Decoloration and recovery process of waste PETG (Polyethylene Terephthalate Glycol) film
By crushing, cleaning, disinfecting, drying and decolorizing the waste PETG film, and mixing with tough PETG polyester, and removing the decolorizer and extracting agent with ester solvent extraction, the problem of difficulty in recycling waste PETG film is solved, efficient resource reuse and process cost is reduced.
Patent Information
- Application Number
- CN202311500642.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-11-13
- Publication Date
- 2025-05-23
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
The prior art is difficult to effectively recycle and reuse waste PETG films, resulting in waste of resources and increased processing costs.
A process is adopted, including crushing treatment, cleaning, disinfection, drying, decolorization treatment with strong oxidant at a certain temperature and alkaline conditions, followed by cleaning, drying, granulation, and then melt blended with tough PETG polyester to modify PETG polyester, and separation of decolorizer and extraction agent through ester solvent extraction for recycling.
Effective decolorization and recycling of waste PETG films is achieved, the ink layer adhesion, color reduction effect and shallow net transfer effect of regenerated PETG polyester are improved, and process costs are reduced.
Smart Images
Figure CN120025665A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of PETG recycling, and in particular to a decolorization and recycling process of waste PETG films. Background Art
[0002] With the development of the economy, in order to attract customers' attention, the styles and demand of outer packaging have increased significantly. PETG film is widely used in food outer packaging due to its outstanding thermoforming performance, toughness, weather resistance and easy processing. During the processing of PETG film, a large amount of PETG film will be scrapped due to printing misalignment, color difference and other reasons. However, due to the complicated ink processing process on PETG film, the waste PETG film cannot be reused. Most manufacturers choose to directly discard it, which increases the processing cost of PETG film and causes waste of resources. Summary of the invention
[0003] The technical problem to be solved by the present invention is to overcome the existing defects and provide a decolorization and recycling process for waste PETG film, so as to solve the decolorization problem of PETG waste flower material and improve the ink layer adhesion, color restoration effect and shallow screen transfer effect of recycled PETG polyester.
[0004] In order to solve the above technical problems, the present invention provides the following technical scheme: a decolorization and recovery process of waste PETG film, the waste PETG flower material film is crushed to obtain PETG flower material fragments, the PETG flower material fragments are cleaned, disinfected and dried to obtain clean PETG flower material fragments, the PETG flower material fragments are decolorized with a strong oxidant under a certain temperature and alkaline conditions to obtain waste liquid and colorless PETG fragments, the colorless PETG fragments are cleaned, dried and granulated to obtain regenerated PETG polyester, the regenerated PETG polyester and tough PETG polyester are melt-blended to obtain modified PETG polyester, the waste liquid is extracted and separated with an ester solvent to obtain an upper alkaline aqueous solution and a lower ester organic solution, the upper alkaline aqueous solution is recycled as a decolorizing agent, the lower ester organic solution is distilled to obtain ester solvent and solid waste, the ester solvent is recycled as an extractant, and the solid waste is treated as solid waste.
[0005] Furthermore, the tough PETG polyester is obtained by esterifying and condensing neopentyl glycol, methyl propylene glycol, ethylene glycol and terephthalic acid at high temperature.
[0006] Compared with the prior art, the present invention has the following beneficial effects: (1) Use a strong oxidant to decolorize the PETG flower fragments to facilitate the recycling of waste PETG.
[0007] (2) Decolorization treatment under certain temperature and alkaline conditions can not only stabilize the reaction rate, but also reduce the corrosion of strong oxidants on PETG polyester itself.
[0008] (3) Through modification, the ink layer adhesion, color reproduction effect and shallow screen transfer effect of recycled PETG polyester are improved.
[0009] (4) Both the decolorizing agent and the extracting agent can be recycled and reused, thus reducing process costs. BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Figure 1 It is the process route map of the present invention; Figure 2 The figure is a process diagram for treating waste liquid after decolorization in the present invention. DETAILED DESCRIPTION
[0011] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Example
[0012] like Figure 1-2 , a decolorization and recycling process for waste PETG film, the waste PETG flower material film is crushed to obtain PETG flower material fragments, which increases the reaction area and is convenient for later processing. The PETG flower material fragments are washed, disinfected and dried to obtain clean PETG flower material fragments, reducing the influence of dust and grease on decolorization and modification. Under certain temperature and alkaline conditions, the PETG flower material fragments are decolorized with a strong oxidant, which can not only stabilize the reaction rate, but also reduce the corrosion of the strong oxidant to the PETG polyester itself. After decolorization, waste liquid and colorless PET are obtained. G fragments, convenient for PETG recycling, colorless PETG fragments are washed, dried, and granulated to obtain recycled PETG polyester, recycled PETG polyester and tough PETG polyester are melt-blended to obtain modified PETG polyester, and the toughness of PETG polyester is increased, the regenerated waste liquid is extracted and separated with an ester solvent to obtain an upper alkaline aqueous solution and a lower ester organic solution, the upper alkaline aqueous solution is recycled as a decolorizing agent, the lower ester organic solution is distilled to obtain ester solvents and solid waste, the ester solvent is recycled as an extractant, the process cost is reduced, and the solid waste is treated as solid waste; Furthermore, the tough PETG polyester is obtained by esterifying and condensing neopentyl glycol, methyl propylene glycol, ethylene glycol and terephthalic acid at high temperature, and is used for modification of recycled PETG polyester.
[0013] Decolorizing PETG flower fragments with strong oxidants is convenient for recycling of waste PETG and reducing the impact of ink on recycled PETG polyester. Decolorizing under certain temperature and alkaline conditions can not only stabilize the reaction rate, but also reduce the corrosion of strong oxidants on PETG polyester itself. Through modification, the ink layer adhesion, color restoration effect and shallow screen transfer effect of recycled PETG polyester are improved. Both decolorizing agents and extractants can be recycled and reused to reduce process costs.
[0014] The undisclosed parts in the present invention are all prior art, and their specific structures, materials and working principles are not described in detail. Although the embodiments of the present invention have been shown and described, it is understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the attached claims and their equivalents.
Claims
1. A decolorization and recycling process for waste PETG film, Features: The waste PETG flower film is crushed to obtain PETG flower film fragments, which are cleaned, disinfected and dried to obtain clean PETG flower fragments. The PETG flower fragments are decolorized with a strong oxidant under certain temperature and alkaline conditions to obtain waste liquid and colorless PETG fragments. The colorless PETG fragments are washed, dried and granulated to obtain recycled PETG polyester. The recycled PETG polyester and tough PETG polyester are melt-blended to obtain modified PETG polyester. The waste liquid is extracted and separated with an ester solvent to obtain an upper alkaline aqueous solution and a lower ester organic solution. The upper alkaline aqueous solution is recycled as a decolorizing agent. The lower ester organic solution is distilled to obtain an ester solvent and solid waste. The ester solvent is recycled as an extractant, and the solid waste is treated as solid waste.
2. A decolorization and recovery process for a waste PETG film according to claim 1, Features: The tough PETG polyester is obtained by esterifying and condensing neopentyl glycol, methyl propylene glycol, ethylene glycol and terephthalic acid at high temperature.