JPS5930987A - Porous endless belt - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a paper machine, and more particularly to a porous paper sheet used to support paper sheets 1 through canning and drying.

Normally, in a paper machine, the aqueous dispersion of papermaking fibers is corrosion-resistant.
``drinier'') is first canned on the wire and assumes the shape of a paper sheet, which when finally dried will have an underside that matches the shape of the wire.Due to the weaving properties. The foil, suction box, etc. that the rewire comes into contact with may be damaged by the rough surface of the wire, and the wire itself may also be damaged, resulting in frequent replacement of these mechanical parts.

Once the bond is internally tight enough to be self-supporting, the paper is lifted off the Fourdrinier wire over a coach roll and conveyed to the wet press by an absorbent press felt. The wet press consists of one or more pairs of opposed rolls which apply pinch pressure to the paper sheet and supporting felt to squeeze moisture from the paper and cause this moisture to be absorbed by the felt. It has become.

The partially dried seaweed 1 is passed through a number of steam-heated dryer sections consisting of three large rotary drying cylinders to other ferns 1. In this case the sheet is pressed against the drying cylinder to remove moisture to the extent desired for the final sheet.

Part of the dryer mentioned above consumes a lot of energy, and although it occupies half of the total length of the paper machine, its water removal capacity is lower than that of the Fordrinier Y)7 and press section, and the investment is lower than the efficiency. Operation and maintenance costs will be extremely high.

Therefore, until now, when drying paper, it has been necessary to downsize a part of the dryer or make the dryer itself unnecessary.
A variety of methods have been proposed that are both effective and efficient at handling paper sheets, but all of these methods simultaneously process paper sheets with high gripping pressure and high temperatures (100%
This is an attempt to vaporize the moisture at a temperature above ℃) to produce lJ+. This technique is called press drying.
ying), an example of which is described in British Published Patent Application No. 2052586A.

However, it is not possible to use a conventional wet press felt in the press dryer for this purpose. This is because the felt is not sufficiently permeable to water vapor, giving the sheet a poor surface finish that cannot be later corrected by calendering. On the other hand, attempts have been made to use Fordrinier wire in conjunction with improved wet-pressed felts, but these results have resulted in more wire marks than in conventional paper machines.

It is therefore an object of the present invention to provide a new porous papermaking element which can be used in conventional dryers as a press drying device in place of a Fourdrinier wire or as part of a paper machine.

In one aspect, the present invention provides a porous endless belt for releasing moisture from a fibrous papermaking dispersion or a sheet made therefrom, the belt being a flexible, corrosion-resistant belt with high tensile strength. It is made of a thin, stretch-resistant and porous sheet member.

In another aspect, the present invention provides a Fourdrinier paper machine equipped with the belt described above.

In yet another aspect, the present invention provides a Fourdrinia paper machine equipped with a press drying section having the bells 1 to 1 described above.

In another aspect, the present invention provides a paper machine having a machine glaze cylinder and provided with the belt described above, in which case belts 1 to 1 are provided.
are arranged so as to come into contact with the outer surface of the paper sheet when the paper sheet passes around the outer periphery of the cylinder.

In another aspect, the present invention provides a paper machine having a drying section in addition to the above-mentioned belt.

The porous bell 1- of the invention is preferably made from a metal plate. The reason for this is that when used for press drying, the elongation must be 1% or less even at high temperatures of 100°C to 150°C. However, the Ford Linear
When used in place of wire at relatively low temperatures, the belt of the present invention may also be made from Plusbook.

The pores in the bell 1 can be created using mechanical or laser punching or even spark techniques.

A porous metal sheet member made of, for example, nickel, can be formed by electrolyzing a matrix in which pores are provided at required geometries and intervals. in this case,
The matrix is provided with an electrically conductive release coating to facilitate the electrodeposition process and to facilitate separation of the sheet member from the 7trix after formation. The shape of the pores is preferably a truncated cone to facilitate release of the sheet member.

The belt sheeting member must have sufficient flexibility to accommodate rolls having a diameter of about 15 cm, while also having a tensile strength of about 40 to 60 units/15 mm. It has been found that a 0.1 to 0.15 IIIll thick nickel plate meets this requirement. This material also contains 200 to 300 benzene
It has a smoothness expressed by ndsten). This means that the woven material from which the Fourdrinier wire is usually made is even smoother. Since nickel material does not have joints like fort linear wire, it has the advantage that it does not leave any traces of wire V on the paper.

When used for press drying, the sheet member according to the invention has a drying capacity of 170 T11'/Tl12 per hour at least at atmospheric pressure.
It must have sufficient permeability to allow the passage of vapor. According to the invention, it is preferred that the endless bells 1 to 1 are made from electrodeposited porous nickel plates.

