• TABLE OF CONTENTS
HIDE
 Front Cover
 Front Matter
 Title Page
 Table of Contents
 Introduction
 Principles
 The basic packinghouse line
 Minimizing fruit damage on the...
 Calculating packingline capaci...
 Literature cited
 Index
 Back Cover






Group Title: Bulletin - University of Florida. Agricultural Experiment Stations ; No. 803
Title: Packingline machinery for Florida citrus packinghouses
CITATION THUMBNAILS PAGE IMAGE ZOOMABLE
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00027224/00001
 Material Information
Title: Packingline machinery for Florida citrus packinghouses
Series Title: Bulletin University of Florida. Agricultural Experiment Station
Physical Description: 30 p. : ill. ; 23 cm.
Language: English
Creator: Grierson, William
Miller, W. M ( William M )
Wardowski, Wilfred F
Publisher: Agricultural Experiment Stations, Institute of Food and Agricultural Sciences, University of Florida
Place of Publication: Gainesville
Publication Date: 1978
 Subjects
Subject: Citrus fruits -- Packing -- Florida   ( lcsh )
Citrus fruits -- Equipment and supplies -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
bibliography   ( marcgt )
non-fiction   ( marcgt )
 Notes
Bibliography: Bibliography: p. 28-29.
Bibliography: Includes index.
Statement of Responsibility: W. Grierson, W.M. Miller, and W.F. Wardowski.
General Note: Cover title.
Funding: Bulletin (University of Florida. Agricultural Experiment Station)
 Record Information
Bibliographic ID: UF00027224
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: aleph - 000929894
oclc - 05243749
notis - AEP0705

Table of Contents
    Front Cover
        Front Cover
    Front Matter
        Page i
    Title Page
        Page ii
    Table of Contents
        Page iii
    Introduction
        Page 1
    Principles
        Page 1
        Page 2
        Page 3
        Page 4
    The basic packinghouse line
        Page 5
        Page 6
        Page 7
        Page 8
        Page 9
        Page 10
        Page 11
        Page 12
        Page 13
        Page 14
    Minimizing fruit damage on the packinghouse line
        Page 15
        Page 16
        Page 17
        Page 18
        Page 19
        Page 20
    Calculating packingline capacity
        Page 21
        Page 22
        Page 23
        Page 24
        Page 25
        Page 26
        Page 27
    Literature cited
        Page 28
        Page 29
    Index
        Page 30
    Back Cover
        Back Cover
Full Text
DECEMBER 1978


Packingline Machinery for Florida
Citrus Packinghouses


W. Grierson, W. M. Miller, and W. F. Wardowski


AGRICULTURAL EXPERIMENT STATIONS
INSTITUTE OF FOOD AND AGRICULTURAL SCIENCES
UNIVERSITY OF FLORIDA, GAINESVILLE
E A. WOOD, DEAN FOR RESEARCH


BULLETIN 803














































Cover design courtesy of Shar Rushing.












Packingline Machinery for Florida
Citrus Packinghouses



W. Grierson, W. M. Miller, and W. F. Wardowski


Agricultural Research & Education Center
Lake Alfred



















Dr. Grierson is a professor of horticulture, Dr. Miller is an assistant
professor of agricultural engineering, and Dr. Wardowski is area Ex-
tension citrus specialist and an associate professor of horticulture at
the Agricultural Research and Education Center, Lake Alfred, Florida.







CONTENTS

Page

Principles .................................-------------------- 1
Width of Equipment ...........................................-------- 1
Logical Order for Packinghouse Processes ..................................---- 2
Packing a Second Grade .............................. --------.... .....- .... 4
Inventory-to-Inventory Packing ...................................................... 4


The Basic Packinghouse Line .........................--... ---.------ --.... 5
Dumping ............................... ---------.................. ---... --- 5
Trash Elimination .................................---- -------------........ 5
Drench ................................................. ......--------------- 6
W asher ..........................................................-------- ----...... 6
Rinsing ......................... ........ ..... .................-------------.. 7
Water Elimination ...................... ........----------- 7
Grading .............. ......... ....... .--............. ....... ----------------- 8
Color-adding ............................. .......... ----.. -..--- ----------........ 11
Water Elimination ..--...-.... ......................--. -------------. 11
W axing ..................................... ...... .. ---............... --------- -. 12
Fungicide Application ...........................--------.....---- ...--------- 13
Drying ................................................----------------- .. 13
Stamping ......................................................---------. --- -----..... 14
Sizing ....................-...-........-............--- ----------------15
Packing Fruit .................................................... ........................ 15


Minimizing Fruit Damage on the Packinghouse Line ......................--. 15
Dumping ....----...... ................... ... --------------...... 16
Deliveries from Roller and Slat Conveyors -------..-............-............---16
Points of Impact ............... ...---. --------.....................-- 16
Turns ........................-----... ................------------.....--------. 18


Calculating Packingline Capacity ................................--.---- ------ 21
Fruit Characteristics .....-....-...........--.. ---........... --------- 23
Equipment Characteristics ....................................--- -- -------- 26
Standard Sizes and Components ........................-- ........................ 27


Literature Cited ...................................-..---........ ------------28
Index ..........-................................. ........ .. .........----- ...-------.... 30







Packingline Machinery for Florida Citrus Packinghouses

INTRODUCTION
Much literature is available on individual packinghouse pro-
cesses, particularly on fungicide application, but very little is
available on the individual items of the citrus packinghouse line
and even less on assembling them together into efficient systems.
Every owner and every equipment supplier has his own ideas
of what he wants to accomplish. The purpose of this bulletin is
to enunciate basic principles that apply to virtually any citrus
packinghouse line, regardless of the particular layout. Errors in
proper choice and matching of packingline components are
extraordinarily costly in money, reduced capacity, and increased
fruit losses and decay claims. Moreover, the same errors occur
repeatedly. They need not do so if the principles given here are
studied before installing or remodeling packinghouse equipment.

PRINCIPLES
WIDTH OF EQUIPMENT
Whatever the function of the individual component, a packing-
line is basically so many square feet of conveying surface. The
necessary number of square feet needed can be calculated. With-
in reason, the wider and shorter the line, the cheaper the initial
cost. This is because:
A. The length of the line largely determines the size of the
building; width makes very little difference to the building size.
B. There is more initial cost in the sides of the line (framing,
bearings, chains, drives, etc.) than in the span.
C. Electrical and plumbing costs relate more closely to the
length than to the width of the line.
Capacity of the line depends on the area of conveying surface
multiplied by linear speed of forward travel. The wider the
line, the slower the linear speed needed for a given capacity. If
the initial linear speed is high, extra capacity can only be ob-
tained by running fruit too fast, with consequent damage and
poor handling generally, or else by building an additional line.
If the initial speed is low (due to starting with wide equipment),
capacity can be increased by merely speeding up those items for
which fruit treatment time is not a factor. When fruit treat-
ment time is critical, the line can be pulled apart, and extra sec-
tions added at a minimal cost.
Start with the widest available equipment.







