GLUKON® farm Spray Adhesive

Table 1: Overview of results

*    Bewertungsbereich: Anforderung erfüllt (✔) / Anforderung nicht erfüllt (X)

Description and Technical Data

GLUKON® farm for gluing silo and asparagus films made of PE, PP and PA. GLUKON® farm is applied to both sides of the overlapping (approx. 50 cm) films. After approx. 60 seconds, the films can be glued together or minor film repairs can be carried out.

• Apply using a spray can or pressure vessel and spray lance
• Bonding of the films due to low contact pressure
• Spray type: web spray
• Flash-off time: approx. 60 seconds, depending on ambient temperature/humidity
• To be processed within 4 hours
• Description:  Solvent-based, sprayable adhesive and  contact adhesive
• Colour: transparent yellowish
• Solids content: approx. 27 %
• Temperature resistance: resistant from approx. -20 °C to approx. 65 °C
• Shear strength: > 80 psi
• Coverage per 13 kg: Pressure vessel approx. 100 m² (application on both sides), can approx. 3 m²
• The hardened adhesive is non-flammable.

Suitability

The suitability of GLUKON® farm spray adhesive was assessed on the basis of laboratory results and practical tests carried out at three farms (one silage film farm, two asparagus film farms).

Strength

Important parameters for the strength of a bonded film are yield stress, elongation and tear elongation.

Yield stress, elongation and tear elongation are evaluated in accordance with DIN EN ISO 527-3:2019-02 
at +23 °C (test speed 500 mm/min; test specimen Type 2). Deformations are measured between the clamping jaws, in new condition and after exposure to climate change, heat stress and acid storage. 

• Acid storage: 10 days storage in mixed acid consisting of 3 % lactic acid, 1.5 % acetic acid, 0.5 % butyric acid
• Climate change: 50 cycles from -20 ˚C to 65 ˚C
• Heat stress: 90 days at 60 °C

Gas permeability

Gas permeability is tested in the glued area in accordance with DIN 53380-3:2021-11 using oxygen  at +23 °C and 0.2 bar.

Continuous monitoring test

Product quality is checked annually by a DLG monitoring test in accordance with the testing regulations. In addition, the manufacturer is obliged to carry out self-monitoring measures during production.

Suitability

Based on laboratory and practical test results, GLUKON® farm spray adhesive is suitable for gluing silage films and asparagus films.

Gluing silage film

Test sample: Silo film (white/white) with central  adhesive seam (approx. 10 cm overlap),  approx. 1.0 m long and 0.4 m wide, thickness approx. 150 μm

• The yield stress was 13.8 MPa.
• The elongation was 4.1 %.
• The tear elongation was 567 %.

After climate change stress
(50 cycles from -20 °C to 65 °C)

• Requirement for change in yield stress, elongation and tear elongation: ≥ - 15 %
• Change in yield stress -7.7 %
• Change in elongation + 24.4 %
• Change in tear elongation +5.9 %

The adhesive remained stable despite changes in climate.

After heat stress
(storage for 90 days at 60 °C)

• Requirement for change in yield stress, elongation and tear elongation: ≥ - 15 %
• Change in yield stress -5.8 %
• Change in elongation + 14.6 %
• Change in tear elongation + 4.5 %

The adhesive demonstrated good resistance to heat stress.

After acid storage
(ten days in a mixture of 3 % lactic acid, 1.5 % acetic acid and 0.5 % butyric acid)

•  Requirement for change in yield stress, elongation and tear elongation: ≥ - 15 %
• Change in yield stress: -  0.3 %
• Change in elongation: + 9.8 %
• Change in tear elongation: + 1.1 %

The adhesive remained stable during storage in an acidic environment.

Gas permeability

The oxygen permeability in the area of the adhesive seam was 82.3 cm³/m² in 24 hours, which was lower than the maximum permissible value of 250 cm³/m² in 24 hours.

Gluing asparagus film
Test sample: Asparagus film (white/black) with adhesive seam in the middle (approx. 10 cm overlap), approx. 1.0 m long and 0.4 m wide, thickness 
approx. 150 µm.

• The yield stress was 13 MPa.
• The elongation was 12.0 %.
• The tear elongation was 538 %.

After climate change stress
(50 cycles from -20 °C to 65 °C)

• Requirement for change in yield stress, elongation and tear elongation: ≥ - 25 %
• Change in yield stress: +1.3 %
• Change in elongation: +14.2 %
• Change in tear elongation: -20.8 %

The adhesive remained stable despite changes in climate.

After heat stress
(storage for 90 days at 60 °C)

• Requirement for change in yield stress, elongation and tear elongation: ≥ - 25 %
• Change in yield stress: + 2.7 %
• Change in elongation: + 17.5 %
• Change in tear elongation: -15.9 %

The adhesive demonstrated good resistance to heat stress.