ES2310337T3 - PAPER MACHINE, ESPECIALLY A TISSUE PAPER MACHINE. - Google Patents

Abstract

In a tissue paper making machine downstream the yankee-cylinder (9) and upstream the tambour roll (14) a spark detector (13) is provided in the vicinity of the paper web running to the winding-up section (4) in order to detect sparks of glowing fibers or fiber conglomerates, which can be enrailed by the high speed run of the paper web and can be transferred to the paper roll (15) where the sparks are trapped between the paper web windings of the paper mill. Knowledge of this fact offers the possibility to avoid fire in the mother-roll storage.

Description

Paper machine, especially a machine tissue paper

Technical field

The present invention relates to the field papermaking technician and especially to manufacturing of tissue paper and the field of the paper machine itself bliss

Background of the invention

If pulp tissue paper is to be made, the process essentially includes

a) form that includes the container and section training wire,

b) the drying section (TAD (air drying)) or conventional drying in a Yankee cylinder) which also includes Generally the essential tissue process for tissues,

c) typically the supervision section and winding.

The paper can be formed by placing the fibers, in a random or oriented manner, in one or between two wires continuously rotating a papermaking machine by removing simultaneously the main amount of dilution water until a dry solids content of generally between 12 and 35%

Drying of the primary fibrous leaf formed takes place in one or more steps by mechanical and thermal means up to a final dry solids content of generally approximately 93 to 97%. In the case of tissue manufacturing, this stage is followed by the correspondent process that influences crucial in the properties of the finished tissue product in processes conventional (see WO-A-02/36881). The process of Conventional dry correspondent implies corresponding in a cylinder of generally dried from 4.5 to 6 m in diameter, the so-called Yankee cylinder, by means of a knife corresponding to said final dry solids content of the raw tissue paper (can be use wet correspondence if lower quality requirements are imposed of tissue). The finally dry tissue paper corresponded (raw tissue) is then available for further processing than paper product or tissue paper product according to the invention.

Instead of the conventional manufacturing process of tissue described above, it is possible to use a technique modified in which a specific volume improvement is achieved by a special type of drying within process section b and of this way an improvement of the volumetric smoothness of the paper is achieved tissue so made. This process, which exists in several subtypes, is called the TAD technique (air drying). It is characterized by the fact that the "primary" fibrous leaf (analogous to a no tissue) that comes out of the formation and sheet formation stage is preseca at a dry solids content of approximately 80% before final drying by contact in the Yankee cylinder blowing air Warm through the fibrous leaf. The fibrous leaf is supported by an air-permeable wire or strap (or TAD cloth) and during its transport is guided on the surface of a drum too rotary cylindrical air permeable (TAD cylinder). The structuring of the wire or support strap makes it possible produce any configuration of compressed zones by deformation in the wet state, also called molding, giving place at increased average specific volumes and giving rise to consequence of an increase in volumetric softness without diminishing decisively the resistance of the fibrous leaf. Such configuration It is fixed in the area of the TAD cylinder.

A tissue paper is defined as a paper Soft absorbent that has a low base weight. Generally select a base weight of 8 to 30 g / m2, especially 10 to 25 g / m2 per layer. The total basis weight of tissue layers multiple is preferably equal to a maximum of 65 g / m2, plus preferably at a maximum of 50 g / m2. Its density is typically below 0.6 g / cm3, preferably below 0.30 g / cm3 and more preferably between 0.08 and 0.20 g / cm3.

Fabric production differs from the paper production due to its extremely low base weight and index much higher tensile energy absorption (see DIN EN 12625-4 and DIN EN 12625-5). Paper and tissue paper also differ in general with respect to modulus of elasticity that characterizes the properties of stress-strain of these flat products as A parameter of the material.

A high rate of energy absorption of tissue traction results from the outer or inner correspondent. He first it is produced by compression of the sheet of paper that adheres to a dry cylinder as a result of the action of a matching blade or in the last example as a result of a speed difference between two threads ("fabrics"). This makes the sheet of plastically deformable paper still wet break internally by compression and cutting, thus becoming more stretchable under load than unrequited paper.

