KR810000790B1 - Treatment of fibrour material - Google Patents

Abstract

A process of producing a mult-laminated web having a outermust layers comprising at least one cellulosic fiber which is dipped with a curing agent, and dried until convert into thermoplastics, and an inner layers comprising at least piled cellulosic material which is dipped with a sizing agent are described.

Description

Manufacturing method of multiple fiber wave

1 is a schematic view of an apparatus for forming multiple layers of fibrous material in accordance with the present invention.

2 is a cross-sectional view of an intermediate product according to the present invention.

3 is a cross-sectional view of the final product produced according to the invention.

4 shows a variant of the device shown in FIG.

The present invention relates to a method for producing a multi-fiber web suitable for folding box boards.

In a typical method of dry forming a fiber web of wood cellulose which is broken down into a raw material of dry fiber such as a hammer mill, the fiber is conveyed to a distributor by conveying air flow. Wherein the fibers are placed on the porous molding surface or the band by the conveying air and sucked underneath the band by direct suction to the fiber web by suction. Form

In order to manufacture paper or boards of multi-fiber webs in this way, it is convenient to install a series of distributors, either of which is positioned in response to continuous and spaced inhalations along the respective bands. In doing so, the plies are formed one after another. The fibers supplied to each distributor are fed under the hammer and combined with each other.

The above method for forming dry-laid paper or multiple layers for boards is referred to as "form" above.

According to one embodiment of the present invention, the method of the above-described method impregnates the outer layer with a curing agent in the method of producing a multilayered solidified formed fiber web having at least three layers, and further comprising a first layer in the intermediate layer. It impregnates a sizing agent and makes it comparatively inpermeable with respect to the hardening | curing agent of an outer side surface.

The first sizing agent is preferably added to the body of the fibers constituting the intermediate layer in a hammer mill for formation of the intermediate layer. The layered web is then solidified by hot wet pressing. Once the web has solidified, when it dries, a second sizing agent is added to the web again to give the web moisture, which also hot-forms the surface of the wetted web.

When the present method is used for the production of folding box boards made of a multi-layer paper, the curing agent is starch and the first sizing agent is a wax 1 rosin sizing agent. The second sizing agent is preferably selected from among those containing starch, gelatin, latex compounds, vinyl polyphosphate or mixtures thereof, and in some cases, minerals such as clay may be added.

The second sizing agent is added to one or both sides of the web.

According to a second embodiment of the present invention, a multi-layered solidified dry forming fiber web is produced, which together with a pair of outer surfaces impregnated with a curing agent and an intermediate layer impregnated by an agent which makes the curing agent relatively impermeable. Will have.

The hardener is starch and the bed of intermediate layer is a wax rosin sizing agent.

The difference in the starch content of each layer ensures that, as with other factors, the elevation of the intermediate layer is reduced compared to the degree of solidification of the outer layer. This difference, together with the starch content and fiber supply, increases the strength at the surface, prevents cracking between the outer and inner surfaces of the board and facilitates gluing.

Hereinafter, an example of the present invention will be described with reference to the accompanying drawings.

Referring to FIG. 1, there is shown an apparatus for producing a board of multiple layers from dry placed fibers. The device includes a plastic endless porous band 9, on which dry fibers are placed in a series of distributor heads 10, 11, 12 and 13 spaced apart along the band. A vacuum or suction box 14 is placed below the band 9 at the bottom of each distributor head to thereby keep the fibers on the band. Thus each distributor head supplies one layer of the final board, heads 10 and 13 provide the outer side and 11 and 12 the inner side.

Each distributor head 10, 11, 12, 13 is supplied with a mixture of finely divided fibers or finely divided fibers and other materials in the hammer mills 15, 16, 17 and 18, respectively.

Hammer mills 15 and 18 are fed with wood pulp at reels 19 and 20, respectively. About 8% by weight of dried Viscosol dried starch is added to the pulp of Hemmer Mill 18 at the starch source21.

The pre-crushed dry wood pulp is fed to the hammer mills 16 and 17 in containers 22 and 23, respectively, and the sizing agent of water-resistant wax / rosin is sprayed in sprays 26 and 27 respectively before it enters the hammer mill. 10% by weight of bicosol dried starch is applied to the pulp in Hemmer Mills 16 and 17 in the same starch sources 24 and 25, respectively. As a result, the inner furries arranged by the distributor heads 11 and 12 become water resistant by the sizing agent of the water resistant rosin / wax contained therein.

The web 8 of the multiple layers of the resulting dry batch is then wetted by a water spray 28 on its top face (ie, arranged by the distributor 13) and has a water content of 35% by weight. The wet web is passed through the surface of the Silinda 29 heated with steam at a temperature of 110 ° C. and is also pressured by a pressure roller 30 to a pressure of 17.8-44.5 kg / cm (100-250 pounds / inch) over a quarter of its surroundings. Press to solidify.

Leaving cylinder 29, web 8 is wetted underneath (ie the layer disposed by distributor 10) with a water spray 31 of 5-10% solution of biscosol starch. The water content of the wet web is 15-20% by weight. The web passes through a nip 32 formed by a roller heated to 110 ° C. and a pressure roller exerting a pressure of 3.5-17.7 kg / cm (20-100 pounds / inch) to solidify the bottom or back of the layer. do. The web passes the attention of a dry cylinder 33 at a temperature of 110 ° C. The drying web, typically containing 6-8% by weight of moisture, is then passed through a sizing press roller 80 at a pressure of 8.9-44.3 kg / cm (50-250 pounds / inch). For example, a solution of 20% bicosol starch and 38% polyvinyl acetate is applied upon pressing through nozzle 38. The pressurized web is passed through a cylinder 35 steam heated to a temperature of 110 ° C. and press contacted by a rubber press roller 36 at a nip pressure of 3.5-8.9 kg / cm (20-50 lbs / inch). Wet press molding takes place. This action smoothes and solidifies the top of the board. Different heating cylinders and press rollers give the same hot wet pressing action on the opposite side. The web is generally passed through a coating and aftertreatment device as seen at 37.

