JP2022049541A5

JP2022049541A5 -

Info

Publication number: JP2022049541A5
Application number: JP2020155784A
Authority: JP
Filing date: 2020-09-16
Publication date: 2023-08-17
Anticipated expiration: 2040-09-16

Claims

(i) preparing a dewatering channel which is an open channel , comprising a bottom surface which is the surface of the papermaking net and has a longitudinal direction , and two side walls each extending along the longitudinal direction of the bottom surface; (ii) introducing the carbon fiber suspension into the dewatering channel from the upstream end side of the dewatering channel while running the papermaking net in the direction from the upstream end of the dewatering channel to the downstream end; (iii) drying the carbon fiber web obtained by dewatering the carbon fiber suspension while flowing from the upstream end side to the downstream end side in the dewatering channel ;
An introduction channel, which is an open channel having a non-permeable bottom surface and two side walls sandwiching the bottom surface, is coupled to the upstream end of the dewatering channel;
The carbon fiber suspension is supplied to the dewatering channel through the introduction channel,
A carbon fiber sheet manufacturing method , wherein the carbon fibers in the carbon fiber suspension are oriented in the flow direction in the introduction path .

(i) preparing a dewatering channel that is an open channel, comprising a bottom surface that is the surface of a papermaking net and has a longitudinal direction, and two side walls that each extend along the longitudinal direction of the bottom surface; ii) introducing a carbon fiber suspension into the dewatering channel from the upstream end side of the dewatering channel while running the papermaking net in a direction from the upstream end of the dewatering channel toward the downstream end; iii) drying the carbon fiber web obtained by dewatering the carbon fiber suspension while flowing from the upstream end side to the downstream end side in the dewatering channel;
An introduction channel, which is an open channel having a non-permeable bottom surface and two side walls sandwiching the bottom surface, is coupled to the upstream end of the dewatering channel;
The carbon fiber suspension is supplied to the dewatering channel through the introduction channel,
The introduction channel has a laminar flow section with a downstream end at a joint with the dewatering channel,
A method for producing a carbon fiber sheet, wherein the laminar flow section has a length sufficient to orient the carbon fibers in the carbon fiber suspension in the flow direction.

At the joint between the dehydration channel and the introduction channel, the width (W2) of the bottom surface of the introduction channel is 0.8 times or more, preferably 0.9 times or more, the width (W1) of the bottom surface of the dehydration channel. , The carbon fiber sheet manufacturing method according to claim 1 or 2 .

4. Any one of claims 1 to 3, wherein at the joint between the dehydration channel and the introduction channel, the liquid depth of the introduction channel is 0.8 times or more, preferably 0.9 times or more, the liquid depth of the dehydration channel. The method for producing a carbon fiber sheet according to 1 .

The method for manufacturing a carbon fiber sheet according to any one of claims 1 to 4 , wherein the surface roughness Rz of the inner surface of the introduction path is 5 µm or less.

The carbon fiber sheet manufacturing method according to any one of claims 1 to 5 , wherein the width of the bottom surface of the introduction path is larger than the liquid depth of the carbon fiber suspension in the introduction path.

The carbon fiber sheet manufacturing method according to any one of claims 1 to 6 , wherein a partition for dividing the introduction path into sub-paths is provided in at least part of the introduction path.

The carbon fiber sheet manufacturing method according to claim 7 , wherein the downstream end of the partition is streamlined when the introduction path is viewed from above.

The carbon fiber sheet manufacturing method according to any one of claims 1 to 8 , wherein the introduction path has a reduced width portion.

When the introduction path is viewed from above, the maximum inclination of the side edge of the bottom surface of the introduction path with respect to the longitudinal direction of the dewatering path is 10 to 80°, preferably 10 to 40° at the width reduction portion. and more preferably 10 to 30°, the carbon fiber sheet manufacturing method according to claim 9 .

11. The method of manufacturing a carbon fiber sheet according to claim 9 or 10 , wherein when the introduction path is viewed from above, the side edge of the bottom surface of the introduction path is curved with a radius of curvature of 1 mm or more at the upstream end of the reduced width portion. .

12. The carbon fiber according to any one of claims 9 to 11 , wherein when the introduction path is viewed from above, the side edge of the bottom surface of the introduction path is curved with a curvature radius of 1 mm or more at the downstream end of the reduced width portion. sheet manufacturing method.

The liquid depth at the downstream end of the introduction passage is 0.8 to 1 times the liquid depth at the upstream end, preferably 0.9 to 1 times, more preferably 0.95 to 1 times, according to any one of claims 1 to 12 . The carbon fiber sheet manufacturing method according to any one of the above.

