Injection Mold Fluororesin Coating Surface Defect Prevention
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Solution Overview
Problem
Existing injection molding technologies face challenges in producing aesthetically pleasing products without surface defects like swirl marks, silver streaks, glass fiber floating, and weld lines, especially in foam molding, which often require specialized and costly equipment like rapid heating/cooling molding or counter-pressure molding.
Innovation Solution
An injection mold with laminated deposition layers of polytetrafluoroethylene (PTFE) and perfluoroalkoxy (PFA) resin, where the first layer is 10-40 μm thick and the second layer is 40-70 μm thick, providing thermal insulation and preventing surface defects without the need for special equipment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If foam molding is used to reduce weight, then weight reduction is achieved, but surface appearance defects such as swirl marks and silver streaks occur
Solution Approach 1:
A fluororesin coating layer is applied as an intermediary substance between the mold cavity and the foaming resin. This coating layer prevents direct contact between the foaming gas and the mold surface, thereby preventing surface defects like swirl marks and silver streaks while allowing the foam molding process to proceed for weight reduction
Solution Approach 2:
The invention changes the surface properties of the mold by applying a fluororesin coating layer with specific thermal and surface energy characteristics. This parameter change in the mold surface properties prevents gas adhesion and allows smooth release of the foamed product without surface defects
2Manufacturing precision
If rapid heating/cooling molding or counter-pressure molding is used to prevent surface defects, then surface appearance quality is improved, but manufacturing cost increases and control difficulty increases
Solution Approach 1:
Instead of investing in expensive and complex rapid heating/cooling molding equipment or counter-pressure molding systems, the invention uses a relatively simple and cost-effective fluororesin coating layer applied to the mold surface. This coating can be reapplied when worn, providing a economical alternative to complex equipment modifications
Solution Approach 2:
The fluororesin coating acts as a mediator that simplifies the molding process by preventing surface defects through its non-stick and thermal insulation properties, eliminating the need for complex control systems required by conventional methods
3Manufacturing precision
If fluororesin coating is applied to mold surface to prevent surface defects, then surface appearance quality is improved, but coating durability decreases requiring frequent replacement
Solution Approach 1:
The invention uses fluororesin materials with inherently high durability and resistance to thermal and mechanical degradation. The coating formulation and application process are designed to create a robust multi-layer structure that maintains its protective properties for extended periods, reducing replacement frequency
4Ease of manufacture
If conventional molding is used without special equipment, then manufacturing cost is reduced, but surface appearance defects such as swirl marks and silver streaks occur
Solution Approach 1:
The fluororesin coating serves as a simple intermediary that can be applied to conventional mold surfaces without requiring modification of the base mold or injection molding machine. This maintains the simplicity and low cost of conventional equipment while dramatically improving surface appearance 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
Enables the production of injection-molded products with improved aesthetics and reduced manufacturing time and costs, as the mold can be used semi-permanently without frequent coating replacements, effectively eliminating swirl marks, silver streaks, and other defects.
Implementation Method 1
a first deposition layer which comprises polytetrafluoroethylene (PTFE), and a second deposition layer which comprises perfluoroalkoxy (PFA) resin
Implementation Method 2
US 2006/228434 A1 relates to a molding tool for producing molded foam bodies... whereby the shaping inner surfaces of the tool are provided with a microstructuring with the lotus leaf effect and/or with a durable nonstick coating made of a fluoroplastic or of a diamond-like coating
Data Source
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AI summary
The present invention relates to an injection mold, an injection molding machine including the injection mold, and a method of manufacturing an injection-molded product using the injection molding machine. More specifically, the present invention relates to an injection mold including a mold having a mold surface on which one or more deposition layers are laminated, wherein the deposition layer includes a fluororesin homopolymer or polyether ether ketone (PEEK); an injection molding machine including the injection mold; and a method of manufacturing an injection-molded product using the injection molding machine. According to the present invention, even without special equipment, an injection-molded product having an aesthetically pleasing appearance without surface appearance defects, such as swirl marks, silver streaks, glass fiber (G/F) floating, and weld lines, may be manufactured. In addition, the injection mold of the present invention may be used semi-permanently without replacing parts. Therefore, according to the present invention, manufacturing process time and costs may be reduced, and manufacturing process precision may be improved.