In this case, the processed nickel plate preferably has the following properties.

Nickel plate thickness: O, lnv Pore diameter: O, l+m to 0.15 mm Pore pitch: 0.25 Illl Il Open area ratio of sheet: 32.5% (vapor permeation rate of 1200 Tn!/Tl12 per hour at atmospheric pressure 8- In the case of replacing the Fourdrinier wire, it is desirable to use a belt with a larger opening area than in the case of press drying to facilitate drainage.

As a result, in order to maintain the desired tensile strength, the sheet member must be relatively thick (for example, approximately 0.15 mm if made of metal). The particular sheet shape to be selected will depend on various conditions under which the belt will be used, such as paper making material, operating speed, and vacuum conditions.

Since the belt used in the present invention is endless, if it is not made seamless, it will leave marks on the paper.

Therefore, it is necessary to join both ends of the belt by butt welding, and to provide pores in this joint to make the belt uniformly permeable throughout. In this case, it is necessary to reduce the thickness of the sheet member before providing the pores.

Alternatively, a seamless joint can be formed by electrodepositing both ends of the belt and providing pores in these areas. In addition, when producing the belt, it can also be produced by electro-deposition M-4 on an endless matrix.

Hereinafter, the present invention will be explained in detail based on the drawings.

The sheet member (1) shown in FIGS. 1 and 2 has circular pores (2) of the same shape Xj and regularly spaced apart. In particular, as shown in FIG. 2, the pores (2) taper in a direction perpendicular to the plane of the sheet member (1). This pore (2) is an electric appetizer.
The holes are drilled by protrusions formed on the matrix. The method for applying the electric appetizer to the sheet portion H is known per se, and therefore does not constitute the essential part of the present invention.

FIG. 3 is a cross-sectional view similar to FIG. 2, and shows a sheet member (3) with a number installed in a pore (4) having parallel sides.
Pores of this type are formed in metal or plastic sheet materials by conventional mechanical or laser punching techniques.

FIG. 4 shows a plastic sheet member (5) having irregularly sized and irregularly spaced pores (6) formed by the known spark process.

FIG. 5 schematically shows the wet end of a paper machine with a four-linear wire (8), which is conventionally connected to a head box (9),
Foil (50), Suction box (51), Presto・
It consists of a roll (52) and a coach roll (53). The wire (8) consists of a porous (perforated) metal or plastic sheet material according to the invention.

The 1 press drying device shown in Figure 6 each has a horizontal axis (12).
It consists of two heating drying cylinders (10, 11) that rotate around and (13). Drying cylinder (10,
11) is heated, for example by steam, and the arrow (14)
), they move in opposition to each other to form a meshing portion designated by (15).

The drying device further comprises two endless porous metal belts (16, 17) according to the invention. The bells 1~ or niremen]~ (16) are guided from the tension roll (18), go around the roll (25) and pass under the pressure roll (19) to the drying cylinders (10, 11) and the second pressure roll. Pressure roll (
20) and return to the tension roll (18). The belt or element (17) is guided from the tension roll (21), passes between the cylinder (10) and the bell h (16) via the guide roll (22), and roughly connects the cylinder ( 11) go around bell 1
- Pass outside of (16). Bells 1 to (17) further pass between the belt (16) and the pressure roll (20) and pass through the second belt.
Tension roll (
Return to 21).

The squeeze-dried filter paper (24) is passed around the cylinder (10) via the roll (25) and is passed through the bell l-(16°17
) led between. Drying cylinder (10, 11) is 100
The temperature is maintained between 150° C. and 150° C., and the paper (24) is substantially heated before it reaches the meshing portion of the cylinder (10) and roll (19). Paper (2
4) When passing through the cylinders (10, 11), the bell l
to (16, 17), and in this case, an appropriate knob IF is applied between the cylinders as necessary. When the paper is dried, the moisture is converted to steam and the C belt (16,
17) is released from the pores. The pores must be sufficiently dimensioned to leave no wire traces and to provide substantially the same finish on both sides of the paper. cylinder (10
, 11) must be such that the paper does not shrink when drying.

The press drying apparatus shown in FIG. 7 uses only one metal porous belt according to the invention. This device is equipped with a drying cylinder maintained at 100°C to 150°C by steam heating, and a belt (31
) is now allowed to pass. The belt (31) and the cylinder (30) are engaged with the rolls (32) and (33).
). The return of the belt (31) is constrained by guide rolls (34) and tension rolls (35). Around the cylinder (30) are press rolls (36A, 36B, 36C, 36D).
, 36E) are arranged to apply pinch pressure to the cylinder as shown in the figure. Paper to be dried (37
) is guided around the roll (32) and is positioned between the belt (31) and the roll (32). As the paper moves around the cylinder (30), pressure is applied to the squeeze orifices (36A) to 36E), which causes moisture to be evacuated as steam from the pores of the belt (31).