The carbon fiber sheet manufacturing method according to any one of claims 1 to 13 , wherein the introduction path does not have a portion where the flow velocity of the carbon fiber suspension decreases from upstream to downstream.

The carbon fiber sheet manufacturing method according to any one of claims 1 to 14 , wherein the introduction path has a curved boundary between the bottom surface and the side wall.

At the joint between the dehydration channel and the introduction channel, the width and liquid depth of the bottom surface on the dewatering channel side are respectively 0.9 to 1.1 times the width and liquid depth of the bottom surface on the introduction channel side, preferably 0. 0.9 to 1 times, more preferably 0.95 to 1 times, the carbon fiber sheet manufacturing method according to any one of claims 1 to 15 .

The carbon fiber sheet manufacturing method according to any one of claims 1 to 16 , wherein the carbon fiber suspension comprises water, a viscous agent, and short carbon fibers having a fiber length in the range of 3 to 100 mm.

a dewatering channel comprising a bottom surface having a longitudinal direction and two side walls each extending along the longitudinal direction of the bottom surface, the bottom surface being the surface of a papermaking net ;
The upstream end of the dehydration channel has a non-water-permeable bottom surface and two side walls sandwiching the bottom surface, and does not have a portion where the width of the bottom surface increases from the upstream side to the downstream side. a lead-in path coupled to
has
When the carbon fiber suspension is introduced into the dewatering channel from the upstream end side of the dewatering channel using the introduction channel while the papermaking net is traveling in the direction from the upstream end to the downstream end of the dewatering channel. , the carbon fiber web manufacturing apparatus, wherein the carbon fiber suspension is dehydrated while flowing through the dewatering channel from the upstream end side toward the downstream end side.

At the joint between the dehydration channel and the introduction channel, the width (W2) of the bottom surface of the introduction channel is 0.8 times or more, preferably 0.9 times or more, the width (W1) of the bottom surface of the dehydration channel. 19. The apparatus for producing a carbon fiber web according to claim 18 .

20. The carbon according to claim 18 or 19 , wherein at the joint between the dehydration channel and the introduction channel, the bottom surface of the introduction channel is continuous with the bottom surface of the dehydration channel, or is located lower than the bottom surface of the dehydration channel. Textile web production equipment.

The carbon fiber web manufacturing apparatus according to any one of claims 18 to 20 , wherein the surface roughness Rz of the inner surface of said introduction path is 5 µm or less.

The carbon fiber web manufacturing apparatus according to any one of claims 18 to 21 , wherein partitions for dividing said introduction path into sub-paths are provided in at least part of said introduction path.

The carbon fiber web manufacturing apparatus according to claim 22 , wherein the downstream end of the partition is streamlined when the introduction path is viewed from above.

The carbon fiber web manufacturing apparatus according to any one of claims 18 to 23 , having a width reduction portion provided in said introduction path.

When the introduction path is viewed from above, the maximum inclination of the side edge of the bottom surface of the introduction path with respect to the longitudinal direction of the dewatering path is 10 to 80°, preferably 10 to 40° at the width reduction portion. and more preferably between 10 and 30 °.

26. The carbon fiber web manufacturing apparatus according to claim 24 or 25 , wherein when the introduction path is viewed from above, the side edge of the bottom surface of the introduction path is curved with a radius of curvature of 1 mm or more at the upstream end of the reduced width portion. .

27. The carbon fiber according to any one of claims 24 to 26 , wherein when the introduction path is viewed from above, the side edge of the bottom surface of the introduction path is curved with a radius of curvature of 1 mm or more at the downstream end of the reduced width portion. web manufacturing equipment.

The carbon fiber web manufacturing apparatus according to any one of claims 18 to 27 , wherein the bottom surface of said introduction path is a single plane.

The carbon fiber web manufacturing apparatus according to any one of claims 18 to 28 , wherein the introduction path has a curved boundary between the bottom surface and the side wall.

At the joint between the dewatering channel and the introduction channel, the width of the bottom surface on the dewatering channel side is 0.9 to 1.1 times, preferably 0.9 to 1 time, the width of the bottom surface on the introduction channel side, The carbon fiber web manufacturing apparatus according to any one of claims 18 to 29 , which is more preferably 0.95 to 1 times.

A carbon fiber sheet manufacturing apparatus comprising the carbon fiber web manufacturing apparatus according to any one of claims 18 to 30 and a dryer.

A carbon fiber sheet manufacturing method using the carbon fiber sheet manufacturing apparatus according to claim 31 .

A prepreg comprising manufacturing a carbon fiber sheet by the carbon fiber sheet manufacturing method according to any one of claims 1 to 17 and 32 , and impregnating the carbon fiber sheet with a thermosetting resin or a thermoplastic resin. manufacturing method.