Packingline Machinery for Florida Citrus Packinghouses

INTRODUCTION
Much literature is available on individual packinghouse pro-
cesses, particularly on fungicide application, but very little is
available on the individual items of the citrus packinghouse line
and even less on assembling them together into efficient systems.
Every owner and every equipment supplier has his own ideas
of what he wants to accomplish. The purpose of this bulletin is
to enunciate basic principles that apply to virtually any citrus
packinghouse line, regardless of the particular layout. Errors in
proper choice and matching of packingline components are
extraordinarily costly in money, reduced capacity, and increased
fruit losses and decay claims. Moreover, the same errors occur
repeatedly. They need not do so if the principles given here are
studied before installing or remodeling packinghouse equipment.

PRINCIPLES
WIDTH OF EQUIPMENT
Whatever the function of the individual component, a packing-
line is basically so many square feet of conveying surface. The
necessary number of square feet needed can be calculated. With-
in reason, the wider and shorter the line, the cheaper the initial
cost. This is because:
A. The length of the line largely determines the size of the
building; width makes very little difference to the building size.
B. There is more initial cost in the sides of the line (framing,
bearings, chains, drives, etc.) than in the span.
C. Electrical and plumbing costs relate more closely to the
length than to the width of the line.
Capacity of the line depends on the area of conveying surface
multiplied by linear speed of forward travel. The wider the
line, the slower the linear speed needed for a given capacity. If
the initial linear speed is high, extra capacity can only be ob-
tained by running fruit too fast, with consequent damage and
poor handling generally, or else by building an additional line.
If the initial speed is low (due to starting with wide equipment),
capacity can be increased by merely speeding up those items for
which fruit treatment time is not a factor. When fruit treat-
ment time is critical, the line can be pulled apart, and extra sec-
tions added at a minimal cost.
Start with the widest available equipment.







LOGICAL ORDER FOR PACKINGHOUSE PROCESSES


The conventional order in which fruit treatments are arranged
along the packingline goes back to the days when fresh fruit was
paramount, several grades were packed, the cannery was a small
consideration, and residues of pesticides, etc. were simply not
considered. Today, it is common to pack just one grade, though
provision for an occasional second grade may be an advantage.
Large amounts of fruit (recently 35% in Florida (15)) are
graded out and sent to the cannery, and any avoidable residues in
fruit going to the cannery are very much to be avoided.
With these considerations in mind, it is apparent that every
fruit that is not going to be shipped as fresh fruit should be re-
moved as soon as possible (Fig. 1). Immediately after dumping
and trash elimination, the over- and under-sizes can be removed
mechanically with a presizer. Removal of fruit with exterior
blemishes is usually not possible until after washing, but pro-
vision should be made prior to the washer for removing rotten or
split fruit before it contaminates the rest of the equipment.
Washing should be followed by a water eliminator to remove ex-
cess water and grading should follow immediately. There is no
point in putting fungicides, waxes, and possibly color-add, on
fruit that are to be sent to the cannery. This costs the packing-
house money and gives the cannery problems (6).
Grading immediately after the washer considerably reduces the
amount of machinery necessary between the washer and the
sizer. If 30% or 40% of the fruit are being graded out to the
cannery, the size and horsepower requirements of the remainder
of the line can be decreased proportionately. Alternatively, if the
width of the line is not reduced, that much more packable fruit
can be handled on it. In either case, the machinery cost per box
is decreased by grading immediately after washing.
The order in which the other operations are done depends, in
part, on the types of fungicide and wax being used. When SOPP1
is used (12), it can be combined with the washing, and the excess
must be rinsed off. Other fungicides have To be applied to clean
fruit and allowed to dry.
Color-adding is best done prior to fungicide applications (ex-
cept for SOPP at the washer) ; otherwise fungicide is removed
in the color-add emulsion.
When fruit is being stamped, the type of wax being used affects
the position of the stamper in the line (see below).

1. Sodium ortho-phenylphenate or Dowicide A.








DUMP

TRASH
ELIMINATION
OVER S UNDER
PRESIZE SIZES CANNERY

WATER SPRAY

T-WASH (SOAP OR DETERGENT)

RINSE

WATER
ELIMINATION

2nd GRADE --- GRADE-- BLEMISHED FRUIT
(PACK LATER) (ELIMINATIONS)


I --I-I


FUNC
APPLI


T-COLOR-ADDz

RINSE

WATER
ELIMINATION
ICIDE Y
CATION


T-DRYx WATER
L EMULSION
WAX
SOLVENT W
WAX

T-DRYX

STAMP

SIZE


PACK
T TIME DEPENDENT OPERATION
A-ALTERNATE PATH

sOptional, and only for oranges and tangelos.
yAlternate locations for application of fungicides (see 11) are at the washer (SOPP), in
water emulsion wax or diphenyl pads placed in the packed cartons.
xHigh energy (hot air) drying is prior to solvent wax or following water emulsion wax.
Drying following solvent wax is with ambient temperature air.
wStamping can be done prior to a solvent wax, but not prior to a water-emulsion wax.

Figure 1. Logical order for a packingline when only one grade is packed
most of the time. Degreening and frozen fruit separation are not included
here, being covered in separate publications (16, 17).







PACKING A SECOND GRADE


In citrus producing areas such as Florida, where a second
grade is of very minor importance, it is not logical to have a
complete line of sizing and packing equipment for the second
grade fruit. The fluctuation in volume between first and second
grades precludes advantageous use of equipment and labor. In-
stead, the second grade should be accumulated in pallet boxes
(Fig. 2) and run on the same equipment once the No. 1 grade
fruit is packed. If the equipment is correctly sized, this will not
mean working a longer day.





i










j I





Figure 2. The most common Florida decelerator pallet box filler for citrus.
These counter-weighted devices begin low in the pallet box and are gradually
raised manually as the box fills. There are two pallet boxes per fruit size to
allow ample time to remove a full box and replace it with an empty without
interrupting the fruit flow.

INVENTORY-TO-INVENTORY PACKING
A logical approach for ultimate complete mechanization of
packing and palletizing is to use an inventory-to-inventory sys-
tem (6) ; that is, accumulating an inventory of sized, prepared
fruit from which packing equipment draws one size at a time, and
accumulating an inventory of packed, refrigerated fruit. Such






broad considerations of packinghouse layout are not, however,
considered in this bulletin. Such a design change also involves
changes in fruit scheduling, inclusion of refrigeration, and other
matters not discussed here. It should be noted, however, that
an inventory-to-inventory system that packs one size at a time
can utilize a standard single channel palletizer. Conventional
packinghouses packing several sizes simultaneously can only use
a mechanical palletizer by first investing in an extremely ex-
pensive accumulation system.

