The DLG QUALITY SEAL for operating equipment and consumables encompasses products, which are subjected to extensive testing of their value-determining and advertised characteristics. The tested criteria and the requirements to be fulfilled are specified by independent commissions and are designed – over and above legal requirements – to prove the product’s fitness for purpose, its advertised characteristics and practical requirements. Testing contents and requirements are developed further by the responsible specialist departments of the DLG e.V. in line with the applicable legislation, as well as with technical and scientific progress. Successful testing is concluded with the assignment of the DLG QUALITY SEAL. The approved products are then published.
The DLG quality seal test included technical measurements in the laboratory. The test basis was the DLG test frame for recyclate-free and recyclate-containing silage films made of low-density polyethylene (PE-LD) with and without barrier layers, as of November 2022.
No other criteria were examined.
The silage film V 12 Silver Cover, silver/black, UV-stabilized, 80 microns tested here, was tested in the DLG quality seal test in the laboratory on mechanical, physical, chemical and aging properties.
|DLG QUALITY PROFILE||Requirement||Evaluation*|
|Film dimensions||≥ nominal length, ≥ 98 % nominal width|
|Film thickness||0,076 ≤ d ≤ 0,084 mm|
|Material condition||evenly coloured, free of streaks and pores|
|Tearing force in new condition||longitudinally, transversely, over folds: ≥ 25 N/cm|
|Elongation of tears in new condition||longitudinally, transversely, over folds: ≥ 400 %|
|Tear resistance in new state||longitudinally, transversely, over folds: ≥ 17 MPa|
|Dart drop resistance in new condition||compliance with the manufacturer's declaration|
|Elongation of tear transversely after acid storage||reduction: < 15 %|
|Tear resistance transverse after acid storage||reduction: < 10 %|
|Elongation of tears transversely after aging (weathering)||> 350 %; reduction in new condition: < 30 %|
|Change in size after warm storage after aging||longitudinal: ≤ 2 % / transverse: < 2 %|
|Oxygen permeability in 0,2 bar||< 250 cm³/(m² · d)|
* Evaluation range: requirements fulfilled (✔) / requirements not fulfilled (X)
Description and Technical Data
Silver/black oxygen barrier silage film polyethylene (PE) and ethylene vinyl alcohol copolymer (EVOH), UV-stabilized, nominal thickness 80 microns. The silage film V 12 Silver Cover is produced in rolls up to 4 meters wide and produced with high-frequency welding technology to the desired width. The rollers are fitted with a protective case combination wrapped in film with welded fleece. This is to avoid transport damage.
Table 2: Technical data (company information)
|Nominal thickness||80 µm|
|Length||35 m, 50 m, 75 m, 150 m, 300 m, 600 m|
Individual widths and sizes available on request.
The suitability of the silage film was determined on the basis of the laboratory results judged.
The length and width of the silage film are calibrated band measurement.
The film thickness is calculated in accordance with DIN ISO 4593:2019-06 at +23 °C (stay with regenerate film the stalks are not taken into account).
It is visually checked whether the film has a evenly has opaque colouring and is free of smears and pores.
Important parameters for the strength of a silage film are tearing force (per cm film width), tear resistance (based on the cross-section of the sample body) and the elongation of the rip (elongation of the specimen to the breaking).
Tear force, elongation and tear resistance longitudinal, transverse and over folds are measured in accordance to DIN according to DIN EN ISO 527-3:2019-02 at +23 °C; test speed 500 mm/min; Type 2 sample body; deformation measurement between measuring marks, in new condition
measured by acid storage.
Acid storage: 10 days storage in mixed acid from 3 % milk, 1.5 % vinegar, 0.5 % butyric acid. The penetration resistance of the film is applied in surface, fold and the weld based on DIN EN ISO 7765-1:2004-10, procedure A performed. In doing so, the values specified by the manufacturer are checked.
Aging behaviour/weather resistance
The weathering of the material is controlled with xenon arc lamps according to DIN EN ISO 4892-2, method A, synchronisation with irrigation 102/18 to 2000 MJ/m2, black standard temperature 60 ±3 °C, relative humidity 65 ±3 %, EUV=60 W/m2. After that, the elongation of the tear is DIN EN ISO 527-3:2019-02 measured in transverse direction.
