Method and device for the production and/or processing of a nonwoven glass fabric web

Abstract

A method for producing and/or processing a nonwoven glass fabric web includes thermally drying the nonwoven glass fabric web via infrared radiation from an infrared radiation dryer. A specific power density of at least 153 kW/m.sup.2 is applied by the infrared radiation dryer to the surface of the nonwoven glass fabric web facing toward the infrared radiation dryer. After the irradiation by the infrared radiation dryer, the nonwoven glass fabric web has a temperature of at least 40° C. and at most 105° C. on its surface facing toward the infrared radiation dryer.

Claims

1. A method for processing a nonwoven glass fabric web, which comprises the steps of: thermally drying the nonwoven glass fabric web by means of infrared radiation from an infrared radiation dryer, a specific power density of at least 153 kW/m.sup.2 is applied by the infrared radiation dryer to a surface of the nonwoven glass fabric web facing toward the infrared radiation dryer, a length of the infrared radiation dryer in the process direction and a speed with which the nonwoven glass fabric web moves past the infrared radiation dryer being selected such that after irradiation by the infrared radiation dryer, the nonwoven glass fabric web has a temperature of at least 40° C. and at most 105° C. on the surface facing toward the infrared radiation dryer.

2. A method for processing a nonwoven glass fabric web, which comprises the steps of: thermally drying the nonwoven glass fabric web by means of infrared radiation from an infrared radiation dryer, a specific power density of at least 153 kW/m.sup.2 is applied by the infrared radiation dryer to a surface of the nonwoven glass fabric web facing toward the infrared radiation dryer, and in that after irradiation by the infrared radiation dryer, the nonwoven glass fabric web has a temperature of at least 40° C. and at most 105° C. on the surface facing toward the infrared radiation dryer; and applying a coating onto the surface of the nonwoven glass fabric web facing toward the infrared radiation dryer immediately before drying of the nonwoven glass fabric web by means of the infrared radiation from the infrared radiation dryer, such that no other machinery is provided that contacts the coated surface of the nonwoven glass fabric web between the coating being applied and the nonwoven glass fabric web entering the infrared dryer.

3. The method according to claim 1, wherein after a drying of the nonwoven glass fabric web by means of the infrared radiation from the infrared radiation dryer, the nonwoven glass fabric web is furthermore dried by hot air in a hot air dryer.

4. The method according to claim 3, wherein the infrared radiation dryer and the hot air dryer, which follows in a direction of movement of the nonwoven glass fabric web, are configured as a combination dryer unit.

5. The method according to claim 4, which further comprises disposing a plurality of combination dryer units successively in the direction of movement of the nonwoven glass fabric web.

6. The method according to claim 3, wherein the hot air from the infrared radiation dryer is aspirated and at least partially delivered to the hot air dryer.

7. The method according to claim 3, wherein there is a distance of less than 50 cm between the hot air dryer and the infrared radiation dryer.

8. The method according to claim 3, wherein there is a distance of less than 30 cm between the hot air dryer and the infrared radiation dryer.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

(1) FIG. 1 is a diagrammatic, illustration of a first embodiment of a device according to the invention; and

(2) FIG. 2 is a diagrammatic, illustration of a second embodiment of a device according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

(3) Referring now to the figures of the drawings in detail and first, particularly to FIG. 1 thereof, there is shown a first embodiment of a device according to the invention. In this case, a nonwoven glass fabric web G coated with a binder or a coating is guided through a dryer 10 (from left to right in FIG. 1). The binder or the coating may have been applied immediately before the drying of the nonwoven glass fabric web G onto a surface thereof, for example by a curtain application mechanism (not represented here).

(4) The dryer 10 contains an infrared radiation dryer 20 arranged upstream as seen in the process direction, and a hot air dryer 30 arranged downstream. The distance A between the infrared radiation dryer 20 and the hot air dryer 30 is in this case less than 30 cm. The infrared radiation dryer 20 may itself contains a plurality of modules, of which each module may in turn contain a plurality of rows of individual infrared radiators. In the exemplary embodiment represented here, the infrared radiation dryer contains two modules 21, 22, each of which contains two rows of infrared radiators. Furthermore, each of the two modules 21, 22 also contains a fresh air supply and a used air discharge, the air flows being denoted by arrows in FIG. 1. The dryer in this case extends over the entire width (orthogonally to the plane of the image in FIG. 1) of the nonwoven glass fabric web G to be dried.

(5) According to the invention, a specific power density of at least 153 kW/m.sup.2 is applied by the infrared radiation dryer 20 to the surface of the nonwoven glass fabric web G facing toward the infrared radiation dryer. At the same time, by suitable selection of the overall length of the infrared radiation dryer 20 and of the speed with which the nonwoven glass fabric web G is guided through the dryer 10, it is ensured that, after the irradiation by the infrared radiation dryer 20, the nonwoven glass fabric web has a temperature of at least 40° C. and at most 105° C. on its surface facing toward the infrared radiation dryer 20. In order to monitor the surface temperature, a temperature sensor T which is suitable for contactlessly determining the temperature on the surface of the nonwoven glass fabric web at the end of the infrared radiation dryer 20, for example by use of laser technology, may be installed in the dryer 10.

(6) The hot air dryer 30 is configured to blow hot air, which it draws from a source (not represented here), onto the surface to be dried of the nonwoven glass fabric web G. In this case, the drying is carried out primarily by the impingement principle.

(7) The second exemplary embodiment of a device according to the invention, represented in FIG. 2, differs only slightly from the first exemplary embodiment represented in FIG. 1. Only the differences will therefore be discussed below, and in other regards reference is made to the description above. The main difference is that the dryer in the second exemplary embodiment is configured as a combination dryer unit 12. In this case, warm air from the used air discharge of the two modules 21, 22 of the infrared radiation dryer 20 is at least partially delivered to the hot air dryer 30. This does not mean that the hot air dryer 30 is not connected to a further source of hot air, but that the guiding of hot air from the infrared radiation dryer 20 to the hot air dryer 30 helps to reduce the energy consumption overall. The infrared radiation dryer 20 and the hot air dryer 30 of the combination dryer unit 12 may furthermore contain a common housing.

LIST OF REFERENCES

(8) 10 dryer 12 combination dryer unit 20 infrared radiation dryer 21 module 22 module 30 hot air dryer G nonwoven glass fabric web T temperature sensor