Learn The 3 Ways Landscape Rock Is Sorted

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Learn The 3 Ways Landscape Rock Is Sorted
Decorative landscape rock is generally sorted by
3 methods. Static Grizzly Screen  Static
screens are commonly referred to as Grizzlies and
are the most basic and simple of all screens used
to sort rock sizes. This type of screen is often
used to prescreen out the larger rock before
sending material into a crusher or screening
plant. Grizzlies are made of parallel bars
running at an angle from front to back. The bars
are set at an equal distance apart. This allows
material smaller than the set distance to fall
through to the belly of the screen and larger
material to slide off the front.
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Learn The 3 Ways Landscape Rock Is Sorted
Material is dumped onto the backside of the
grizzly with a loader. This is a fairly slow
method, as nothing is being processed until a new
load of material is dumped onto the screen. It
also requires constant removal of both the
oversize and undersized material to make room for
the next load to be processed.
The advantages of this screen are a construction
of extremely heavy duty steel and no moving
parts. It is able to process very large rock
without damaging the screen up to ¼ ton rip
rap. The drawback to this method of screening is
that it doesnt produce very well sized material.
Since material is only being separated by a
single dimension (bars on only 2 sides of rock),
there is a higher possibility of getting material
that is larger or smaller than desired.
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Learn The 3 Ways Landscape Rock Is Sorted
Weve heard it described as the phonebook
phenomena.  If a phone book were to fall on a
grizzly screen in the upright vertical position
it would pass through the screen.  If the same
phonebook were to fall on the screen in a
horizontal position, it would be wider than the
distance between the bars and slide off onto the
oversize pile.   This helps explain why there is
typically a percentage of oversized material in
any product that has to be screened by a grizzly.
 If bars are set to an 8 distance for a 4-8
rock, the reality is that some pieces larger than
8 are going to pass through because they fell on
the screen with one of their dimensions that is
less than 8. Vibrating Deck Screen Mesh This
type of screen is placed at an angle and
mechanically shaken/vibrated so that material
moves across it.  It looks like an extremely
heavy duty version of a typical window screen,
with square openings. This process provides a
truer size than the static screening method, as
there is a four sided hole that the material must
fall through. This type of screen is typically
limited to only handling smaller material
(4-6maximum).
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Learn The 3 Ways Landscape Rock Is Sorted
Larger rock material is very hard on the screens
metal mechanical parts, and will cause premature
wear and expensive repairs. The advantage of this
method is material can be measured based on the
size of the screen openings. As the material
dances across the screen, particles that are
smaller than the openings fall through. Particles
that are larger stay on top and eventually exit
the end of the screen into a pile.
The material that stayed on top of the screen now
has a minimum dimension of what the width of the
screen opening is. For example If the screen
openings measured 2 across, the sorted material
that did not pass through the screen will be 2
and larger. Most decorative stone screening
plants will have several decks or layers of
screens, one over another. The screen with the
largest openings will be on the top level,
followed by a smaller sized screen on the 2nd
level, then even smaller screens on the following
levels. Material smaller than the last screen
would typically be considered fines.
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Learn The 3 Ways Landscape Rock Is Sorted
Hand Sorted and Palletized As it sounds
 Material is sorted by hand for color, shape and
size.  This is obviously the most labor intensive
and expensive way to sort rock, but it yields the
most consistent and cleanest product with very
little waste. Material is typically eyeballed for
size.
A tape measure is not used to verify the sizing
of each piece selected, and can occasionally
create issues when there are multiple laborers
sorting the same product. What one person
considers a 6-10 may not be the same as the
person next to them. Slight size variation can
be expected from pallet to pallet. Decorative
Stone Solutions strives to provide you with the
highest quality landscape stone. We know the
importance of your project looking its absolute
best. Thank you for trusting us with your
landscape stone needs.
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