EP1809825B1 - A method for improving wood sound-absorbance and a sound-absorbing wood thereby - Google Patents

A method for improving wood sound-absorbance and a sound-absorbing wood thereby Download PDF

Info

Publication number
EP1809825B1
EP1809825B1 EP05856497A EP05856497A EP1809825B1 EP 1809825 B1 EP1809825 B1 EP 1809825B1 EP 05856497 A EP05856497 A EP 05856497A EP 05856497 A EP05856497 A EP 05856497A EP 1809825 B1 EP1809825 B1 EP 1809825B1
Authority
EP
European Patent Office
Prior art keywords
wood
sound
absorbing
disc
absorbance
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
EP05856497A
Other languages
German (de)
English (en)
French (fr)
Other versions
EP1809825A4 (en
EP1809825A1 (en
Inventor
Chun-Won Kang
Chae Eul Kwak
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
ECOWELL Co Ltd
KANG, CHUN-WON
Original Assignee
ECOWELL CO Ltd
Kang Chun-Won
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by ECOWELL CO Ltd, Kang Chun-Won filed Critical ECOWELL CO Ltd
Publication of EP1809825A1 publication Critical patent/EP1809825A1/en
Publication of EP1809825A4 publication Critical patent/EP1809825A4/en
Application granted granted Critical
Publication of EP1809825B1 publication Critical patent/EP1809825B1/en
Expired - Fee Related legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/162—Selection of materials
    • E—FIXED CONSTRUCTIONS
    • E04—BUILDING
    • E04B—GENERAL BUILDING CONSTRUCTIONS; WALLS, e.g. PARTITIONS; ROOFS; FLOORS; CEILINGS; INSULATION OR OTHER PROTECTION OF BUILDINGS
    • E04B1/00—Constructions in general; Structures which are not restricted either to walls, e.g. partitions, or floors or ceilings or roofs
    • E04B1/62—Insulation or other protection; Elements or use of specified material therefor
    • E04B1/74—Heat, sound or noise insulation, absorption, or reflection; Other building methods affording favourable thermal or acoustical conditions, e.g. accumulating of heat within walls
    • E04B1/82—Heat, sound or noise insulation, absorption, or reflection; Other building methods affording favourable thermal or acoustical conditions, e.g. accumulating of heat within walls specifically with respect to sound only
    • E04B1/84—Sound-absorbing elements
    • E04B1/86—Sound-absorbing elements slab-shaped
    • E—FIXED CONSTRUCTIONS
    • E04—BUILDING
    • E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
    • E04C2/00—Building elements of relatively thin form for the construction of parts of buildings, e.g. sheet materials, slabs, or panels
    • E04C2/02—Building elements of relatively thin form for the construction of parts of buildings, e.g. sheet materials, slabs, or panels characterised by specified materials
    • E04C2/10—Building elements of relatively thin form for the construction of parts of buildings, e.g. sheet materials, slabs, or panels characterised by specified materials of wood, fibres, chips, vegetable stems, or the like; of plastics; of foamed products
    • E04C2/12—Building elements of relatively thin form for the construction of parts of buildings, e.g. sheet materials, slabs, or panels characterised by specified materials of wood, fibres, chips, vegetable stems, or the like; of plastics; of foamed products of solid wood
    • E—FIXED CONSTRUCTIONS
    • E04—BUILDING
    • E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
    • E04C2/00—Building elements of relatively thin form for the construction of parts of buildings, e.g. sheet materials, slabs, or panels
    • E04C2/44—Building elements of relatively thin form for the construction of parts of buildings, e.g. sheet materials, slabs, or panels characterised by the purpose
    • E—FIXED CONSTRUCTIONS
    • E04—BUILDING
    • E04B—GENERAL BUILDING CONSTRUCTIONS; WALLS, e.g. PARTITIONS; ROOFS; FLOORS; CEILINGS; INSULATION OR OTHER PROTECTION OF BUILDINGS
    • E04B1/00—Constructions in general; Structures which are not restricted either to walls, e.g. partitions, or floors or ceilings or roofs
    • E04B1/62—Insulation or other protection; Elements or use of specified material therefor
    • E04B1/74—Heat, sound or noise insulation, absorption, or reflection; Other building methods affording favourable thermal or acoustical conditions, e.g. accumulating of heat within walls
    • E04B2001/742—Use of special materials; Materials having special structures or shape
    • E—FIXED CONSTRUCTIONS
    • E04—BUILDING
    • E04B—GENERAL BUILDING CONSTRUCTIONS; WALLS, e.g. PARTITIONS; ROOFS; FLOORS; CEILINGS; INSULATION OR OTHER PROTECTION OF BUILDINGS
    • E04B1/00—Constructions in general; Structures which are not restricted either to walls, e.g. partitions, or floors or ceilings or roofs
    • E04B1/62—Insulation or other protection; Elements or use of specified material therefor
    • E04B1/74—Heat, sound or noise insulation, absorption, or reflection; Other building methods affording favourable thermal or acoustical conditions, e.g. accumulating of heat within walls
    • E04B1/82—Heat, sound or noise insulation, absorption, or reflection; Other building methods affording favourable thermal or acoustical conditions, e.g. accumulating of heat within walls specifically with respect to sound only
    • E04B1/84—Sound-absorbing elements
    • E04B2001/8457—Solid slabs or blocks