THE BASIC PACKINGHOUSE LINE
Figure 1 shows various packinghouse operations in logical
order for a packinghouse in which only one grade is packed most
of the time, or in which a second grade is a small proportion of
the fruit even when packed regularly. Several operations are
indicated as being time dependent; those not so marked are not
time dependent. That is, operations such as dumping, trash
elimination, and presizing do not involve retaining the fruit for a
given length of time. Time dependent processes, on the other
hand, take a certain length of time which must be taken into con-
sideration in calculations to determine the necessary area of con-
veying surface.

DUMPING
Dry dumping is firmly recommended. If the machinery is well
designed with unimpeded fruit flow, the fruit will suffer no ap-
preciable damage. Whereas, dumping into water inevitably sub-
jects the fruit to an inoculum of fungus diseases, some of which
are resistant to any available fungicides.

TRASH ELIMINATION
Few if any packinghouses have provision for coping with the
trash that is commonly included in deliveries of fruit from hand
picking. The same problem may exist with mechanical harvest-
ing of some kind in the near future. A sloping belt trash elimi-
nator (5) will remove most loose trash and deliver it to a con-
veyor or container. A vacuum brusher (5) can be used to re-
move loose sand, which is otherwise extremely injurious to the
packingline equipment. Roller conveyors should always be self-
cleaning (i.e., with angled supports that wipe the whole length
of each roller with openings to shed trash (Fig. 3). Several pre-
graders with clippers are needed to remove any adhering stems,


















LEAVE "V" OPEN TO
PREVENT ACCUMULATION
S OF TRASH
-ROLLERS
FIBRE OR HARDWOOD
-__ CHANNEL IRON
SUPPORTED FROM BELOW
X-SECTION



Figure 3. Angled supports under roller conveyors. Spacing such that:
(1) Every roller is supported by at least two supports at all times; (2) Wear
is distributed evenly over whole length on each roller; (3) Rollers are par-
tially self-cleaning.

and provision needs to be made for removing any rots and splits.
Rots should be minimal if the grove has been chopped or disked
immediately prior to picking.

DRENCH (WETTING)
The fruit needs to be wet before it reaches the washer. Dip
tanks or "soak" tanks are not recommended for the same reasons
mentioned above for water dumps. A coarse water spray over
rollers is adequate.

WASHER
Use of transverse rotating brushes is virtually universal, as is
some form of foam application of soap. The foam curtain should
be located immediately above the space between the first and
second brushes, not immediately over a brush, because each row







of fruit pauses between the brushes. A minimum of 20 seconds
exposure time on the brushes is necessary for adequate washing;
30 seconds is much better in districts where fruit have much
sooty mold. There is evidence that slower brush speeds are more
efficient than faster speeds (14).

RINSING

Thorough rinsing is necessary after washing and is best done
over the last of the washer brushes or over a roller conveyor.
Each fruit should pass under at least two nozzles.

WATER ELIMINATION

With today's fuel costs, it is far more economical to remove
excess water mechanically rather than by heat and air move-
ment. The common form of eliminator consists of sponge rubber
rollers (usually made up of sections of foam rubber or foam
plastic known as "do-nuts"). The effectiveness of these foam
rollers depends on the water being "wrung out" by spring-loaded
wringer rolls on the underside. For really efficient operation
(and hence cheaper drying) the wringer rolls are themselves
wiped dry by neoprene blades held rigid between metal straps


HORSEHAIR BR SHF, F FRUIT
-FOAM "DO-NUT"
WRINGER ROLL
NEOPRENE WIPER
\ *PAN

FLICK BAR IN FLICK BAR IN
OPERATIVE POSITION IDLE POSITION
\ /





IRON FRAME


Figure 4. Combined water-eliminator and fungicide-wax applicator. A.
Shows all components of the unit: sponge rubber rolls with wringer rolls
wiped by neoprene wipers constitute the water-eliminator section; horsehair
brushes with flick bars follow as a brush-bed for application of water-
emulsion wax or fungicide. Note that the flick bars are moved manually and
only in operative position when rinsing the brushes. B. Flick bar detail.






(Fig. 4). A less complicated, but still quite efficient, water elim-
inator can be made from soft brushes (plastic of approximately
horse hair grade), on the underside of which are metal "flick
bars" which, by barely touching the rotating bristles, throw
off much of the water. Remember that it is much cheaper to re-
move water mechanically than by the use of heated air.

GRADING
The usual situation is that blemished fruit are removed and the
"in-grade" fruit are left on the line. In Florida, it is normal to
grade on a simple roller conveyor, although various improved
graders have been devised (1, 9). The common arrangement is
for culls (inedible fruit) and eliminations (cannery fruit) to be
graded into chutes beside the grader, with a second grade going
to a conveyor down the center of the grade table. The points to
observe in designing and operating a grade table are:
A. Good lighting is essential. An extensive study of lighting
for apple graders (8) resulted in a recommendation for 178 foot-
candles at the fruit surface using high output, cool white fluores-
cent lamps. This should be very suitable for citrus grading.
B. A minimum of lifting should be involved. Cull elimination
chutes are normally at the same height as the edge of the grade
table. When a center belt is used, a lift or no more than 2 inches
should be necessary to cross the separator between the rollers and
the center belt. It is most undesirable to lift to one or more belts
above the grading surface. The graders are usually women, and
when removing an orange every two seconds to a belt above the
grading surface, we are asking them to lift over 3 tons in the
course of a working day. If grapefruit are run all day, it can
amount to lifting more than 10 tons in the course of an 8-hour
day.
C. The number of grade positions is determined by the num-
ber of individual fruit (Table 1), which also determines the num-
ber of decisions to be made and consequent actions. Presuming
a 60% pack-out and 200 boxes per hour being graded, approx-
imately 5,300 grapefruit per hour would need to be removed, but
16,000 fruit per hour when running oranges and 24,000 per hour
when running tangerines. Ideally the number of graders should
vary with the type of fruit. However, the usual tendency in a
packinghouse running the three types of fruit is to set the num-
ber of graders for oranges, which then means that tangerines get
under-graded and grapefruit get over-graded.







