DE1217775C2 - Process for the production of paper-like non-woven fabrics - Google Patents

Description

After drying, the material had a weight of 190 g / m *. It would smoothed by calendering at 90 ⁰ C and 50 kg / cm line pressure. Then a line was applied from the following mixture:

Acrylic ester mixture polymer .. 15 parts

Casein .... ■ '. · ■. 8TeHe

Kaolin ..,. 40 parts

Barium sulfate 40 parts

Calcium sulfate. 20 parts

The end product had a coating mix uptake of 25 g / m ² . It was then satinized. It could be written on with ink and Indian ink as well as with pencil and was erasable. ¹ p

The tear strength was a maximum of 3.2 kg. In the case of a drawing board of comparable weight, the value betrayed the tear strength maximum 0.2 kg.

Example 2 ^ao

A nonwoven fabric ^{weighing 60 g / m 2 was} produced from polypropylene fibers having a length of 40 mm (1.5 denier). It was made to skid through the gap in a roller mill. The latter consisted of hot * 5 of 150 ⁰ C steel top roll and a Baumwoüunterwaize, which was heated to 120 ⁰ C. The line pressure in the gap was 70 kg / cm. After passing through the latter, the pre-consolidated nonwoven web was turned so that the layer previously lying on the cotton roller now came against the steel. She was sent for the second time through the rolling mill, this time under a pressure of 80 kg / cm and a temperature of the steel roll of 16O ⁰ C and 15O ⁰ C. cotton roll from the solidified nonwoven fabric was treated with an aqueous dispersion of

Vinyl acetate-vinyl laurate mixed

poiymerisat 100 parts

Titanium dioxide 100 parts

soaked.

The material was dried and had a vinyl ^{resin uptake of 40 g / m 2.} It was now passed through a heated two-roller calender at a line pressure of 90 kg / cm and a temperature of 100 ° C. It was then given a line for further improvement the printability provided.

The following comparison tables result in; that the excellent properties of the invention produced polypropylene paper is not based on the strength of the starting fibers. As Table I shows the strength and elongation at break of the polypropylene fibers are even less than with other synthetic fibers.

Table 1 Polyamide-6 1* Polypropylene
(linear) Polyethylene
(linear) fiber Polyethylene glycol
terephthalate 6th
47.0 5.15
43.6 4.69
20th Strength, g / den
Elongation at break,% 5.45
47.6

If a fleece is welded to one another from the respective fibers, the resulting fleece weight of 100 g / m ^{2 is} produced and this according to material still has a strength and elongation at break ^ Example! solidified with hot rollers, so the 40 each is about the same as with similarly produced fibers at their points of intersection with nonwovens made of other fibers. This follows from Table 2:

table

Thermoplastically welded fleece
Weight per unit area 100g / m ^a Polyethylene glycol
terephthalate. ■ polyamide-6 Polypropylene
(linear) Polyethylene
(linear) Strength in kg / 5 cm strips .....
Elongation at break,% 8.4
12.5 8th
15th 8th
11 9
11

Only when you have the pores of a polypropylene nonwoven filled with high polymer substances such as acrylates, PVC and the like, you get a writable Flat structure, its strength and elongation at break

table

Surprisingly, it is much higher than that of nonwovens made from other fibers, but with the same High polymers were filled (see Table 3).

After pore filling
Weight per unit area 220 g / m ² Polyethylene glycol
terephthalate Polyamide-6 Polypropylene
(linear). Polyethylene
(linear) Strength in kg / 5 cm strips
Elongation at break,%
Strength, elongation at break 48
25.5
1224 21
22.5
477 37
49.5
1831 15th
15th
225

The increased elongation at break is an advantage, since the ⁶ 5 of a flat structure can be made more elastic in the last structure and, generally speaking, the product of strength and breakage, increased "durability" is obtained. evaluate elongation. As an approximate guide to the "durability"

