Colored Pencil Lead Using Oxidized EVA and Metallocene Wax
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Solution Overview
Problem
Existing colored pencil leads and crayons face challenges in application behavior, stability, and production efficiency, particularly requiring high temperatures for extrusion and involving energy-consuming water removal steps or high costs for achieving optimal spreading behavior.
Innovation Solution
Incorporating oxidized ethylene vinyl acetate wax and functionalized metallocene polyolefin wax into the lead base material, allowing for extrusion at lower temperatures and improved mechanical stability, while eliminating the need for water removal and enhancing light fastness and flexibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If cellulose derivatives are used as binders in pre-waxed leads, then the leads can be produced with waxes and fats included, but water must be added to swell the cellulose derivative and later removed by drying in an energy-consuming processing step
Solution Approach 1:
The invention extracts and eliminates the water addition and drying steps from the manufacturing process by using a binder system that does not require water for swelling, thereby removing the energy-consuming drying step while maintaining the ability to incorporate waxes and fats in the lead composition
Solution Approach 2:
The invention changes the binder system from water-swelling cellulose derivatives to a binder that does not require water, fundamentally altering the processing parameters and eliminating the need for energy-intensive drying while maintaining manufacturing feasibility
2Productivity
If thermoplastic binders like polystyrene or polyvinyl butyral are used for extrusion processes, then the leads can be produced continuously, but relatively high temperatures are necessary for thermoplastic softening and extrusion
Solution Approach 1:
The invention changes the binder material from thermoplastic polymers requiring high extrusion temperatures to a binder system that enables extrusion at lower temperatures, thereby maintaining continuous production capability while reducing energy consumption and improving colorant stability
3Strength
If thermoplastic binders are used to provide sufficient strength, then the leads have adequate mechanical strength, but they are not optimal in terms of spreading behavior since relatively high forces are required when producing the spread
Solution Approach 1:
The invention uses a composite binder system combining natural resins and synthetic polymers in specific ratios, creating a material that balances mechanical strength with optimal spreading behavior, allowing the lead to be applied with minimal force while maintaining sufficient covering power
Solution Approach 2:
The invention optimizes the binder composition parameters by using natural resins with specific softening points and combining them with synthetic polymers, achieving a balance between strength and spreading characteristics that reduces the force required for application
4Reliability
If aluminum distearate is used as a lubricant in fat and wax-based leads, then the property profile is improved, but the melting point is comparatively high at 140 °C and aluminum limit values must be observed
Solution Approach 1:
The invention extracts and replaces aluminum distearate with alternative lubricants having lower melting points and no aluminum content, eliminating the high melting point issue and aluminum limit value concerns while maintaining the improved property profile
Solution Approach 2:
The invention uses alternative lubricants that are safer for children's toys and have lower melting points, replacing the aluminum-containing compound with materials that meet safety requirements without compromising performance
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 combination of these waxes results in colored pencil leads with improved application behavior, stability, and light fastness, enabling efficient production at lower temperatures and increased extrusion speeds, with reduced brittleness and breakage, and maintaining mechanical stability.
Implementation Method 1
the two waxes to soften to a consistency that is such that, despite the fillers and color pigments it also contains, lead strands with a diameter of 3 to 5 mm for colored pencil leads and up to 20 mm for colored crayons can be extruded
Implementation Method 2
lead strands with a diameter of 3 to 5 mm for colored pencil leads and up to 20 mm for colored crayons can be extruded
Data Source
AI summary
The invention relates to a colored pencil lead or colored chalk with a lead base containing waxes, at least one filler and at least one colorant, wherein the waxes include at least one oxidized ethylene vinyl acetate wax (EVA) and at least one functionalized metallocene polyolefin wax.