D. There is a very marked tendency for graders to throw off
a given number of fruit per minute, regardless of the quality of
the fruit. Either the rate of fruit flow or the number of graders
should logically be varied according to the proportion of fruit to
be graded out.
E. With high pack-out fruit, the limitation is how many fruit
the graders can observe per minute. With low pack-out fruit, the
limitation is how many fruit the graders can pick up per min-
ute. A study in apple packinghouses showed that with good fruit
and well designed grade tables, each worker could cope with over
7,000 fruit per hour. With poorly designed grade tables and low
pack-out fruit, this value could drop to little more than 2,000 (9).
In Florida citrus packinghouses, the workers are expected to
grade twice as many fruit per hour, per person as in a typical
apple house, so obviously they should be given as much help in
doing so as possible.
F. An inexperienced grader should not be checking the grad-
ing of an experienced grader. When there is much difference in
experience or skill, graders working on the same stream of fruit
should be positioned with the least experienced upstream and the
most experienced downstream. It is common to see as many as
7 or 8 graders working on the same stream of fruit. This is in-
efficient. The fruit flow should be broken into several streams
with no more than 3 or 4 graders per stream of fruit (Fig. 5).
Not only is less fruit being "eyeballed" several times, but each
time the stream of fruit is divided, the rate of forward travel is
lowered. With four short grading lines instead of two long ones,
the fruit passes before the workers at half the linear speed.
G. A very reasonable provision is to put the graders inside an
enclosed air conditioned room to provide better conditions for
grading. However, with the eliminations (off grade fruit) being
tossed onto metal chutes, noise in such an enclosed area can be
excessive. This is exhausting for the graders and can reach
illegal limits under OSHA regulations (13). A very simple and
effective device is to pad the undersides of the chutes with foam
rubber. So used, foam rubber never wears out and the sound
deadening effect is just as effective as putting the foam rubber
on the surface of the metal contacted by the fruit.
H. A sharp limitation on the efficiency of the customary roller
grader is that rate of forward travel and speed of rotation of the
fruit cannot be varied independently. This problem has been
solved with various types of "reverse-roll" grade tables developed









A CULL )CHUTES
CANNERY v


SHEAR /
ROD









CHUTE


150 15 0

Figure 5. Multiple grade tables. When by contrast with a single long grader, the stream of fruit divides into three standard
width graders, speed of forward travel is slowed to one third and each fruit is examined by one third as many graders. A. Dia-
gram of an installation with three two-sided graders. B. An installation with six single grade channels.







for the apple industry (9). These are now beginning to appear
in Florida citrus houses. If properly used, they definitely in-
crease the work-capacity of the workers as well as improving the
grade. They must, however, be constantly adjusted for the type
and volume of fruit being run.
I. Electronic sorting is not currently used in Florida, although
there is ample evidence that available machines are technically
capable of sorting for both color and blemishes (3). It has been
suggested that the best prospects for economic use of such equip-
ment in Florida might well be in a highly mechanized, combined
fresh fruit and cannery operation (7).

COLOR-ADDING
Color-adding is an optional treatment since it is only used on
oranges, 'Temples,' and tangelos-and then only on crops which,
due to climatic conditions, do not have a distinctive varietal color
(10). The logical arrangement is to have the color-add tank as
a by-pass to the main line, not vice versa. The color-add tank is
always a wide piece of equipment in which the fruit stacks very
deep and hence moves forward very slowly. When fruit is not
being color-added, it moves forward very quickly on a belt, and it
is logical to have this in a straight line with no diversions, to re-
duce possibilities of fruit damage.
Color-adding is a time-dependent operation. For a given color-
add emulsion, the intensity of color and the amount of residue is
determined by the temperature of the emulsion and the time for
which the fruit is exposed. Maxima for both temperature and
time are set by the rules of the Florida Citrus Commission (2).
Color-add must always be followed by a thorough rinse. Apart
from the problem of excess color "bleeding" through the wax,
there is a legal necessity for a good rinse in that the FDA max-
imum residue is 2 parts per million (ppm) of Citrus Red. No. 2.
Such rinsing is best done over washer-brushes or moving rollers
rather than on a mesh belt or a slat conveyor on which the fruit
does not move.

WATER ELIMINATION
If an emulsion wax is to be used, the water eliminator at this
position can be combined with a bed of horse hair brushes to also
serve as a fungicide applicator (Fig. 4). When a solvent wax is
being used, the water eliminator is the first step in achieving the
complete dryness that is necessary before a solvent wax can be







applied. The more water removed inexpensively by mechanical
means at the water eliminator, the less that has to be removed
expensively with hot air drying.

WAXING
Two types of so-called waxes are used. (Ingredients usually in-
clude food-grade synthetic resins.) In one form, the wax solids
are dissolved in an organic solvent and fogged on over rollers in
a chamber run under slight vacuum (by forced venting to the
outside) to minimize fire hazard. This is normally done under
contract and so not covered in detail here (10).
The other type of wax application involves use of a water
emulsion that can be applied as a dip, foam, or spray. The spray
is the conventional method in Florida, the emulsion typically
being applied over a bed of slowly rotating (not over 100 rpm)
brushes. For this application, horse hair is superior to plastic
bristle, as its rough texture tends to hold the emulsion and wipe
it on the fruit rather than throwing it off by centrifugal force.
The application of the emulsion can be by a bank of fixed nozzles,
but the traveling nozzle system ("wig-wag") is usually preferred.
In this system, an oscillating nozzle goes to and fro putting out a
fine fog of emulsion. It is preferable to have two small nozzles
on the wig-wag rather than one large one so that some potential
remains if one nozzle blocks. (A handy system for cleaning out
wax applicator lines is to have a steam line connected to the
emulsion delivery line with shut-off valves so that the emulsion
can be shut off and the lines blown out with steam.)
A very special problem occurs when packing for an export
market with regulations on waxes and/or fungicides differing
from those of the domestic market. Unless precautions are
taken, a brushbed used for application of wax, fungicide, or both,
can contaminate fruit being run over it long after the changeover
has been made. Very efficient cleansing of the brushbed can be
obtained by the use of "flick bars" under the brushes (Fig. 4).
These are on a sliding rack under the horse hair brushes of the
applicator. Except when rinsing, they are positioned with the
flick bars between the brushes and so inoperative.
First rinse out the wax lines and nozzles thoroughly. There is
no point in cleaning the brushbed and then flushing out the noz-
zles onto the brushes.
To rinse:
1. Start the brushes. (Never start the brushes with the flick
bars in place because of the excessive drag on the motor.)







2. Pull flick bars back so each is in contact with its equivalent
brush.
3. Hose down for at least a minute with the flick bars in place
and the brushes revolving.
4. After hosing, leave flick bars in place for another 15 or 20
seconds to dry off brushes and avoid diluting the wax.
5. Push flick bars into the "neutral" position and start up with
the next lot of wax.

