Coating dipping related basics (material types, processes, special techniques)
When producing reusable supported gloves such as coated seamless or cut & sewn gloves, the coating dipping process is critical to achieving the desired grip, durability, chemical resistance, and mechanical protection. So, below are the key dipping-related basics to consider here.
Coating Materials
The selection of polymer coating/material mainly depends on the intended application.
Common coating materials & their properties:
Coating Material | Properties | Applications |
Nitrile (NBR) | Excellent abrasion, puncture resistance to oils, fuels, and certain organic solvents. Durable and provides a good grip in both wet and dry conditions. | Oil handling, automotive, general industry. |
Latex (NR) | High elasticity, good grip, good tear resistance. In chemical protection, it is used as a barrier in the presence of water-soluble substances. In mechanical protection, ensures excellent grip in dry and wet environments. It contains a potentially allergenic protein. | General-purpose, construction, and household use. Well-suited for tasks requiring precision but can cause allergic reactions in some individuals. |
Polyurethane (PU) | Lightweight, flexible, high dexterity, good dry grip. | Precision work, assembly, electronics. |
Neoprene | Excellent chemical resistance (acids, oils, solvents). | Chemical handling, lab environments. |
PVC | Good chemicals (particularly against acids and alkalis), abrasion, and water resistance. It can be more rigid, affecting dexterity. To improve performance, knitted gloves can be coated on the palm with PVC dots to improve grip and durability. | Oil & gas, chemical handling, wet environments. |
Coating Process Techniques
(a)Types of Dipping:
Full Dipping – Coats the entire glove for full hand protection (e.g., chemical-resistant gloves).
Palm Dipping – Leaves the back palm uncoated for breathability while providing grip at palm side.
Finger Dipping – Only fingertips are coated, enhancing dexterity there.
Double Dipping – A second layer is applied to improve durability or provide different surface properties.
Foam Dipping – A foamed polymer structure provides better grip in oily conditions.
(b) Dipping Process Steps:
Surface Preparation – The glove liner (knitted or cut-and-sewn) must be clean and dry for proper adhesion. The molds (usually ceramic or aluminum) are also cleaned using various agents to remove dirt and ensure proper coating adhesion.
Coating Dip – The cleaned molds are dipped into a coagulant solution (e.g., calcium nitrate) followed by the coating material (e.g., latex, nitrile, PU), and excess coating is removed.
Leaching: This process involves soaking the coated gloves in water to remove residual chemicals and proteins, reducing the risk of allergic reactions.
Drying & Curing – Here the moisture is removed, and the gloves are dried. Adequate heat treatment ensures polymer crosslinking (Vulcanization) and bonding to the liner.
Post-Treatments (if required) – Texturing, finishing, or chlorination (for latex) to modify surface properties.
Special Techniques for Coated Gloves
Sandy/Crinkle Finishes – Textured coatings improve grip. Sandy Nitrile finish features a unique honeycomb surface that soaks up oil, improving grip on smooth, oily surfaces.
Foam Coatings – Micro foam nitrile enhances breathability and provides a sponge-like texture that absorbs liquids, maintaining a firm grip in oily conditions.
Hybrid Coatings – Combining different coatings (e.g., PU + nitrile, HCT – Hybrid Coating Technology) for multipurpose performance.
Antimicrobial/ESD Additives – Used for specialty gloves in medical or electronic applications.
Dotted coatings – For enhanced grip, improved durability, oil resistance and comfort fit.
Key Considerations for Dipping Quality Control
Coating thickness – Must be controlled for consistency.
Curing temperature & time – Impacts flexibility and adhesion.
Glove liner compatibility – Different liner constructions (e.g., cotton, nylon, HPPE) require specific coatings adjustments for the compatibility.
Batch-to-batch consistency – Viscosity and dip time must be controlled.