Definitions

  • the present invention relates to a method of improving the sound-absorbing performance of wood as a sound-absorbing material, and more particularly to a method of improving the ability of wood to absorb sound waves incident in the fiber direction of the wood in a given frequency range by delignifying it.
  • An object of the present invention is to provide a sound-absorbing board having sound-absorbing properties superior to that of unmodified wood by chemically treating wood.
  • glass fiber, rock wool, gypsum board and the like which are used as internal or external sound-absorbing materials, are frequently used as building materials, because they have excellent sound-absorbing capacity and insulation properties.
  • these materials when exposed in air during use, they will have a harmful effect on human health due to dust, etc., so that their use has gradually been restricted.
  • these materials have low intrinsic strength, and so require a supporting frame.
  • Wood with the potential to replace non-eco-friendly materials, is a recyclable natural material and has a beautiful appearance and good processability, as well as excellent strength compared to other materials.
  • wood resources in Korea mainly consist of small-diameter logs, curved logs and the like, and thus, there is a need to maximize the utility of the small-diameter logs or curved logs, having low added value.
  • the present inventor has delignified wood materials, using small-diameter logs or curved logs, by chemical treatment, and discovered that delignification resulted in substantial improvement in the sound-absorbing capacity of the wood materials thereby completing the present invention.
  • Wood is a sound reflective material having a sound absorption of about 5% in a frequency range that human beings mainly use during their life.
  • Korean Patent Application No. 99-38842 (entitled “a sound-absorbing wood material and a preparation method thereof") filed by the applicant discloses a wood board having improved sound-absorbing performance and low density and, at the same time, requisite strength, which is prepared by a method comprising the steps of: adding a synthetic resin adhesive to wood particles in an amount of about 5-30% by weight and stirring the mixture; forming the stirred mixture into a mat; placing the mat into a mold having a plurality of discharge holes form in the circumferential surface thereof; interposing the mold between upper and lower cowls each having a plurality of core pins, which have different diameters and are arranged on the same axis; and pressing the upper and lower cowls, in which the pressing step is performed at a temperature of about 140-240 °C and a pressure of about 20
  • Korean Patent Laid-Open Publication No. 2003-30645 discloses a wood floor structure comprising: a sound-absorbing elastic material having perforated adhesive holes to be filled with an elasticity-reinforcing adhesive; and a wood floor panel placed on the sound-absorbing elastic material after being filled with the elasticity-reinforcing adhesive.
  • the above-published wood materials comprise, in addition to wood, a separate material for improving sound-absorbing performance, these materials are difficult to realize and do not meet the eco-friendly trend. For this reason, the present inventor developed a method capable of improving the sound-absorbing performance of wood using wood anatomical approach and based on his through study of wood structure, thereby completing the present invention.
  • the sound-absorbing performance will now be described in order to fully understand the present invention.
  • the absorption of sound is a process for removing or reducing the energy of sound. Sound absorption is achieved by contact with a sound-absorbing material having many pores, or by the vibration of a thin plate disposed on the wall surface with an air layer interposed therebetween, or by a sound-absorbing device including a single resonator.
  • a sound-absorbing material having many pores
  • the absorbance of sound by the porous material varies depending on the thickness of the porous material, it shows an excellent effect in a wide frequency range, but the porous material needs structural support.
  • the plate vibration shows good sound absorbance only in low frequency range.
  • the absorbance of sound by the single resonator shows high sound-absorbing effects only in a narrow frequency range.
  • glass wool or rock wool is frequently used in buildings, owing to the advantages of good insulation properties in addition to sound-absorbing effects, but when exposed to air, during use, it can have a harmful effect on the human health due to dust. Also, this material has poor strength, and thus requires a supporting frame. Accordingly, the present inventor believes that there is a need to develop new materials, which have suitable levels of sound-absorbing and insulation properties and, at the same time, are not harmful to the humans, one of these materials being a wood material.
  • the main objective of the present invention is to provide an eco-friendly, sound-absorbing material.
  • Another objective is to provide a method for improving the sound-absorbing properties of wood by removing substances from wood cell walls through a wood anatomical approach.
  • the present invention provides a use of a deliguified wood as a material with improved sound absorbance.
