Mandrel Cooling Assembly Friction Reduction

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Solution Overview

Problem

Current pipe production methods face inefficiencies due to reduced heat transmission and increased friction between molten plastic and the mandrel, leading to extended cooling times and reduced production rates, as well as the need for post-production lubrication to achieve a slippery inner wall.

Innovation Solution

A mandrel cooling assembly that delivers a lubricating fluid between the pipe and the mandrel, reducing friction and enhancing heat transfer by positioning a transfer pipe to align with the mandrel and nozzle outlet, allowing the molten plastic to contact the fluid instead of the mandrel surface, and utilizing a dispersing disc to ensure even distribution of the fluid for efficient cooling and lubrication.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If molten plastic contacts the mandrel surface for cooling and shaping, then the pipe inner wall is formed, but heat transmission is reduced due to microsize gaps and friction increases

Engineering Contradiction:
Improvecooling efficiencyVSAvoidfriction
Core Design Contradiction:
TemperatureVSForce

Solution Approach 1:

A lubricating fluid is introduced as an intermediary substance between the mandrel surface and the molten plastic. The fluid is delivered through channels in the mandrel and dispersed onto the mandrel outer surface, creating a lubricating layer that reduces friction and improves heat transmission while allowing the molten plastic to slide smoothly over the mandrel.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system uses hydraulic principles to deliver the lubricating fluid through channels within the mandrel structure. The fluid is pumped through internal channels and discharged onto the mandrel outer surface, utilizing fluid pressure and flow control to ensure proper distribution and maintenance of the lubricating film.

Inventive Principle:
Principle #29Pneumatics and hydraulics

2Temperature

If cooling time is extended to improve heat transmission, then cooling effectiveness increases, but production rate decreases

Engineering Contradiction:
Improvecooling effectivenessVSAvoidproduction rate
Core Design Contradiction:
TemperatureVSProductivity

Solution Approach 1:

The lubricating fluid acts as a thermal mediator that enhances heat transmission between the mandrel and molten plastic. By improving the thermal contact through the fluid layer, the system achieves more efficient heat transfer, allowing for shorter cooling times while maintaining effective cooling, thus increasing production rate without sacrificing cooling effectiveness.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Force

If friction is reduced through material additives, then some friction reduction is achieved, but adequate efficiency cannot be attained

Engineering Contradiction:
Improvefriction reductionVSAvoidproduction efficiency
Core Design Contradiction:
ForceVSProductivity

Solution Approach 1:

Instead of relying solely on material additives within the plastic, the system introduces an external lubricating fluid as a mediator between the mandrel and plastic. This fluid-based approach provides superior and controllable friction reduction that material additives alone cannot achieve, enabling adequate production efficiency.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system changes the friction reduction approach from internal material properties to an external controllable parameter - the lubricating fluid. By controlling the fluid delivery rate, pressure, and distribution, the system can dynamically adjust friction levels to optimize production efficiency, whereas material additives provide fixed, less controllable friction modification.

Inventive Principle:
Principle #35Parameter changes

4Ease of operation

If lubricants are applied on the inner wall after production, then slippery inner wall is achieved, but additional cost and inconvenience are incurred

Engineering Contradiction:
Improveinner wall lubricityVSAvoidpost-production processing
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The lubricating fluid is applied to the mandrel surface before the molten plastic contacts it, during the forming process itself. This preliminary application ensures the inner wall of the produced pipe has the desired lubricity built-in, eliminating the need for post-production lubrication operations and reducing overall process complexity.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system incorporates the lubrication function directly into the pipe production process through the mandrel's internal fluid delivery system. The mandrel serves its primary cooling and shaping function while simultaneously providing lubrication, making the system self-sufficient and eliminating the need for separate post-production lubrication equipment or operations.

Inventive Principle:
Principle #25Self-service

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 solution significantly reduces friction and enhances heat transfer, resulting in faster pipe production, improved mandrel longevity, and the ability to produce pipes with a lubricous inner wall without the need for post-production lubrication, thereby increasing production efficiency and reducing costs.

Implementation Method 1

delivering a friction-reducing fluid to the surface of the mandrel... reduces the friction between the mandrel surface and the pipe inner wall

Methodology Applied
Scientific EffectLubrication: Lubrication

Implementation Method 2

cooling water channels in the inner part of the mandrel for cooling the molten raw material... heat transmission efficiency between the same

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 3

directing the coolant passing through the mandrel... enables cooling

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP3311977B1Plastic pipe machine mandrel cooling and lubricating assembly
Publication Date: 2020.06.24 CANLAR BORU PROFIL PLASTIK ELEKT INS MAK NAK SANAYI VE TICARET LTD SIRKETI
  • EP3311977B1 patent drawingFigure 1
  • EP3311977B1 patent drawingFigure 2
  • EP3311977B1 patent drawingFigure 3

AI summary

The present invention relates to a pipe mold system (1); which comprises an external mold (2) on which the molten plastic is placed to be shaped and to acquire the form of a pipe, a head mold (3) which includes passage holes thereon that enable to deliver the molten plastic to the external mold (2), a first nozzle (31) located on the end of the passage hole, a mandrel (4) which is located inside the external mold (2) and which shapes the plastic pipe (B) inner wall, a channel (5) which passes through the mandrel (4) and the head mold (3) and carries the coolant (S), a transfer pipe (6) which extends through the channel (5) towards between the mandrel (4) and the first nozzle (31), and a lubricating fluid (7) which is spread from the transfer pipe (6) onto the mandrel (4); and which, in plastic pipe (B) production, enables the inner wall of the plastic pipe (B) to be exposed to less friction and increases heat conductivity and helps to cool the molten plastic and enables to shorten the plastic pipe (B) production time.