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Sound insulation eng


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sound insulation materials

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Sound insulation eng

  1. 1. Sound insulation materials W
  2. 2. Noise reduction — for a better working environment High noise levels have a serious impact on the workforce: reducing working capacity, impaired hearing and illness- related absenteeism. The risk of other injuries also increases when excessive noise causes communication breakdowns between workers. Trelleborg manufactures sound insulation materials and Novibra' anti—vibration mountings to combat various types of noise and vibrations. I Sound insulation materials for isolation and absorption of airborne noise. I Novibra" anti—vibration mountings offer flexible installations for machines, fans and other equipment which would otherwise generate structure borne noise. See our separate Novibra' brochure for details. Highly effective damping and insulation. The inner qualities of Trelleborg's range of sound insu- lation materials — high density, low fiexural rigidity and inherent attenuation properties - make it outstanding for noise insulation and damping purposes. The product range comprises three types of material, for a variety of applications: Insulating film. Suitable for sound insulation of machine housings, thin sheet—metal surfaces, etc. Due to its high density and inner losses, the film is both an effective insulating and vibration damper. Insulating film with absorbent layer. For sound insulation of marine engine housings, com- pressors and other noisy machines where insulation film with an additional absorbent is required. In this case, the film is laminated with a plastic foam layer. All films can be ordered with or without a self- adhesive surface. Product range. Insulating curtains. Ideal for enclosing or screening machines and other sources of noise that must be easily accessible. The material consists of a rubber layer with a heavy filler. Designed to hang freely, the curtain can be repeatedly rolled or folded without affecting its performance. Sound transmission loss according to SS-EN ISO 140/3:95. STL50 10 125 250 500 1000 2000 4000 Hz Frequency Tirellehog insulating film and curtains combin: high density and law flrxural rigidity. This mrans a high coincidence limiting frequency (over 10 kHz) is obtained Yhtst products 117! thrrrfimr particularly mfectivtfor insulating against high frequency sound Sound transmission loss (5 TI. ) mtasurzmmtsfor Trtllehorg insulating film of various thicknesses glued on 3 mm aluminium can hr sun in the diagram about. For comparison, the corresponding STI. measurements for th: aluminium variant (rrd line) are presented in the guidelines section. Approx, Approx. Approx. rated APlJI0X- 70" thickness, mm with. mm weight. kg/ m1 length. "1 Film 1.3 1200 3.5 black 1526540 10 2,6 1200 7.0 1526500 10 5,2 1200 14.0 1526460 5 Film, seIf~adhesive 1.3 1200 3,5 black 1526530 10 2,6 1200 7,0 1526490 10 film, absorbent layer 1.3+20 1200 3,9 black/ grey 1526520 5 2,6+20 1200 7.4 1526480 5 film with absorbent 131-20 1200 3.9 black/ grey 1526510 5 layer, self-adehesive 2.6+2O 1200 7,4 1526470 5 curtain 2.7 1200 7,0 blue 1526960 10 All materials withstand continual exposure up to +70 ° C. Flame resistant according to [M0 Resolution A. 653 (I 6) and ISO 5660. More detailed information is at/ ailahlefiom Trellehorg. Sound insuhztion in EPDM is available on special request.
