinding of the at least one of sweet grass, sedge, seagrass, and algae; e) after fibrillating grinding, pelleting the at least one of sweet grass, sedge, seagrass, and algae, individually or in combination; f) after pelleting, suspending the at least one of sweet grass, sedge, seagrass, and algae in water; and g) adding predefined fractions of at least one of fresh fibres, waste paper, and adjuvants to the suspension.

18. The method of claim 17 further including at least partially drying the at least one of sweet grass, sedge, seagrass, and algae, individually or in combination.

19. The method according to claim 17 further including using the fibrous material composition to produce at least one of paper, board, card, print substrates, isolating material, insulating material, fibre boards, filler material, and combinations thereof.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic diagram for the variables in the production of grass-containing products. FIG. 2 shows the fibre length distribution in fibre length classes of the material systems used in this experiment and compared to other common fibrous material systems. FIGS. 3-6 show the property values of corresponding magazine papers which have been manufactured from the aforesaid fibrous material system. FIGS. 7-9 show the property values of corresponding corrugated board liners which have been manufactured from the aforesaid fibrous material system.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

(2) In the figures:

(3) FIG. 1 is a schematic diagram for the variables in the production of grass-containing products. Here it is shown how the fibrous material composition in its possible variations among other things influences the opacity and therefore also the classification into product groups, e.g. cardboard packagingvery opaquelarge grass fraction. In the example shown here, the fibrous material composition can consist of pulp, grass fibres (grass), waste paper and material residues which are added to the fibrous material composition in different fractions. It is further shown that both the time, the amount of water and also the water temperature have a direct influence on the properties, in particular the opacity of the fibrous material composition when processing the fibrous material. The possibly substantial variation takes place during grinding where the processing time during the grinding increases with increasing sweet grass and/or sedge fraction. Schematically different groups are listed among the range of products which are determined by the respective requirement profile of the particular application and further processing.

(4) For example, conventional meadows, lawns (sports turf, private households, cities and communities)hereinafter only called grasscan be used to produce grass paper. In this case a plurality of grasses of the order sweet grass like (Poales) or sedge-like (Cyperaceae) can be used where for the subfamily Cyperoidorae such as, for example, coco grasses and papyrus, certain restrictions can apply. For these grasses an additional peeling must be performed during further processing. This would possibly be (energy) expensive.

(5) When using ordinary meadow grass, the leaves present on the meadows can be co-processed without any problems. For better further processing, storage and more efficient transport, the grass can be dried (hay), freed from impurities and comminuted. A compression such as pelleting for example can also be useful here. The grass is then added without additional processing to a material suspension in the mixing ratio of, for example, 10% or placed in water. The further additives can be pulps of fresh fibres or also secondary fibres such as, for example, lumps or waste paper. These additives can also be combined.

(6) The ratio of the fibrous material components can be increased as far as 99% grass fibre fraction. The higher the grass fraction, the lower is the energy expenditure in the production of the raw material compared with conventional paper. Among other things, due to the natural colour of the grass, the material achieves a high opacity. Due to the high opacity the user of the paper can use lighter grammages without allowing translucence. In order to ensure a wide field of application, colour can be added to the material as desired, e.g. by painting, the mass or by gluing. A white fraction in line with market requirements can thus be obtained. By using the calender the surface can be additionally smoothed as desired.

EXPERIMENT 1

(7) In this series of tests dry hay having a dry content between 75 and 85% was used. This was coarsely cleaned so that it was freed from impurities such as, for example, soil. It was then shortened to a third of the length (about 20 cm) and then washed out with warm water at about 15 degrees and wrung out in a filter. This procedure was repeated three times and a quantity of green coloration was washed out in each case. The correspondingly cleaned hay was added to a hollander still wet. Also added were fresh fibre pulp, waste paper (120 g/m.sup.2 natural paper with 1.9 times volume) and an adjuvant. In a second batch filler was additionally added in order to see what influence this has on the surface and the whiteness. After suspending for twenty two minutes in the hollander, the material preparation was completed and test sheets were produced. A printing test was performed with these sheets in order to check whether the possibly lacking whiteness can be improved, for example, by means of offset printing in white. This was also successful.

