Acoustic glass in accordance with the different production processes, can be broadly divided into the following three categories
1. insulating glass
2. vacuum glass
3. laminated glass
In terms of acoustic each type of glass has its own characteristics, now these types of glass to do a general description Many customers think of insulating glass is vacuum glass, in fact, the two are There is a certain difference. Vacuum glass is generally composed of two layers of 4mm thick plate glass, two layers of glass in the middle to leave 0.28mm space thickness for vacuum (there are other thickness). Because in the process of vacuuming the formation of negative pressure between the two pieces of glass (Note 2), will make the two pieces of glass suction together, thus losing the vacuum layer, therefore, the production of vacuum glass should be lined with a certain density of flexible support between the two layers of glass or strip support frame, as shown in the figure.
Because the vacuum glass between the two layers of glass is pumped into a near-vacuum, so it has the characteristics of high thermal resistance (Note 3), is a very good thermal insulation products, which is the original intention of the design of the vacuum glass, the thermal insulation performance is also very difficult to compare with the insulating glass.
In terms of acoustic performance vacuum glass is also better than insulating glass, this is because the air inside the insulating glass and the outside world is the same, and vacuum glass is nearly vacuum, and the vacuum state noise is not conductive, so insulating glass than vacuum glass in the sound insulation is not comparable to the vacuum, the vacuum, the two pieces of glass are almost pasted together, so the production of vacuum glass should be in the double or triple glass lined with some tiny So when producing vacuum glass, it is necessary to line some tiny supports between the double or triple glass. Although these supports become the sound bridge for sound transmission. But these supports in a window is only one-thousandth of the area, almost negligible, and most of the vacuum parts can be isolated from the dry sound, so no matter what the soundproof window can not be completely isolated from all the dry sound, so in the choice of soundproof windows must look at the quality of the vacuum glass. Laminated glass is a kind of safety glass production process, also known as laminated glass abroad, can be two layers pressed together, can also be multi-layer pressed together. Some laminated glass will blister after a long time in the sun, this is because of the use of wet clamping method, so the application of laminated glass used in architectural glass class generally use dry clamping method, so that you can avoid blistering of the laminated.
Laminated glass has a good sound insulation effect, but there is still a lack of, but in the composition of the interlayer adjustment and after professional technical processing but can achieve quite good sound insulation effect, which is insulating glass and vacuum glass can not be compared. Of course, laminated acoustic glass due to different manufacturers of different technical content, the resulting sound insulation effect is not the same.
General laminated glass is actually sandwiched in the middle of the stuff is polyvinyl butyral as the main component of the PVB interlayer (such glass is commonly known as "PVB glass"). But the professional soundproof glass interlayer is soundproof film (sound damping adhesive), which can play a key role in the weakening of the sound propagation and filtration, with the sound insulation function of the glass products is actually a laminated glass. And laminated glass in the acoustic film (acoustic damping glue) if the more soft, the more elastic, the more it can increase the sound insulation damping coefficient of laminated glass, thus improving the sound insulation of laminated glass. Ordinary PVB glass sound insulation is only 28-34 dB, acoustic film (acoustic damping rubber) sound insulation can reach 35-40 dB or even higher.
Note:
1.*** vibration: refers to the two objects due to *** the same vibration and sound phenomenon, such as two tuning forks with the same frequency close to one of the vibration of the sound, the other will also sound.
2. Negative pressure: is lower than the atmospheric pressure of the vacuum, the size of the negative pressure expressed in Mpa.
3. Thermal resistance: a comprehensive parameter reflecting the ability to prevent the transfer of heat.
4. Acoustic bridge: that is, the solid rigid connection between the two pieces of glass, should be avoided as far as possible. If there is a sound bridge, will destroy the role of the elastic layer of the air layer, so that the sound insulation decreased.