Gate Seal Design Guidelines H4

TEFLON CLADDING:

A Teflon ® · (flouro-carbon) abrasive resistant sheath shall be bonded to the sealing surface by the "molded only" form of manufacture. The Teflon ® · sealing surface shall be kept clean and free of bonding agents and rubber. The Teflon ® · shall meet the following minimum requirements:

Tensile strength 2000 PSI(min.)
Elongation 250% (min.)

Test of the bond strength of the Teflon ® · to the rubber shall be performed per ASTM D413-39. Samples shall be cut from the molded lengths and corners where masking has been applied to prevent bonding. The samples shall be trimmed to 1" wide and tested with a tension at approximately a 90 degree angle to the rubber, by either the machine method at 2"/minute or deadweight method at 30#/inch width, without separation.

FACTORY HOT VULCANIZE SPLICING:

Hot vulcanized splices are the preferred choice for joining ends of cured rubber profiles. Hot vulcanized spliced joints should be kept to a minimum. The joints shall be prepared with a 45 degree bevel relative to the cross-section and where possible avoid bolt hole locations. The joint shall be properly cleaned and prepped for placement into a splice mold where heat and pressure can be applied. The attained strengths typical of hot vulcanized splices are 50% of the tensile for straight sections and 35% of the tensile for corner/transitional sections

     NOTE 1: Where possible a fully molded corner/transitional section should be used.

     NOTE 2: Where possible, splices should be made at the seal factory.

     NOTE 3: Splices for seals with cladding should allow for cladding gaps up to 3/8"
                      long providing the gaps are filled with rubber for a uniform profile.

® · Teflon is a registered trademark of the Dupont Company