Plastic Container Dual Watermarks for Reliable Recycling Sorting
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Solution Overview
Problem
Existing waste sorting systems face challenges in reliably identifying and sorting plastic items due to limited processing time and the need for distinct recognition of retail and recycling watermarks, leading to confusion and inefficiencies in both retail checkout and recycling processes.
Innovation Solution
Implementing two distinct digital watermarks on plastic items, one printed and one textured, using different signaling protocols to ensure rapid and accurate decoding by point-of-sale scanners and recycling systems, respectively, with a recycling apparatus configured to read both types of watermarks and utilize a database for plastic identification.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single watermark is used on plastic items, then the system complexity is reduced, but the ability to distinguish between retail and recycling identification is compromised
Solution Approach 1:
The patent divides the identification system into two separate watermarks: a first watermark for retail identification and a second watermark for recycling identification. Each watermark is encoded with different signaling protocols, allowing dedicated readers to accurately decode the appropriate type without interference, thus resolving the contradiction between system simplicity and identification reliability.
Solution Approach 2:
Different regions of the plastic item are assigned different functions: the first watermark is positioned and encoded for optimal reading by retail scanners, while the second watermark is positioned and encoded for optimal reading by recycling sorters. This local differentiation ensures that each identification system can reliably access its designated watermark without confusion from the other type.
2Loss of information
If both retail and recycling watermarks are read simultaneously, then information processing time increases, but the speed of checkout and recycling operations decreases
Solution Approach 1:
The patent segments the watermark reading process into parallel independent channels: retail scanners read only the first watermark while recycling sorters read only the second watermark. This segmentation allows simultaneous processing without interference, maintaining complete information extraction while avoiding time penalties from sequential processing.
Solution Approach 2:
The patent introduces distinct signaling protocols as intermediaries between the watermarks and their respective readers. Each protocol is optimized for its specific reader type, enabling rapid and accurate decoding without requiring the reader to process unnecessary or conflicting information from the other watermark type.
3Reliability
If watermark encoding is made more complex to improve accuracy, then the decoding speed decreases, but the reliability of plastic identification improves
Solution Approach 1:
The patent applies different encoding complexities locally to different watermarks based on their specific requirements. The first watermark uses an encoding optimized for retail scanner reliability, while the second watermark uses an encoding optimized for recycling sorter reliability. Each local encoding is matched to its dedicated reader, ensuring both high reliability and maintained decoding speed.
Data Source
AI summary
A plastic item, such as a beverage bottle, conveys two distinct digital watermarks, encoded using two distinct signaling protocols. A first, printed label watermark conveys a retailing payload, including a Global Trade Item Number (GTIN) used by a point-of-sale scanner in a retail store to identify and price the item when presented for checkout. A second, plastic texture watermark conveys a recycling payload, including data identifying the composition of the plastic. The use of two different signaling protocols assures that a point-of-sale scanner will not spend its limited time and computational resources working to decode the recycling watermark, which lacks the data needed for retail checkout. In some embodiments, a recycling apparatus makes advantageous use of both types of watermarks to identify the plastic composition of the item (e.g., relating GTIN to plastic type using an associated database), thereby increasing the fraction of items that are correctly identified for sorting and recycling. A great number of other features and arrangements are also detailed.