JP2012021199A - Method of recovering aluminum resource from packaging material waste - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of recovering aluminum efficiently as a resource from wastes of packaging material of a resin film deposited with aluminum.SOLUTION: Wastes of the packaging material of the resin film deposited with aluminum are recovered, and the recovered packaging material is subjected to a dry distillation treatment at a temperature within a range of 200-350°C, so that an aluminum component is collected as a residue to attain resource recovery.

Description

  The present invention relates to a method for recovering aluminum resources from packaging material waste in which a thin aluminum film is formed on a resin film substrate.

An aluminum vapor deposition film in which aluminum is heated and evaporated in a high vacuum state by resistance heating or high-frequency heating and the vapor is adhered to a film substrate is widely used.
Aluminum vapor-deposited film has a beautiful metallic luster, high water vapor and gas barrier properties, can block most of ultraviolet rays, visible rays, and infrared rays, hardly generates pinholes even when bent, and reduces electrostatic damage. It is used for many packaging materials because it has many merits.

However, the aluminum vapor deposition film has a thin aluminum film layer of 1.0 μm or less formed on the surface of the film substrate, and there has been no practical aluminum recovery method so far.
Patent Document 1 discloses a technique for recovering pulp by adding a label obtained by depositing aluminum on a base paper made of wood pulp to a pulper and adding a surfactant, but it cannot recover the aluminum content.

JP-A-8-127888

  An object of the present invention is to provide a method for efficiently recovering aluminum from waste of packaging material in which aluminum is deposited on a resin film.

  The method for recovering aluminum resources from packaging material waste according to the present invention comprises collecting packaging material waste deposited on aluminum on a resin film, and subjecting the collected packaging material to a dry distillation treatment within a range of 200 to 350 ° C. It is characterized by recovering resources as a residue.

  Here, the packaging material is not only a bag used for food packaging and pharmaceutical packaging, but also a lid, a label, etc., which is a resin film base material on which aluminum is vapor-deposited. All of the items collected as waste are eligible.

There are no particular limitations on the material of the resin film, but polyethylene, polypropylene, nylon, cellophane, and polyvinyl chloride are examples of widely used packaging materials.
Although the thickness of the film substrate can be applied in a wide range of 10 μm to 500 μm, it is a level of 10 μm to 100 μm from the viewpoint of easy melting, and the thickness of aluminum vapor deposition is 1.0 μm or less, generally 5 to 200 nm. It is a range.
Conventionally, the decomposition temperature of the above resin was generally said to be 400 ° C. or higher, but according to the study by the present inventors, the thickness of the film base material of the packaging material is thin, and sufficient thermal analysis can be performed at 200 to 350 ° C. It becomes clear that the oxidative decomposition of aluminum is suppressed because of the low temperature.

  In the present invention, dry distillation treatment refers to thermal decomposition under the condition of suppressing spontaneous ignition, and may be heated in a state where the inflow of air is cut off. What is necessary is just to heat in the reducing atmosphere under a property gas.

  Conventionally, when heated to 400 ° C. or higher, the aluminum thin film is oxidized and it is impossible to recover the metal aluminum. Recovery becomes possible.

The dry distillation treatment conditions and aluminum resource recovery results for packaging waste are shown.

A confectionery packaging bag (polyethylene, polypropylene) was collected and inserted into a ceramic pipe, and then the air was cut off, followed by heat treatment for a predetermined time at the heating temperature shown in the table of FIG.
The result of visual evaluation of the state of the residue at that time is shown in the table of FIG.

As a result, the resin component remained in the dry distillation treatment at 200 ° C. × 60 minutes, but most of the resin component disappeared at 200 ° C. × 120 minutes.
Further, although metallic luster aluminum is observed in the residue even at 250 ° C. × 90 minutes and 300 ° C. × 60 minutes, the metal aluminum residue is NO. 4 (300 ° C. × 60 minutes), and almost no residue was observed at 400 ° C. × 30 minutes. Therefore, it is presumed that metal aluminum was also oxidized.
Therefore, a heating time of 120 minutes or more is required at a heating temperature of 200 ° C., and a processing time of 30 minutes to 90 minutes is preferable as a dry distillation treatment condition in the range of 250 ° C. to 350 ° C.

Claims (2)

Collect the packaging material waste deposited on the resin film with aluminum,
A method of recovering aluminum resources from packaging material waste, characterized in that the recovered packaging material is subjected to dry distillation treatment in the range of 200 to 350 ° C. to recover resources as an aluminum component residue.   2. The aluminum resource recovery method according to claim 1, wherein the resin film is one of polyethylene, polypropylene, nylon, cellophane, and polyvinyl chloride.

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