What is Mold Coating?
Traditional methods like die coating involve pulling the wire through a small reservoir of liquid varnish. This is effective but can lead to uneven coating, ovality, and varnish buildup.

Mold Coating is a precision extrusion process. The bare wire is pulled through a precisely engineered mold or nozzle that has a slightly larger inner diameter than the wire. Liquid varnish is fed under pressure into this mold, completely surrounding the wire and forming a perfectly concentric, uniform layer of insulation as it exits.

Advanced Equipment: The "How" of Mold Coating
A state-of-the-art enameled wire production line with mold coating is a fully integrated system. Here are the key components:

1. Pay-off System
Advanced Feature: Dual pay-off stands with automatic splicing. This allows for continuous, non-stop operation when one spool of bare wire runs out, crucial for high-volume production.

2. Pre-heating and Cleaning
Technology: The wire passes through an electric or gas-fired pre-heater to remove moisture and contaminants. It may also pass through ultrasonic cleaning baths. A clean, hot wire ensures perfect varnish adhesion.

3. The Coating Unit (The Heart of the System)
Precision Molds/Nozzles: These are not simple holes. They are made from wear-resistant materials like tungsten carbide or synthetic diamonds. They are engineered with specific geometries to control varnish flow and prevent turbulence.

Multi-Axis Alignment: The mold holders have micro-adjustments to ensure perfect concentric alignment with the wire path. Any misalignment ruins the coating uniformity.

Precision Metering Pumps: These pumps deliver a highly consistent and pulsation-free flow of varnish to the mold. The pressure and flow rate are critical process parameters.

4. The Curing Oven
Technology: This is a multi-zone, vertical or horizontal catalytic gas oven.

Multiple Zones: Each zone has a precisely controlled temperature profile. This allows the solvents to evaporate slowly in the first zone(s) and the resin to polymerize (cure) in the later zones without forming bubbles or defects.

Catalytic Combustion: This advanced technology incinerates the solvent vapors, using them as a fuel source to heat the oven. This makes the process highly energy-efficient and environmentally friendly by destroying VOCs.

5. Cooling System
Technology: After the oven, the wire passes through a series of cooling chambers, often using forced air or controlled water jackets. Proper cooling sets the varnish and prepares the wire for the next coating pass or final spooling.

6. In-line Monitoring and Control (The "Brain")
This is where the most significant advancements lie:

Laser Micrometers: Multiple lasers continuously measure the diameter of the coated wire in real-time, often in two perpendicular axes to check for ovality.

Spark Testers: The wire passes through a ring electrode that applies a high voltage. Any pinhole or thin spot in the insulation will cause a spark, and the system will log the fault or stop the line.

Centralized PLC/HMI: A Programmable Logic Controller (PLC) and Human-Machine Interface (HMI) integrate all data. Operators can set and monitor all parameters: oven temperatures, wire speed, pump pressures, etc. The system can automatically adjust to maintain quality.

7. Take-up System
Advanced Feature: Computer-controlled tensioners and traverse systems that wind the finished enameled wire onto spools with perfect tension and layering, preventing tangling and damage.

Mold coating--Advanced technology and equipment.Pursuing high quality is always our goal.