Acoustic protection – laminated glass with higher performance

Noise surrounds us in many forms. With increasing urbanization and volume of traffic, the effects of noise are getting worse and cause stress, tiredness and even loss of hearing. In most cases we are unable to reduce the cause of the noise and must find an effective way of protection against it. To counteract the effects of noise, we need to understand its nature, know how to measure noise and how glass can be used against its pollution. An explanation of the theme is provided by our technical introduction – Noise, how it is measured ….

Acoustic glazing is often also required to provide additional security.

1. technical data

Acoustic values of monolithic
STADIP SILENCE laminated glass

Glass type1)	Thick in mm2)	Rw in dB	C, Ctr	Light- trans- mission τv to DIN EN 410 in %	Total energy trans- mittance (g-Value) to DIN EN 410	Ug- Value to DIN EN 673 in W/m².K
STADIP SILENCE 33.1	6	36 dB	-1, -4	88	79	5,7
STADIP SILENCE 44.1	8	38 dB	-1, -3	87	77	5,7
STADIP SILENCE 55.1	10	39 dB	-1, -4	86	75	5,6
STADIP SILENCE 66.1	12	39 dB	0, -3	85	73	5,6
STADIP SILENCE 66.2	13	40 dB	-1, -3	85	72	5,5
STADIP SILENCE 88.1	16	42 dB	-1, -3	83	69	5,4
STADIP SILENCE 1010.2	20	44 dB	-1, -3	81	65	5,3
STADIP SILENCE 1212.2	25	45 dB	-1, -3	79	62	5,2

¹⁾ Type description: Glass thickness/Glass thickness.min. PvB interlayers x 0,38 mm
²⁾ Total glass thickness nominal glass thickness without PvB interlayers

2. Dimensions

Float glass

Up to max.	2650 x 5000 mm or 2500 x 5200 mm or 2000 x 5500 mm or 1500 x 5900 mm
Maximum weight	1000 kg
Min. size	250 x 400 mm
Max. aspect ratio	Einzelglasdicke < 8 mm 1:10 Einzelglasdicke > 8 mm 1:20
Max. total thickness	100 mm Multiple ply

For combinations with PLANITHERM II Fully Tempered and COOL-LITE SKN 174 II - see Production sizes.

3. Application technical notes

Definition and explanation of „Spectrum weighted values“ C and C_tr

The „Spectrum-Weighted values“ C and C_tr correct the evaluated acoustic value R_W: For noise sources with higher frequencies it is necessary to add value C. For opposite noise sources, in particular those with low frequencies, C_tr must be added to R_W .

Both correcting values are always negative of equal zero, i.e. they always correct the acoustic value downwards.

The acoustic behaviour of building substances is therefore given in the form R_W (C,C_tr). That means that a building element with the values R_W (C, C_tr) = 40 (-2, -8) indicates a „medium“ acoustic performance of 40 dB. Particularly for noise sources with higher tones, the acoustic value is about 2 dB less, most low frequencies will be even lower by about 8 dB.

Requirements on acoustic performance

It is normal that requirements will be set for the complete window element and not just on the glass.

It is typical that sound insulation required of glazing is always higher than that required of the window. It is the job of the architect or acoustic consultant to determine the level of external noise and then set the requirement for sound insulation.

For the application of glass in Austria the regulation 4 is relevant. Therein the use of STADIP laminated safety glass is regulated for the following:

Must be used for
glass walls where danger of falling is possible overhead glazing

also foreseen for
glass walls, windows and doors up to 1,5 m over finished floor facade cladding

Certification for glass walls where danger of falling is possible can be achieved through testing or structural analysis, whereby size, connection method and interfaces need to be considered. Laminated safety glass will generally fulfill these requirements.

Ball-impact safety

For particular requirements in sports arenas, halls etc. STADIP can fulfill the requirements of DIN 18032 Part 3.

Moisture effects on laminated safety glass

The PvB interlayers used are hygroscopic and extremely dry. The PvB is exposed to air at the edges of the laminate. Air humidity or standing water and water droplets at the edge of the laminated glass generally means that there is a high air-moisture content. Moisture can therefore ingress to the interlayer which has a tendency to absorb more and more. This can lead to visual „fogging“ or de-lamination at the edge, however, it does not result in any reduction of the performance of the laminate as this effect remains only at the edge.

It is important to consider when installing the glass that the glass edge is kept free of standing moisture. The above mentioned moisture appearances at the edge of the glass can also be caused by sealants or blocking materials, which depend on the compatibility of the materials used. Different substances which come into direct contact with the PvB interlayers must not have chemical or physical reactions (e.g. solvent evaporation) which may be caused by their normal application. Sealants, glazing blocks, tapes etc. which may be used must be checked for compatibility with the PvB interlayer. We recommend that you check compatibility with the manufacturer.

Laminated glass with free-standing edges

Protection of the edges against the above mentioned situations is currently not possible. It is often thought that using a thin covering of sealant or varnish will cover the outside of the interlayer and protect it. We must advise that sealants such as silicone do not adhere to PvB interlayers – they only lay against them. Even these sealants are not moisture-proof, i.e. moisture can in the form of vapour penetrate these „preventive measures“ and ingress between the „protection” and PvB.

UV-Transmission

PvB interlayers have a very minimal level of UV-Transmission. Special UV absorbing interlayers can reduce the UV-Transmission to < 1%. We must advise that the discolouration of objects behind glazing with such interlayers is not only caused by UV Light in the spectral area 280 – 380 nm but also from radiation of sunlight in the visible spectrum. We are unable to accept responsibility for such solar caused aging effects.

[PDF] Tolerances
[PDF] General Glazing Guidelines
[PDF] Cleaning- and maintenance recommendations

4. Processing

4.1 Edge treatment

STADIP has straight-cut edges as standard.

Edge quality of laminated safety glass

All laminated safety glass produced by ECKELT is fixed dimension i.e. each individual sheet is cut and edge-worked before it is laminated. This process improves the edge quality in comparison to laminated glass which is cut, mainly because the cutting and snapping actions on finished laminate have the danger of causing small or even large shelling to occur along the edges.

4.2 Drilled holes and cut-outs

Due to the potential danger of breakage we recommend laminated glass which has drilled holes, corner or edge cut-outs to be made of PLANIDUR (HS) or SECURIT (FT) glass.

Production technical edge distances are to be considered.

5. Marking

STADIP made from Float glass is not normally marked. Dependent on the application (e.g. in Lift-shafts) there may be legislature which requires the glass to be marked. This must be advised when ordering glass.

6. Certification

ECKELT possesses all certification for such requirements in accordance with 89/106/EEC of the Council of the European Community. The applicable CE harmonization statements can be downloaded on the right.

ECKELT has carried out impact testing to the requirements of the SGCC and has certification to ANSI Z 97.1-1984 and 16 CFR 1201 (Download right).