WO2013153416A1

WO2013153416A1 - Glass wool compact production method, glass wool compact, and vaccumed heat insulator

Info

Publication number: WO2013153416A1
Application number: PCT/IB2012/002660
Authority: WO
Inventors: Seiichi KUBONIWA
Original assignee: Mag-Isover K.K.
Priority date: 2012-04-13
Filing date: 2012-12-11
Publication date: 2013-10-17

Abstract

In a glass wool compact production method comprising a) fiberizing glass raw materials to form glass wool (3), b) fluffing the glass wool to form a glass wool mat that has a unit weight equal to or greater than 2000 g/m2, c) press forming the glass wool mat to form a glass wool compact that has a thickness equal to or greater than 10 mm, before press forming, a water content ratio of the glass wool mat is controlled to be larger than 7.0 mass % and less than or equal to 30 mass % by applying water from nozzles (5) and them The press forming is done while keeping the temperature of the glass wool mat between 250 to 450°C.

Description

GLASS WOOL COMPACT PRODUCTION METHOD, GLASS WOOL COMPACT, AND VACUUMED HEAT INSULATOR

BACKGROUND OF THE INVENTION

1. Field of the Invention

[0001] This invention relates to a glass wool compact production method, a glass wool compact produced by the production method, and a vacuumed heat insulator which utilizes the glass wool compact as its core material.

2. Description of Related Art

[0002] Glass wool compact is light in weight and has heat insulation ability, sound insulation ability, sound absorbing ability, and so on. That is why the glass wool compact is utilized in various fields, for example, for construction heat insulator, heat insulator for automotive vehicles, refrigerator and freezer, and so on, for the purposes of heat-retention, cool-retention, heat barrier, sound barrier, or the like. Especially, vacuumed insulator that inserts the glass wool compact into an airtight package and that the package being depressurized to improve the heat insulation ability is being utilized in the various fields.

[0003] As an example of a production method of the glass wool compact for the vacuumed insulator as described above, Japanese Patent No. 3712129 (JP 3712129 B) is known. In JP 3712129 B, when producing glass wool by the spinner method, vaporized water is sprayed onto the glass wool while the glass wool is in the aerial, that is after being ejected from the orifices of the spinner and before being banked, to adhere water onto the surface of the glass wool. This water elutes the sodium oxide inside the glass that forms the glass wool, and the eluted sodium oxide dissolves into the adhered water to form sodium hydroxide. This sodium hydroxide easily reacts with silicon dioxide, that is the main composition of the glass, to form sodium silicate. Sodium silicate is a water glass that is known as an inorganic binder, therefore, the glass wool fibers bond to each other without the need of an extra binder.

[0004] Specifically, in JP 3712129 B, the amount of water applied to the glass wool is controlled, so that the water content ratio of the glass wool in the state of glass wool mat (before being pressed) is set to 0.1 to 7.0 mass %. Also, the pressing temperature is set to 250 to 450°C.

[0005] As described in paragraphs 0022 to 0025 of JP 3712129, a glass wool compact with its density 125 kg and thickness of 20 mm was achieved by press forming at 350°C for 10 minutes the glass fiber having diameter of 4μιη and water content ratio of 1.5 mass %, and this glass wool compact did not change in its density after leaving it for 24 hours.

[0006] When the glass wool compact has its unit area weight of 500 to 2000 g/m² and the thickness after being press formed is 5 to 15 mm, the production method according to JP 3712129 B can be successfully used, but when the unit area weight is over 2000 g/m and the thickness after being press formed is over 10 mm, 10 minutes of the press forming time becomes too short and it may require almost twice the time. Therefore, the extended press forming time leads to cost increase.

SUMMARY OF THE INVENTION

[0007] This invention provides a glass wool compact production method, a glass wool compact produced by the production method, and a vacuumed heat insulator which utilizes the glass wool compact as its core material, even when a unit weight of glass wool is greater than 2000 g/m and the thickness after being press formed is over 10 mm.

