DD271078A1 - PROCESS FOR ENZYMATIC TREATMENT OF WOOD - Google Patents

Abstract

The invention relates to a process for the enzymatic treatment of wood prior to the pulping process. The object of the invention is achieved by wood chips with pure cultures of the brown fungal fungus Fomitopsis pinicola (Sw) Karst. be fermented. The enzymatic pretreatment of the wood saves 37% of the energy required for fiberization. In addition, the low shear forces cause gentle treatment of the wood fibers (less fiber shortening, more fibrillations). As a result, higher quality fiberboard can be produced with reduced binder addition.

Description

Object of the invention The aim of the invention is to find an economically favorable Verfanren for the defibration of wood. Explanation of the essence of the invention The object of the invention is to provide a fungus for the enzymatic structure-loosening pre-treatment of the wood as a precursor of Fibers find that does not or only slightly degrades the lignin. According to the invention the object is achieved in that wood chips with pure cultures of the brown rot fungus Fomitopsis

Pinicola (Sw) karst, inoculated and fermented in a solid reactor for up to 7 days, taking on a homogeneous

Mixing is to be respected. The enzymatic pretreatment of the wood saves 37% of the energy required for fiberization. also

The lower shearing forces cause a gentle treatment of the wood fibers (less fiber shortening, higher quality

Fiberboard with simultaneously reduced binder usage through improved fibrillation). embodiment Spruce wood chips are inoculated with mycelium of the brown rot fungus Fomitopsis pinieol (Sw) karst, and then at a Temperature of 25 ⁰ C ± 1 K with a relative humidity of 65 ± 5% 7 days to a mass loss of 4% under sterile conditions Conditions fermented in the dark. It is important to ensure a homogeneous mixing. The further processing of the wood chips thus treated is carried out by known Zerfaserungsverfahren. Table 1 below shows, on the basis of the shear strength data, that the enzymatically treated woodchips undergo an approx Vs require less Zerfaserungsaufwand than the untreated wood chips. The improvement in fiber fiber bonding capacity, expressed by the longitudinal tensile strengths, enables one Binder savings of about 35% (Table 2).

Table 1: Shredding effort (shear strength) in spruce wood chips

Pretreatment Shear strength

absolute (MPa) relative (%)

1.1. without pretreatment 10.8 100

1.2; enzymatic pre-treatment 6.8 63

with brown rot fungus

Fomitopsis pinicola (Sw)

Karst.

Note: Target grade 19 ⁰ SR

Table 2: Binding capacity of hardboard made from the pulps according to table

Pretreatment longitudinal tensile strength

Binder addition absolute (MPa) relative (%)

2.1. OhneVorbehandiung 12.9 100 without additional binder 2.2. enzymatically pretreated 17.4 135 without additional binder 2.3. ohneVorbehandiung 22.0 170 mitZusatzbindemittel (2.5% phenolic resin)

Remarks: Plate production by wet process 190 "C Preßiemperatur 4 MPa pressing pressure 8,5 minutes press time 850 kg / m ³ Plattenrohdichte

Claims (2)

1. A process for the enzymatic treatment of wood chips in preparation for their defibration, characterized d idurch that pure cultures of the brown rot fungus Fomitopsis pinicola (Sw) karst, be used for enzymatic treatment. 2. The method according to claim 1, characterized in that the wood chips are inoculated with the brown rot fungus F. pinicola and fermented in a solid reactor for about 7 days. Field of application of the invention The invention relates to a process for enzymatic wood treatment prior to the defibration process. Characterization of the known prior art The defibration of wood is one of the most energy intensive processes in the field of fiber board production (up to 45% of the total) Total expenditure). It is already known, through the use of wood-destroying fungi (Basidiomycetes) on the enzymatic way the To loosen fiber composite and thereby energy during mechanical defibration of wood chips in the defibrators save. So z. For example, in the myko-wood method, the structure of the wood is loosened by a few weeks of enzymatic treatment of the wood with white rot fungi (Luthardt 1962). Disadvantages of this process are the long fermentation times and the inhomogeneous structure loosening of the wood. It is also known that white rot fungi have the property of degrading the lignin. This effect is for example when Biopulping-Verfahnn used for pulp production (Erikson 1982). However, a high lignin degradation is undesirable for the wood-based material production, since then the binder use considerably would rise.