US 5,344,026 A · Method and apparatus for sorting plastic items

Abstract

A method of sorting plastic items by measuring the effect an item has on light directed at a stream of items from a light source, then selectively removing items from the stream based on a comparison of the light measured and the light emitted from the detector is provided. The invention also includes an apparatus for separating plastic items which comprises a light source, a detector for measuring the effect an individual item has on light emitted from the detector, and sortation means for selectively removing items from the stream based on a comparison of the light emitted by the light source and that measured at the detector. A method for separating single plastic bottles from engaged interlocked bottle clusters comprising directing an air jet at an item sufficiently forceful to displace a single bottle to a collection means but insufficiently forceful to displace an interlocked bottle cluster is also provided.

Claims35

Dependent claims

A method of separating individual plastic items from a mixture of plastic items, and that is particularly useful in recovering recyclable plastics from waste sources such as municipal waste, and in which each of the individual items is formed predominantly of a single type of plastic, but in which different individual items within the mixture are made of different types of plastic, the method comprising:

measuring the effect that each individual item has on light of a predetermined character directed at the item from a source and measured with a line scan camera detector opposed to the source as a sliding stream of the items is successively directed past the source and the line scan camera;
and
selectively removing individual items from the sliding stream based upon a comparison of the light produced by the source and any light received by the line scan camera detector.

An apparatus for separating individual plastic items from a mixed stream of plastic items, and that is particularly useful in recycling plastic items from waste sources such as municipal waste, and in which each of the individual plastic items is formed predominantly of a single type of plastic, but in which different individual items within the mixture are made of different types of plastic, the apparatus comprising:

(a) a conveyor for presenting a sliding stream of items;
(b) a light source for emitting light of a predetermined character;
(c) a line scan camera detector opposed to said light source for measuring the effect each individual sliding item has on light emitted by said light source as a stream of sliding individual items is successively directed between said light source and said line scan camera detector;
and
(d) sortation means responsive to said line scan camera detector for selectively removing individual sliding items from the stream based on a comparison of the light produced by said source and any light detected by said line scan camera detector.

2 more elements

Dependencies are inferred from the claim text.

Method and apparatus for sorting plastic items

Life of this patent

Method and apparatus for sorting plastic items

Life of this patent

Abstract

Claims35