FUNGICIDE APPLICATION
For details of fungicide application, see Extension Circular
359A (12). It should be noted, however, that fungicides applied
on the packingline fall into two classes, depending on whether
used on unwashed or washed fruit. Sodium o-phenylphenate, as
prepared for use on fruit, is an excellent detergent and is "fixed"
in minor wounds on the surface of the fruit. It is usually applied
at the washer. Other fungicides are best applied (usually over
a brushbed) after grading and before drying. Some fungicides
can be incorporated in fruit waxes.

DRYING

Fruit drying is normally done with hot air, which used to be
delivered over fast-moving polisher brushes. The combination
of hot air and brushing can be a source of considerable damage
to tender fruit, and is sharply discouraged. Where brushes are
used, they should turn no more than 100 RPM.
The most common error in dryer design is to have the moist
air blown out below the dryer and immediately returning to the
air intake of the radiator above the dryer. A certain percentage
of heated air can be recirculated for improved energy efficiency,
but continuous recirculation of the same air will result in satura-
tion. The exhaust air should be expelled elsewhere, preferably
out of the packinghouse. This arrangement has the added ad-
vantages of reducing heat, humidity, and noise for the comfort
of nearby workers. Radiators should be cleaned frequently.
Drying is a time-dependent operation. The time necessary
depends on whether wet fruit is being dried prior to waxing, in
which case 13/ to 2 minutes of drying time is usually adequate.
When wax is being dried on the fruit, 21/2 to 3 minutes is usually
necessary to dry a water wax and approximately 1 minute for a







solvent wax. Dryers for waxed fruit should always be in two
sections: a short initial section and a longer final section. This
very largely confines wax accumulation on the equipment to the
first short section. Waxed fruit should not roll while drying.
This is usually achieved by using either a slat conveyor or
"stilled" rollers, i.e., rollers supported by the pin chain at the
sides so that they do not turn. An occasional support activates
the rollers to roll the fruit over once to expose the undersides.
The temperature of the hot air that can be used without dam-
aging fruit depends on several factors. The first of these is
obviously the frailty of the fruit. Tender specialty fruit, such as
degreened 'Robinson' tangerines, should be heated as little as pos-
sible and not brushed at all. Mid-season grapefruit seldom suffer
damage during drying. Wet fruit will stand very much higher
air temperatures than dry fruit. 'Valencia' oranges subjected
to 150 air showed no increase in pulp temperature as long as
the fruit surface was still wet (4). However, temperatures
above 130F are not recommended, particularly at the down-
stream end of the dryer where the fruit are dry or nearly so.
Very rapid drying is possible with infra-red rays from either
electrical or gas-fired units. However, this is line-of-sight radia-
tion and does not heat the air through which it passes. Thus
infra-red effectively dries a band around the fruit, but not the
ends of the fruit. This makes it suitable for predrying and is
doubly effective as, after infra-red exposure, the fruit no longer
wet the rollers as they move into the conventional dryer. Metal
absorbs infra-red, so metal rollers cannot be used and all metal
surfaces exposed to the rays must be shielded wherever they
might touch the fruit lest a severe peel burn results.

STAMPING
Various equipment is available for stamping trade names,
source of origin, etc., upon fruit. When a solvent wax is being
used, the best job can be obtained by stamping on the dry fruit
prior to waxing. When an emulsion wax is being used, stamping
has to follow waxing.
Because of the ever-increasing restrictions on food additives
(which inks can be considered to be), interest has arisen in fruit
labelers, which are more expensive than ink stamping. These
attach paper or plastic labels to individual fruit with pressure
sensitive glue. Such machines are fully automatic but can only
be used on dry fruit after waxing. The pressure sensitive ad-
hesive must be FDA approved.







SIZING
Various types of sizers are available, and almost all modern
packinghouses use a central sizing system from which pull-out
belts remove the individual sizes. The best advice with sizers is
to respect the manufacturer's design and not tamper with them.
Inevitably, however, equipment is accelerated; a particular cau-
tion in this regard is given for belt-and-roll sizers, as efficiency
depends on the relationship between the "surface speeds" of the
belt and roller. For example, on a widely used Florida belt and
roll sizer, the belts move at 225 linear feet per minute and the
3-inch diameter rollers turn at 102 RPM, giving a linear roller
surface speed of 80 FPM. This relationship of 2.8:1 must be
maintained.

PACKING FRUIT
Details of fruit packing methods are not dealt with here. At-
tention is drawn, however, to the fact that in any new equipment
being set up, provision should be made for ultimate mechaniza-
tion, as the trend is sharply away from individual place packing
to mechanized packing with an operator running one or several
machines. The system should always allow for maximum flow
to every machine, which is not possible when packing machines
are merely substituted for people in a traditional packinghouse
layout (6).

MINIMIZING FRUIT DAMAGE ON THE
PACKINGHOUSE LINE
Damage to fruit on the packinghouse line can take several
forms. One of these is inoculation with decay organisms. This
is very common when water dumps or soak tanks are used, even
when a fungicide is put into the water. This is because there are
several minor diseases, such as anthracnose (Colletotrichum),
sour rot (Geotrichum, also known as Obspora), black rot (Alter-
naria), and various resistant strains of Penicillium that are not
controlled by legal fungicides. A particularly subtle type of
damage occurs due to excessive polishing. Fruit that has been
through a hot polisher-dryer can look beautiful when packed, but
look crisp and brown a few days later. Polisher-dryers are never
advised. The third, and probably most common, type of damage
is mechanical injury due to cuts and abrasions. Citrus fruits are
comparatively resistant to bruising, but are very susceptible to
decay after being scratched or scraped enough to cause small,
often invisible, breaks in the peel.







Mechanical damage most commonly happens at the transfer be-
tween pieces of equipment or going around corners. The most
usual sources of damage are dealt with below.

DUMPING
Today most dumping is from pallet boxes that empty approx-
imately 900 pounds (400 kg) of fruit at once. It is imperative
that this large mass of fruit be leveled out as rapidly as possible,
both to avoid squeezing and scraping of the fruit and to make it
possible to get the trash out. Some form of "anti-surge" device
is necessary. A common, and effective, form is to have the
dumper deliver to two belts, one fast and one slow, which in
turn deliver to a roller-spreader. For optimum performance, the
width of these two belts should be inversely proportional to their
speed. If the fast belt is twice as fast as the slow belt, it should
be half the width of the slow belt.

DELIVERIES FROM ROLLER AND SLAT CONVEYORS
All deliveries from roller conveyors should be equipped with
ejector slats on the drive shafts (Fig. 6). The deliveries from
slat conveyors should be equipped with spinner rolls (Fig. 7).
Chutes (transfer plates) from roller and slat conveyors should
be aligned as an extension of a radius from the head shaft (Fig.
6 and 7). The slight resulting amount of drop from the roller
to the chute will not damage the fruit, but having too flat a chute
on which flat or irregular shaped fruit can back up is very dam-
aging indeed.