The sizing agent applied to the web 8 by the nozzle 38 is moist and the amount of sizing agent used is adjusted so that the sized web has a water content of 15-30% or possibly 25% by weight when leaving the sizing agent press 34.

An alternative method of treating this wet sized web after the web leaves roller 34 is described in FIG.

The wet web that has been sized after leaving the sizing agent roller 34 is then hot formed and pressed while passing through the guide roller 46 and through the press nip of the large heating roller 45, and the electric heating roller 45 hits the circumference. (felt) 7 moves along with the pressure roller passing through. The molded web is then notified of the remaining post-treatment section, which is then subjected to painting and calender roller processing before being wound on the feed drum as a final production board.

As a liquid alternative sizing agent, gelatin, latex compound, vinyl polyacetate or a mixture thereof may be added to mineral materials such as clay as necessary.

The sizing agent is added in any suitable way. Instead of applying this to both sides of the web, it may be applied to only one side.

An example web is rated 50-500 g / cm ² and also passes a sizing agent press and hot forming roll at a speed of 61 metres / minute (200 feet / minute). Roll 45 is steam heated to a surface temperature of 93-204 ° C. The nip pressure between the forming rolls 45 and 47 shall be 8.9-44.5 kg / cm (50-250 lbs / inch).

The surface of the roller 45 is smoothed or patterned according to the required surface of the web. The roller 45 acts on the upper surface of the web, that is, on the surface where the mark of the cast iron is not attached.

In one variant of the invention, the web deviating from the forming rollers 45, 47 is hot-molded at a time, but at this time the other side of the web, i.e. the surface with the iron mark, is acted upon by a set of large heating rollers of the other forming rollers. If the web leaving the forming roller 45,47 does not have enough moisture for the next hot forming, it is resized and the necessary amount of water is added before entering the next forming roller. For resizing, only two or one side of the web is sized.

If roller 45 forms a smooth surface, one web of the present invention can provide a good smooth surface for future printing.

An example of the present invention shown in FIG. 4 is to provide a method of web processing as a fiber material manufactured according to the dry forming technique, in which case the web is sized after forming, solidifying and drying and the water content is about 25% by weight. After the next sizing the wet web is formed by a heating roller cooperating with the press roller and hot formed by passing through the press nip.

The starch-containing outer surfaces of the webs shown in FIGS. 1 and 4 are treated with a sizing agent and pressed and hot pressed to obtain the effect of curing and strengthening these outer surfaces. Penetration into the inner surface is limited by the amount of water-repellent sizing agent treated on the inner surface. The hardener (such as starch) is thus concentrated at the outer side but this is an ideal area for improving the hardness of the web.

Thus, the sizing of the inner bottom suppresses the absorption of the curing agent such as starch applied to the outer surface.

2 shows a cross section immediately after the web passes through the drying roller 33. The inner surface 41,42 contains a water repellent sizing agent and the outer surface 40,45 contains starch. Both sides are solidified. Waves are typically 8 kenley units in intensity. After passing through the sizing agent roller 34, the hardness of the web is typically 12 Kelly units.

3 shows the cross section after the web has passed through the sizing press roller 34 and the hot-wet press (solidified) cylinder 35. Significant additional strength is given to the outer surfaces 40,43 but most do not transmit to 41,42. Typically the hardness of the web amounts to 15 Kenley units. The aftertreatment web is typically a mechanical pulp of surface and backliner plies and 8% biscosol starch and 3% sizing agent, with 18% biscosol starch and 1% vinyl polyacetate as chemical pulp. It has an inner surface. Each layer is usually not homogeneous but increases the concentration of adduct towards the surface.

The use of an inner side sizing agent (for example, a wax base "base") can reduce the heightening of the inner side as compared with the outer side by the action of resisting penetration of each layer itself and the curing agent. The change in degree of solidification is influenced by other factors such as moisture content and heat. These differences, along with the difference in the content of the curing agent in each layer, create a barrier between the inner and outer surfaces. This barrier, when decorated, affects the degree of bilayer between the inside and the outside, as a result of which the web's flexibility can be improved.

Thus the strength and hardness of the final web is concentrated in its outer layer and also a barrier is formed between the inner and outer sides to facilitate the bilayers between each of these layers when the board is decorated.

The above-described method can be modified. As for the inner surface, less or no starch is applied to the pulp. The sizing agent used for the inner surface includes an adhesive or a cross-linking agent such as rubber or hemicellulose. The pulp of the first distributor 10 is adjusted to the amount of starch that is applied to the quarter or to the distributor 13 or the atomizer 31 or 28.

Instead of using starch as a curing agent, for example, a curing agent such as hemicellulose or calvokimethyl cellulose can be used to impart a predetermined hardness, strength and decorating properties. The nip pressure and cylinder temperature are adjusted to meet the needs of the individual web. Other types of pulp may be used.

The present invention can be applied to folding box boards or other container board webs.

Claims (1)

A pair of outer layers comprising a cellulose fiber material impregnated with a curing agent and an intermediate layer bonded to a folding box board composed of cellulose fiber material, wherein the outer layer is a dry cellulose fiber. Wherein the material is solidified by pressurizing and heating means and the intermediate layer is relatively impermeable to the hardener by impregnating the first sizing agent.

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