Ink Removal for Fiber Recovery from Packages
In paper and cardboard recycling facilities, ink contaminants pose significant challenges to fiber recovery. Traditional de-inking processes require intensive chemical treatments and mechanical separation, with typical fiber losses of 15-20% and water consumption exceeding 60 cubic meters per ton of recovered fiber. These challenges are amplified by the increasing complexity of modern packaging materials and printing techniques.
The fundamental challenge lies in separating inks and adhesives from cellulose fibers while maintaining fiber integrity and minimizing environmental impact.
This page brings together solutions from recent research—including pressure-sensitive adhesive technologies, alkaline-releasable compounds, mechanical separation systems, and automated detection mechanisms. These and other approaches focus on improving fiber recovery rates while reducing chemical usage and processing costs in industrial recycling operations.
1. Multi-Layer Packaging with Aqueous-Releasable Layer for Material Separation and Identification
TOYO INK SC HOLDINGS CO LTD, 2023
Recycling packaging materials like flexible films and pouches that contain multiple layers by providing a release layer containing releasable materials like ink and adhesive. This layer can be peeled off from the base material using basic aqueous solution to separate and recycle the base material. The release layer has identification information to determine recyclability. By providing releasability and identification, the base material can be easily separated and recycled from waste.
2. Separable Packaging Bag with Distinct Upper and Lower Sections for Ink and Glue-Free Recycling
TOKYO YOSHIOKA CO LTD, 2022
Separable packaging bag for contents like clothes that allows easy recycling without mixing ink or glue into the recycled material. The bag has a separable upper section for discarding and a lower section for recycling. The upper section has an easy-to-cut boundary between the sections. This allows opening the bag by separating the upper section instead of cutting it off. This prevents mixing of ink and glue when recycling the lower section.
3. Packaging Material with Acidic Primer Layer for Separation of Printed Layers
TOYO INK SC HOLDINGS CO LTD, 2022
Recyclable packaging material that allows easy separation and recycling of the base material from the printed layers. The packaging structure includes a base material, a primer layer with acidic groups, and a printing layer with inks. The acidic primer layer desorbs and separates from the base material during recycling. This allows recycling the base material without contamination from the printing ink. The acidic primer prevents adhesion of the base material to the printing layer. The printing layer can contain dispersants and pigment derivatives. The recycled base material can be processed into pellets for reuse.
4. Heat-Shrinkable Film Comprising Recycled Resin with Fluff and Repellet Layers
MITSUBISHI CHEMICAL CORP, 2021
Heat-shrinkable film made from recycled material for packaging applications that can be easily recycled. The film is composed of a layer made from a resin composition containing fluff and repellet obtained by recycling the packaging material itself. The fluff and repellet are produced through treatments like printing ink removal, cutting, pulverization, and drying. This allows using the recycled packaging material as a starting point to make a new heat-shrinkable film. The recycled film has properties like transparency, heat shrinkage, and block resistance similar to virgin heat-shrinkable film. It enables closed-loop recycling of packaging materials by using the recycled film as a new packaging material.
5. Single-Step Chemical Treatment for Selective Polyester Dissolution in Multilayer Plastic Packaging
MR VAVIYA LADHA GELA, 2015
A single-step chemical treatment method for recycling multilayer plastic packaging waste containing polyester, paper, aluminum, and ink. The method involves dissolving the polyester layer without affecting other layers like low density polyethylene (LDPE), biaxially oriented polypropylene (BOPP), cast polypropylene (CPP), and aluminum foil. The treatment involves contacting the waste with concentrated sulfuric acid for 30 seconds to 5 minutes, followed by sodium hydroxide solution, water, and drying. This removes the polyester, ink, and metallized aluminum, leaving behind the other layers like LDPE, BOPP, CPP, and intact aluminum foil.
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