  • the deliguified wood is obtained by the following steps of processing normal wood into a wood disc; removing lignin from the wood disc; and drying the delignified wood disc under reduced pressure.
  • Wood mainly consists of cellulose, hemicellulose and lignin, in which the lignin to be removed according to the present invention is a polymer having a molecular weight of more than 50,000 and including a phenylpropane-type carbon framework deposited between the cellulose microfibrillar structures of wood. Lignin accounts for 20-30% of the dry weight of wood.
  • the delignification step can be performed using a known method, such as the chlorine-monoethanolamine method, comprising chlorinating the wood discs, which renders wood discs brighter, or the peracetic acid method. It is preferable in the present invention to use the sodium chlorite method for oxidizing, degrading and dissolving out the lignin.
  • the delignified wood discs are dried under reduced pressure conditions (pressure: 70-90 cmHg; and temperature: 30-50 °C) to a water content of 10-15%, which results in fine cracks on the surface of the wood discs.
  • pressure 70-90 cmHg
  • temperature 30-50 °C
  • the present invention is described with respect to the improvement of sound-absorbing performance only for the wood discs, the inventive idea of improving sound absorbance by increasing the wood pores can likewise be applied to plywood, particle board and fiber board.
  • the present invention will be described in detail with examples, but it is to be noted that these examples are for illustrative purpose only and are not construed to limit the scope of the present invention.
  • a sound reflective wood material having a sound absorbance of about 5% can be significantly improved with respect to sound-absorbing performance in a frequency of 2 KHz-4 KHz, in which the human hearing sense is generally most sensitive.
  • rock wool, glass fiber and the like which have been used as sound-absorbing internal materials, can be substituted with inexpensive wood.
  • the sound-absorbing wood material according to the present invention is eco-friendly, and so can be used without fear of health hazard or damage to environment.
  • the inventive material is recyclable so that it is superior to other materials in the efficiency of resource utilization, whereby it can contribute to the efficient utilization of resources and to an increase in the value of wood products.
  • Larch wood was processed in the transverse direction (to a 100-mm diameter for a middle and low frequency specimen and a 29.9-mm diameter for a high frequency range specimen, and a 30-mm thickness), to prepare wood discs.
  • Each of the wood discs was degreased with a mixture of alcohol and benzene and kept in a water bath with 1.21 of water containing 8 g of sodium chlorite and 1.6 ml of glacial acetic acid at 80 °C for 120 hours.
  • Each of the delignified wood discs was dried to a moisture content of 12% in a vacuum dryer at a pressure of 76 cmHg and a temperature of 40 °C.
  • FIG. 1 is a photograph showing the result of visual observation for a wood disc treated with the inventive method for improving sound-absorbing properties
  • FIG. 2 is an electron micrograph showing a portion of the cross section of the wood disc shown in FIG. 1 .
  • FIG. 1 pluralities of fine cracks are distributed on the surface of the disc after treatment according to the present invention. This indicates that, on the surface having weak strength due to delignification, small splits were generated even under reduced-pressure drying conditions, which cause low drying stress.
  • intracellular substances between the wood cell walls were dissolved and removed.
  • the surface of the wood disc according to the present invention feels soft compared to untreated conventional wood discs. Also, because the portion between the wood cell walls, which has a high content of lignin, showing an elastic behavior in wood, was removed, the wood has an increased porosity leading to a reduced reflectivity to sound waves, thus showing improved sound-absorbing properties.
  • FIG. 3 shows the sound-absorbing properties of a wood disc treated with the inventive method and an untreated wood disc.
  • the wood disc according to the present invention showed improved sound-absorbing performance over the entire measured frequency range, compared to the untreated wood disc.
  • the inventive wood disc showed a 30% higher sound absorbance than that of the untreated wood disc.
  • the inventive wood disc was almost twice as high in sound absorbance as the untreated disc.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Architecture (AREA)
  • Acoustics & Sound (AREA)
  • Civil Engineering (AREA)
  • Structural Engineering (AREA)
  • Electromagnetism (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Wood Science & Technology (AREA)
  • Multimedia (AREA)
  • Chemical And Physical Treatments For Wood And The Like (AREA)
EP05856497A 2004-10-20 2005-10-08 A method for improving wood sound-absorbance and a sound-absorbing wood thereby Expired - Fee Related EP1809825B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
KR1020040083840A KR100692509B1 (ko) 2004-10-20 2004-10-20 목질 흡음성 개선방법 및 목질 흡음재
PCT/KR2005/003350 WO2006080731A1 (en) 2004-10-20 2005-10-08 A method for improving wood sound-absorbance and a sound-absorbing wood thereby

