Types and Processing Methods of Threads in Injection Molded Parts
Threads are common features in injection molded parts, and they come in various types with different processing methods to suit different needs.
I. Types of Threads in Injection Molded Parts
By Thread Location:
External Threads: Threads located on the external surface of a product, commonly found in bolts and nuts.
Internal Threads: Threads located on the internal surface of a product, commonly found in threaded holes and pipe fittings.
By Thread Profile:
Triangular Threads: The most common thread profile, such as the M series.
Trapezoidal Threads: Suitable for transmission and guiding, such as screw threads.
Sawtooth Threads: Good self-locking performance, often used for high-strength connections.
Rounded Threads: Easy to seal, commonly used in bottle caps.
II. Processing Methods for Threads
Direct Molding:
Advantages: High production efficiency and low cost.
Applications: Most internal and external threads in injection molded products.
Post-processing:
Advantages: High thread precision, capable of processing various complex threads.
Applications: Products with high precision requirements or those difficult to mold directly.
Insert Molding:
Advantages: High thread strength, wear resistance, suitable for parts that are frequently disassembled and subjected to high loads.
Applications: High-strength connections, parts that are frequently disassembled.
III. Precautions for Thread Processing
Precise Mold Design: The mold design for the threaded portion must ensure dimensional accuracy to avoid thread misalignment, unclear thread profiles, and other issues.
Appropriate Material Selection: Choose materials with good fluidity and stable shrinkage to ensure the integrity of the thread.
Optimization of Process Parameters: Through experiments and analysis, optimize injection process parameters to achieve the best thread quality.
Thorough Post-processing: For post-processed threads, deburring, chamfering, and other post-processing operations should be performed to improve the product's appearance and performance.
