초록 ▼

The invention concerns a method for producing a microporous film with strong isotropic tendency permeable to gases and impermeable to aqueous liquids, consisting of at least one layer, comprising the following successive steps: preparing a mixture consisting of a polyolefin matrix containing at leas

The invention concerns a method for producing a microporous film with strong isotropic tendency permeable to gases and impermeable to aqueous liquids, consisting of at least one layer, comprising the following successive steps: preparing a mixture consisting of a polyolefin matrix containing at least a polymer and at least a mineral and/or organic filler; extruding at least a ply by hot-casting the mixture; pre-stretching the ply with a drag roll; cooling and solidifying the pre-stretched ply, using the drag roll; drawing the solidified ply at sufficient temperature for forming the microporous film. The invention is characterised in that the cooling of the pre-stretched melting ply with the drag roll is partial and limited in controlled manner at a temperature in the temperature range required for its drawing; the drawing of the ply, brought to the temperature required for drawing, by the partial cooling is carried out by traction, at the time of its tangential separation from the drag roll, said roller acting as take-up roller for drawing. Said microporous film can be used on its own or combined with other porous supports for various applications such as corporal hygiene articles, dressings, medical articles, protective clothing, sportswear, insulating coats in the building industry, and the like.

대표청구항 ▼

The invention concerns a method for producing a microporous film with strong isotropic tendency permeable to gases and impermeable to aqueous liquids, consisting of at least one layer, comprising the following successive steps: preparing a mixture consisting of a polyolefin matrix containing at leas

The invention concerns a method for producing a microporous film with strong isotropic tendency permeable to gases and impermeable to aqueous liquids, consisting of at least one layer, comprising the following successive steps: preparing a mixture consisting of a polyolefin matrix containing at least a polymer and at least a mineral and/or organic filler; extruding at least a ply by hot-casting the mixture; pre-stretching the ply with a drag roll; cooling and solidifying the pre-stretched ply, using the drag roll; drawing the solidified ply at sufficient temperature for forming the microporous film. The invention is characterised in that the cooling of the pre-stretched melting ply with the drag roll is partial and limited in controlled manner at a temperature in the temperature range required for its drawing; the drawing of the ply, brought to the temperature required for drawing, by the partial cooling is carried out by traction, at the time of its tangential separation from the drag roll, said roller acting as take-up roller for drawing. Said microporous film can be used on its own or combined with other porous supports for various applications such as corporal hygiene articles, dressings, medical articles, protective clothing, sportswear, insulating coats in the building industry, and the like. ans in response to the signal from the first or second position sensor. 12. The method of claim 11, wherein said drive signal reverses the drive means thereby causing the translation of the apparatus toward the other of the first or second position sensors. 13. The method of claim 11, wherein said drive signal stops the translation of the apparatus. 14. The method of claim 11, further comprising repeating the method so long as the sensed pressure is above the ambient pressure. 15. The method of claim 14, further comprising: sensing the pressure in the pipe during the operation of the apparatus; and communicating a drive signal from the controller to stop the drive means in response to the signal from the position sensor indicating that the apparatus is in a desired stop position and a signal from the pressure sensor that the sensed pressure in the pipe is the ambient pressure.