POINTS OF IMPACT
One of the commonest points of impact is when fruit drop onto
a belt. Drops of several inches can be allowed onto a belt if there
is no support under the belt at the point of impact (Fig. 6 and 8).
Where the belt is carried on rollers, the rollers are removed at
the point of impact; where the belt is carried on a pan, the pan
should be cut away under the impact area. Rollers, rather than
pans, for supporting the belts are always recommended, as drag-
ging the belts over a metal pan can increase the necessary horse-
power by as much as 30 %.
Another typical point of impact is where fruit is delivered at
right angles onto a belt, as from a dumper. A second point of
impact is then on the side of the machinery, not on the belt itself.
Most forms of padding wear away rapidly or build up with wax







ROLLER
CONVEYOR


B. CHUTE ( ALIGN AS A
RADIUS FROM THE DRIVE
SHAFT AT APPROX. 200
SLOPE )


TOR ) --
TS ROLLERS


C. UNSUPPORTED BELT AT
POINT OF IMPACT


Figure 6. Delivery from roller conveyor to a belt. A. Ejector slats.
B. Chute aligned as the radius of the head shaft. C. Delivery onto unsup-
ported belt where one roller has been removed.


CHAIN DRIVE FROM
HEADSHAFT SLAT
CONVEYOR


ROLLER HEADSHAFT
CONVEYOR H



SPINNER ROLL

CHUTE (ALIGN AS A RADIUS
OF THE HEADSHAFT)

Figure 7. Spinner roll on a slat conveyor delivery.








SOLID RUBBER OR PLASTIC
HOSE (NO FABRIC)

SEE AUXILIARY VIEW
TEE-
BOLT )o P O CHUTE
BELT
TEE-BOLTS INSERTED THROUGH SLITS IN HOSE NO
MORE THAN 6" ON CENTER WITH STAGGERED
PLACEMENT
SIDE OF
CONVEYOR
6 -6"-- AUXILIARY VIEW /
|- -- BELT
SURFACE

ROLLERS REMOVED UNDER IMPACT AREA
Figure 8. Solid rubber or plastic hose (no incorporated fabric) used as a
bumper opposite a right-angle delivery.

which catches debris and becomes abrasive. An excellent form
of "bumper" is made from plastic hose attached with Tee-bolts
such as are used for attaching slats in a slat conveyor (Fig. 8).
The bumper hose should be continued along the conveyor until
the point at which the fruit is no longer rolling. The bumper
can then be discontinued and the fruit will continue on the belt
without scraping against the sides, materially reducing the wear
and tear on both the fruit and the equipment.

TURNS
More damage is done to fruit at turns of various kinds than
anywhere else in a normal packinghouse. Most turns are at right
angles and many involve delivery from one type of conveyor onto
another. In general, "over-the-end" delivery from one conveyor
to the other (Fig. 9) is preferable to the use of a shear (Fig. 10).
When two belts intercept at right angles, the belt pulling the
fruit out of the corner should be on the top (Fig. 11).


























I 1: C o n OnO "c 1 ---



Figure 9. Over-the-end delivery for a right-angle turn onto a belt, roller
conveyor, or slat conveyor. This method is preferable to the use of a shear.
Triangular delivery chute is necessary when delivering onto a slat conveyor,
but not essential for belts and roller conveyors.

Most places, where the fruit is to turn at right angles, a shear
is commonly used. It is at such turns that most fruit damage
occurs, largely due to the almost inevitable error of not cutting
back the inside corner of the turn, thereby restricting the fruit
flow and forcing it against what is usually a sharp edge at the
inside corner (Fig. 10). It is preferable to keep the angle of a
shear no more than 30 degrees. However, there are many cases
where this is not possible, particularly when shearing from a
narrow belt onto a wider conveyor, as in Figure 12. In such
cases, rods should be used parallel to the shear and riding on the
delivery belt. In most instances, a i-inch steel rod is adequate.
Where several successive rods are used, they should increase in
diameter-e.g., 1/4", 3/%", and 1/2". When fruit has to change
directions rapidly, as in bypass belts into and out of a color-add
tank, the fruit flow can be aided, and damage minimized, by
sloping belts 5 degrees in the direction of fruit exit.


PLAN VIEW





X- SECTION























PARALLEL TO ANGLE
OF SHEAR


DISTANCE "X" TO BE NEVER LESS
THAN DISTANCE "Y"


Figure 10. Cutting back the inside corner of a sheared turn. A shear
angle of 30" is optimum, but 40 can be used. A supporting plate that pre-
vents the belt from sagging under the shear helps to minimize the chance of
fruit injury.


Figure 11. When taking a corner on two belts at the same elevation, the
belt pulling out from the corner should be on top. Over-the-end delivery
(Fig. 9) is preferred.






The surface of the shear contacting the fruit should be slick
and of a material that does not tend to accumulate fruit wax.
Metal shears should not be painted, and wooden shears are best
covered with laminated plastic. At the early part of the fruit
line, where there may be twigs and leaves carrying over, shears
should be made "self-cleaning" by cutting back the downstream
corner so that twigs caught under the shear will come free in-
stead of catching (Fig. 13).

CALCULATING PACKINGLINE CAPACITY
The capacity of a given item of equipment or the size of equip-
ment necessary to handle a given volume of fruit can be calcu-
lated. For this, it is necessary to know certain characteristics of
both the fruit (Table 1) and of the equipment (Table 2). Note
that all conveyor capacities in Table 2 are based on 100% utiliza-
tion. In most instances, the actual utilization will be somewhat

1/4" DIAMETER RODS
EVENLY SPACED



-BELT-



CHUTE




TOP VIEW
THIS END IN 3/8"
HOLE IN SIDE THIS END DROPS INTO
ROD3/8" HOLE IN CHUTE
RO DH LEIN
BELT

SIDE VIEW

Figure 12. Use of diversion rods with a fixed shear. The rods are NOT
fixed in place. They are inserted through holes in the chute and the side of
the conveyor and ride on the surface of the belt.












TABLE 1. PHYSICAL CHARACTERISTICS OF FRUIT.