Publications (3)

Publication Number Publication Date
EP1809825A1 EP1809825A1 (en) 2007-07-25
EP1809825A4 EP1809825A4 (en) 2007-11-14
EP1809825B1 true EP1809825B1 (en) 2009-07-29

Family

ID=36740701

Family Applications (1)

Application Number Title Priority Date Filing Date
EP05856497A Expired - Fee Related EP1809825B1 (en) 2004-10-20 2005-10-08 A method for improving wood sound-absorbance and a sound-absorbing wood thereby

Country Status (4)

Country Link
EP (1) EP1809825B1 (ko)
KR (1) KR100692509B1 (ko)
DE (1) DE602005015744D1 (ko)
WO (1) WO2006080731A1 (ko)

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20090049800A (ko) * 2007-11-14 2009-05-19 전북대학교산학협력단 폭쇄처리에 의한 고 흡음성보드 제조방법 및 이에 의한흡음성보드
US11958209B2 (en) 2017-09-15 2024-04-16 University Of Maryland, College Park Delignified wood materials, and methods for fabricating and use thereof
EP4107219A4 (en) * 2020-02-18 2024-03-13 Dte Mat Incorporated CELLULOSIC COMPOSITE MATERIALS AND CORRESPONDING PROCESSES
CN111341291B (zh) * 2020-03-04 2023-06-16 云南电网有限责任公司电力科学研究院 一种降噪装置及制备方法

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB719245A (en) * 1951-04-03 1954-12-01 Onera (Off Nat Aerospatiale) Process for treating wood
JPS5478112A (en) * 1977-12-03 1979-06-22 Nippon Gakki Seizo Kk Soundboard for musical instruments
DE3739313A1 (de) * 1987-11-20 1989-06-08 Pape Hans Verwendung einer holzwerkstoffplatte mit deckschicht als schallabsorbierende wand- oder deckenverkleidung und verfahren zur herstellung einer solchen holzwerkstoffplatte
DE9414943U1 (de) * 1994-09-14 1996-01-18 Faist M Gmbh & Co Kg Folienresonanzabsorber
JPH08120878A (ja) * 1994-10-25 1996-05-14 Yamazaki Mokuzaiten:Kk 建築用内装材
IT241053Y1 (it) * 1996-12-06 2001-04-20 Locatelli Laminati S A S Di Lo Pannello fonoassorbente
SE514825C2 (sv) * 1999-09-16 2001-04-30 Aga Ab Oxygendelignifiering av cellulosamassa med oxiderad vitlut som alkalikälla
KR100417452B1 (ko) * 2002-01-07 2004-02-11 박춘종 목재 방음판넬
JP4108512B2 (ja) * 2003-03-17 2008-06-25 学校法人同志社 吸音材およびその製造方法