Change in measure after hot storage
The dimensional measured is changed in accordance with DIN 53377:2007-10 Change in moderation after 1/2 hour storage in +80 °C hot air.
The gas permeability is determined according to DIN 53380-3: 1998-07 with oxygen at +23 °C; 0.2 bar, investigated.
Continuous monitoring audit
The product quality is determined according to the annually by a DLG monitoring audit controlled.
In addition, the manufacturer must measures of self-control in production obliged.
The silage film V 12 Silver Cover, silver/black, UV-stabilized, 80 microns, is suitable for silage cover.
The measured film dimensions corresponded to film length and film width of the declaration.
As an average value for the film thickness, 0.080 mm was determined. The measured microvalue was 0.072 mm and the measured maximum value was 0.086 mm. As a result, the requirements for the mean for the film thickness and the permissible deviations are of the average value have been complied with.
The film was uniformly opaquely coloured, free of streaks and pores.
In new condition
The tearing force was 27.0 N/cm, transverse 27.5 N/cm and over folds 26.1 N/cm (minimum value 25 N/cm each). Taking into account the film thickness resulting in a tear resistance longitudinally of 33.3 MPa, across 33.7 MPa and over folds 31.2 MPa (minimum value 17 MPa each). The elongation at the break was 602 %, transversely 619 % and over folds at 601 % above the required minimum value of 400 %. The film thus fulfilled the requirements.
After acid storageAfter ten days of storage in a mixed acid (3 % milk, 1.5 % vinegar and 0.5 % butyric acid) reduction in tear resistance transversely was 1.4 % (permissible ≤ 10 %); the reduction of the elongation of the transversely was 5.8 % (allowed ≤ 15 %). Acid resistance was thus given.
Dart drop resistance
When checking the penetration resistance in the surface, fold and weld are Manufacturer specified values area ≥ 500 g, fold ≥ 200 g and weld ≥ 200 g.
Aging behaviour/weather resistance
After simulation of a one-year natural outdoor weathering with 2000 MJ/m2, the elongation of the 611 % (minimum value 350 %), i.e. equivalent to a reduction in elongation of 1.3 % (permissible 30 %) related to the new state. Weather resistance was
Change in measure after hot storage
The dimensional changes after hot storage at 80 °C of warm air was longitudinally at -0.1 % and transversely -0.1 % below the permitted limit of
≤ 2 %. The temperature resistance was thus given.
Oxygen permeability at 0.2 bar was film with 2.0 cm³/(m² · d) and at the weld with 0.58 cm³/(m² · d) lower than the maximum permissible value
250 cm³/(m² · d).
The criteria tested in this DLG quality seal test are evaluated on the basis of laboratory tests the mechanical, physical, chemical and aging properties of the V 12 Silver Cover silage film, silver/black, UV-stabilized, 80 microns. The tested silage film V 12 Silver Cover, silver/black, UV-stabilized, 80 microns, has met the requirements of the test frame with regard to the criteria examined.
Novagrar GmbH & Co. KG,
27419 Lengenbostel, Germany
Phone +49 (0) 4282 50952-12,
Mobil Phone +49 (0) 170 2172830
DLG TestService GmbH, Gross-Umstadt location
The tests are conducted on behalf of DLG e.V.
DLG test framework
DLG quality seal test "for regenerate-free and regenerate-containing silos made of polyethylene of low Density (PE-LD) with and without barrier layers", (current as of 11/2016)
Head of Department
Dr. Ulrich Rubenschuh
Dr. Harald Reubold *
SKZ-Testing GmbH, Friedrich-Bergius-Ring 22, 97076 Würzburg
Kunststoff-Zentrum in Leipzig GmbH, Erich-Zeigner-Allee 44, 04229 Leipzig
DLG Test commission
Stefan Wolf, 63110 Rodgau Weiskirchen
Christof Löffler, LAZBW Aulendorf, 88326 Aulendorf
Karsten Bommelmann, AG FUKO, 26160 Bad Zwischenahn
Willi Schüler, 64395 Brensbach Wallbach
Dr. Klaus Hünting, VBZL Haus Riswick, 47533 Kleve
Dipl.-Ing. Udo Dengel, SKZ-Testing GmbH, 97076 Würzburg