Abbreviation

lb/box
No./box
US Measures
ft2/box
boxes/ft2
lb/ft2
No./ft2
ft/box
lb/ft
Metric measures
m2/10 kg
kg/m2
No./m2
m/10 kg
kg/m


Characteristic

Pounds per Florida field box'
Average number of fruit per box

Area (ft2) per field box
Field boxes per square foot (ft2)
Pounds (lb) per square foot (ft2)
Average number of fruit per ft2
Linear feet per field box
Pounds (Ib) per linear foot

Area (m2) per 10 kilograms of fruit
Kilograms per square meter (m2)
Average number of fruit per m2
Linear meters per 10 kilograms
Kilograms per linear meter


Grapefruit Oranges Tangerines Lemons


85' 90"
70 200


9
0.111
9.44
7.78
30
2.83

0.22
45.5
83
2.37
4.22


11
0.091
8.18
18.2
48
1.88

0.25
40
196
3.58
2.79


95"
300


12
0.083
7.92
24.9
60
1.58

0.26
38.5
267
4.24
2.36


95'
250

11.5
0.087
8.26
21.8
52
1.83

0.25
40
231
3.67
2.72


Persian
limes Key limes

95' 100'
400 1,200


14
0.071
6.79
28.4
75
1.27

0.30
33.3
308
5.30
1.89


20
0.050
5.00
60.0
178
0.58

0.41
24.4
644
12.00
0.83


'See Table 3.
YFlorida field box = 4,800 cu. ins. (approx. 2.23 U.S. bushels)
xLegal measure
"Estimated
NOTE: Area per box and linear feet per box have been determined experimentally. Such figures vary slightly from theoretical values when fruit are not spherical, e.g., oblate for
grapefruit, elliptical for lemons, etc.


Symbol'






























Figure 13. Self-cleaning shear.


less, but will vary according to the machine and the matching of
capacities for various machines.

FRUIT CHARACTERISTICS
The capacity of a packinghouse line is sharply dependent on
certain characteristics of the fruit, most particularly fruit size,
although weight and shape can also be limiting factors in certain
circumstances. On belts, capacity is determined by the speed of
the belt (Table 2) and by the area occupied by a "box" or other
unit of fruit (Table 1). On slat and roller conveyors, capacity
is determined by the number of linear feet when that same unit
of fruit is lined up in a row. This ranges from 30 linear feet for
a Florida field box of grapefruit to about 60 linear feet for a box
of tangerines. Because of these factors, a belt that can carry
10 boxes of grapefruit at a given speed can carry only 8.2 boxes
of oranges and less than 7.5 of tangerines. A slat or roller con-
veyor that can carry 10 boxes of grapefruit can carry only 6.25
boxes of oranges or 5.0 of tangerines.














TABLE 2. FORMULAS INVOLVED IN CONVEYOR CAPACITY.


Belt Conveyor


U.S. Measures7


Capacity of a given conveyor (boxes'/hr)



Necessary linear speed (ft/min) for a given capacity



Necessary drive shaft rpm for a given linear speed (ft/min)



Necessary rpm for a given capacity (boxes/hr)


w X s X 60
c -
a

cXa
s = ------
w X 60

S 7Xs
rpm = or ---
r X d 22Xd

cXa
rpm =
w X X d X 60


Slat or Roller Conveyor'


60 X rpm X NX w
C =


cXlXrX2Xr

w X N X 60


rpm =
2XrXr

cXl
rpm =
60 X N X w


Value Needed









Value Needed Belt Conveyor Slat or Roller Conveyor,


Metric Measures'


Capacity of a given conveyor (tonnes/hr)



Necessary linear speed (m/min) for a given capacity



Necessary drive shaft RPM for a given linear speed (m/min)



Necessary RPM for a given capacity (tonnes/hr)


WXSX6
C =
10 X A

10 X A X C

6XW

S 7xS
RPM = or ---
r X D 22 X D

A X C X 10
RPM =
6XW X vXD


RPM X N X W X6
C =
L X 10

CXLX R X10 X2X

W X N X 6
WXNX6

S
RPM =
2X2rXR

C X L X 10
RPM =
6XWXN


ZN=number of fruit rows/revolution; r=pitch radius, ft.; R=pitch radius, m.
YU.S. measures: c = capacity (boxes/hr); w = width of conveyor (ft) ; s = linear speed (ft/min) ; a = area (sq. ft) of a box spread 1 fruit deep; d = diameter of drum (ft)
rpm = revolutions/min; 1 = length of I box as a single row of fruit (ft).
-A Florida box = 90 lbs oranges, 85 lbs grapefruit, or 95 lbs tangerines.
-Metric measures: Tonne = 1,000 kg = 2,205 lbs. C capacity (tonnes/hr) : W = width of conveyor in meters (m); S = linear speed (m/min) ; A = area (m2) of 10
kilograms (kg) of fruit; RPM = revolutions per minute; W = width of conveyor (m) ; L = length of 10 kg fruit in a single row; D = diameter of drum
(m).








--- DRIVEo

REGULAR
CONFIGURATION DUAL MOTOR DRIVE
"AUTOMATIC TAKE-UP PULLEY
INCLINED CONVEYOR



DRIVE

'-DRIVE
TWO-WAY DOUBLE WRAP HIGH INERTIA APPLICATION
DOUBLE WRAP

Figure 14. Various belt drive configurations.

It is in grading that the size of fruit becomes most critical.
Not only is the fruit normally lined up in rows on rollers, which
limits the capacity of a conveyor, but, more critically, each
grader can make only so many decisions and carry out so many
motions per minute. There is also a human element in that, as
has been noted previously, graders tend to throw off a given
number of fruit per minute regardless of the condition of the
fruit.
Equipment should never need to be run so fast that appreciable
damage happens along the line. However, in actual practice,
lines do get overcrowded. Then the point at which damage first
occurs when the line is speeded up or overcrowded becomes one
of the limiting factors. This tends to increase the spread among
different types of fruits, as grapefruit are the least liable to
mechanical damage, and tangerines, lemons, and limes are most
susceptible.

EQUIPMENT CHARACTERISTICS
Packinghouse machinery in Florida, and to a certain extent
elsewhere, has standardized on certain components. This is most
helpful, not only in equipment maintenance, but also in calculat-
ing equipment capacities. The amount of fruit per row will vary
with the fruit characteristics and the width of the line, but once







known, volume or weight of fruit for each revolution is also
known.
Table 3 shows equipment characteristics of the machinery com-
ponents most commonly used in Florida citrus packinghouses.
Deviation from such standard specifications, particularly in
width of conveyor, can be expected to entail extra costs.

TABLE 3. STANDARD EQUIPMENT DIMENSIONS.


Belt Conveyors
Width (in.)
Drum size (in.)
Roller and Slat Conveyors
Width (in.)
Chain

Rollers*


Washers and Water Eliminators
Brush length
Brush diameter (in.)
Moisture eliminators (in.)


Standard Sizes
14, 18, 24, 36, 48, 60
6, 8, 10, 12, 14, 18


12, 18, 24, 30, 36, 48, 60, 72, 84
RC2060 with D5 attachment (roller)
RC2060 with A3 attachment (slat)
2" Aluminum tubing
2" Sch. 40 Steel pipe
2" Sch. 40 PVC pipe

(As required)
Less than 6
4 to 6.25 (various sizes)


*Pipe diameters are nominal. Sch 40 2" pipe is 2.375" OD.


