Laser Transmission Welding Filter Element End Cap

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Solution Overview

Problem

Current methods for producing filter elements are time-consuming and costly due to complex joining processes required for fluid-tight and mechanically strong connections between the filter medium and end caps, which hinder efficient and cost-effective manufacturing.

Innovation Solution

The method employs laser transmission welding with a laser-impermeable barrier layer between the end cap and filter medium, using a welding foil or in-mold injection molding to absorb laser energy and fuse the components, allowing for efficient welding of polyamide end caps and filter media, even when they are not directly weldable.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If complex joining processes (e.g., gluing) are used to connect the filter medium to the end cap, then fluid-tight and mechanically strong connections are achieved, but production time increases and manufacturing costs rise

Engineering Contradiction:
Improveconnection strengthVSAvoidproduction efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent replaces mechanical joining processes (gluing, bonding) with laser transmission welding. The laser beam transmits through the end cap and is absorbed by the filter medium, directly melting and fusing the materials together without requiring additional adhesives or complex mechanical fastening systems.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the optical parameters of the materials involved. The end cap is designed to be laser-permeable (transparent to laser wavelength), while the filter medium is laser-impermeable (absorbs laser energy). This parameter differentiation enables the laser to selectively heat and weld the filter medium to the end cap interface.

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If conventional welding methods are used on metal-free filter media, then direct welding might be attempted, but the materials are not suitable for absorbing welding energy

Engineering Contradiction:
ImproveweldabilityVSAvoidenergy absorption
Core Design Contradiction:
Ease of manufactureVSUse of energy by moving object

Solution Approach 1:

The patent introduces an intermediary layer (laser-impermeable barrier layer) on the filter medium surface. This intermediary layer acts as the energy absorption interface for the laser beam, converting optical energy to thermal energy, which then melts the filter medium and end cap materials together. The intermediary enables welding of materials that would otherwise be incompatible with direct laser welding.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of manufacture

If the end cap is made laser-permeable to allow laser transmission, then laser welding becomes possible, but the end cap itself absorbs little laser light and releases little thermal energy

Engineering Contradiction:
Improvelaser welding capabilityVSAvoidthermal energy release
Core Design Contradiction:
Ease of manufactureVSTemperature

Solution Approach 1:

The patent applies local quality differentiation: the end cap is laser-permeable in the bulk material to allow laser transmission, but the interface region where the filter medium contacts the end cap receives concentrated laser energy. The laser-impermeable barrier layer on the filter medium ensures localized energy absorption precisely at the welding interface, generating sufficient thermal energy only where needed for fusion.

Inventive Principle:
Principle #3Local quality

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach significantly reduces production time and costs by enabling efficient and strong connections between the filter medium and end caps, facilitating the manufacture of filter elements with improved structural strength and fluid-tight seals.

Implementation Method 1

laser transmission welding

Methodology Applied
Scientific EffectLaser transmission: Laser

Implementation Method 2

laser-impermeable barrier layer... absorbs laser energy

Methodology Applied
Scientific EffectLaser absorption: Absorption (EM radiation)

Implementation Method 3

absorb laser energy and fuse the components

Methodology Applied
Scientific EffectInductive heating: Induction Heating

Data Source

PatentEP2134437B1Method for the production of a filter element and filter element produced according to said method
Publication Date: 2018.06.13 HYDAC FILTERTECHNIK GMBH
  • EP2134437B1 patent drawingFigure 1~2
  • EP2134437B1 patent drawingFigure 3

AI summary

1. A method for the production of a filter element. 2. A method for the production of a filter element (1) comprising the steps: a) Providing a filter medium (3) surrounding an inner filter cavity (7) and comprising a heat-sealable material; b) Providing at least one end cap (9, 13) made of thermoplastic, laser-permeable material, forming a covering of the filter cavity (7) on at least one end; c) Forming a laser-impermeable barrier layer (31) between the end cap (9, 13) and the adjacent end of the filter medium (3) and d) Welding the end cap (9, 13) and filter medium (3) by irradiating laser-permeable material adjacent to the barrier layer (31) with laser energy such that, by heating the region adjacent to the barrier layer (31), a welding volume is provided as a joining element for the welded joint created by laser-transmission welding.