Claims (1)

written process Papers with particularly high patent claims: qualities that can be produced. To produce the new type of paper, Process for the production of paper-like and next a wholly or partially wet-strength nonwovens from polypropylene fibers, which wholly or partly consist of 5 existing dry nonwoven, e.g. B. consist of polypropylene fibers by pressing, characterized in that a dry polymeric air-permeable fiber sheet solidifies by means of two heated rollers. propylene fiber fleece in the heat over 100 ° C and for this purpose the pressure and the temperature with line pressure over 10 kg / cm to an equal- within certain limits. If you lead moderately air-permeable fabric solidified io _z . ß. solidification under too high a pressure or if the pores then pass through at too high a temperature per se, then in extreme cases high polymer substances, in the case of a film, have the above-mentioned disadvantages, such as PVC, polyacrylate, polyvinyl acetate, their low strength and poor printability, softening point lower than that in the fiber. But also a uniformly consolidated fleece is used fibers to be filled. 15 air-permeable fiber sheet is still poor to describe. This is evident on the hydrophobic, not absorbent polypropylene fibers. Ver , to increase the absorbency, use im It. it is known that in the production of the usual 20 fiber structures, some cellulose fibers are used; Cellulose papers on the wet route also have short syn- other disadvantages, such as deterioration of the to use synthetic fibers. It is also dimensional stability, with itself. known, only made of synthetic fibers papers According to the invention, therefore, a uniform verzu produce. This happens - in contrast to the solid air-permeable fiber sheet, the Manufacture of cellulose papers - on dry 25 entirely or partially made of polypropylene fibers, Paths, so it is usually made of several centimeters with high polymer substances, if necessary long thermoplastic fibers prepare a fleece with the addition of pigments or dyes imdas nian then impregnated through the gap between two hot ones. Preferably thermoplastic Rolling sends. The thermoplastic high polymers, such as acrylic ester, PVC etc., are used to soften Fibers on the surface. As a result of the simultaneous 30 the softening point lower than the exercised The pressure in the nip is found to have used fibers. Be by calendering Gluing the fibers at their points of contact smoothed the fiber structures produced in this way. this instead of. 'happens at temperatures at which the thermo- With some synthetic fibers, the surface of plastic fibers cannot be attacked. The can be made sticky with the help of swelling agents. 35 then shows sheet-like structure in a microscopic section The subsequent application of pressure also allows fibers to stick together at their points of contact, whereby here a gluing of the fibers at the intersection, the gaps or pores through polymeric sub-points forming a paper. punch ~ are filled out. On this material will The strength of all these "synthetic papers" may depend on a final stage of the process depends on the strength of the fibers used. 40 a final line is applied, depending on how it is used The fibers - as in the case of softening, are made from high-polymer substances Swelling agents - damaged, then also leaves the quality or mixtures of high polymers with Pigdes corresponding paper left a lot to be desired. ments or dyes. The last two This also applies to other properties, such as dimensional process steps can also be used under certain circumstances resistance, etc. In the preparation of the synthesis 45 can be carried out in one step. It's on this Papers are preferably used polyamide type possible, papers with excellent wet and / or polycaprolactam fibers. strength, high number of double folds and excellent It has also already been proposed to fiberize polyethylene-marked tear strength and tear strength to be slurried in water and in the usual places, which are related to printing and writing, So on the wet route, synthetic paper can behave like normal paper. The following to manufacture from it. The strength of the same, examples illustrate embodiments of the invention, speaks to that of ordinary writing paper. Better are the polypropylene films according to Example 1 in this regard Austrian patent specification 200 342. For production In the same, polypropylene is dissolved in a boiling earth oil fraction of 40 mm in length and then spread out on a base and a fiber fleece was poured with a thickness of 3 denier. The solvent evaporates, a weight of 100 g / m ^{2 being} produced. A transparent and smooth film was left behind. then through the nip of two 14O ⁰ C hotter This is, however - like all of the slides - sent with the usual steel rollers. The resulting material means that it is not printable or writable. 60 had an air permeability of 9001 / sec / m ² But you can print and write syn- 20 mm water column. It was subsequently linked to a thesis papers of high toughness, tear resistance and a moderate aqueous dispersion of - resistance using polypropylene vinyl chloride copolymer. producing fibers This fact is surprising (softening point 50 ⁰ C) ...... 50 Teüe as the mechanical properties of the polypropylene 0.5 _SO like fiber from those of other ^v synthetic fibers. Titanium dioxide 50 parts to speak. It could therefore not be foreseen that with r "" ' With the help of polypropylene fibers impregnated at the bottom.