PC Strand Rustproof Film Formation via Dual-Stage Heating
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional rustproofing methods for PC strands face challenges such as low production efficiency, high manufacturing costs, and shape failures due to pinholes and cob-webbing phenomena, which are exacerbated by the need for precise control of resin powder particle diameters and temperature settings.
Innovation Solution
A method that involves pre-heating the PC strand to a lower temperature before applying the synthetic resin powder coating material and post-heating to a higher temperature, allowing for the use of a wide range of particle diameters and increasing line speed to improve productivity while preventing foaming and cob-webbing, resulting in a uniform and rustproof film without impairing flexibility or shearing resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the line speed is increased to improve productivity, then production efficiency is improved, but the film thickness becomes insufficient and pinholes form
Solution Approach 1:
The patent changes the particle diameter parameter of the powder coating material from the conventional narrow range (40-50 μm) to a wider range (10-100 μm) with specific distribution characteristics. This parameter change allows the coating system to maintain adequate film thickness and quality even at higher line speeds (5-10 m/min), thereby resolving the contradiction between productivity improvement and manufacturing precision.
2Reliability
If the pre-heating temperature is set higher than post-heating temperature to improve coating adhesion, then adhesion is improved, but cob-webbing phenomenon and pinholes occur
Solution Approach 1:
The patent inverts the conventional temperature sequence by setting pre-heating temperature (60-150°C) lower than post-heating temperature (150-250°C). This inversion prevents the powder particles from melting too early during pre-heating, eliminating the cob-webbing phenomenon that occurs when melted powder is blown by air conveyance. The lower pre-heating temperature maintains powder integrity while still improving adhesion, and the subsequent higher post-heating temperature ensures proper curing.
3Speed
If the pre-heating temperature is increased to accelerate drying, then drying speed is improved, but air bubbles are trapped and pinholes form
Solution Approach 1:
The patent implements periodic heating action through two distinct heating stages: pre-heating (60-150°C) and post-heating (150-250°C). The pre-heating stage gently removes moisture and prepares the substrate without causing rapid vaporization that would trap air bubbles. The subsequent post-heating stage completes the drying and curing process at higher temperature. This periodic heating approach achieves both fast drying speed and pinhole-free film uniformity.
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 enhances productivity, reduces material costs, and ensures a uniform, pinhole-free film with improved corrosion resistance and tensile fatigue characteristics, effectively addressing the limitations of existing methods.
Implementation Method 1
The heating includes a pre-heating before applying the synthetic resin powder coating material and a post-heating after the application of the synthetic resin powder coating material, the temperature of the pre-heating is set within a range from 60 to 150°C
Implementation Method 2
the temperature of the post-heating is set within a range from 150 to 250°C, the temperature of the pre-heating is set to be lower than the temperature of the post-heating by 20°C or more
Implementation Method 3
forming a resin film having a predetermined thickness... without forming pinholes
Implementation Method 4
heating the adhesion film at a temperature of 250°C... the resin film is formed uniformly
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
In a method for forming a rustproof film on a PC strand, the thickness of the resin film (26) is set to 200 ± 80 µm, the pre-heating is performed within a temperature range from 60 to 150°C to prevent an occurrence of a cob-webbing phenomenon as a result of melting of the synthetic resin powder coating material and the post-heating is performed within a range from 150 to 250°C in order to uniformize the thickness of the coats adhered to the outer peripheral surfaces of the core wire and the surrounding wires, and the temperature of the pre-heating is set to be lower than the temperature of the post-heating, and the synthetic resin powder coating material including particles having diameters in a range from 0.1 to 250 µm is used, and the line speed in the series of steps is set to 5 to 10 m/min.