DE102009037701A1 - Transparent, water permeable textile shading area for use as shading cloth for e.g. greenhouse, has transparent polyester threads with specific gram equivalent weight percentage and containing UV and hydrolysis stabilizer - Google Patents

Abstract

The shading area has a transparent polyester threads with 70 gram equivalent weight percentage and containing UV and hydrolysis stabilizer. The polyester threads consist of polyethylene terephthalate, polypropylene terephthalate and polybutylene terephthalate. The polyester threads comprise a yarn count between 33 decitex and 40 decitex. The shading area is formed as a multifilament yarn or monofilament yarn, and is made of metallic threads i.e. aluminum. The polyester threads have non-round cross-section i.e. point or axially symmetric cross-section.

Description

Technical area

The This invention relates to shading fabrics for agricultural use Cultures.

State of the art:

In South and Central Europe, shading fabrics are used to produce crops to protect against intense sunlight. They become overcast Sky and pushed to the side in the rain, with intense direct Solar radiation as protection extended to a portion of the sun's rays to absorb. As a guide and carriers The shading fabric usually serve wires that are in appropriate Mounts are anchored on the edge of the fields or over greenhouses.

Becoming present Shading fabric used from natural fibers or synthetic fibers. There they are exposed to direct sunlight and also rain, Their durability is limited by UV degradation and hydrolytic degradation. For higher quality shading fabrics UV stabilizers used. They extend the durability in sunlight, but not the hydrolytic Degradation.

hydrolysis are also known, for. B. carbodiimides for the stabilization of Polyesters. However, they are only used in technical fabrics. For the direct or indirect food contact are these stabilizers not allowed.

• – fest über den Kulturpflanzen verbleiben kann,
• – auch bei bedecktem Himmel ausreichend transparent ist
• – und deren auf die Kulturpflanzen tropfendes Regen- oder Kondenswasser keine Schadstoffe enthält, die von der chemischen Zusammensetzung der Beschattungsfläche herrühren.

Object of the present invention is to provide a textile UV and hydrolysis stable shading surface, the

• - can remain firmly above the crops,
• - is sufficiently transparent even in overcast skies
• - And whose dripping on the crops rain or condensation water contains no pollutants resulting from the chemical composition of the shaded area.

Is solved the task by using transparent bottle raw material from polyethylene terephthalate (PET): The PET granule stream is present Extruding gravimetrically a masterbatch with UV stabilizer and also gravimetrically polycarbonate as a hydrolysis stabilizer added. The material is then melted in the extruder, over a Gear pump pumped into a spinning pack, over there sand, Metal powder or ceramic filtered and finally through the fine bore the spinneret pressed. Below the spinneret is the preformed filament, consisting of still liquid polymer, in cooled in a laminar air stream or in a water bath, then multi-stage stretched and wound up. The processes for the production of filaments are known in the art, so that will not be discussed in more detail must become.

The so produced filaments become a relatively open, water-permeable textile Surface processed. Therefor are particularly suitable monofilaments.

monofilaments have a relatively large Diameter, generally ≥ 15 μm all the way up to a few millimeters. Multifilament threads, in contrast, consist of several Single filaments with diameters <15 μm, mostly in the range between 1 μm and 10 μm. multifilament are less stiff because of their smaller diameter.

Same textile surface constructions made of multifilaments allow less water through than textile surfaces Monofilaments of the same titer. The reason for this is the lower surface and higher Stiffness of the monofilaments.

If necessary. are also metal threads, in particular aluminum threads woven into the fabric. This can be confectioned directly over the Crops are used as a transparent shade dispenser. Even in intense sunlight, a diffused light is created below the shading network. When it's raining, you can still get water penetrate the net and reach the plants. Likewise the water discharged from the soil and the plants as steam that Shadow tissue happen.

Advantage of the network according to the invention is the UV stability combined with the polycarbonate as hydrolysis stabilizer. Neither the dripping on the crops rainwater nor the direct contact between ghost net or degraded polymer with the crop plants is critical because the polycarbonate hydrolysis stabilizer is food grade and thus there is no risk of contamination of crops with hazardous substances.

