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materials, food equipment manufacturing and composition,
plumbing, refuse containers,and dishwashing equipment.More details
can be found at http://www.nsf.org/business/about_NSF/
Standard DevelopmentNSF
S
tandards are developed, maintained, and revised by the committee
ballot system,similar to that used by ANSI and ASTM. The committees
consist of equal numbers ofrepresentatives of groups affected by
the scope of the standard. For instance, forStandard 61, Drinking
WaterSystems Components - Health Effects, The committee ismade of
manufacturers of plumbing parts, material manufacturers (plastics,
metals, etc),toxicologists, state regulatory officials, and the
like. Any changes related to testingrequirements are vetted through
lab testing, and balloting ensures majority rule.FacilitiesNSF
headquarters in Ann Arbor, Michigan, contains both administrative
staff andsignificant technical labs. All testing forNSF standard
compliance is conducted in-house.
Lab capabilities include Trace Metals, Microbial, and Organic
analysis.F
or plasticsmaterial, NSF has internal capability to injection
mold plaques and IZOD bars fortesting.HistoryNSF International was
founded as the National Sanitation Foundation in 1944, as aproject
of the University of Michigan's School of Public Health.
Stainless Steel
Stainless steels are primarily used when corrosion or oxidation
is a problem. Thefunction that they perform cannot be duplicated by
other materials for their cost. Over 50years ago, it was discovered
that a minimum of 12% chromium would impart corrosionand oxidation
resistance to steel. Hence the definition Stainless Steels, are
thoseferrous alloys that contain a minimum of 12% chromium for
corrosion resistance. Thisdevelopment was the start of a family of
alloys which has enabled the advancement andgrowth of chemical
processing and power generating systems upon which ourtechnological
society is based. Food grade stainless steel is widely considered
to be asanitary material (non-reactive properties) excellent for
containing and preparingfoodstuffs.
Anodized aluminium
Aluminium alloys are anodized to increase corrosion resistance,
to increase surfacehardness, and to allow dyeing (coloring),
improved lubrication, or improved
adhesion.
Anodizing
Anodizing, or anodising, is an electrolytic passivation process
used to increase thethickness of the natural oxide layer on the
surface of metal parts. Anodizingincreases corrosion resistance and
wear resistance, and provides better adhesion forpaint primers and
glues than bare metal. Anodic films can also be used for a numberof
cosmetic effects, either with thick porous coatings that can absorb
dyes or with
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thin transparent coatings that add interference effects to
reflected light. Anodizing isalso used to prevent galling of
threaded components and to make dielectric films forelectrolytic
capacitors. Anodic films are most commonly applied to protect
aluminiumalloys, although processes also exist for titanium, zinc,
magnesium, and niobium.This process is not a useful treatment for
iron or carbon steel because these metals
exfoliate when oxidized; i.e. the iron oxide (also known as
rust) flakes off, constantlyexposing the underlying metal to
corrosion.Anodization changes the microscopic texture of the
surface and can change thecrystal structure of the metal near the
surface. Coatings are often porous, evenwhen thick, so a sealing
process is often needed to achieve corrosion resistance. Theprocess
is called "anodizing" because the part to be treated forms the
anodeelectrode of an electrical circuit. Anodized aluminium
surfaces, for example, areharder than aluminium but have low to
moderate wear resistance that can beimproved with increasing
thickness or by applying suitable sealing substances.
Anodic films are generally much stronger and more adherent than
most types ofpaint and metal plating, making them less likely to
crack and peel.