Also Published As

Publication number Publication date
KR100692509B1 (ko) 2007-03-09
WO2006080731A1 (en) 2006-08-03
EP1809825A4 (en) 2007-11-14
DE602005015744D1 (de) 2009-09-10
EP1809825A1 (en) 2007-07-25
KR20060034838A (ko) 2006-04-26

Similar Documents

Publication Publication Date Title
EP2414600B1 (en) Panels including renewable components and methods for manufacturing same
EP1809825B1 (en) A method for improving wood sound-absorbance and a sound-absorbing wood thereby
US20090260770A1 (en) Panels including renewable components and methods for manufacturing
CN103971670A (zh) 一种吸隔声复合板
JP4867005B2 (ja) 竹維管束鞘繊維で形成された断熱及び吸放湿シート
JP2012111063A (ja) 木質繊維板の製造方法及び木質繊維板
EP2310588A2 (en) Panels including renewable components and methods for manufacturing
TR201809297T4 (tr) Cam elyaf ile geliştirilmiş mineral yün esaslı akustik levha.
Coutts From forest to factory to fabrication
Mahzan et al. Investigation on sound absorption of rice-husk reinforced composite
CA2307326A1 (en) Method of producing insulation material, organic fibrous material, and blow insulation method for performing insulation
Bunzel et al. Structural sandwich composites out of wood foam core and textile reinforced concrete sheets for versatile and sustainable use in the building industry
Abdullah et al. Investigation on natural waste fibers from dried paddy straw as a sustainable acoustic absorber
US20210115603A1 (en) Textile structure based on glass fibers for acoustic ceiling or acoustic wall panel
JP2001293706A (ja) パーティクルボード
CN105269881A (zh) 一种棕榈原纤非织造吸声材料的制备方法
KR102432045B1 (ko) 셀룰로오스계 다공성 물질의 제조 방법 및 이에 의해 제조된 셀룰로오스계 다공성 물질
JP3496107B2 (ja) バルカナイズドファイバーの製造方法
Nasidi et al. The effect of natural fiber sound absorption performance on sodium hydroxide treatment
Barth et al. Impregnation of Wood Derived Scaffolds
CN112225913A (zh) 一种纳米纤维素/丙烯酰胺/氧化石墨烯自愈合水凝胶的制备方法
FR3033789A1 (fr) Plaque acoustique a base de platre
WO2006044117A3 (en) Temporary wet strength system for tissue paper
Barth et al. Impregnation of Wood Derived Scaffolds with Cellulose Acetate
Chen et al. Windmill Palm Waste Fiber Used as a Sustainable Nonwoven Mat with Acoustic Properties

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20070521

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): DE FR GB

A4 Supplementary search report drawn up and despatched

Effective date: 20071017

RIC1 Information provided on ipc code assigned before grant

Ipc: G10K 11/162 20060101ALI20071010BHEP

Ipc: E04B 1/86 20060101ALI20071010BHEP

Ipc: B27K 5/02 20060101AFI20071010BHEP

DAX Request for extension of the european patent (deleted)
RBV Designated contracting states (corrected)

Designated state(s): DE FR GB

17Q First examination report despatched

Effective date: 20080206

GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: ECOWELL CO. LTD.

Owner name: KANG, CHUN-WON

RIN1 Information on inventor provided before grant (corrected)

Inventor name: ECOWELL CO. LTD.

Inventor name: KANG, CHUN-WON

RIN1 Information on inventor provided before grant (corrected)

Inventor name: KANG, CHUN-WON

Inventor name: KWAK, CHAE EUL

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE FR GB

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

REF Corresponds to:

Ref document number: 602005015744

Country of ref document: DE

Date of ref document: 20090910

Kind code of ref document: P

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20091013

Year of fee payment: 5

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed

Effective date: 20100503

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

Effective date: 20100630

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20100501

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20091102

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20101008

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20101008