  3. 3. Sound absorption of film with absorbent layer according to EN 20354 (ISO 354). 0.1 0.9 0.8 0.7 0.5 0.5 0.4 0.3 0.2 0.1 0 125 250 500 1000 2000 4000 H1 Frequency T 40 mm absorbent i 20 mm absorbent Trr/ /eborg insulating film is also supplied wit/ J 11 param p/ amt‘ flmm layer in narrow I/ Jit‘l’7I(. ‘5t’S. 771:’ p/ «zstirfbizzrzk open prim‘ at‘! as 11 sound absorbent. T/ Je diagrmn 5/. ww. r ahmrbtiou mcfiirienr nmuztrmzmrsfar 5/(flint 50mm’ irxvideme onfi/ m xvi! /7 41 p/ astirflmm layer nfmriam‘ I/ Iirkrzmes. Principles of passive reduction of airborne/ structure borne sound propagation. EU health & safety directives. In the EU, the Directive 86/ 188/ ECC ”Protection of workers from the risks related to exposure to noise at work” applies. Two sets of exposure limits are indicated: When the equivalent sound level exceeds 85 dB(A) during an 8-hour working day: I Staff are informed of the current noise level. I Hearing protection is available. I Staff are offered checks on hearing. In addition, when the equivalent sound level exceeds 90 dB(A) during an 8-hour working day or unweighted instantaneous level exceeds 200 Pa (140 dB(C)); I The cause of the excess noise is to be identified. I Reduction measures are to be worked out. I Use of personal hearing protectors is obligatory. I Warning signs are to be put up. — structure borne sound (vibration) Insulation (Reflection of sound energy) Ahsoptlon = ‘unplug E (Conversion of sound "' energy into heat) 5,5 Em. <): I
  4. 4. Guidelines for Trelleborg film for soundinsulation of machine Sound transmission loss for housing walls. housings and enclosures. Sn lfit is not possible to reduce machine noise. enclosure is ' an alternative. The criteria for an effective enclosure are: so I The enclosure (housing) should be as l1€'. l')' as possible and sealed tightly. I The inside should be lined with sound absorbent. I Openings for cooling air, materials. etc require 40 silencers. e. g lined ducts. I Easy—to—opcn covers. The guidelines on these pages demonstrate machine enclosure using Trelleborg insulating film. It is possible 20 to use supporting housings. The film can also be used as an inner massive lining and sound absorbent. And. film is particularly suitable as .1 sound—reducing flexible cur— tain. for example. in openings for the flow of materials. The guidelines show the expected insertion loss for a [_'- pical machine housing. which is coated with Trelleborg 10 mo 1000 10009 H, insulation film. This is glued to the interior on 1 mm F'°°“°"°’ _ _ . 1- Sealed housings with lining sheet—sreel. with and without a 0.1% open surface. 1 Sealed housings without lining j Housing with lining and openings 2- Housing without lining. with openings . ur. /i. 'r/ .’/ ".I7l: '7I]IJ: I(77l /03) .1! III. ’ / m11.~'I71g. ~ 11'.1// _-’. u‘iI/ V .12/1/1. 1// mm / in/1'. ~ . mr/ /mmg / H,/ /,/ ;/rzig wrmrl / m1./ .1117‘/ _g /1'/ H/, ., Insertion loss for an enclosure with openings. Insert. damping. dB 40 30 20 10 10 100 1000 10000 Hz Frequency -2- Interior average absorption coefficient = 0.1 —u— Interior average absorption coefficient : 0.4 j Interior average absorption coefficient : 0.9 rl / j/2/or/1:'.1m/ v/1' qf’. 'r1.rn't1a11 /11;: in .1 11ni5¢--117/1n‘1'11g 1'11.’/1:5/411’ ll‘/ I/v n/ vmriiigx. // iv n/ m1i11g. ~' / um’ .111 tjffhr .11/1711' fi2'1]r1t'7rt'i1'5 / /111' In HA’/77]/7/7/(S r'¢'. i'1n1.11I. ‘r, .1; 11 ‘c’/ /.1! .1! / rig/7 f77r1]rm71.'rz{~ » 1)/ rrrriirgs / imiz I/72’ n1.1.'1'wIm1 / rm’. -’1'/ I/1' 1''7‘I1'm1 /1155.
  5. 5. h' I mac me enc osure. ... Type of enclosure Typical sound reduction as n“ 5-10 dBA 100 Ifllhout Mitt 1. Enclosure using insulating Film or curtain effectively insulates airborne 60 sound over a wide frequency range. 31.5 63 125 250 500 1000 20004000800016000flz I as V _ 11° Absorbent only . ‘ 10° Ivfllhout 3-5 dBA , so In combination with 1. - " 80 5-15 dBA 2. Absorbent material reduces noise 7° levels, particularly at high frequencies. so 31.5 63 125 250 500 1000 20004000B00016000}u I «:3 11° 15-20 dBA 100 uhllhoul . _ so so 3. Machine enclosure in a sheet—metal casing 10 W” using interior selfiadhesive sound insulating 60 film with absorbent. The film increases the casing's STL, vibration damping 50 and absorption inside the enclosure. 3”‘ 63 "5 25° 5'” 1°°° 2°°° ‘°°° a°°°1°°°°"‘ an no In machine shop 100 0-3 dBA go in adjacent room i 10-20 dBA so 4. Isolation using Novibra” anti—vibration— -,0 mountings prevents transmission of so structure borne noise, especially at low frequencies. so 31.5 83 1.25 250 500 1000 20004000 800016000“; I as * - no 15-30 dBA ~ 100 Irfllhoru (often limited by ‘ openings) : 90 5. To achieve best results, measures 3. 10 och 4. should always be applied in so ‘Hm combination. 31.5 63 125 250 500 100020004000800016000H1 S 8
