Page 163 - Fendercare Marine - The Book

Drawings and picture references are for illustration purposes only.
Subsurface Buoys
The Materials
As with surface buoyancy, there are two application
dependent material parameters to subsurface buoyancy:
the foammaterial which forms the core of the product
the external coating material
Based upon the use our products are being put to and
the depths to which they need to be rated, we select from
a number of possible material combinations to ensure
maximum product life and integrity at minimum cost.
For shallower depths, we are typically offering either
high-density polyethylene foam or expanded polymer
foam. The significant benefit both these foams offer
over the polyurethane foam, which most other
manufacturers will offer for these depths, is that the
foams we offer are of a closed cell nature. This means
that if the outer skin of a Hippo shallow water buoy is
breached, our customers can be assured that the result
will not be a rapid and catastrophic absorption of water
followed by failure of the product.
For deepwater applications, we are formulating and
processing our own pure syntactic foam into which we
will then generally introduce moulded macrospheres to
reduce the weight and the ultimate cost of the product.
Subsurface Flotation Materials Overview
External Coatings
There are 3 main material possibilities for encapsulating
the core of Hippo subsurface buoys:
polyurethane elastomer is a highly abrasion-resistant,
reinforceable coating which we can either spray-apply or
cast around the foam core. For ultimate durability, this
form of coating can be Kevlar™ reinforced
rotationally-moulded polyethylene is a cheaper and more
uniformmethod of mass-producing a protective shell for
the foam core in applications where the resilience and
flexibility of PU elastomer is not required
PU paint is mainly used in applications where the core
material is resilient in itself but requires some level of
protection from UV degradation
The primary product applications for these materials are:
pipeline installation buoys
Modsyn™ top-up buoys, general subsea installation buoys
transponder collars
modular subsea buoys
distributed buoyancy modules
submersible/ROV/AUV buoyancy systems