STANDARD SIZES AND COMPONENTS

Numerous sizes of belts, rollers, and slats are utilized through-
out the citrus industry. Roller and slat conveyors are typically
found in 6-inch width increments from 12" to 84". Standard
drum diameters for belt coveyors range from 6" to 18". Pre-
ferred belt widths are 14", 18", and 24" for small capacities with
belts in 1-foot increments above 2' for larger fruit volume.
Typical belt drive configurations are shown in Figure 14. Double-
pitched roller chain is used for most roller and slat conveyor ap-
plications. Chain size and number of sprocket teeth will depend
upon design capacity of the system. For all equipment, OSHA-
approved machine guards should be installed. A list of typical
components have been assembled in Table 3.







LITERATURE CITED


1. Bowman, Earl. 1975. Efficiency in manually grading citrus fruit.
Packinghouse Newsletter No. 73, Univ. of Fla., AREC, Lake Alfred, FL
33850.

2. Florida Department of Citrus. 1975. Official rules affecting the Florida
citrus industry, pursuant to Chapter 601, Florida Statutes. Rule No.
20-32, Artificial coloring of fresh fruit.

3. Gaffney, J. J. 1973. Potentials for photoelectric grading equipment in
the Florida citrus industry. Trans. 1973 Citrus Eng. Conf. XIX, Fla.
Section, Amer. Soc. Mech. Engrs. March 22.

4. Grierson, W. 1957. Preliminary studies on cooling Florida oranges
prior to packing. Proc. Fla. State Hort. Soc. 70:264-272.

5. -- 1971. Trash elimination. Packinghouse Newsletter No. 39.
AREC-LA-71-41, Univ. of Fla., Lake Alfred, FL 33850.

6. Grierson, W., and W. Wardowski. 1973. Development of mechaniza-
tion programs for harvesting and packing citrus for the fresh fruit
markets. Proc. Int. Soc. Citriculture (Spain), III:633-639.

7. -- 1977. Packinghouse procedures relating to citrus processing.
Chap. 2:128-140 in Citrus Processing, Science & Technology. Vol. 2
Eds. M. K. Veldhuis, S. Nagy and P. E. Shaw. AVI Publishing Co.,
Inc., Westport, CT.

8. Heft, Marvin E., Jr. and Dennis E. Wiant. 1962. Lighting apple pack-
ing areas. Illuminating Engrs. 57(6) :5 p (page numbers not given on
reprint).

9. Hunter, D Loyd, Francis Kafer, and Charles H. Meyer. 1958. Apple
sorting: Methods and equipment. Marketing Research Report No. 230.
Agricultural Marketing Service, Marketing Research Division, U. S.
Department of Agriculture.

10. Long, W. G. 1964. Ed. Better handling of Florida's fresh citrus fruit.
Fla. Agr. Exp. Sta. Bull. 681.

11. Malcolm, Donald G. and E. Paul DeGarmo. 1953. Visual inspection
of products for surface characteristics in grading operations. Market-
ing Research Report No. 45, Production and Marketing Administration,
U.S. Department of Agriculture.

12. McCornack, A. A., W. F. Wardowski, and G. E. Brown. 1976. Post-
harvest decay control recommendations for Florida citrus fruit. Fla.
Coop. Ext. Serv. Circ. 359-A.

13. Occupational Safety & Health Admin. 1974. Occupational noise ex-
posure. Federal Register 39(125):23596-23597.

14. Rejimbal, T. R., Jr. and R. E. Bigler. 1972. Cleaning efficiency of
brush washers in citrus concentrate plants. Proc. Fla. State Hort. Soc.
85:254-257.







15. Hooks, R. Clegg, and Richard L. Kilmer. 1977. Estimated costs of
packing and selling fresh Florida citrus 1975-76 season. Economic In-
formation Report 72. Food & Resource Economics Dept., Univ. of Fla.,
Gainesville.

16. Wardowski, W. F., and W. Grierson. 1972. Separation and grading of
freeze damaged citrus fruits. Fla. Coop. Ext. Serv. Circ. 372.

17. Wardowski, W. F., and A. A. McCornack. 1973. Recommendations for
degreening Florida fresh citrus fruits. Fla. Coop. Ext. Serv. Circ. 389.







INDEX


Anti-surge devices ..................16

Belts .....................................-- 16
Brushes ...........---......................-----6, 12

Capacity .............................----1, 21
Chutes ..--. ........................-... 16
Cleaning brushes .. -----............... 12
Color-adding ........................2, 11
Conveyors ..--..................... 16, 23
Corners ..... ....-.~..... ....-- .... 18
Costs .......................----......--.......... 1

Damaged fruit ......-----..... 1, 5, 11,
15, 16, 18, 19, 21
Decay control ................---2, 13, 15
Deliveries ................................---- 16
Dip tanks ...................................------ 6
Diseases .................................--------- 15
Drenching ................................... 6
Drying ------........................... 7, 13
Dumping ..............................5, 16

Electrical costs .....................----.....1
Electronic sorting ..................--11
Equipment standards .-.....26, 27
Export ..........................----.............--12

Flick bars .............----- .......... 8, 12
Food additives -----................. 14
Fruit characteristics ......-.23, 26
Fruit damage ................ 1, 5, 11,
15, 16, 18, 19, 21
Fungicide application ........2, 13
Fungicide residues ....................1

Grading .......................2, 8, 9, 11


Inclined belts ............................19
Infra-red drying ......................14
Inventory to inventory ..............4

Lighting .................-- ------------....-- 8

Noise ..................--.-----------9

Packing .............-----------...................15
Padding ......................-..............16
Pallet boxes ...............---- ...........16
Pesticide residues ......................2
Plumbing costs ..............------..---.........1
Polishing ............................13, 15

Radiators .......................-----...-...--13
Rinsing .----...........-------...........................7

Second grade ................................4
Shears .....- ...................-....-18, 19
Size of equipment ........ 1, 26, 27
Sizing fruit .......------..................15
Sloping belts ..............................19
Soak tanks ..................................6
Soap ..................................--------6
Stamping fruit ..................... 14
"Stilled" rollers ........................14

Tangerines ................................14
Trash elimination ........................5
Turns ..........-----..............................---18

Washing ...................----------.................6
Water elimination ...............-7, 11
Waxing ...............................2, 12
Wetting fruit ...........................-----
Width of equipment ....................1











































This public document was promulgated at an annual cost of
$2201 or a cost of 44 per copy to provide information of use in
developing efficient citrus packinghouse systems.




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