Dry-Grinding Release-Coated Sheet Recycling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The recycling of release-coated cellulose or polymeric sheet materials, commonly used as liners for self-adhesive labels and films, is challenging due to the difficulty in separating the release agent from the sheet material, which hinders the production of high-quality recycled paper and insulation materials with effective thermal and acoustic insulation properties.
Innovation Solution
A dry-grinding method is employed to separate the release coating from the sheet material, producing a carrier-rich fraction for insulation or recycled paper and a release agent-rich fraction, which can be further processed or blended with other materials to create insulation materials with enhanced properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional repulping methods are used to recycle release-coated sheet material, then the process is simple and familiar, but the quality of recycled paper deteriorates due to insufficient disintegration of fibers and sticking of resin particles
Solution Approach 1:
The patent changes the fundamental parameter of the recycling process from wet repulping to dry grinding. This parameter change allows the release coating to be mechanically removed without causing fiber damage or resin sticking problems, thereby maintaining both process simplicity and recycled material quality
Solution Approach 2:
The patent replaces the chemical/wet mechanical action of conventional repulping with a dry mechanical grinding system. This substitution enables effective separation of the release coating through mechanical forces without the negative effects of water and chemicals on fiber disintegration and resin adhesion
2Manufacturing precision
If chemical separation methods using salts of phosphoric esters are used to remove silicone release agent, then the release agent can be effectively separated, but the process complexity and chemical usage increase
Solution Approach 1:
The patent extracts the release agent from the sheet material through dry grinding and mechanical separation, taking it out as a distinct fraction without requiring chemical reagents. This extraction method simplifies the process by eliminating chemical handling while achieving effective separation
Solution Approach 2:
The patent uses a dry grinding medium or air stream as an intermediary to facilitate the separation of release agent particles from the ground sheet material, avoiding the need for complex chemical separation systems while maintaining separation efficiency
3Ease of operation
If release-coated sheet material is disposed of rather than recycled, then the disposal process is straightforward, but environmental impact and disposal costs increase
Solution Approach 1:
The patent applies the principle of recovering valuable materials (cellulose fibers) from what would otherwise be discarded waste. By separating and recycling the cellulose fraction, the process transforms a disposal problem into a resource recovery opportunity, reducing environmental impact while maintaining operational simplicity
Solution Approach 2:
The patent changes the end-use parameter of the recycled material from traditional paper applications to insulation material applications. This parameter change allows the use of materials that would be difficult to recycle into conventional paper, thereby expanding recycling options and reducing environmental impact
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
This method allows for the efficient recycling of release-coated materials, producing insulation materials with improved thermal and acoustic insulation, reduced embodied energy, and lower VOC content, while also addressing the challenge of recycling difficult-to-process release-coated sheet carriers.
Implementation Method 1
A dry-grinding method is employed to separate the release coating from the sheet material
Implementation Method 2
A dry-grinding method is employed to separate the release coating from the sheet material
Data Source
AI summary
The present invention concerns a method for treating waste material comprising: —Collecting release coated cellulose or polymeric sheets from producers and end-users thereof in the form of dense, bulky masses, such as rolls and stacks; —Pre-shredding the dense, bulky masses of release coated sheets into smaller, less dense masses in preparation to the following process steps; —Preparing the pre-shredded material by mixing, separating foreign bodies like metals, etc., and feeding it to a primary grinding station (3);—Grinding the materials into small pieces, of the desired size, preferably down to less than 1 mm; —Adding additives selected from flame retardant, hydrophobic material, pesticide and mixtures thereof and mixing them with the recycled material; —Optionally forming a batt or a sheet by a wet process and/or by adding a binder.