Stretchable Tube Inner Microstructure for Water-Repellent Liquid Transfer

Solution Overview

Problem

Existing polytetrafluoroethylene tubes lack flexibility and have insufficient water repellency, making them difficult to handle and limiting their applications, especially when used in wound or fixed states, and existing surface treatments do not effectively address inner surface water repellency.

Innovation Solution

A stretchable tube with protrusions on its inner surface, made of a silicon compound with a higher oxygen content, having a pitch of less than or equal to 1.5 μm, which provides excellent water repellency and facilitates handling by maintaining a stable fixed state when wound or fixed to another member.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a tube is made of polytetrafluoroethylene to provide water repellency, then water repellency is improved, but flexibility and handling properties deteriorate

Engineering Contradiction:

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The patent applies different surface properties to different locations: the outer surface is treated to enhance water repellency while the inner surface maintains smoothness for liquid flow. This local differentiation allows the tube to exhibit both excellent water repellency and good handling properties simultaneously.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The tube employs a composite structure combining polytetrafluoroethylene base material with surface treatments (fluorine gas treatment on outer surface). This composite approach maintains the inherent flexibility of PTFE while adding enhanced water repellency through surface modification.

Inventive Principle:

Principle #40Composite materials

2Reliability

If the outer surface is made slippery to improve water repellency, then water repellency is improved, but the ability to hold fixed state deteriorates

Engineering Contradiction:

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent creates distinct surface characteristics at different locations: the outer surface receives fluorine gas treatment to maximize water repellency, while the inner surface remains smooth for optimal liquid transfer. This spatial differentiation of surface properties resolves the contradiction between slipperiness and fixed-state stability.

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

The tube's stretchability and water-repellent inner surface allow for easy handling and efficient liquid transfer without waste, as the protrusions' height is adjustable based on tension, ensuring reliable water repellency and preventing liquid adhesion.

Implementation Method 1

It is known that water repellency is expressed or improved by utilizing a fine concavo-convex structure of μm level

Methodology Applied

Scientific EffectWater repellency through fine concavo-convex structure: Lotus Leaf Effect

Implementation Method 2

a stretchable tube with protrusions on its inner surface, made of a silicon compound with a higher oxygen content

Methodology Applied

Scientific EffectWater repellency: Hydrophobe

Data Source

PatentUS11077605B2Tube

Publication Date: 2021.08.03

AI summary

The tube is stretchable. The tube is stretched by applying tension in a longitudinal direction. The tube returns to its short state by releasing the above-described tension applied in the longitudinal direction. A plurality of protrusions are formed on an inner surface of the tube. Each of the plurality of protrusions extends in a circumferential direction. The plurality of protrusions are arranged side by side in the longitudinal direction of the tube. A pitch of the protrusions is less than or equal to 1.5 μm.