The wet tissue paper sheets are dried usually by the so-called Yankee drying or air drying (TAD)

The fibers contained in the tissue paper are mainly cellulosic fibers, such as chemical pulp fibers (for example, sulphite and Kraft sulfate pulp), mechanical pulp (for example, ground wood), thermomechanical pulp, pulp chemomechanics and / or pulp chemo-thermo-mechanics (CTMP). Be you can use pulp derived from deciduous (hardwood) and conifers (softwood). Fibers can also be or include recycled fibers, which may contain some or all of the previous categories. The fibers can be treated with additives, for example softeners, such as ammonium compounds quaternary, and binders, such as conventional agents of wear resistance or wet strength agents used to facilitate the manufacture of original paper or to regulate its properties. Tissue paper may also contain other types of fibers, for example regenerated cellulosic fibers or fibers synthetics that improve, for example, resistance, absorption, the softness or softness of the paper.

The tissue paper can be converted to the product final tissue in many ways, for example, embossed or lamination to a multilayer product, laminated or folded. Such Products can be paper towels, paper compresses, tissues of paper, facial towels, etc.

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Description of the invention

The inventor realized that, increasing the ambient temperature in special areas of the paper machine especially behind the drying section located further towards below, for example the Yankee cylinder, sparks of fibers or fiber conglomerates and these sparks can be dragged and transported by the high speed of the blade to the winding section and get caught between the winding layers of the sheet of paper and produce hot flashes inside the roll of paper (mother roll). If this mother roll is then stored in a storage room of mother roll and luminescence inside of the mother roll becomes fire, there is a high risk that the Fire destroy all storage contents.

The problem (object) of the present invention is avoid it and ensure that such a disaster can be avoided.

This problem is solved with a machine make paper according to claim 1 wherein behind the drying section located further down, or at least up of the winding section, a spark detector has been arranged near the sheet of paper that advances to the winding section.

If the detector then detects the presence of sparks as described above, not only does the possibility of eliminating the formation of fiber sparks, but of storing the corresponding mother roll separate from storage of mother roll in a safe area at least temporarily for security.

Preferably in a tissue paper machine the spark detector is arranged down the Yankee cylinder where it is very likely that sparks may appear.

To prevent detector malfunction of sparks if it gets dirty with paper dust and other debris from environment, means of cleaning air jet are provided, where Its air jet is directed to the spark detector.

According to another possibility, the spark detector is combined with a means of advance-guide of leaf that stabilize the advance of the blade. The spark detector will place there near the paper sheet in advance so that the Sparks can be detected safely.

In order to avoid extra jet means of air cleaner, sheet guide advance means include at least one guiding surface behind which provided a space surrounded at least partially by a box, in that an air inlet hole is arranged in such a way that the air sucked by a low pressure created by the advance of the blade Go to the spark detector for cleaning. However, this system can be combined with air jet means cleaner.

A preferred position for the detector sparks is down a sheet measuring means, where it measure the base weight and water content of the leaf. It's a position where the paper sheet stabilization can be maintained what as short as possible and there is no need to install other media there.

With the invention the spark detector remains clean and you don't have to do a special cleaning to which would have to stop the machine. Either way, despite the presence of the spark detector, for example, between the Yankee cylinder and winding section, it maintains a good paper sheet stability.

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Brief description of the drawings

Figure 1 schematically represents a realization of a tissue paper machine.

And figure 2 represents, enlarged in comparison with figure 1, a sheet of paper sheet guide containing a spark detector.

