Core-Sheath Filament Adhesive Dispensing for Non-Planar Substrates
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional pressure-sensitive adhesives face challenges in achieving high bond strength on non-planar, low-surface-energy substrates like thermoplastic olefin, requiring additional primers and surface treatments, which increase complexity and cost, and traditional dispensing systems struggle with soft viscoelastic materials like core-sheath PSAs.
Innovation Solution
A system and method using an autonomous robotic dispensing apparatus with a computer-controlled dispense head and sensor system to apply core-sheath filament adhesives in a bead application plan, allowing precise placement and adaptation based on substrate topography, eliminating the need for surface pretreatments and handling the soft consistency of core-sheath PSAs effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional pressure-sensitive adhesives are used on low-surface-energy substrates like thermoplastic olefin, then bonding is simpler without additional treatments, but bond strength is insufficient due to poor wet out
Solution Approach 1:
The patent changes the physical state and delivery parameters of the adhesive from conventional sheet/roll form to extrudable filament form. The filament is extruded through a heated nozzle that melts and deposits the adhesive directly onto the substrate, enabling controlled application without primers or surface treatments while achieving adequate bond strength through precise material placement and thermal activation
Solution Approach 2:
The patent replaces manual or mechanical dispensing systems with an automated extrusion-based deposition system. The filament is fed through a heated extrusion nozzle that melts and deposits the adhesive in a controlled manner, substituting traditional mechanical application methods with a thermally-assisted extrusion process that provides better control over adhesive placement and bonding performance
2Strength
If primers and surface treatments are used to improve wet out on low-surface-energy substrates, then bond strength increases, but process complexity and cost increase
Solution Approach 1:
The patent extracts and eliminates the primer and surface treatment steps from the bonding process. By using extrudable filament adhesive that is directly deposited and thermally activated, the system achieves adequate bond strength without requiring additional chemical treatments or primers, thereby simplifying the overall bonding process and reducing cost
Solution Approach 2:
The extrusion-based system provides self-service bonding capability where the adhesive filament contains all necessary bonding functionality in one material form. The heated extrusion process simultaneously delivers, places, and activates the adhesive in a single integrated operation, eliminating the need for separate primer application and curing steps
3Ease of operation
If traditional FFF printheads are used to dispense core-sheath PSA filaments, then filament feeding is enabled, but the soft viscoelastic material buckles and jams in the melt zone
Solution Approach 1:
The patent modifies the thermal and mechanical parameters of the extrusion system to accommodate soft viscoelastic PSA materials. The heated nozzle maintains optimal melt temperature and viscosity control, while the extrusion geometry and feeding mechanism are adjusted to prevent buckling and jamming, enabling reliable dispensing of core-sheath PSA filaments that traditional FFF printheads cannot handle
Solution Approach 2:
The patent introduces dynamic control of the extrusion process including variable heating zones, controlled melt flow rates, and adaptive feeding mechanisms. These dynamic adjustments allow the system to respond to material properties in real-time, preventing buckling and jamming by optimizing the balance between material softness and extrusion force throughout the dispensing process
4Adaptability or versatility
If filament adhesive is extruded in hot melt form and cooled, then pressure-sensitive adhesive is formed in situ, but precise placement control is challenging
Solution Approach 1:
The patent incorporates feedback control mechanisms in the extrusion system that monitor and adjust extrusion parameters in real-time. Sensors detect actual bead placement and dimensions, and the system automatically adjusts extrusion rate, nozzle position, and heating parameters to maintain precise placement control while forming pressure-sensitive adhesive from hot melt filament
Solution Approach 2:
The extrusion-based system provides multi-functionality by combining precise material delivery, thermal activation, and controlled deposition in a single integrated process. The system can adapt to different filament types, substrate materials, and bonding requirements while maintaining consistent placement precision through unified control of extrusion and cooling parameters
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
Enables precise, high-strength bonding on complex substrates without additional surface treatments, improving versatility and reducing costs by ensuring adequate bond formation and material efficiency.
Implementation Method 1
Filament adhesives include those that use a core/sheath configuration, including adhesives that are dispensed in hot melt form and then cooled to provide a pressure-sensitive adhesive
Implementation Method 2
adhesives that are dispensed in hot melt form and then cooled to provide a pressure-sensitive adhesive
Data Source
AI summary
Provided are methods and systems for dispensing filament adhesive onto a target substrate. A filament adhesive is applied on a target substrate according to a bead application plan, then the applied bead is checked against performance criteria. A second bead application plan is generated, and subsequent filament bead applied according to the second bead application plan.