Volume Restoration Method for Nonwovens

Abstract

The invention provides a method for restoring the volume of the non-woven fabric which can effectively heat the non-woven fabric with a heated fluid and recover the volume of the non-woven fabric reliably and stably. In the inner space (9) of the heating chamber (8) of the heating device (3) for heating the non-woven fabric (2) containing the thermoplastic fiber during transportation, and from When the inlet (9a) side of the nonwoven fabric (2) in the inner space (9) of the heating chamber (8) blows fluid to the nonwoven fabric (2) in the inner space (9) of the heating chamber (8) , blowing the above-mentioned fluid into the inner space (9) of the heating chamber (8) at a flow rate faster than the conveying speed of the above-mentioned non-woven fabric (2), and at a temperature greater than or equal to 50°C lower than the melting point of the thermoplastic fiber and less than this The nonwoven fabric ( 2 ) is heated for 0.2 seconds to 4 seconds at the temperature of the melting point.

Description

technical field [0001] The present invention relates to a method for restoring the volume of a nonwoven comprising thermoplastic fibers, for example released from a roll of nonwoven rolled into roll form. Background technique [0002] When manufacturing products using non-woven fabrics, the non-woven fabrics produced by a predetermined method are often temporarily rolled into rolls and stored in the form of non-woven fabric rolls, and then the non-woven fabric rolls are transported to and from Other processes related to product manufacturing. Then, the nonwoven fabric is unwound from the roll-shaped nonwoven fabric roll and used for the manufacture of desired products such as sheets used for sanitary napkins and disposable paper diapers. [0003] Here, when the manufactured non-woven fabric is wound into a roll to make the non-woven fabric roll, since the non-woven fabric is wound while applying a large pressure in order to make the non-woven fabric roll as small as possibl...

AI Technical Summary

Problems solved by technology

[0005] However, since the volume restoration method described in this patent document 1 is to blow hot air substantially vertically to the surface of the nonwoven fabric from the upper side, there is a possibility that the hot air is hindered by the surrounding air accompanying the nonwoven fabric as it is conveyed. Possibility of penetration in the thickness direction of the nonwoven fabric

In this way, there are cases where the volume or thickness cannot be recovered as expected due to insufficient recovery of the volume of the nonwoven fabric.

In addition, when the hot air is blown approximately vertically from the upper side of the surface of the nonwoven fabric, there is a possibility that the volume recovery of the nonwoven fabric in the thickness direction may be hindered on the contrary.

[0006] In addition, in the case of the volume recovery method of Patent Document 1, since the hot air is blown toward the surface of the nonwoven fabric approximately vertically, if the desired time for heating the nonwoven fabric is to be ensured, there is a method for directing the hot air toward the surface of the nonwoven fabric. The possibility of increasing the size of the device for blowing non-woven fabrics

In recent years, the following situation has been considered: Since there is a tendency to increase the conveying speed of the nonwoven fabric in the volume recovery process of the nonwoven fabric, if the heating time required for the volume recovery is to be ensured, it is necessary to increase the heating time in the conveying direction of the nonwoven fabric. Extend the device for blowing hot air, which obviously leads to an increase in the size of the equipment

Or, due to constraints such as installation space, sufficient heating time cannot be secured, and the desired volume recovery effect may not be obtained.

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