Download Water-based Adhesives for Flexible Packaging

Eco-Efficiency Analysis: Water-based
Adhesives for Flexible Packaging
AIBO Seminar – Desenzano June 23rd 2016
Andrea Sergio, BASF Italy
01
WATER-BASED
LAMINATION ADHESIVES
Water-based adhesives combine long
polymer chains with good coatability
Solvent-based /
solvent-free adhesives
vs.
Water-based adhesives
 Short-chain components dominate
 Long-chain polymers
 Reactive system: Long polymer
chains develop between films
 Chemical reaction already took
place at BASF
 Adhesion increases over time
 Good adhesion right from the start
3
High molecular weight from the very
beginning reduces migration risk
Molecular weight distribution of typical lamination adhesives
Potential
zone of
migration
4
High initial peel strength gives process
speed
Time dependence of peel strength
(PETink/PE, 2.5 g/m²; peel at 300 mm/min; with cross-linker)
N/15mm
MB > 5N
5
4
3
2
1
0
Water-based adhesive
Peel 1 min
Peel 1 h
Peel 2 h
Solventless adhesive
Peel 4 h
Peel 6 h
Peel 8 h
Peel 24 h
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No primary aromatic amines from
water-based adhesives
Risk of toxic migratable components with solvent-based and solventless
systems if not fully reacted
Film / foil
Monomeric MDI
Adhesive
Film
Food
Primary Aromatic Amines
(PAA)
Suspected to be carcinogenic
Storage time up to 2 weeks
can be necessary between
lamination and filling with
food to avoid PAAs
+ H2O
- CO2
6
Water-based adhesives contain no
monomeric diisocyanates
 Solvent-based and solventless
adhesives contain up to 20%
monomeric diisocyanate (MDI)
 Diisocyanates are increasingly under
attack by authorities due to e.g.
occupational respiratory diseases
 European Chemical Agency (ECHA)
thrives for additional regulation / use
restrictions of such substances
 Water-based adhesives are not
concerned
Source: http://echa.europa.eu/registry-of-current-restriction-proposal-intentions/-/substance-rev/10698/term
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No solvent retention with water-based
adhesives
Risk of migratable organic solvents if not dried carefully in SB systems
Film / foil
Adhesive
Organic solvents
Film
Food
Organic solvents
Very intensive drying of
solvent-borne adhesives
required (ppm level)
 slow down of coating
speed may be necessary
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Only with water-based adhesives
immediate laminate processing possible
Multi layer laminates
Printing
Laminating
Storage
3-6 hours with solventborne and solventless
adhesives
More
frequently
changing
product
designs
Smaller
packaging
units
Slitting
Storage
Filling with
Food
2-14 days with solventborne and solventless
adhesives
Brand
owners
demand
shorter lead
times
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Water-based adhesives work well
together with digital printing
 Customized printing
HP Indigo 20000 Digital Printing Press
 Fast changes
 From file to pouch making in 24h
 Fast curing required
 Instant slitting
 Fast set-up with low waste
 Excellent lamination quality and
transparency
+
Comexi Nexus L20000 Laminator
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Water-based adhesives also need a risk
assessment
Risk assessment of water-based laminating adhesives
Polyacrylate
dispersion
ISEGA
Polyurethane
dispersion
ISEGA

Residues
of
monomers
Approved monomers
(10/2011)
Info about SML

Approved monomers
Info about SML
Extraction tests for amines
and isocyanates
VOC
Info about VOC content

Info about VOC content

Oligomers
Assessment in FCN
Overall migration

Assessment in FCN
Overall migration

Biocide
Approved biocides
Info about content

Approved biocides
Info about content

ISEGA … ISEGA certificate for typical application
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Water-based adhesives as a solution
for sustainable flexible packaging
Benefits of water-based adhesive
technology
Cost reduction
 No off-spec resulting
from telescoping and mixing errors
 Reduced bonded capital
Time saving / increased flexibility
 Direct slitting, lean production
 No interim storage
 Shortest lead times
Improved safety
 No aromatic isocyanates
 No organic solvents, low VOCs
 Very low residual odor / taste
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4:3 PowerPoint Template
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Eco-Efficiency Analysis to compare the
different adhesive technologies
 Eco-efficiency analysis considers
environmental (life cycle
analysis) and
economic (life cycle costs)
impacts
Impacts on
environment
Life cycle
costs
 Eco-Efficiency methodology
validated by TÜV Rheinland
(2002), TÜV Rheinland do Brasil
(2008) and NSF International
(2009, 2013, 2016)
Impacts on environment and costs
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4:3 PowerPoint Template
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4:3 PowerPoint Template
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Whole life-cycle of packaging was
considered
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Various ecologic factors are considered
in eco-efficiency analysis
Freshwater overfertilization
Marine overfertilization
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Climate Change
 Also referred to as global warming potential
(GWP) and carbon footprint (CF)
 This category reflects the climate change
impact of air emissions of greenhouse gases
(GHGs). Increased GHGs in the troposphere
result in warming of the earth’s surface.
 The impact of greenhouse gas emissions –
such as carbon dioxide (CO2), methane (CH4),
and nitrous oxide (N2O) – is assessed over a
fixed time period of 100 years.
Climate Change
 The climate change category takes into
account that different gases have different
climate change impacts on global warming.
The total impact is described in CO2
equivalents.
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Human Toxicity
Health & Safety

The human toxicity potential takes into consideration all
substances handled at any time during the life cycle of a
product. Only toxicity potentials are assessed, not
actual risks.

Substances are assigned toxicity points based on their
hazard phrases (H-phrases) of the Globally Harmonized
System (GHS). The H-phrases indicate human health
hazards associated with exposure to specific
substances. These toxicity points are multiplied with the
amounts of substances used and report life cycle human
toxicity potentials expressed in terms of dimensionless
toxicity points.

The method is described in detail in R. Landsiedel, P.
Saling, Int. J. LCA 7 (5), 261-268, (2002). In
cooperation with toxicologists, toxicity points were
assigned to each H-phrase. For example, the
classification H330 (fatal if inhaled) was assigned 750
toxicity points and the considerably less critical category
H312 (harmful in contact with skin) 300 points.
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Critical Panel Review Statement
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Aggregated Results
Solventless and water-based adhesives are more
eco-efficient – base case
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Solventless and water-based adhesives are more
eco-efficient – differential approach
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Contributions from environmental impact
categories – Base case
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Solvent-based adhesives have a less
favorable environmental fingerprint
Relative results – smaller values indicate better performance. All product systems are normalized between 0
and 1 by the product system with the highest impact per impact category
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4:3 PowerPoint Template
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Conclusions
 The purpose of the present study is to investigate the differing environmental and
economic impacts originating from different adhesive systems for producing a two layer
flexible packaging for general-purpose and medium-performance applications by
lamination.
 The results of this study show that under the given conditions and chosen assumptions the
three adhesive product systems, the solventless PU, the water-based PU and the
water-based acrylate system, are about equally eco-efficient and have a clear advantage
over the solvent-based PU adhesive system.
 The main driver of environmental differences among the alternatives is the production
of the solvent of the solvent-based PU adhesive system.
 The main economic differences originate from the additional costs for the solvent of
the solvent-based PU system and from differences in the adhesive production costs.
 The environmental differences between the four alternatives are larger than their economic
differences.
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4:3 PowerPoint Template
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