Zibo Hondo Chemical Co., Ltd. is one of the most experienced manufacturers and suppliers of welding grade cmc in China. Our factory offer high quality products made in China with competitive price. If you have any enquiry about quotation, please feel free to email us.
Welding Grade CMC is a water-soluble cellulose derivative that is chemically modified to give it unique bonding, thickening and film-forming properties. In the field of welding, welding Grade CMC is mainly used as a core additive for electrode coatings and is widely used in the production of various types of electrodes, especially in alkaline low-hydrogen electrodes and special environment welding materials. And now welding Grade CMC become an economic and environmental materials in the production of the welding.From an electrode manufacturing perspective, Welding Grade CMC is not only a binder, but also a process-regulating additive that directly influences coating adhesion strength, drying behavior, baking stability, slag formation, and welding arc stability. Its molecular design allows manufacturers to balance mechanical strength, coating integrity, hydrogen control, and production efficiency in modern welding rod production lines.
Hondo Chem Welding Grade CMC Used In Different Items
-
1. Basic Welding Rods
Such as E5015 (J507) item welding rods, Welding Grade CMC is compounded with water glass to provide high adhesion and moisture resistance, ensuring that the coating still maintains strength after baking at 350-400℃.This synergy is particularly critical for alkaline electrodes where coating brittleness and moisture reabsorption can lead to coating detachment and hydrogen pickup during storage.
-
2. Stainless Steel Welding Rods
Such as E308L rods, adding 0.3-0.5% Welding Grade Sodium CMC can improve the fluidity of the coating, reduce the redness during welding, and improve the corrosion resistance of the weld.Optimized coating rheology also improves wire feeding stability and reduces coating eccentricity, contributing to consistent weld bead appearance in stainless steel applications.
-
3. Ultra-low Hydrogen Welding Rods
Such as E7018 rods, welding grade CMC and rare earth fluoride work synergistically to reduce the content of diffusible hydrogen while improving the crack resistance of the welding rod.This formulation approach is widely adopted in structural steel and pressure vessel welding, where hydrogen-induced cracking control is a critical quality requirement.
-
4. Special Purpose Welding Rods
Nuclear power welding rods: Welding grade CMC compounded with CaF₂, TiO₂, etc., to adapt to the high temperature strength requirements in radiation environments.
Corrosion-resistant welding rods: Add CMC for Welding Electrodes to the coating to enhance the ability to resist salt spray and humid environments.
For hot forging die repair welding rods, adding 0.5-1% CMC for Welding Electrodes can enhance the wear resistance and hardness of the coating and make the uniformity deviation of the deposited metal hardness ≤5%.These applications demonstrate Hondo Chem's capability to tailor Welding Grade CMC for high-temperature resistance, moisture stability, and coating hardness control under extreme service conditions.
Core Function
1. Bonding and forming
Binder function: The polymer chain of Carboxymethyl Cellulose for Welding forms a mesh structure in the aqueous solution, which tightly bonds the coating powder through hydrogen bonds and van der Waals forces, so that the coating and the welding core are firmly combined. For example, in alkaline welding rods, welding Grade CMC and water glass are used in combination to form a high-strength coating after drying, and the peeling resistance is improved by more than 30%.
Improving the pressure coating performance: Welding Grade CMC's thickening characteristics reduce the fluidity of the coating slurry, so that it adheres evenly to the surface of the welding core during the pressure coating process, reducing eccentricity. For example, in stainless steel welding rods, adding 0.3-0.5% CMC can control the coating thickness deviation within ±0.1mm.
This directly improves finished electrode dimensional consistency, which is a key quality indicator for automated welding and robotic welding applications.
2. Water retention and crack resistance
Water retention effect: The hydrophilic carboxyl group of welding Grade CMC can absorb and lock water, slow down the drying speed of the coating, and prevent cracking caused by rapid water loss during the drying process. Experiments show that the cracking rate of the electrode coating with 0.5% welding Grade CMC added is reduced to less than 5%.
Thermal stability: During the baking stage of 200-250℃, the Welding Electrode Grade Sodium Carboxymethyl Cellulose's molecular chain gradually degrades, but it can still maintain a certain bonding force to prevent the coating from falling off. When the temperature exceeds 300℃, CMC for Welding Electrodes is completely decomposed into carbon dioxide and carbonized products. At this time, the coating mainly relies on the sintering effect of water glass to maintain its structure.
