Polyguard SP-6 Outerwrap

POLYGUARD SP-6 UNBONDED OUTERWRAP

is an integral part of the RD-6 Coating System.

It consists of a strong non woven, felt-like polypropylene fabric. The product is engineered to provide high bursting strength and low tensile and elongation properties. The result is an outerwrap with improved soil stress resistance.

PROPERTY	ASTM METHOD	TYPICAL RESULTS (METRIC)	TYPICAL RESULTS (ENGLISH)
Weight	D 5261	140 g/m2	4.1 oz / yd2
Tensile Strength – Grab	D 4632	0.45 KN	102 lbs.
Elongation	D4632	50%	50%
Burst Strength – Mullen	D 3786	1378 kPa	200 PSI
Thickness	D 1000	.69mm	.027”
Permittivity	D 4491	2.5 sec. -1	2.5 sec. -1

There is no adhesive

on the surfaces of

either side of the

fabric outerwrap.

For years, the pipeline coating industry relied upon bonded outerwraps. However, permanent adhesion of the outerwrap to the corrosion coating underneath is not desired. Quite the opposite. The fabric when unbonded has the freedom to be moved by the forces of soil stress, independently of the coating over which it has been applied. If the fabric of the outerwrap had been bonded to the coating underneath, the soil stresses would be transferred to the corrosion coating underneath, and could cause deformation of the corrosion coating.

The fabric permits

water and cathodic

protection currents to

pass through it.

This porous property keeps the outerwrap from contributing to the cathodic protection shielding problem. Solid film back corrosion coatings and outerwraps have been proven to shield (block) the passage of protective currents.

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DOWNLOAD SP-6 DATA SHEET