Embodiments of the Invention

Figure 1 schematically illustrates a tissue paper machine including a container 1, a section of formation 2, a drying section 3 and a winding section 4. The reference number 5 denotes a forming tissue and the number of reference 6 downwards a felt that guides the sheet of paper W from training section 2 to drying section 3. There are a pickup 7 which transfers the sheet of paper from the section of formation 2 to felt 6. Reference number 8 denotes a roll trainer In the drying section 3 a cylinder has been arranged Yankee 9 partially surrounded by a drying bell 10. A Corresponding blade 11 removes the Yankee cylinder coated with a special chemical agent of the circumferential surface of the Yankee cylinder From there the sheet of paper W is guided to a measuring device 12 where, for example, the content of moisture and the basis weight of the paper sheet. Behind, for example, down the measuring device, a detector of sparks 13 near the sheet of paper, where the sheet of paper is guided to the winding section where the sheet of paper is rolled in a tissue drum 14 that converts the sheet of paper into a paper roll as the so-called mother roll 15. Such sparks that they can be especially present and created when the material fiber, possibly combined with dust and lumps of paper, probably combined with the chemical agent with which it Covers the Yankee cylinder, fill the space between the bell dryer 10 and the Yankee cylinder 9. This results in friction, which could produce higher temperatures that lead to sparks fiber The sheet of paper W is extended in Figure 1 according to the arrow 16 from right to left.

The spark detector 13 is illustrated with more detail as an embodiment in figure 2. There is no need to use a Spark detector in this way. The only spark detector is can place anywhere down the Yankee cylinder and up the drum 14. Ensure that the detector is keep clean, what can be done with a positive jet of air directed to the detection part 17 of the spark detector 13.

In the special embodiment illustrated in the Figure 2 the spark detector 13 is combined with a device paper sheet (sheet) 18 feed guide that includes a box closed 19 provided with guide surfaces 20 to stabilize the advance of the sheet of paper at high speed. Such guiding means they are used anyway in the papermaking machine and it is possible to form the guide means in the manner illustrated in the figure 2 and combine the guide device 18 with the spark detector 13. By advancing the sheet of paper W along the guide surfaces 20 a subpressure is created in space 21 of the box and through a hole 22 near the spark detector 13 se breathes air into space 21 along the dotted line in the Figure 2. Thus, the detection part 17 of the spark detector 13 It is kept clean during the operation of the paper machine so that the operation of the paper machine does not have to interrupt to clean the spark detector 13. In this way, the spark detector 13 is arranged near the sheet of paper W and incandescent fiber sparks from fiber conglomerates can be detected when transported on top of the sheet W paper and rolled in the mother roll 15.

Separately or in addition, a positive air jet device 23 on the wall 24 of the case 19. The air jet is directed to the detection part 17 of the spark detector 13, illustrated with the dotted line. The means for supplying air to this device 23 are not illustrated and can be any known means of air supply.

That way, you don't have to set the detector sparks immediately up the drum 14 where normally there is less space because the distance between the cylinder Yankee 9 and the drum will be as short as possible to Stabilize the sheet of paper.

When these sparks are detected, it is possible, on the one hand, stop the machine and try to cancel the creation of such sparks. On the other hand, it is known that such sparks were possibly trapped in the sheet of paper wound in a specific mother roll and it is possible to separate this storage mother roll of the normal mother roll in order to avoid great fire damage inside the roll storage mother.

The box 19 can be a simple steel box as schematically illustrated in figure 2.

Claims (6)

1. Paper machine, especially machine tissue paper, including downward direction at least one container (1), at least one training section (2), at least one drying section (3) and down the drying section located further down a winding section (4) including a roll of winding (14) to form a roll of paper (15), characterized in that behind the drying section located further down (3) or at least upwards of the winding section (4) a spark detector (13) is arranged near the paper sheet (W) that advances to the winding section. (4). 2. Paper machine according to claim 1, characterized in that the paper machine is a tissue paper machine including a Yankee cylinder (9) and because the spark detector (13) is disposed downwards of the Yankee cylinder (9). 3. Paper machine according to claim 1 or 2, characterized in that cleaning air jet means (23) are arranged, wherein its air jet is directed to the spark detector (13). 4. Paper machine according to one of claims 1 to 3, characterized in that the spark detector (13) is combined with a guide-advance means (18) that stabilize the advance of the sheet. 5. Paper machine according to claim 4, characterized in that the sheet advance-guide means (18) include at least one guide surface (20) behind which a space (21) is provided at least partially surrounded by a box (19), in which an air inlet hole (22) has been arranged such that the air drawn at a low pressure created by the advance of the sheet is directed to the spark detector (13) for cleaning . 6. Paper machine according to one of claims 1 to 5, characterized in that the spark detector (13) is disposed downwards of sheet measuring means (12).