Hotmelt Adhesive Stringing Reduction via Polymer Mixing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Non-reactive hot-melt adhesives often exhibit a high tendency to string when applied through nozzles, leading to the formation of adhesive threads, which can tear off and cause application issues.
Innovation Solution
A hot-melt adhesive system comprising a mixture of polyester-based and polyamide-based adhesives with specific melting point ranges and additives, such as fillers and tackifying resins, is developed to reduce stringing by dynamic mixing and foaming, allowing for regular, trace-like application without thread formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If non-reactive hot-melt adhesives are applied through nozzles, then application is achieved, but adhesive threads form and cause stringing
Solution Approach 1:
The patent combines polyester-based hot-melt adhesive (melting point 150-170°C) with polyamide-based hot-melt adhesive (melting point 180-210°C) in specific weight ratios to create a composite adhesive system. This composite formulation exploits the different melting and crystallization behaviors of the two polymers to reduce stringing while maintaining application performance
Solution Approach 2:
The patent modifies the thermal parameters of the adhesive system by selecting specific melting point ranges for the polyester (150-170°C) and polyamide (180-210°C) components. This parameter optimization ensures that the adhesive maintains appropriate viscosity during application and crystallizes properly after application, preventing thread formation
2Object-generated harmful factors
If polyester-based and polyamide-based adhesives are mixed, then stringing tendency is reduced, but formulation complexity increases
Solution Approach 1:
The patent establishes specific parameter ranges for the adhesive components: polyester-based adhesive at 150-170°C melting point, polyamide-based adhesive at 180-210°C melting point, and weight ratios between 20:80 to 80:20. These defined parameters provide a systematic approach that reduces formulation complexity while maintaining effectiveness
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 system significantly reduces the stringing tendency, enabling smooth, uninterrupted application of the adhesive to substrates, particularly fibrous materials like paper, with minimal thread formation.
Implementation Method 1
Melting of a first hot-melt adhesive that is polyester-based and a second hot-melt adhesive that is polyamide-based
Implementation Method 2
dynamic mixing of the two hot-melt adhesives, in particular with the generation of shear forces in the melt
Implementation Method 3
optional foaming of the molten hot-melt adhesive system with a gas
Data Source
Figure 1
AI summary
The invention relates to a hotmelt adhesive comprising a hotmelt adhesive mixture, the mixture comprising a. 15-85% by weight of a first, polyester-based hotmelt adhesive, b. 15-85% by weight of a second, polyamide-based hotmelt adhesive.