CS216252B1 - Method of treating the bamboo - Google Patents

Description

The invention relates to the refinement of bamboo with polymerizable substances.

Currently, bamboo is used without refining with polymerizable substances such as e.g. for the tongues of the blowing machines of the blowing musical instruments, in the furniture industry and for the production of sports equipment. For bamboo products p, prolonged contact with high humidity or water, the properties change. The products are partially wetted and deformed.

Disadvantages of the prior art are largely eliminated by the process of bamboo refinement according to the invention, by vacuum-pressure impregnation followed by in situ curing of the refining composition by irradiation with high energy radiation by absorbing a dose of 2.5 to 25 kJ / kg with subsequent heating at 40-80 ° C for 1 to 4 hours or by curing by adding 0.5 to 3 wt. polymerization initiators such as bezoyl peroxide and azoHbis-isobitironitrile into the quenching mixture followed by heating at 40 to 100 ° C for 3 to 8 hours, characterized in that the quenching mixture is based on a monomer-alcohol system dark phase diagram Water, wherein the monomer or mixture of monomer with oligomers is from the group of substances acrylates, vinyl monomers, polyesters, polyglycols, alcohols such as methanol, ethanol.

By treating the bamboo with a refining composition, the dimensional stability is increased and the mechanical properties such as flexural strength and toughness of the treated bamboo are also improved. Products or parts of refined bamboo products have a longer service life and improved quality. The method of the invention allows the bamboo to crosslink to the desired polymer content in the bamboo. By modifying the treatment conditions, the proportion of polymer in the bamboo varies between 5 and 45% by weight. Example 1.

The natural bamboo stored in the pressure vessel was evacuated for 20 min. at 20 kPa. A refining mixture of 53% by weight is then impregnated in a bamboo pressure vessel. % polyester, 35 wt. % methyl methacrylate and 12 wt. of methanol and pressure is at 0.5 MPa for 1 hour. After discharge of the refining mixture, the pressure is raised to 0.5 MPa and a bamboo pressure vessel is placed in the gamma radiation source. The enhancement mixture in the bambus is cured by gamma irradiation by absorbing a dose of 10 kJ / lkg. The bamboo thus obtained has a polymer content of 5% by weight. Properties of modified bamboo: Coefficient of dimensional stabilization after 1 hour. soaks in water: 32%, after 48 hours soaking: 16%, after 72 hours soaking: 16%. Flexural strength: 110% (original bamboo 100%), toughness: 120% (original bamboo 100%).

Example 2.

The natural bamboo stored in the pressure vessel was evacuated for 20 min. at 20 kPa. A refining composition composed of a ternary phase diagram of the system: methyl methacrylate, methanol, water of 86.8% by weight is then impregnated into a bamboo pressure vessel. % methyl methacrylate, 9.6 wt. methanol and

3.6 wt. water, pressurized to 0.5 MPa for 2 hours. After draining the quencher, the pressure is again increased to 0.5 MPa and the pressure vessel is placed in the gamma radiation source by absorbing a dose of 15 kJ / kg followed by heating to 60 ° C for 3 hours. The bamboo thus treated has a polymer content of 32% by weight. Properties of modified bamboo: Coefficient of dimensional stabilization after 1 hour. soaked in water: 43%, after 48 hours: 36%, after 72 hours soaking: 36%. Flexural strength: 142% (original bamboo 100%), toughness: 113% (original bamboo 100%).

Example 3.

The natural bamboo stored in the pressure vessel was evacuated for 20 min. at 20 kPa. Thereafter, a refining mixture composed according to a ternary phase diagram of the methyl methacrylate, methanol, water 86.8 wt. % methyl methacrylate, 9.6 wt. methanol and

3.6 wt. water and pressurized to 0.5 MPa for 4 hours. The further procedure is identical to Example 1. The ibambusa enrichment mixture is cured by gamma irradiation by absorbing a dose of 25 kJ / kg. The bamboo thus treated has a polymer content of 45% by weight. Properties of modified bamboo: Coefficient of dimensional stabilization after 1 hour. soaks in water: 51%, after 48 hours soaking: 42%, 72 hours soaking: 42%. Flexural strength: 151% (Floating bamboo 100%), toughness: 105% (Floating bamboo 100%).

The refined bamboo according to the invention finds application where increased dimensional stability of products such as e.g. in the manufacture of reeds for the blowing machines of musical instruments, in the furniture industry and in other areas of industry.

Claims (1)

Method of bamboo refining by vacuum-pressure impregnation followed by in situ curing of the refining composition by irradiation with high-energy radiation by absorbing a dose of 2.5 to 25 kJ / kg with optional subsequent heating to 40 to 80 ° C for 1 to 4 hours. or by curing by adding 0.5 to 3 wt. polymerization initiators such as bezoyl peroxide and azo-bis-isobutironitrile into the quenching mixture followed by heating to 40 to 100 ° C for 3 to 8 hours, characterized in that the quenching mixture is a mixture based on a well-known phase diagram of the monomer system. alcohol — water, wherein the monomer or monomer mixture with the oligomers is selected from the group consisting of acrylates, vinyl monomers, polyesters, polyglycols, alcohols such as methanol, ethanol.