Perforation Anvil With Variable Groove Width

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional perforating methods are inefficient for webs with elastic members extending in the machine direction, as they require new knives for pattern changes and do not consistently cut or damage elastic members, leading to variability in force required for web separation.

Innovation Solution

A grooved anvil with tapered grooves is used in conjunction with a pinch cut knife, allowing for adjustable perforation patterns without changing the knife, ensuring consistent cutting or damage of elastic members by positioning the knife relative to the anvil to fine-tune the pattern for various materials and conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional knife and anvil systems are used with notches in the cutting edge, then perforation patterns can be created, but changing the pattern requires obtaining new knives with appropriate notch sizes and spacing

Engineering Contradiction:

Improveperforation pattern flexibilityVSAvoidknife modification requirements

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

Instead of placing features on the knife (notches in cutting edge), the invention places corresponding features on the anvil surface (grooves). The knife becomes a simple continuous cutting edge while the anvil provides the pattern-defining grooves. This inversion allows pattern changes by modifying the anvil rather than the knife, solving the problem of knife complexity and replacement.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The anvil surface with grooves acts as an intermediary between the simple continuous cutting edge and the desired perforation pattern. The grooves guide and shape the cutting action to create the required pattern without requiring complex knife geometry. This mediator approach separates the pattern-defining function from the cutting function.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If conventional knives with notches are used, then perforation patterns are achieved, but the knives must be altered or replaced to achieve desired patterns

Engineering Contradiction:

Improveperforation pattern adjustabilityVSAvoidknife manufacturing and modification

Core Design Contradiction:

Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The invention inverts the conventional approach by placing pattern-defining grooves on the anvil rather than notches on the knife. This allows pattern adjustments to be made to the anvil surface, which can be more easily modified or replaced than knives with complex notch geometries. The knife itself becomes simpler to manufacture with a continuous edge.

Inventive Principle:

Principle #13The other way round (Inversion)

3Productivity

If conventional perforating methods are used on webs with elastic members, then perforation is achieved, but elastic members in uncut regions remain whole and retain strength, impeding web separation

Engineering Contradiction:

Improveweb separation efficiencyVSAvoidconsistent elastic member cutting

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The grooves on the anvil surface create localized zones where elastic members are concentrated and subjected to enhanced cutting action. The grooves modify the local stress distribution and cutting mechanics to ensure elastics within groove regions are consistently cut or damaged, while lands maintain web integrity. This local quality approach ensures reliable elastic member severance.

Inventive Principle:

Principle #3Local quality

4Reliability

If conventional perforating methods are used, then perforation is achieved, but inherent variability in cross-directional tracking and elastic placement results in varying numbers of elastics being cut, causing force variability

Engineering Contradiction:

Improveprocessing stabilityVSAvoidaccommodation of tracking variability

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The invention changes the geometric parameters of the anvil surface by providing grooves with varying widths (tapered from leading to trailing edge). This parameter variation allows the system to accommodate different positions of elastic members and tracking variations. The tapered groove design ensures that elastics are engaged and cut effectively regardless of their precise position, stabilizing the cutting force required.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentEP2268464B1Perforation anvil

Publication Date: 2017.04.05 KIMBERLY CLARK WORLDWIDE INC

AI summary

A method and apparatus for perforating a web includes an anvil roll having an outer surface wherein at least a portion of the outer surface defines an anvil surface. The anvil surface includes a plurality of angled grooves having a variable groove width. The method may include phasing the cutting position on the anvil to effect varying perforation patterns.