[0008] A first aspect of the invention is related to glass wool compact production method comprising a) fiberizing glass raw materials to form glass wool (3), b) fluffing the glass wool to form a glass wool mat that has a unit weight equal to or greater than 2000 g/m , c) press forming the glass wool mat to form a glass wool compact that has a thickness equal to or greater than 10 mm. Before press forming, a water content ratio of the glass wool mat is controlled to be larger than 7.0 mass % and less than or equal to 30 mass %, and the press forming is done while keeping the temperature of the glass wool mat between 250 to 450°C.

[0009] In the above aspect, the press forming time may be less than 5 minutes. [0010] In the above aspect, the press forming time may be substantially 3 minutes.

[0011] In the above aspect, the water content ratio may be equal to or greater than 17%.

[0012] In the above aspect, the water content ratio may be equal to or greater than 25%.

[0013] In the above aspect, the water content ratio may be controlled by spraying water onto the glass wool before the glass wool is fluffed.

[0014] In the above aspect, the water content ratio may be controlled by spraying water onto at least one surface of the glass wool mat.

[0015] A second aspect of the invention is related to a glass wool compact that is produced by the glass wool compact production method according to the above first aspect of the invention.

[0016] A third aspect of the invention is related to a vacuumed heat insulator that includes: an outer material; and a glass wool compact according to the above second aspect of the invention as a core material filling in a vacuumed airtight space formed by the outer material.

[0017] The water content ratio is generally less than 7 mass %, because when the amount of water is too large in the glass wool mat, the water tends to eccentrically-locate by the transformation of the water, so that stabilized quality is difficult to achieve and more energy is required to evaporate the more content of the water.

[0018] However, when the glass wool compact has its unit area weight larger than 2000 g/m2 and the thickness after being press formed is more than 10 mm, there is less affect of eccentrically-located water by the transformation of the water. When the above glass wool compact is produced without changing the water amount, there is a disadvantage of the press forming time being longer. And, it was found that when more water amount was introduced in the glass wool mat, the press forming time could made shorter. [0019] According to the glass wool compact production method of the first aspect of the invention, it is possible to reduce the production cost of the glass wool compact having a large unit area weight and a large thickness after being press formed by not requiring any additional facility and by reducing the press forming time without changing the press forming temperature range.

[0020] Also, because the formed glass wool compact has little thickness return back amount, the cutting ability (dimension accuracy) and handling ability when used as a core material filling for a vacuumed heat insulator tends to be higher, so that insertion of the glass wool compact in the airtight bag is convenient.

[0021] Moreover, the glass wool compact does not consist any organic substance, so formaldehyde which is generally contained in a very small amount in the glass wool is not present at all, so there is no smell as well. Also, no gas will be generated at the portions having temperature of 350°C of the glass wool compact when being press formed.

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Features, advantages, and technical and industrial significance of exemplary embodiments of the invention will be described below with reference to the accompanying drawings, in which like numerals denote like elements, and wherein:

FIG. 1 describes an apparatus that realizes a method according to a present embodiment of the present invention; and

FIG. 2 is a cross sectional view of a vacuumed heat insulator utilizes a glass wool compact produced by the method according to the present embodiment of the present invention.

DETAILED DESCRIPTION OF EMBODIMENTS

[0023] In an embodiment of the present invention, an apparatus described in FIG. 1 was used to produce glass wool strip. This apparatus produces glass wool strip by introducing molten glass raw materials into a high speed rotating spinner 1, projecting glass wool 3 outward of the spinner 1 from orifices 2 located on the side surface of the spinner 1 by the centripetal force produced by the high speed rotating spinner, blowing the glass wool 3 downward by blowing air downward from air nozzles 4 located above the spinner 1 , and the glass wool 3 is banked into a mat formation or the like.

[0024] In this embodiment, by locating spray nozzles 5 in the lateral direction of the spinner 1, the surface of the glass wool 3 while in the aerial can be sprayed by water from the spray nozzles 5. The method to spray the water onto the glass wool is not restricted to the method explained above. Water can be sprayed onto the glass wool 3 after it is being formed into a mat formation. Even, water can be sprayed from the spray nozzles 5 and further water can be sprayed on after the glass wool 3 is being formed into the mat formation. The example below utilizes this method.