This controlled thermal decomposition behavior ensures that organic binders do not leave harmful residues in the weld metal, aligning with low-hydrogen electrode standards.
3. Welding process regulation
Gas protection: Welding grade CMC decomposes at high temperature to produce carbon dioxide, which synergizes with gasifiers such as marble to form a protective gas layer, inhibiting the intrusion of oxygen and nitrogen in the air into the molten pool, and reducing pores and oxidation defects. For example, in ultra-low hydrogen electrodes, Welding Grade CMC is used in combination with rare earth fluoride to reduce the diffusible hydrogen content of the deposited metal to less than 5mL/100g.
Slag modification: The carbides produced by decomposition (such as Na₂CO₃) can reduce the melting point of the slag and improve the slag removal performance. In titanium calcium type welding rods, adding 0.1-0.2% CMC-Na can increase the slag removal rate to more than 95%.
Efficient slag detachability improves welder productivity and reduces post-weld cleaning time.
Specification
|
Spec. |
Standard |
|
Appearance |
White or yellowish powder or granular |
|
Starch |
None |
|
Moisture |
≤10.0% |
|
DS |
0.8min |
|
Mesh size |
10-40 mesh, 80 mesh |
|
Purity |
Technical grade or High purity |
|
pH |
7.0～10.0 |
|
Viscosity (1% solution) |
50-3000 mPa·s |
Quality Control System (Hondo Chem)
To ensure consistent welding performance, Hondo Chem implements a full-process quality control system:
Raw Material Control: Selected high-purity cellulose with controlled DP and impurity limits
Process Control: Real-time monitoring of etherification, viscosity, and substitution uniformity
Finished Product Inspection: Viscosity, DS, moisture, pH, and solubility tested batch by batch
Pre-shipment Inspection: Particle size distribution, flowability, and packaging integrity checked
Quality Assurance: Each batch is traceable with COA support
Why Choose Hondo Chem Welding Grade CMC
Proven performance in low-hydrogen and special welding electrodes
Stable viscosity and predictable thermal behavior
Customizable grades for different electrode formulations
Cost-effective alternative to imported binders
Technical support for formulation optimization
Packing & Storage
Storage:
1. The carboxymethyl cellulose should store in a cool, dry, clean, ventilated environment. Temperature Max. 70℃, with relative humidity ≤80%.
Storage:
2. The CMC for pharmaceutical and food grade should not be put together with the toxic substance and harmful substance or substance with peculiar smell during transportation and storage.
Storage:
3. Since the date of production, a preservation period of textile sodium CMC should not exceed 4 years for the industrial product and 2 years for the CMC in pharmaceutical and food industry.
Storage:
4. The CMC for welding use should be prevented from water and package bag damaging during transportation.
Packing:
25kg kraft paper bag with PE inner, or as clients request.
Summary
Welding Electrode Grade Sodium Carboxymethyl Cellulose (Welding Grade CMC) plays multiple roles in welding rod manufacturing, such as bonding, water retention, and regulating the welding process. Its performance directly affects the quality and processability of welding rods. By rationally selecting welding Grade CMC models, optimizing formula design, and combining advanced production processes, its advantages can be fully utilized to promote the welding rod industry to develop in the direction of high performance, low cost, and greenness. In the future, with the advancement of materials science, the application of welding Grade CMC will continue to expand, providing strong support for the innovation of welding technology.
FAQ – Welding Grade CMC
Q1: Is Welding Grade CMC suitable for automated electrode production lines?
Yes, its controlled viscosity and low dust characteristics support consistent pressure coating and automated feeding.
Q2: Can Welding Grade CMC replace traditional binders completely?
In most alkaline and low-hydrogen electrodes, it can partially or fully replace conventional organic binders when properly formulated.
Q3: Does Welding Grade CMC affect hydrogen control?
When correctly dosed, it helps reduce diffusible hydrogen by stabilizing coating structure and supporting gas-shielding reactions.
Hot Tags: welding grade CMC, China welding grade CMC manufacturers, suppliers, factory, USP EP GMP pharmaceutical grade Sodium CMC, Detergent Grade CMC, CMC Battery, Carboxymethyl Cellulose for Tobacco, CMC Mosquito Coils Grade, Carboxymethyl Cellulose in detergent
