Chemlok 823 Alternative Rubber-Metal Bonding Agent

                                                                                       Chemlok 823 Alternative Rubber-Metal Bonding Agent

Application

823 Rubber-to-Metal Bonding Adhesive

823 is a high-performance topcoat designed for use over 815 Primer. This two-coat system bonds uncured elastomers to metals and rigid substrates during vulcanization.

Key Features:

Heavy metal-free formulation

Polymer-based blend with organic compounds and mineral fillers in organic solvents

815 Primer provides the base layer for enhanced environmental resistance and strong substrate adhesion

Characteristics  

1. Versatile Application: When used with 815 primer, it effectively bonds a diverse range of rubbers including natural rubber, SBR, neoprene, polyisoprene, and polybutadiene to various metals and other rigid substrates.
2. Environmentally Friendly: Formulated without the use of heavy metals.
3. Superior Performance: Provides a smooth, continuous film appearance for excellent results.

Typical Properties

Chemlok 823 Alternative Rubber-Metal Bonding Agent 

Surface Preparation Guidelines:

Proper surface preparation is critical to achieving optimal adhesion and performance of the 823 adhesive system. Follow the guidelines below to ensure consistent and durable bonding.

1. Initial Cleaning

Before applying primer, the metal substrate must be free of all contaminants:

Degreasing: Remove protective oils, cutting fluids, and greases using solvent wiping, vapor degreasing, or alkaline cleaning methods.
Corrosion removal: Eliminate rust, mill scale, or oxide layers through chemical pickling or mechanical abrasion, as appropriate for the substrate.

2. Surface Treatment Methods

The choice of treatment depends on the substrate type, part geometry, and production scale.

Chemical Treatment 
Ideal for automated lines or when dimensional precision must be maintained.  
  – Steel: Typically phosphated to enhance corrosion resistance and coating adhesion.  
  – Aluminum: Often receives conversion coatings (e.g., chromate or non-chromate) to stabilize the surface.

Mechanical Abrasion  
  Recommended for robust substrates or when chemical methods are impractical.  
  – Grit blasting: The most common and effective method.  
  – Alternative methods: Machining, grinding, or wire brushing may be used for localized or heavy-duty cleaning.  
  – Abrasive selection:  
        • Ferrous metals (steel, cast iron): Use steel grit or shot.  
        • Non-ferrous metals (aluminum, brass, stainless steel, zinc): Use aluminum oxide, sand, or non-metallic abrasives to avoid embedment and galvanic corrosion.

3. Post-Cleaning Handling

- Handle cleaned surfaces with clean, lint-free gloves to prevent recontamination from skin oils.
- Apply primer promptly after cleaning; if delay is unavoidable, store parts in a clean, dry environment and protect from dust and oxidation.

4. Adhesive Application

For optimal bonding performance:
- Apply 823 Heat Vulcanization Adhesive over a fully dried coat of 815 Primer.
- Recommended substrates: stainless steel, aluminum, brass, and other non-ferrous metals.
- Ensure the primer is thoroughly dried before topcoat application.

For detailed instructions on primer use, curing conditions, or substrate-specific recommendations, refer to the 815 Primer Technical Data Sheet and the 823 Adhesive Application Guide.

4. Mixing: Thoroughly agitate Heat Vulcanization Adhesive 823 before application over the primer. Maintain agitation during use to ensure uniform suspension of dispersed solids.
-- Depending on container size, use the following guidelines:
-- 1/2 pint: Hand stir or use a paint shaker for 5-10 minutes.
-- 1-5 gallon: Hand stir combined with an air-powered mixer for 15-60 minutes.
-- 55 gallon: Use a hand crank and air motor agitator for 8 hours for a new drum; maintain continuous agitation for an opened drum.

5. Application: Heat Vulcanization Adhesive 823 can be applied by spray, dip, brush, or roll coating. It is typically used at full strength for brush, roll coat, and dip methods.
-- For spray application, dilute with xylene or toluene to achieve a viscosity of 25-28 seconds (Zahn Cup #2). A 25-50% dilution is typical.
-- The optimal film thickness depends on the rubber formulation and required adhesion level. Follow these recommended dry film thicknesses regardless of the application method:
-- Primer 815: 5.1-10.5 µm (0.2-0.4 mil)
-- Adhesive 823: 12.7-25.4 µm (0.5-1.0 mil)

6. Drying/Curing: Allow the applied adhesive to air-dry for 30-60 minutes at 15-32°C (60-90°F). Drying time may extend in high-humidity conditions. To shorten drying time, parts can be preheated to a maximum of 60°C (140°F) before adhesive application or oven-dried after application. If dry spray or cobwebbing occurs, reduce the metal preheat temperature. For coated parts, moderate drying temperatures are recommended, with short-term exposure up to 93°C (200°F) acceptable. Optimal results are achieved with maximum airflow at minimum temperature.

Dried films of Heat Vulcanization Adhesive 823 are non-tacky, allowing coated parts to be stacked in tote pans for subsequent processing. Handle cemented parts with clean gloves and cover tote pans to prevent contamination by dirt, grease, or oil. Limit layover time to less than 30 days. The adhesive cures during the rubber vulcanization process.

7. Cleanup: Clean liquid spills immediately with absorbent rags. Remove dried material from surfaces using spark-proof tools and appropriate dilution solvents.

Packing
18kg/drum; 20kg/drum; 200kg/drum