[0025] And then, as shown in FIG. 2, the mat formed glass wool is press formed to form a glass wool compact 6. The glass wool compact 6 is then packed into an airtight package 7, and then inside the airtight package 7 is vacuumed to form a vacuum heat insulator.

[0026] (Examples)

Press formed in the following conditions, then the thickness after leaving it for 72 hours.

Glass wool: 2500 g/m (thickness before pressing was 80 to 100 mm)

Interspace between the press surfaces: 15 mm

Press surfaces temperatures: 360°C

To increase the water content ratio within the glass wool, water was further sprayed onto both surfaces of the mat formed glass wool. The pressing time was varied in the examples. The size of the samples (glass wool mats) was 300 x 300 mm. Table 1 below shows the thickness of the glass wool compact that is the glass wool mat after being pressed varying according to water content ratio before pressing and pressing time. Table 1

[0027] As shown in Table 1 above, the thickness of the glass wool compact was

19 to 20 mm, when the water content ratio was 5% and pressing time was 3 minutes (example numbers 1-1 and 1-2). And, when the pressing time was changed to 5 minutes, the thickness of the glass wool compact was 16 mm (example numbers 2-1 and 2-2), so that the thickness return back amount decreased. Therefore, it is possible to restrain the thickness return back amount by increasing the pressing time.

[0028] When the water content ratio was increased to 17%, with the pressing time 3 minutes, the thickness of the glass wool compact after 72 hours was 15 to 18 mm (example numbers 3-1 and 3-2). However, when the pressing time was 5 minutes, the thickness of the glass wool compact after 72 hours was 15 mm (example numbers 4-1 and 4-2), so that there was no bulge.

[0029] When the water content ratio was increased up to 25%, with the pressing time 3 minutes, the thickness of the glass wool compact after 72 hours was 16 to 18 mm (example numbers 5-1 and 5-2). However, when the pressing time was 5 minutes, the thickness of the glass wool compact after 72 hours was 15 mm (example numbers 6-1 and 6-2), so that there was no bulge.

[0030] From the above observations, when the water content ratio of the glass wool mat is low, although the pressing time is extended, there may be some bulge. When the water content ratio of the glass wool mat is high, there is less thickness return back (no bulge) even though the pressing time is shortened.

Claims

CLAIMS:

1. A glass wool compact production method comprising a) fiberizing glass raw materials to form glass wool (3), b) fluffing the glass wool to form a glass wool mat that has a unit weight equal to or greater than 2000 g/m , c) press forming the glass wool mat to form a glass wool compact that has a thickness equal to or greater than 10 mm, the glass wool compact production method being characterized in that:

before press forming, a water content ratio of the glass wool mat is controlled to be larger than 7.0 mass % and less than or equal to 30 mass %; and

the press forming is done while keeping the temperature of the glass wool mat between 250 to 450°C.

2. The glass wool compact production method according to claim 1, wherein the press forming time is less than 5 minutes.

3. The glass wool compact production method according to claim 2, wherein the press forming time is substantially 3 minutes.

4. The glass wool compact production method according to any one of claims 1 to 3, wherein the water content ratio is equal to or greater than 17%.

5. The glass wool compact production method according to claim 4, wherein the water content ratio is equal to or greater than 25%.

6. The glass wool compact production method according to any one of claims 1 to 5, wherein the water content ratio is controlled by spraying water onto the glass wool (3) before the glass wool (3) is fluffed.

7. The glass wool compact production method according to any one of claims 1 to 6, wherein the water content ratio is controlled by spraying water onto at least one surface of the glass wool mat.

8. A glass wool compact characterized in that the glass wool compact is produced by the glass wool compact production method according to any one of claims 1 to 7.

9. A vacuumed heat insulator characterized by comprising:

an outer material; and

a glass wool compact according to claim 8 as a core material filling in a vacuumed airtight space formed by the outer material.