Method of recycling and granulating waste container made of resin materials

• US 5,961,054 A
• Filed: 12/11/1996
• Issued: 10/05/1999
• Est. Priority Date: 12/13/1995
• Status: Expired due to Fees

• Current Assignee: EIN Engineering Co., Ltd.
• Original Assignee: EIN Engineering Co., Ltd.
• Inventors: Nishibori, Sadao
• Primary Examiner(s): Rosenbaum, Mark
• Application Number:
  US08/764,013
• Time in Patent Office: 1,028 Days
• Field of Search: 241/24.18, 241/24.13, 241/24.14, 241/24.15, 241/24.28, 241/DIG. 38, 241/29, 241/19, 241/99
• US Class Current: 241/19
• CPC Class Codes: B29B 13/10 by grinding, e.g. by triturating; by sieving; by filtering
• CPC Class Codes: B29B 17/02 Separating plastics from other materials
• CPC Class Codes: B29B 2017/0203 Separating plastics from plastics
• CPC Class Codes: B29B 2017/0244 in liquids
• CPC Class Codes: B29B 7/66 Recycling the material B29B7/566 takes precedence
• CPC Class Codes: B29C 2793/009 after shaping
• CPC Class Codes: B29K 2023/06 PE, i.e. polyethylene
• CPC Class Codes: B29K 2025/00 Use of polymers of vinyl-aromatic compounds or derivatives thereof as moulding material
• CPC Class Codes: B29K 2027/06 PVC, i.e. polyvinylchloride
• CPC Class Codes: B29K 2067/00 Use of polyesters or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2105/065 containing impurities
• CPC Class Codes: B29K 2705/00 Use of metals, their alloys or their compounds, for preformed parts, e.g. for inserts
• CPC Class Codes: B29L 2031/7158 Bottles
• CPC Class Codes: B29L 2031/744 Labels, badges, e.g. marker sleeves
• CPC Class Codes: Y02W 30/52 Mechanical processing of waste for the recovery of materials, e.g. crushing, shredding, separation or disassembly
• CPC Class Codes: Y02W 30/62 Plastics recycling; Rubber recycling

Abstract

The thermoplastic resin waste containers are crushed into coarsely crushed pieces, an impact-grinding force and a centrifugal force are applied on the coarsely crushed pieces so that oily foreign objects be separated; i.e., the oily foreign objects are separated by the impact force and the grinding force. The difference in the centrifugal force separates the resin from the foreign object, the centrifugal force on the resin pieces being controlled by the impact-grinding force, while the centrifugal force on the oily foreign object is free from it. In the course of this process, the crushed pieces to be treated are formed into granules by the impact-grinding force, and the granulated granules are reused as a resin material. Foreign objects other than oils can be separated and removed more easily than oils.

Claims

1. A method for recovering resin material, the method comprising:

a) crushing, into coarsely-crushed pieces, a waste container that is made of thermoplastic resin material and that has a plastic film wrapped around the container;

b) forcing air through the coarsely-crushed pieces, to separate and remove the film from the coarsely-crushed pieces;

c) applying an impact-grinding force to the coarsely-crushed pieces, to separate the resin material from foreign objects;

d) granulating the resin material to form granulated resin material; and

e) recovering the granulated resin material.

2. The method of claim 1, further comprising:

drying the coarsely-crushed pieces after the crushing step.

3. The method of claim 1, further comprising:

shredding the coarsely-crushed pieces to form shredded smaller pieces; and

from time to time, removing the foreign objects that have been separated from the resin material.

4. The method of claim 3, further comprising:

applying an impact force and a centrifugal force to the coarsely-crushed pieces, to separate the resin material from the foreign objects.

5. The method of claim 3, further comprising:

applying an impact force and a centrifugal force to the small pieces, to separate the resin material from the foreign objects.

6. The method of claim 3, wherein

A) the container includes a main body coupled with a skirt underneath;

and

B) the method further comprises;

i) applying an impact-grinding force to the shredded small pieces, to separate the resin material from the foreign objects;

ii) cleaning and drying the resin material;

iii) applying an impact-grinding force to pulverize and granulate the skirt, before the step of recovering the granulated resin material; and

iv) separating and classifying the granulated resin materials of the main body of the container.

7. The method of claim 3, wherein:

A) the container includes a main body coupled with a flanged screw portion; and

B) the method further comprises;

i) applying an impact-grinding force on the small pieces of the main body and screw portion, to separate the foreign objects;

ii) granulating, regulating the size of, cleaning, and drying the resin materials;

iii) separating resin material from the flanged screw portion and from the main body, based on differences in specific gravity, in water; and

iv) recovering the resin material of the main body separately from the resin material of the flanged screw portion.

8. The method of claim 7, further comprising:

drying the crushed pieces of resin material after the shredding step.