EXPERIMENT 2

(8) Dry hay from meadow grass was used in this series of tests. This was cleaned with air and thereby freed from impurities such as, for example, soil and dust and then reduced by means of a cutting unit to about one tenth of its length (about 6 cm). This shortened hay was added still dry to a hollander. Also added were fresh fibre pulp, waste paper and two different adjuvants in order, inter alia, to obtain a better surface. After suspension for about 30 minutes, the material preparation was completed. Approximately 70?100 cm sheets were produced by means of a round screen. These sheets were each transported on a felt above the drying cylinder and dried to about 35% residual moisture. In this test the paper thus produced had a grammage of about 200 g/m.sup.2 or about 110 g/m.sup.2. The volume was about 1.3 g/cm.sup.3. The paper thus produced shows different smoothness values on the top and underside where the screen side was smoother than the top. For this mechanically produced material a printing test was performed on a four-colour offset printing machine. A four-colour motif was tested here, once with previous application of offset printing white and once without. Both variants were absolutely successful.

EXPERIMENT 3

(9) In order to obtain a uniformly good smoothing, another test was performed. The paper from Experiment 2 was calendered with a residual moisture of about 40%, where the calender only works with the pressure of the cylinder's own weight. After this treatment the paper only has a volume of about 1.1 g/cm.sup.3. Paper having a weight of about 90 g/m.sup.2 and 120 g/m.sup.2 was produced during this series of tests. In order to check further processing variants, printing tests were successfully completed by means of a digital printer (OKI C 3200), an HP laser printer and a Brother inkjet printer and a punch and groove test by means of a Planotigel.

(10) The property characteristics of the papers from Experiments 2 and 3 are compared in FIGS. 10 and 11, which are hereinafter referred to respectively as Tables 1 and 2. Here the values relate to Sample 1 from Experiment 2 and Sample 2 from Experiment 3. In addition to the absolute values, Table 1 also gives the variations of the property characteristics where, as predicted, the thickness and the air permeability of the paper decrease due to the calendering and apart from the breaking force transverse, all the other values even tend to increase significantly in relation to the elongation.

(11) Table 2 shows the optical measured values of the two papers studied, where in addition to the distinct coloration, the very high opacity value of nearly 100% can be identified.

(12) The measured values were determined under normal conditions of 23? C. and 50% air humidity as follows: Air permeability according to Bendtsen: DIN-53108 (paper testing), measuring device: Gockel & Co. Model 6, test area: 31.5 mm with a measuring head weight of 267 g, measured value: ml of air per minute, measurement setting: excess pressure of 1.5 kPa (Manostat 150 mm); Brecht-Imset tear strength: DIN 53115, measuring device: Karl Frank, measured value: tear strength in mJ/N; Breaking load and elongation: ISO 527-1, 100 mm clamping length at 10 mm/min rate of elongation, measuring device: Zwick/Roell ZMART.PRO measured value: breaking load in N and elongation in % (relative to 100 mm), modulus of elasticity in the reversible range [N/mm.sup.2]; weight per unit area [g/m2] according to ISO 536, measured value: weight of a DIN-A4 sheet determined, determine area of a DIN A4 sheet. thickness in ?m according to ISO 534, measuring device: Lehmann LDAL-03, measured value: thickness in ?m

EXPERIMENT 4

(13) In another experiment the applicability of the fibrous material system for use in magazine paper and corrugated paper was investigated. The fundamental feasibility of using grass in the said qualities was demonstrated by means of these experiments on a paper machine. For further processing and refinement experiments three rolls having different grammages each of about 100 m were fabricated for each paper quality.

(14) Fibrous material used, magazine paper: 14% long fibre (spruce/pine)/Stendal ECF (Mercer), 33% short fibre (eucaluptus)/Cenibra, 3% CTMP (spruce/pine)/Waggeryd CTMP, 50% grass. The grass here is Southern German meadow grass that is conventionally cut for fodder use and was dried in air to about 8% residual moisture.

(15) Additive (relative to fibrous material): 1% starch/Cargill 35844, 0.8% AKD/Akzo Nobel EKA DR 28 HF (0.5% in Experiments 6-10), 0.025% PAM/BASF-Percol 540.

(16) Preparation of material: the defibration was carried out at a material consistency of 5%, a pulper rotational speed of 990 rpm over a time of 15 minutes. The grinding was carried out at a material consistency of 4%, a cutting angle of 60? , an edge load of 0.7 Ws/m and a grinding energy of 150 kWh/t. The dewatering resistance achieved after the grinding was an SR value of 32? .

