Aliphatic Isocyanate Printable System for Nozzle Clogging
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Solution Overview
Problem
Existing multi-component printing systems face issues with nozzle clogging due to aromatically bound isocyanate components, poor miscibility, and inadequate curing speed, which limits printing interruptions and productivity.
Innovation Solution
A printable multi-component system with an isocyanate component and an isocyanate-reactive component, where the mixture has a pot life of ≤ 30 minutes, service life of ≥ 16 hours, viscosity ≤ 100 mPa s, and Hansen solubility parameter distance ≤ 25, ensuring good miscibility and high curing speed, preventing nozzle blockages and allowing for longer printing interruptions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If aromatically bound isocyanate components are used, then the multi-component system can be printed, but nozzle clogging occurs even with short printing interruptions
Solution Approach 1:
The patent changes the chemical parameter of the isocyanate component from aromatic to aliphatic binding, which fundamentally alters the chemical properties. Aliphatically bound isocyanate groups do not undergo the same discoloration and polymerization reactions as aromatic isocyanates, preventing nozzle clogging during interruptions while maintaining printability and curing performance
Solution Approach 2:
The patent employs a multi-component system where the isocyanate and isocyanate-reactive components are stored separately and mixed only at the point of use. This allows each component to remain stable and non-reactive during storage and transport, eliminating clogging issues associated with pre-mixed aromatic isocyanate systems, while enabling printing operations when needed
2Productivity
If curing speed is increased, then productivity improves, but miscibility of components deteriorates due to premature polymer formation
Solution Approach 1:
The patent optimizes the pot life parameter by selecting specific aliphatic isocyanate compounds and matching them with appropriate isocyanate-reactive components. This creates a controlled reaction window where mixing remains homogeneous during printing, but curing completes quickly after deposition, achieving both miscibility and fast curing
Solution Approach 2:
The patent prepares the isocyanate and isocyanate-reactive components separately in advance, keeping them stable and miscible during storage and handling. The actual mixing occurs preliminarily controlled at the moment of printing, ensuring homogeneous distribution before the curing reaction accelerates and completes the bonding process
3Stability of the object's composition
If curing speed is decreased to improve miscibility, then component mixing improves, but droplet running and spreading on carrier material occurs
Solution Approach 1:
The patent adjusts the chemical composition parameters to achieve optimal pot life characteristics. The aliphatic isocyanate system provides sufficient reaction time for complete droplet mixing and penetration into the carrier material, while the controlled curing kinetics prevent premature surface skin formation that would cause running or spreading
Solution Approach 2:
The patent ensures continuous effective action of the printing system by maintaining components in a stable, miscible state during storage and transport. The curing process continues uniformly after deposition without interruption, ensuring complete reaction and proper droplet fixation on the carrier material without running or spreading
4Stability of the object's composition
If pot life is extended to improve miscibility, then component mixing improves, but curing speed decreases reducing productivity
Solution Approach 1:
The patent precisely controls the pot life parameter by selecting specific aliphatic isocyanate compounds with appropriate reactivity and matching them with suitable isocyanate-reactive components. This creates an optimized balance where the mixture remains stable and miscible during the printing process, but achieves complete curing within an acceptable time frame for high productivity
Solution Approach 2:
The patent creates a dynamic system where the reaction kinetics change over time. Initially, the system maintains low reactivity for complete mixing and penetration, then accelerates to complete curing. This dynamic control of reaction speed allows both good miscibility during printing and high curing speed for productivity
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 enables efficient printing with improved miscibility and curing speed, preventing nozzle clogging and allowing for extended printing interruptions without affecting print quality, while maintaining high productivity.
Implementation Method 1
the reaction of the isocyanate component with the isocyanate-reactive component begins. The common drop steel is directed onto a carrier material, where it is used to build a three-dimensional body to form a polymeric polyurethane
Implementation Method 2
it has proven to be difficult to ensure good miscibility of the isocyanate component with the isocyanate-reactive component
Data Source
Figure 1~4
AI summary
The invention relates to a printable multi-component system comprising at least one isocyanate component and at least one isocyanate-reactive component, wherein the isocyanate component comprises at least one compound with aliphatic isocyanate groups and the isocyanate-reactive component comprises at least one compound with isocyanate-reactive groups, characterized in that a mixture of the isocyanate component and the isocyanate-reactive component has a pot life at a temperature of 23 °C of ≤ 30 minutes, and the isocyanate component and the isocyanate-reactive component each have a shelf life of ≥ 16 hours at 20 °C and a relative humidity of 50%.the isocyanate component and the isocyanate-reactive component each have a viscosity of ≤ 100 mPa·s measured at 70 °C and a constant shear rate of 100 1/s, and the difference Ra between the Hansen solubility parameter of the compound with aliphatic isocyanate groups or optionally a mixture of all compounds with isocyanate groups and the Hansen solubility parameter of the compound with isocyanate-reactive groups or optionally a mixture of all compounds with isocyanate-reactive groups is ≤ 25, and wherein the surface tension of the isocyanate and/or isocyanate-reactive component is ≤ 30 mN/m at 23 °C.