DE2343357B2 - REINFORCED PAPER LAYERED MATERIAL - Google Patents

Description

35

The invention relates to a reinforced layer material with at least two paper layers and at least one interposed layer of synthetic fiber material, the paper layers of short Cellulose fibers are formed and through the gaps in the synthetic fiber material without a binder are matted together.

Efforts have long been made, a light, soft reinforced paper product in particular as a substitute for conventional woven products in the field of hospital and medical services to create in order to save the laundry costs, which are particularly high in this area (US Pat. No. 25 64 689 and 31 93 436). In particular, according to US Pat. No. 33 41 394, paper products are to be made from staple fibers Fiber fleece are reinforced. This patent discloses a host of uses for a nonwoven fabric made of polyester; one of these uses is in reinforcement of paper products. However, there is no specific information about the properties of such a composite material made; there is also no mention of how the composite material is constructed or produced target. The US-PS 26 38 146 discloses a method for (> o Preparation of paper which is reinforced with randomly deposited continuous glass fibers. at Other known proposals for the production of fiber-reinforced paper structures are woven and knitted goods, staple fiber fleece or 6s as reinforcement material parallel continuous filaments and yarns are used. So it is known (FR-PS 16 03 320) a reinforced Cardboard material by slumping two paper cover layers and a reinforcement layer in between from a knitted fabric or from fibers made of synthetic material in the usual way in the Making paper in the dewatering part of the paper machine. It is similarly known (DT-PS 646 265), on a forward moving fleece from parallel in the direction of travel Raw fibers lay a second fleece of the same kind in a zigzag shape and this multi-layer fleece or to slump away on both sides with paper webs that are in the process of being created. Another popular suggestion (DT-PS 98 711) refers to the production of sack material, in which a jute or linen fabric in the tensioned state a flowing paper pulp is fed separately from both sides, whereupon the intimate connection by pressing between metal rollers. Laminated materials produced in this way ; n are, however, relatively heavy and unwieldy. It is also difficult to achieve a steady Coating of the reinforcing insert to achieve when the paper plies during papermaking be applied.

In contrast, the invention makes the task solved to create a reinforced cellulose layer material, which is light, supple and soft and has excellent tear resistance.

This is achieved according to the invention in a reinforced layer material of the type mentioned in that the synthetic fiber material consists of a fast fleece with a basis weight of no more than 13.5.5 g / m ² and a projected gap area of more than 50% of continuous nylon fibers autogenous at a plurality of intersection points of touching fibers, e.g. B. are connected to one another by pressure welding, and that the paper layers are felted together as tissue paper-like cellulose layers in the form of finished webs.

Process for the basic production of such a fiber fleece from synthetic material are known from US-PS 35 42 615 and 33 41 394. For the purpose according to the invention, however, the fiber fleece must not ^{weigh more than 13.53 g / m 2} and must be on one level have a gap area projected parallel to the fiber fleece layer of more than 50 area percent. The cellulose layers are composed of short cellulose fibers, the fibers of adjacent cellulose layers being felted together through gaps in the fiber fleece layer, so that the cellulose layers are mechanically fastened to one another. Since the cellulose layers in the form of finished webs are felted through the gaps in the fiber fleece, easy handling of the cellulose layers is achieved during the production of the layer material and there are no difficulties in covering the reinforcing insert completely and evenly. At the same time, in comparison to known layer materials, in which a fiber fleece with fibers lying loosely on top of one another at the intersection points or a fabric is used as a reinforcement insert, according to the invention a better dimensional stability and increased tear strength is obtained, since fibers of the fiber fleece or the fabric are not connected to one another at the intersection points can slip against each other when stretched, which can lead to the destruction of the binding of the top layers. In contrast, such a destruction of the bond of the cellulose layers does not take place in the layer material according to the invention because the autogenous bond of the reinforcing fibers at their crossing points

prevents relative movement of the fibers at the intersection points, regardless of whether in which direction the tensile stress acts

The layer material according to the invention is such a light, high-strength reinforced paper product which for use as face wipes, toilet paper, hospital gowns, easy-to-use wipes, in particular for hospital beds, and is advantageously suitable for all kinds of kitchen towels.

In one embodiment of the invention, the fibers of the cellulose layers are shorter than 9.53 mm. Through this are enough for the felting of the cellulose layers in the form of finished webs through the gaps of the Fiber fleece passing through free ends of the cellulose fibers present.

In a further embodiment of the invention it is proposed that the continuous fibers of the synthetic fiber fleece are arranged in the plane without any apparent order. By using such a "tangled fleece" in which the fibers are autogenously connected to one another at the intersection points are, the stretchability is reduced when the tear strength is increased and there are many gaps in irregular distribution available through which the cellulose fibers from the cellulose layers can tangle with one another, so that there are many binding sites per unit area.

Furthermore, it is proposed in a further embodiment of the invention that 20 to 50% of the surface The cellulose layers are embossed according to a specific pattern formed by elevations are. The embossing can be carried out, for example, with the aid of a pair of pressure rollers one of which has a specific embossing pattern and the other has a flexible surface have so that the embossed surface of the former pressure roller can enter and the embossing pattern is transferred to the reinforced sheet of sheet material lying between the pressure rollers. if the embossing pattern is such that less than 20% of the surface of the cellulose layers is embossed, no longer finds a good bond between the cellulose layers. On the other hand, if more than 50% are embossed on the surface of the cellulose layers, the embossing does not produce any significant Achieve improvement in the suppleness of the layer material.

