High Transparency And Biocompatibility Rubber To Metal Bonding Agent 830 As Medical Device And Optical Component Coating

High Transparency And Biocompatibility Rubber To Metal Bonding Agent 830 As Medical Device And Optical Component Coating

(Equivalent to Chemlok 220LF/6125/6220, Chemosil 225/222/222NL, Thixon 520/526) 

1. Introduction
 830 is a one-coat adhesive used to bond a variety of elastomers to various substrates during vulcanization of the
 elastomer. It is composed a mixture of polymers, organic compounds and mineral fillers dissolved or dispersed in
 an organic solvent system.
 A single coat of 830 adhesive will bond compounds based on natural rubber (NR), polyisoprene (IR),
 styrene-butadiene (SBR), polybutadiene (BR), polychloroprene (CR), nitrile (NBR), butyl (IIR), EPDM and
 polyepichlorohydrin (ECO) polymers to a variety of metals. These metals include carbon and alloy steels,
 stainless steel, aluminum, copper and copper alloys, magnesium and zinc, as well as a variety of plastics,
 composites and fabrics.
 2. Features and Benefits
 Convenient – requires only a single coat for most applications, reducing labor, solvent usage, inventory and
 shipping costs.
 Versatile – bonds a wide variety of elastomers to metals, plastics and fabrics; suitable for existing production
 lines; tolerates a wide variety of stock formulations.
 Durable – provides rubber tearing bonds; provides superior adhesion to plated metals, lowering scrap rates.
 3. Typical Propertie
 

4. Applying  830
 • Chemical Cleaning
 Chemical treatments are readily adapted to automated metal treatment and adhesive application lines. Chemical
 treatments are also used on metal parts that would be distorted by blast cleaning or where tight tolerances must

be maintained. Phosphatizing is a commonly used chemical treatment for steel, while conversion coatings are 
commonly used for aluminum. 
• Mechanical Cleaning
 Grit blasting is the most widely used method of mechanical cleaning. However machining, grinding or wire
 brushing can be used. Use steel grit to blast clean steel, cast iron and other ferrous metals. Use aluminum oxide,
 sand or other nonferrous grit to blast clean stainless steel, aluminum, brass, zinc and other nonferrous metals.
 For further detailed information on surface preparation of specific substrates, refer to Adhesives application
 guide. Handle clean metal surfaces with clean gloves to avoid contamination with skin oils. Apply 830 adhesive
 to stainless steel, aluminum, brass and other nonferrous substrates within one-half hour after cleaning. For
 ferrous substrates such as steel, a long layover can be tolerated if no rust is formed.
 Mixing – Thoroughly stir 830 adhesive before use, and agitate sufficiently during use to keep dispersed solids
 uniformly suspended. If needed, proper dilution for the various application methods is best achieved by
 experience. Give careful attention to agitation since dilution will accelerate settling.
 Applying – Apply 830 adhesive by brush, dip, roll coat, spray or any other method that gives a uniform coating
 and avoids excessive runs and tears. When using 830 adhesive as a one-coat adhesive, the dry fi lm thickness
 should be 17.8-30.5 micron (0.7-1.2 mil). When used as a covercoat over a primer, the dry film thickness of 830
 adhesive should be 15.2-20.3 micron (0.6-0.8 mil).
 • Brushing
 Apply full strength. The best bonds will be achieved by a uniform and complete surface coverage.
 • Dipping
 Dilute adhesive with 10-25% xylene or toluene, by volume, to a Zahn Cup #2 viscosity of 30-48 seconds. Proper
 withdrawal will help reduce the tears and drip edges.
 • Roll Coating
 Apply full strength. For best results, apply uniformly to surfaces.
 • Spraying
 Dilute 830 adhesive with 25-50% xylene or toluene, by volume, to a Zahn Cup #2 viscosity of 21-24 seconds.
 The adhesive must be wet when it reaches the metal part. If drying occurs in the air before reaching the metal,
 cobwebbing and poor adhesion will result.
 For electrostatic applications, dilute adhesive to a Zahn Cup #2 viscosity of 30 seconds, using technical grade
 methyl ethyl ketone (MEK) in ratio of 4 parts adhesive to 1 part solvent.
 Drying/Curing – Allow the applied adhesive to dry until visual examination of the fi lm has shown that all
 solvent has evaporated. This will take approximately 20-40 minutes at room temperature. Drying time can be
 shortened by either preheating the metal inserts or oven
 drying after application. Metal parts may be preheated to a maximum of 65°C (150°F) prior to adhesive
 application. For coated parts, moderate drying temperatures should be used, but temperatures as high as
 149°C(300°F) may be used for very short periods of time. Maximum air flow at minimum temperatures will give
 the best results.
 Dried films of 830 adhesive are non-tacky; therefore, coated parts can be piled into tote pans for subsequent
processing. Wear clean gloves when handling coated parts and cover the tote pans to prevent contamination by 
dirt, dust, grease, oil, etc. If coated parts are properly protected, long layover times between adhesive application 
and bonding usually have no adverse effect on the bond. If humidity is high, layover time will be shortened. If 
830 adhesive has been removed by chipping or abrasion during handling, these damaged areas can be recoated 
before bonding. 
830 adhesive can be used to bond rubber by compression, transfer, injection or other molding procedures used to 
make bonded parts. Maximum adhesion is obtained when the rubber has completely cured. Ideal bonding 
conditions exist when both the adhesive and the rubber cure at the same time. To accomplish this, load the 
adhesive coated metal parts in the mold and quickly fill the cavity with rubber. 
Dry films of 830 adhesive remain firm at molding temperatures. During transfer or injection molding operations, 
the adhesive shows minimal tendency to wipe or sweep. 
While it is desirable to keep mold loading cycles to a minimum to prevent pre-cure of the adhesive and the 
rubber, 830 adhesive will resist moderate prebaking times without affecting bond performance. Transfer or 
injection molds need properly designed runners and sprues, as well as adequate pressures. This prevents rubber 
pre-curing before the mold cavities are completely filled. 
Cleanup – Use solvents such as xylene and MEK to remove adhesive before heat is applied. Once cured, 
removal by solvent is not possible.