The cylinder (30) is large and has a high flat surface like an M-G (machine glaze) or A7 key cylinder.
It may be finished in one step, and by using this, the press roll (36) can be omitted. With such a configuration, it is possible to obtain so-called MG paper having a flattened back surface 1 more roughly than usual. The press rolls (36A) and (36B) can be used as M/G presses if necessary.

Figure 8 shows a series of steam-heated upper drying cylinders (40) and a similar series of lower drying cylinders (41).
A conventional paper drying apparatus is shown having a. However, instead of conventional dry felt, the bells 1-(
42), guide this belt to the roll (43) and wrap it around the upward surface of the cylinder (41).
On the other hand, a tensioning device (44) schematically shown is used to apply appropriate tension to the belt.

Similarly, the second belt (45) is guided by rolls (46) and tensioned by a tensioning device (47);
Wraps the downward surface of the cylinder (41) J: Passes through the sea urchin.

The paper (48) to be dried is dried in the paper machine's wet 1~press (
(not shown) and alternately passes through the cylinders (40, 41) between the first cylinder (41) and the belt (45). The paper is held tightly between cylinders (40) and (41) by bells 1 to (44) and (45). In this way, shrinkage of the paper due to drying can be suppressed, and at the same time, moisture can be easily drained to the outside from the pores of the belt.

Once the paper leaves the last cylinder (41), it is either wound onto a size press or passed through this press to a drying section as well before further winding.

Neither the size press nor the winding device is a component of the present invention.

[Brief explanation of drawings]

Fig. 1 is a detailed plan view of the porous belt according to the present invention, Fig. 2 is a sectional view taken along the line ■-■ in Fig. 1, Fig. 3 is a sectional view similar to Fig. 2, and Fig. 4 is a cross-sectional view of the porous belt according to the present invention. Further detailed plan views of the belt according to the invention; FIG. 5 is a schematic side view of the wet end of the paper machine; FIG. 6 is a schematic side view of the first device for press drying the paper; FIG. A schematic side view of a second drying device similar to FIG. 6; FIG. 8 is a schematic side view of a conventional paper drying device according to the present invention; (1, 3, 5): Sheet member, (2, 4, 6): Pore, (8): Feudrine wire, (10, 11, 30, 40, 41) Nijilinda, (2
4, 37, 48): Paper. 16-FIG, 5°

Claims (1)

[Claims] 1) A belt used for draining water from a male papermaking dispersion or a sheet made from the same, the belt being flexible, corrosion resistant, stretch resistant, and A porous endless belt comprising a sheet member having pores with high tensile strength. 2> The porous endless belt according to claim 1, wherein the belt is a metal sheet member. 3) The porous endless belt according to claim 2, wherein the metal sheet member is formed by electrodeposition on a matrix having protrusions arranged at intervals. 4) The porous material according to claim 3, wherein the matrix is coated with an electrically conductive release coating that promotes electrodeposition and facilitates separation of the sheet member from the matrix. Sexless belt. 5) The porous endless belt according to claim 3 or 4, wherein the shape of the protrusion is a truncated cone. 6) The porous endless bell 1 according to claim 5, wherein the sheet member is made of nickel with a thickness of 0.1 mm to 0.15 mm. 7) The thickness of the bell 1 is 0.1111111. Pore diameter 0
．． 11III to 0.15 mm, pore pitch 0.
25111 m and a sheet opening area ratio of 32.5%, the nickel plate is formed by electrodeposition processing.
Porous endless bells 1 to 1 described in Section 1. 8) Both ends of the belt are butt-welded, and fine holes are formed in the welded portion by spark processing to seamlessly join the belt. The porous endless belt according to item 1. 9) The porous endless bell 1 according to any one of claims 1 to 8, wherein the seamless joint is formed by electrodeposition. 10) The porous endless belt according to claim 1, characterized in that the belt is made of a plastic deck material. 11) A fort linear paper press drying apparatus characterized by having a bell I according to any one of claims 1 to 9. 12. Any one of claims 1 to 9
A machine glaze cylinder for a paper machine machine, characterized in that the bell 1- described in paragraph 1- is pressed against the outer surface of the paper around most of the circumference of the cylinder. 13) Any one of claims 1 to 9
A paper drying apparatus characterized in that it is equipped with bells 1 to 1 as described in 11''l.