A preferred embodiment of the invention is described in detail with reference to the drawing. In the drawing shows

F i g. Figure 1 is a schematic representation of one used for the manufacture of reinforced cellulosic fabrics Device and

F i g. Fig. 2 is a pictorial sectional view of the fabric showing how and how the cellulose layers are cut through Gaps in the non-woven fabric made of synthetic material penetrate and bond together by entanglement short cellulose fibers are bound, which are present in the cellulose layers.

According to FIG. 1, web-shaped cellulose layers 6 and 8, respectively, form a gap through the paper rolls 10 and 12 fed, which is formed between rollers 13 and 14. A fiber fleece 7 made of staple fibers is withdrawn from the feed roller 11 and into the through the Rolls 13 and 14 fed into the gap formed. The fiber fleece 7 comes into the gap when it enters to lie between the cellulose layers 6 and 8. Dip β. 7 and 8 will be after between the

Rollers 13 and 14 are pulled through, immersed in a water bath 15 and guided -inter guide rollers 16 and 17, so that a thorough impregnation of the layers with the water is guaranteed. The layers are then led out of the water bath 15 and passed between pinch rollers 18 and 19 which wring excess water out of the layers. The layer web is then passed between pressure rollers 20 and 21. The pressure roller 20 is up to 150 ⁰ C heated to about 12G, the pressure rollers 20 and 21 bringing about 178 kg of nip pressure on the plies per running cm. The heat and pressure transmitted to the sheets by rollers 20 and 21 removes the water therefrom and causes the cellulose sheets to pass through the gaps in the nonwoven fabric, thereby mechanically bonding the cellulose sheets together by the entangle the cellulose fibers present in them with one another. The laminate 9 composed of paper and fiber fleece is then wound onto a winding roller 22.

In Fig. 2 is a part of the layer material made of cellulose layers 30 and 31 with an intermediate layer Nonwoven fabric 32 shown in section. The fiber fleece 32 is made up of continuous fibers 33. Numeral 34 denotes a gap area between the Fibers 28 and 29. When the wet cellulose and fleece layers are passed through between the pressure rollers 20 and 21, the small cellulose fibers present in the cellulose sheets 30 and 31 become through the gap 34 pressed through one another and as the layer material dries, the cellulose fiber becomes mechanical matted along the contact surface denoted by the reference numeral 35 and locked together. It is it can be seen that in the synthetic fiber fleece layer there are enough gap areas to achieve a sufficiently good mechanical connection between the; Cellulose layers 30 and 31 are present, though the cellulose fibers of which the cellulose sheets are made do not readily adhere to the organic synthetic ones Fibers that make up the fiber fleece layer because of the smooth and glass-like surface of the synthetic one Fibers adhere. The cellulosic fibers were also found to be no longer than about 9.5 mm need to have enough ends that pass through the gaps in the nonwoven fabric and matt together. In this way a reinforced cellulose laminate is created without any external appearance Binders are used.

It has been found that the synthetic fiber fleece must have a void area of more than 50 area percent so that a sufficiently good bond between the cellulose layers is achieved. The void area can be measured visually under a microscope or using a planimeter. It has also been found that a void area of more than 50% can only be achieved by synthetic nonwovens that weigh ^{no more than 13.53 g / m 2.}

The reinforced cellulosic sheet material can be made more pliable and softer in that it before binding is passed between a pair of pressure rollers, one of which is connected to a embossed surface pattern is provided and the other has a resilient surface, so that in this can enter the embossed surface of the former. It can so the heated pressure roller 20 with a embossed surface so that the embossed pattern on the reinforced cellulose laminate

will wear. This transfer of the embossing pattern results in the surface of the laminate in register embossed with the pattern of the embossed roll. It has been found to have maximum suppleness is achieved when 20 to 50% of the laminate surface with the above-described pattern of raised Area parts of the embossing roller are embossed.

If less than 20% of the area is embossed, there is no good bond between the cellulose layers instead, whereas above 50% the layer material regains properties that are obtained, when the sheet material is calendered with a smooth pressure roller.

1 sheet of drawings

Claims (4)

Patent claims: 1. Reinforced layer material of at least two paper layers and at least one intermediate layer of synthetic fiber material, wherein the paper layers are formed from short cellulose fibers and are felted together through the gaps in the synthetic fiber material without a binder, characterized in that the synthetic fiber material consists of a fiber fleece with a basis weight of not more than 13.53 g / m ² and a projected void area of more than 5% of continuous nylon fibers, which are autogenous at a variety of points of intersection of touching fibers, z. B. by pressure welding, are interconnected, and that the paper layers are felted together as tissue paper-like cellulose layers in the form of finished webs. 2. Layer material according to claim 1, characterized in that the fibers of the cellulose layers are shorter than 9.53 mm. 3. Layer material according to claim 1 or 2, characterized in that the continuous fibers of the synthetic fiber fleece are arranged in its plane without any apparent order. 4. Layer material according to one of claims 1 to 3, characterized in that 20 to 50% of the Surface of the cellulose layers according to a certain pattern formed by elevation are embossed.