Also becomes the otherwise labor-intensive step of pulling or opening conventional Shadow nets with it redundant.

in the The following example illustrates the properties of the threads according to the invention: Basic raw material is the PET bottle raw material RT 16 from Invista Resins & Fibers GmbH, Philipp-Reis-Straße 2. D-65795 Hattersheim on the Main.

• - CESA f-/light NBAADH 12020 der Firma Clariant Masterbatches GmbH, Hohenrhein 1, D-56112 Lahnstein, bzw.
• – LIFOSTAB HL 3011 PET/UV der Firma Lifocolor Farben GmbH, Reundorfer Str. 18, D-96215 Lichtenfels.

As described, a UV masterbatch is added to this raw material. The following masterbatches were used:

• - CESA f- / light NBAADH 12020 the company Clariant Masterbatches GmbH, Hohenrhein 1, D-56112 Lahnstein, respectively
• LIFOSTAB HL 3011 PET / UV from Lifocolor Farben GmbH, Reundorfer Str. 18, D-96215 Lichtenfels.

added each 0.5% by weight to 5.0% by weight in 0.5% by weight increments.

When food grade Hydrolysis stabilizer was the polycarbonate Makrolon 2458 from Bayer AG, Liver cough used. Again, in steps of 0.5% by weight added from 1.5% by weight to 5.0% by weight.

With These doses were round monofilaments in 0.15 mm diameter spun and tested (internal type designation 0.15 mm 900 NR).

The Textile values and UV stability tests showed no significant differences between the two UV stabilizers. The results with 3% to 4% UV stabilizer were within the Measurement spread equal. This corresponds to a UV stabilizer content from about 0.75% to 1.6% by weight in the polyester melt, as appropriate Concentration of the masterbatch.

In dosing of the hydrolysis stabilizer turned out 2% 3% as optimal. At more than 3% by weight, the initial strength decreased of the monofilament, to 1.5% wt.% Makrolone was not a significant increase H-resistance across from the standard without Makrolon detectable.

• *Anm.: Alle Beispiele enthalten 3 Gew-% CESA f-/light NBAADH, den genannten Gehalt an Makrolon und additiv auf 100 Gew-% PET-Rohstoff RT 16.

The textile values are listed in the following table: Table 1 0.15 mm 900 NR RT 16 standard variant 1 RT 16 2% Makrolon variant II RT 16 3% Makrolon variant III titres 243 dtex 239 dtex 232 dtex diameter 148 μm 147 um 145 μm spec. strength 36.2 cN / tex 36.7 cN / tex 33.5 cN / tex elongation 45.2% 41.8% 33.7% free thermoshrink 180 ° C 30 min 3.5% 4.8% 4.9% Residual strength after Hydrolysis at 109 ° C - 24 hours 45% 57% 66% - 48h not measurable 11% 19% - 72h not measurable not measurable 7%

• * Note: All examples contain 3% by weight CESA f- / light NBAADH, the stated content of Makrolon and additive to 100% by weight PET raw material RT 16.

Claims (9)

A transparent, water-permeable textile shading surface, characterized in that it is constructed to at least 70% by weight of transparent polyester yarns, each containing a UV and a hydrolysis stabilizer. A textile shading surface made of polyester threads Claim 1, characterized in that the polyester threads Polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate or mixtures thereof. A textile shading surface made of polyester threads the claims 1 and 2, characterized in that the polyester threads 0.01 % By weight to 5% by weight UV stabilizer and 1 wt% to 5 wt% polycarbonate. A textile shading surface made of polyester threads the claims 1 to 3, characterized in that it is a multifilament yarn or preferably a monofilament yarn. A textile shading surface made of polyester threads the claims 1 to 4, characterized in that the polyester threads a Titers between 33 dtex and 40,000 dtex have. A textile shading surface made of polyester threads the claims 1 to 5, characterized in that the polyester threads a do not have round cross-section, in particular a regular n-corner with n ≥ 3 or a point or axisymmetric cross section. A textile shading surface made of polyester threads the claims 1 to 6, characterized in that the textile surface a Tissue, knitted fabric, scrim, knit or braid is. A textile shading surface according to claim 1, characterized characterized in that the non-polyester yarns are metal threads, in particular of aluminum. The use of a textile surface after the previous ones claims as a shading fabric for Outdoor crops and / or greenhouses.