(17) Fibrous material used: corrugated paper comprising about 50% AP grade 1.02/50% AP Grade 1.04, 50% grass. The grass used here is also Southern German meadow grass that is conventionally cut for fodder use and was dried in air to about 8% residual moisture.

(18) Additives (relative to fibrous material): 1% starch/Cargill 35844, 0.025% PAM/BASF-Percol 540.

(19) Preparation of material: the defibration was carried out at a material consistency of 5%, a pulper rotational speed of 990 rpm over a time of 15 minutes.

(20) In addition, the grass used in the aforesaid material composition was prepared as follows:

(21) The grass was defibred at a material consistency of 10%, a pulper rotational speed of 990 rpm over a time of 20 minutes. This was followed by deflaking at a rotational speed of 2200 rpm over a time of 5 minutes. The grass was ground at a material consistency of 8%, a cutting angle of 60? , an edge load of 0.7 Ws/m and grinding energy of 25 kWh/t. After this the grass fibrous material had a dewatering resistance measured as SR value of 52? .

(22) FIG. 2 shows the fibre length distribution in fibre length classes of the material systems used in this experiment and compared to other common fibrous material systems. Here the fibre length classeslength weighted are plotted on the x axis and the percentage fraction in the fibre length class is plotted on the y axis. Curve 1 shows the fibre length distribution of straw after defibring, curve 2 shows fibre length distribution of straw after 5 min, curve 3 shows short fibre pulp of eucalyptus, curve 4 shows grass with a dewatering resistance of 52? SR and curve 5 shows grass with a dewatering resistance of 49? SR.

(23) Here it is shown that the two grass fibrous materials used 4 and 5 have a more homogeneous fibre length distribution compared to other fibrous material systems since the main emphasis in the length classes 0.2-0.5 mm or 0.5-1.2 mm are not so strongly defined.

(24) Paper rolls or paper sheets having various grammages between 40 g/m.sup.2 and 80 g/m.sup.2 for the magazine paper and between 90 g/m.sup.2 and 250 g/m.sup.2 for the corrugated board line were manufactured under comparable conditions from the corresponding material systems.

(25) FIGS. 3 to 6 show the property values of corresponding magazine papers which have been manufactured from the aforesaid fibrous material system. FIG. 3 shows the evolution of the specific volume in cm.sup.3/g (y axis) as a function of the area-related mass in g/m.sup.2 (x axis) for the cellulose/grass fibrous material system 31 and a pure cellulose fibre system 32. FIG. 4 shows the longitudinal 41 and transverse 42 breaking elongation in % (y axis) as a function of the area-related mass in g/m.sup.2 (x axis). FIG. 5 shows the longitudinal 51 and transverse 52 tensile strength index (y axis) as a function of the area-related mass in g/m.sup.2 (x axis) and FIG. 6 shows the longitudinal 41 and transverse 42 energy absorption capacity in J/g (y axis) as a function of the area-related mass in g/m.sup.2 (x axis).

(26) FIGS. 7 to 9 show the property values of corresponding corrugated board liners which have been manufactured from the aforesaid fibrous material system. FIG. 7 shows the evolution of the specific volume in cm.sup.3/g (y axis) as a function of the area-related mass in g/m.sup.2 (x axis) for a liner/grass fibrous material system 71 and a pure liner fibrous material system 72. FIG. 8 shows the (Mullen) bursting index in kPa (y axis) as a function of the area-related mass in g/m.sup.2 (x axis) and FIG. 9 shows the longitudinal 91 and transverse 92 compression strength (y axis) as a function of the area-related mass in g/m.sup.2 (x axis).

(27) The results of the fibre length investigation and the fibre length distribution show a similarity with fibrous material such as, for example, fibrous material systems comprising straw. The fibrous material has a relatively large fibre diameter and a high fibre wall thickness. In particular with low weight per unit area, this has the effect of increasing the volume of the paper. The tensile strength for magazine paper is approximately at the level of wood-free unpainted paper comprising 100% short fibre cellulose with about 20% filler. The measured strengths for the liner are also at a good basic level where the higher volume has an advantageous effect on the stiffness properties.