Tearable Stock Material with Varying Perforation Rows
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Solution Overview
Problem
Previous dunnage conversion machines often experience premature tearing and jamming due to uniformly perforated stock materials, leading to unsightly products and operational issues.
Innovation Solution
A stock material with transversely-extending rows of perforations or weakened areas, where each row has varying parameters such as spacing, size, shape, and orientation, is used to minimize premature tearing and facilitate controlled separation into discrete dunnage products, with the lateral edges being free of perforations to reduce tension-induced tearing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If uniformly perforated stock material is used, then separation of discrete dunnage products is facilitated, but premature tearing and machine jamming occur
Solution Approach 1:
The patent applies local quality by creating non-uniform perforation patterns where different regions of the stock material have different perforation characteristics. Specifically, the lateral edges have reduced or no perforations to prevent tearing, while central regions have perforations to facilitate separation. This localized differentiation resolves the contradiction by making the material both tear-resistant at edges and separable at designated locations.
Solution Approach 2:
The patent segments the perforation pattern into distinct zones: edge regions with minimal or no perforations and central regions with perforations for separation. This segmentation allows different functional requirements to be met in different areas - structural integrity at edges and ease of separation in the center - thereby resolving the contradiction between preventing premature tearing and facilitating product separation.
2Ease of operation
If perforations are present across the entire width of stock material, then separation is easier, but tension-induced tearing at lateral edges increases
Solution Approach 1:
The patent implements local quality by varying the perforation density and presence across different regions of the stock material. The lateral edges have reduced or absent perforations to maintain strength and resist tension-induced tearing, while the central portions have perforations that facilitate separation. This spatial differentiation of perforation characteristics directly addresses the contradiction between ease of separation and resistance to tearing.
3Productivity
If stock material is converted into dunnage products, then void filling and cushioning are achieved, but machine jamming and operational interruptions occur
Solution Approach 1:
The patent applies preliminary action by pre-configuring the stock material with a specific perforation pattern before conversion that anticipates and prevents operational problems. The non-uniform perforation pattern is designed in advance to guide the conversion process smoothly, preventing jamming and tearing that would interrupt production. This preliminary structuring of the material ensures both productivity and reliability during the conversion process.
Data Source
AI summary
A stock material (16) for use with a dunnage conversion machine (14) includes at least one ply of sheet material having spaced along the length thereof a plurality of transverse rows (22) of weakened areas (24). The weakened areas (24), which can be formed by perforations, for example, have a reduced strength relative to adjacent portions of the sheet material. Each row (22) of weakened areas (24) has at least one parameter that varies along the row (22). The strength of the stock material at the row (22), in response to a force applied across the row (22), varies across the stock material (16).