Starch Adhesive for Multi-Wall Bag Lamination
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Starch-based adhesives face challenges in achieving high solids content and strong adhesion to polyethylene surfaces, while maintaining flexibility and cohesive strength, particularly in lamination adhesives for multi-wall bags.
Innovation Solution
A combination of unmodified or slightly thinned starch, partially hydrolyzed starch derivatives like maltodextrin, and modified starches such as hydroxypropyl starch, with the addition of a plasticizer, is used to create an adhesive that can be jet-cooked to achieve high solids content and effective adhesion to polyethylene and paper surfaces, inhibiting retrogradation and providing flexibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If starch is modified with acid to reduce molecular weight, then solids level can be increased, but adhesion to polyethylene deteriorates
Solution Approach 1:
The patent combines multiple starch derivatives with different properties: acid-modified starch (for high solids content and paper adhesion), oxidized starch (for polyethylene affinity), and hydroxyethyl starch (for flexibility and retrogradation inhibition). This composite approach allows the adhesive to achieve both high solids level and effective adhesion to polyethylene simultaneously.
Solution Approach 2:
The patent systematically varies multiple parameters including degree of substitution, molecular weight distribution, and composition ratios of different starch derivatives to optimize both solids content and adhesion performance. By adjusting these parameters, the adhesive achieves the desired balance between solids level and polyethylene affinity.
2Loss of time
If higher solids content is achieved, then drying time is reduced, but liquid component can warp or damage substrates
Solution Approach 1:
The patent formulates the adhesive with optimized solids content (35-65%) and adjusts the composition of starch derivatives to achieve rapid drying without excessive liquid component effects. The specific combination of starch derivatives allows control over viscosity and drying characteristics.
Solution Approach 2:
The patent uses starch-based materials that are biodegradable and environmentally friendly, replacing petroleum-based adhesives. The short drying time is achieved through the specific starch derivative composition that allows rapid water evaporation without damaging substrates.
3Quantity of substance
If maltodextrin is used to achieve high solids content, then adhesion to polyethylene improves, but cohesive strength deteriorates
Solution Approach 1:
The patent combines maltodextrin (for polyethylene affinity and high solids content) with hydroxyethyl starch and oxidized starch (for cohesive strength). This composite formulation ensures that the adhesive maintains both high solids content and adequate cohesive strength by leveraging the complementary properties of different starch derivatives.
Solution Approach 2:
The patent uses oxidized starch as an intermediary component that bridges the gap between maltodextrin (which provides polyethylene affinity) and hydroxyethyl starch (which provides cohesive strength). The oxidized starch enhances both adhesion and cohesion, ensuring balanced performance.
4Reliability
If starch adhesive is used for paper to paper applications, then good adhesion is achieved, but affinity to polyethylene deteriorates
Solution Approach 1:
The patent creates a multi-component starch derivative system where acid-modified starch maintains paper adhesion, while oxidized starch and hydroxyethyl starch provide polyethylene affinity. This composite approach enables the adhesive to effectively bond both paper and polyethylene surfaces.
Solution Approach 2:
The patent develops a universal adhesive formulation that can bond dissimilar materials (paper and polyethylene) simultaneously. The specific combination of starch derivatives provides both paper-to-paper adhesion and paper-to-polyethylene adhesion, making the adhesive versatile for multi-wall bag lamination.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The resulting adhesive has a solids content exceeding 50% and exhibits strong adhesion to both polyethylene and paper, maintaining flexibility and preventing delamination, suitable for commercial use in multi-wall bags.
Implementation Method 1
an adhesive that adheres well to polyethylene and to paper
Implementation Method 2
the adhesive can be jet-cooked to achieve high solids content
Implementation Method 3
a modified starch, the modified starch being present in an amount effective to inhibit retrogradation of the starch component of the adhesive
Data Source
AI summary
Disclosed is an adhesive that may include two or more starches or starch derivatives with different molecular weights. In many embodiments, the adhesive includes (1) unmodified or slightly thinned starch, (2) maltodextrin or syrup solid, and (3) a hydroxypropyl starch. In most embodiments, the adhesive includes a plasticizer. The adhesive may be prepared by blending the starch and starch derivatives, and cooking the blended slurry, preferably under acidic conditions. The adhesive may be employed for various purposes including as an adhesive for a multi-wall bag.