  6. 6. .. .and for sound insulating partition walls Noise level at source Noise level behind insulation Type of insulation Noise level outside insulation’ 100 dBA 100 dBA without insulation 100 dBA 100 dBA 102 dBA l-‘ilm or curtain 8085 dBA — single layer 100 dBA 98 dBA Film with absorbent 7580 (BA - single layer 100 dBA 102 dBA I-‘ilm or curtain 65-70 dBA - double layer 100 dBA 102 dBA film + film with absorbent 60-65 dBA - double layer 100 dBA 98 dBA Film with absorbent 5560 dBA - double layer 100 dBA 100 dBA 70 mm lightweight ' concrete wall. 6570 dBA Approxirmzte iia/ rmfor 7 kg/ rrr’ round insu/ trzion material. Typiral mlues. Insulation and sound transmission loss. Sound transmission i055. typical W3"- When sound waves hit a wall, only a fraction of the sound energy gets through, as most of the energy is reflected. The sound insulation properties of a wall are so indicated by the sound transmission loss in dB. A wall with a 10 dB STL lets through 10% of the sound energy, 20 dB corresponds to 1%, etc. Insulation of a thin typical wall is determined by density so (kg/ ml) up to a limiting frequency (coincidence) where flexural rigidity begins to deteriorate the sound trans- mission loss. Above this frequency, sound transmission loss increases even faster with frequency than below it. 40 STL dB 20 0 10 100 1010’ 1-10‘ Hz Frequency j o, o5 j 0,2 j 43,45 -2 03 Sound mmmzission / ossflzr (I typical zm/ I, / osyfizrtor nmzmrnnentsfor 0. 05, 0.2, 0.45 mm’ 0.8 (smrting with the lowest). 7/Jr / assfizrtor ha: 11 positive cflert at and above the rririrrz/ fieqztenzjy.
  7. 7. Suitable applications for Trelleborg sound insulation mateials r»: 77Je inside aft/ Je nmuldedfibre- glass engine housing is lined wit/ J film. Film wit/ J absorbent is used In line the impettian lvarrlz. Illmmrtion xlmwing typiml in- lientilntion duets and other Free-/ Jimging rurmin. subzrion ofa driver} rub. All metal lig/ Jt 5heet—meta/ structures can su are: in the mlz are lined with be eflertiz/ ely insulated will} an film. Film wit/ J alnorlzent is used exterrml layer affilm arfilm to line the roof Red areas indimle u’i! lJ Ilbiorbrnl. insulated sunjizres. Sound insulation of engine compartments and cabs. Typical sound silencers for openings. '—| __| —> = /lir tlmmzelx Effect of openings on an enclosure's total sound 30 31.5 63 125 250 500 1ooo 2000 4000 B0001S000:: !1500Hz tfansmission | ost_ '°q”°"°Y Sound insulating film in mmlzimrtian with absorbent (rm reduce tlye "“ 5“-' . . . . CB °P°“| ng5 ‘5 * nwte level submmtuzlly, m the cockpit: ofbzrge momrboats. ,, mm sum“ for example. Effective sealing enhances sound insulation. To achieve the best possible sound insulation of enclosed machines or a partition wall between two rooms, it is important to minimise openings and gaps. For example, a 3 mm aluminium housing lined with Trelleborg sound insulation material weighing 7 kg/ ml allows a sound transmission loss of 23 dB at 250 Hz. Assuming there is an opening that corresponds to 10°/ o of the insulated surface, the net reduction will be only 10 dB — unless the area is properly sealed. Openings For controls can, for instance, be sealed with rubber bellows. Silencers are an effective solution if other openings, e. g. for cooling air, are absolutely essential. 10 20 30 40 50 60 STL of sealed enclosure, :13
  8. 8. Trelleborg Elastomer Laminates produce and market rubber sheeting. sound insulating materials and rubber mats for a large variety of applications. Trelleborg AB has more than 100 years experience of rubber production. Our sales stall. chemists and engineers work to Find better solutions for our customers through continuous development of new materials, design and production methods. The Trelleborg group employs more than 22.000 people and is established in more than 40 countries. W TRELLEBORG ENGINEERED SYSTEMS Trelleborg Elastomet Laminates Trelleborg lndustri AB. SE-231 81 Trelleborg. Sweden. Tel: +46 (0)410 510 00. Fax: +46 (0)410 456 34. Internet: w*w. trelleborg. com 50057 ' VVW. l.lllUllll. -ll'}'k'l(£'l’l. M'