Kraft Liner Board Flame Retardancy via Layered Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current kraft liner boards lack effective flame retardant properties and physical strength, particularly in high-grade wrapping cartons, leading to fire hazards and limited performance in wrapping and transportation, while existing solutions either compromise on cost or physical properties.
Innovation Solution
A high-performance environment-friendly kraft liner board is developed with a layered structure comprising a bottom layer of modified wood powdery pulp, a top layer of long and short fiber pulp, and a coating layer of flame retardant styrene-acrylic latex, using a combination of composite flame retardants and functional modified styrene-acrylic latex, which enhances flame retardancy without compromising physical strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If flame retardants are added in large amounts to the pulp, then flame retardant performance is improved, but production cost increases and physical strength deteriorates
Solution Approach 1:
The patent divides the flame retardant treatment into two separate layers: a bottom layer containing flame retardant master batch and a top layer without flame retardants. This segmentation allows the flame retardant to be concentrated where needed (bottom layer) while keeping the top layer clean for printing and avoiding excessive flame retardant addition throughout the entire board, thus reducing overall cost while maintaining effective flame retardancy.
Solution Approach 2:
The patent applies flame retardant properties locally to the bottom layer rather than uniformly throughout the entire kraft liner board. The bottom layer contains the flame retardant master batch at a specific concentration (5-15 parts by weight per 100 parts pulp), creating a localized flame-resistant zone that provides adequate protection without requiring large amounts of flame retardant across the whole product, thereby controlling production costs.
2Reliability
If flame retardants are added in large amounts to the pulp, then flame retardant performance is improved, but physical strength deteriorates
Solution Approach 1:
By segmenting the flame retardant application to only the bottom layer, the patent prevents flame retardant particles from being distributed throughout the entire board structure. This localized application ensures that the top layer maintains its full physical strength properties for printing and surface performance, while the bottom layer provides the necessary flame resistance without compromising overall board strength.
Solution Approach 2:
The patent concentrates flame retardant properties in the bottom layer where they are most needed for fire protection, while keeping the top layer free of flame retardants to maintain optimal physical strength, tensile properties, and printability. This local quality differentiation resolves the contradiction between flame retardancy and physical strength.
3Manufacturing precision
If surface sizing is used to improve surface strength and water resistance, then surface properties are improved, but overall physical strength improvement is limited and cost increases
Solution Approach 1:
The patent incorporates flame retardant master batch during the pulp preparation stage itself, before the papermaking process begins. This preliminary action integrates flame retardancy into the base material structure, eliminating the need for separate surface sizing treatments to achieve adequate surface strength and water resistance, thereby reducing production costs while maintaining surface quality.
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 solution provides excellent flame retardancy, physical strength, and water resistance, reducing production costs and environmental impact, while improving the printing quality and overall performance of the kraft liner boards.
Implementation Method 1
a coating layer which is arranged at the top; the coating layer is formed by coating a flame retardant styrene-acrylic latex on the top layer
Implementation Method 2
the coating layer is formed by coating a flame retardant styrene-acrylic latex on the top layer
Data Source
Figure 1
AI summary
The present invention discloses a high-performance environment-friendly kraft liner board, comprising a bottom layer, a top layer and a coating layer, which are arranged successively in an order from bottom to top; wherein: the bottom layer is made of a bottom layer pulp composed of a modified wood powdery pulp and a short fiber pulp; the top layer is made of a top layer pulp composed of a long fiber pulp and a short fiber pulp; the coating layer is formed through coating a flame retardant styrene-acrylic latex on the top layer; the long fiber pulp and the short fiber pulp are formed through pulping old domestic corrugated boxes; the flame retardant styrene-acrylic latex consists of modified composite flame retardants, a functional modified styrene-acrylic latex and water. The prepared kraft liner board produced by the invention has good flame retardancy, low cost and environmental protection.