Adhesive for bonding Fluoroelastomers to Metals and Fabrics.
Superior environmental and chemical resistance.

Introduction

Polyloc 470 is a single coat adhesive system for bonding unvulcanised fluoroelastomer compounds to metals during the vulcanisation of the elastomer. This adhesive system produces bonds that are outstandingly resistant to all kinds of environmental conditions and corrosion, and capable of withstanding extreme static and dynamic stresses.

Polyloc 470 is used in the manufacture of various industrial items like Oil Seals, Reed Valves, and other rubber to metal bonded products.

Properties of Polyloc 470

Composition	Synthetic organic silicones and dispersed solids in methanol
Color	White / pale yellow solution
Reactive Mat’l	10 ~ 12%
Diluents	Methanol
Specific Gravity	0.83
Flash Point	11 dC
Shelf Life	At least 1 year

Preparation of metal Surface

This is the most critical step for any rubber to metal bonding process. The metal surface should be cleaned of all contaminants such as oil, rust, dirt, etc. by suitable mechanical and/or chemical methods.

Grit/sand blasting, and wire cloth abrading are commonly established mechanical methods of metal preparation for most metals, and give excellent results. Chemical treatment (phosphatising) of the metal surface results in a corrosion resistant and bondable surface. The general steps are: Water rinse - Acid pickle - Water rinse - Phosphatise - Water rinse - Chromate rinse.

Application of the Adhesive

Polyloc 470 must be stirred well before use. It may be applied by dip, spray or brush. Brushing is the most widely used method. The application of a thin and uniform coating of the adhesive, free from excessive runs or fatty edges is an essential condition for optimum bonding results. The adhesives may be colored by adding 0.1% by weight of powdered Phenol Red or Methylene Blue dyes.

Dilution of the adhesive should be done just before application. Do not return unused adhesive to the original container. It takes 10-20 minutes for Polyloc 470 to dry at room temperature. For faster drying, hot air tunnels or drying ovens can be used. The coated part should be used within 36 hours of adhesive application. It should be given another coat of the adhesive if it is not used within this period of time.

For consistent bonding results, partial pre-cure (pre-baking) of the adhesive at 150 ~ 160oC for 5 ~ 10 minutes is recommended.

Vulcanisation / Bonding

Prepare compound of the elastomer and vulcanise as per manufacturer’s specifications. Appropriate post-vulcanisation treatment (with gradual increase in temperature) for the elastomer will not deteriorate bond strength.

Presentation of a fresh rubber stock surface at the bond interface results in better bonds. Although the adhesive can be subjected to reasonable pre-baking periods, it is advisable to load the adhesive coated metal parts and fill the cavity with rubber compound in the minimum amount of time.

Basic care should be taken in removing the hot bonded parts from the molds so as to prevent any damage to the bond. The bonds will gain their full strength after cooling and maturing for 10-12 hours.

Cautionary Information

This product is meant for industrial use only. It contains highly volatile solvents; keep product away from heat and flame. Vapors are harmful and prolonged breathing should be avoided. May be harmful or fatal if swallowed.