Primary-Pulp Packaging Paper for Sharp-Edge Puncture Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing packaging papers fail to effectively protect sharp-edged or unevenly surfaced objects from penetration or tearing, especially when made from recyclable materials, due to limitations in strength and elasticity, necessitating the use of non-rottable polymers or plastic coatings.
Innovation Solution
A packaging paper composed of at least 95% primary pulp with specific fiber length and cationic starch, achieving a strain at break of at least 6.0% and puncture energy index of 30 to 75 mJ·m2/kg, ensuring resistance to puncturing and tearing from sharp edges.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If packaging paper is made from recyclable materials with standard composition, then environmental sustainability is improved, but strength and elasticity are insufficient to protect sharp-edged objects
Solution Approach 1:
The patent changes the physical-chemical parameters of the paper by using highly refined pulp (≥95% primary pulp with average fiber length ≥2.0 mm) and controlling filler content (<4.5%), along with specific processing conditions, to achieve superior strength and elasticity without compromising recyclability
Solution Approach 2:
The patent creates a composite paper structure combining high-quality primary pulp fibers with controlled filler content and specific adjuvants, achieving a material that simultaneously provides enhanced mechanical properties for protecting sharp-edged objects and maintains recyclability
2Strength
If plastic coatings or polymer inserts are added to packaging paper, then tear resistance and elasticity are improved, but environmental sustainability deteriorates due to non-rottable materials
Solution Approach 1:
The patent uses purely organic, biodegradable paper materials that can be disposed of naturally without plastic coatings, achieving sufficient tear resistance through optimized fiber composition (≥95% primary pulp with length ≥2.0 mm) and processing to enable the paper to protect sharp-edged objects while remaining environmentally friendly and recyclable
3Strength
If filler content in packaging paper is increased, then manufacturing cost is reduced, but puncture resistance and strength deteriorate
Solution Approach 1:
The patent changes the composition parameters by limiting filler content to <4.5% and using ≥95% primary pulp with specific fiber length characteristics, achieving optimal balance between puncture resistance and material efficiency without excessive filler addition
Data Source
AI summary
A packaging paper for sharp-edged objects and/or objects having unevenly arranged, protruding, substantially non-deformable elevations on at least one of the surfaces of the object, consisting of kraft pulp as the main constituent and fillers, starch, sizing agent and additional process aids. The packaging paper containing at least 95% primary pulp having a length-weighted average fiber length of at least 2.0 mm and cationic starch and other process aids. The packaging paper has an elongation at break in the machine direction (MD) according to ISO 1924-3:2005 of at least 6.0%, a puncture energy index according to DIN EN 14477:2004 at a test speed of 10.0 mm/min, measured on any side of the packaging paper, in the range of 30 to 75 mJ·m2/kg and a kappa number according to ISO 302:2015 of between 35 and 38.