Automatic produce-bagging machine that uses factory-roll polyethylene net tubing

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Do not assume content reflects current
scientific knowledge, policies, or practices.

AUTOMATIC

PRODUCE -BAGGING MACHINE
THAT USES FACTORY-ROLL
POLYETHYLENE NET TUBING

ARS-S-18
July 1973

SOUTHERN
REGION

AGRICULTURAL RESEARCH SERVICE e U.S. DEPARTMENT OF AGRICULTURE

ee a Reh ae ey

PREFACE

The work on equipment development described in this report was con-
ducted by the Agricultural Research Service, US. Department of Agriculture,
in cooperation with the Florida Agricultural Experiment Stations, Institute
of Food and Agricultural Sciences of the University of Florida. It was
initiated and mainly carried out under the general supervision of Joseph F.
Herrick, Jr., now agricultural marketing specialist, Horticultural Crops Mar-
keting Laboratory, Agricultural Marketing Research Institute, Northeast
Region, Agricultural Research Service, U.S. Department of Agriculture.
The concluding portion was under the general supervision of Dean F. Davis,
area director, Florida-Antilles Area, Southern Region, Agricultural Re-
search Service, U.S. Department of Agriculture. Ernest T. Smerdon, chair-
man, Agricultural Engineering Department, Institute of Food and Agri-
cultural Sciences, University of Florida, acted jointly in general supervision
during the entire period of work.

Grateful acknowledgment is made to American Machinery Co., Or-
lando, Fla., for supplying staples, air staplers, and a Pac-Rite count-fill
unit. Deep appreciation is expressed to E. I. du Pont de Nemours & Co.
for furnishing polyethylene net tubing (Vexar).

CONTENTS

Page

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Applying ilabelis%%). eateries bee. se 8 tes pene meh tain ease 13
Opening and) erippingamechanism™ =r. 2s 0see eee eee eee 13
Top-closinge-emechanisny Mie tr cick Reeves <2. aa eee 13
Economic aspects of automatic bagging machine ..................... 13
Literatureccited 325 te tee reer ac eke ace te er 16

Trade names are used in this publication solely to provide specific information.
Mention of a trade name does not constitute a guarantee or warranty of the

product by the U.S. Department of Agriculture or an endorsement by the De-
partment over other products not mentioned.

AUTOMATIC PRODUCE-BAGGING MACHINE
THAT USES FACTORY-ROLL
POLYETHYLENE NET TUBING

By Earl K. Bowman and John C. Teele!

SUMMARY

An experimental model produce-bagging ma-
chine is described. The machine forms bags from
factory-roll polyethylene net tubing, fills and
closes them, and ejects them onto a conveyor in
a continuous automatic cycle. Test bagging of
oranges showed that the basic design concepts
in the machine are sound. With refinements,
equipment manufacturers can build commercial
models based on it.

The machine has economic advantages over
the semiautomatic equipment now widely used.
First, being entirely automatic, the bagging op-
eration requires less labor. Second, bag forming
is incorporated into the automatic cycle, a fea-
ture not found on currently available automatic
bagging machines. Thus the expense of manu-
factured bags is eliminated.

Costs based on 5-pound bags of oranges
packed in master cartons show that a saving of
$7,257 may be realized on an annual volume of 1
million bags (125,000 master cartons) with a
commercial machine incorporating the features
of the experimental model, compared to the pre-
vailing semiautomatic method for filling and
closing polyethylene net bags. On 31 million
bags, the total for citrus fruit shipped in poly-
ethylene net bags from Florida in the 1970-71
season, this would amount to a saving of better
than $233,000. Commercial models of the ma-
chine should be usable for 8-pound bags as well
as 5-pound and for grapefruit of bagging size
as Well as oranges.

1 Industrial engineer and industrial engineering tech-
‘Nician, respectively, Florida-Antilles Area, Southern

Region, Agricultural Research Service, U.S. Department
of Agriculture, Gainsville, Fla.

INTRODUCTION

Oranges and grapefruit have been packaged
in bags at the shipping point for more than
three decades in Florida. For about 20 years it
was all done manually. Only fabric mesh bags
were used before polyethylene film bags, which
first appeared in Florida statistics for the 1958—
59 season, were introduced (fig. 1). Polyethyl-
ene net bags (Vexar) first appeared in Florida
statistics for the 1966-67 season (2).?

2Ttalic numbers in parentheses refer to items in
“Literature Cited” at the end of this report.

Figure 1.—Representative bags used in Florida citrus
industry. A, Polyethylene film, heat-sealed, “pillow”
type, more commonly gathered and stapled for top
closing . B, Polyethylene net.

In Florida most citrus bagging in polyethyl-
ene film bags is done by semiautomatic ma-
chinery; some automatic machines are in use.
In all semiautomatic bagging operations, pur-
chased (premade) bags are used entirely. The
representative semiautomatic equipment used
in a large portion of the packinghouses counts
the desired quantity of fruit into the bag upon
actuation of a foot pedal or other control by the
operator. The operator holds the bag in position
to catch the fruit, then closes it by a tape or
stapling device, and places it in a master carton
(fig. 2). Similar semiautomatic equipment is
used elsewhere for packaging such produce as
apples, onions, and potatoes in polyethylene
film bags. Generally, this equipment measures
quantity by weight instead of count. Machine
action or the operator pours the measured quan-
tity from a pan or accumulating chamber into
the bag after the machine feed has stopped at
a preset weight. Bag closing practices are simi-
lar to those employed in semiautomatic citrus
bagging operations. Semiautomatic machines
suitable for polyethylene film bags are also gen-
erally usable for bagging fruit in polyethylene
net bags.

Automatic polyethylene film bagging’ ma-
chines have been installed in several Florida
packinghouses over approximately the past 3

Figure 2.—Semiautomatic count-fill units,
four, currently predominant in Florida citrus pack-
inghouses. Air stapler with nearest unit is at left
foreground; empty master cartons on monorail sup-

group of

ply conveyor. Packing stands and filled-carton
takeaway conveyor are also visible.

years. Premade bags are used by all of them ex-
cept for one make that uses specially prepared
film, doubled, in a ribbon with perforations in
heat-sealed strips between bags. The bagging
machine heat-seals the top after filling except
where twist-tie or Kwik-lok closing has been
substituted. Bags separate along perforation
lines in passing out of the machine onto the

takeaway conveyor (fig. 3). Manual checking

of bag weight is required in operating one make
of these machines, a carrousel type (fig. 4).

No fully automatic machines are available
for handling polyethylene net bags except one
type, recently offered in the Florida citrus area,
with an attachment for automatically handling
net bags supplied on wickets. Thus far, the tool-
ing of bagmakers has not provided for supply-
ing polyethylene net bags in this way. Even if
manufacturers were to supply these bags on
wickets, the price of the bags might be higher
than that for net bags supplied in the usual
manner.

Polyethylene net bags are being used more
and more for packaging produce. In Florida,
for example, 6.8 percent of fresh fruit shipped

was in net bags (31,061,651 bags) during the
1970-71 season—more than double the 3.1 per-
cent (16,879,502 bags) shipped during the
1966-67 season, when net bags first appeared

in Florida statistics. Although part of the in-

Figure 3.—Automatic bagging machine using poly-
ethylene film in special ribbon form, perforated
between bags. Special material input shown in
foreground; count-fill unit and fruit guide are at
upper center. Filled bags are like A, figure 1.

|

|
|
|

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Figure 4.—Carrousel bagging machine. (Top) Workers hanging polyethylene net bags on filling heads. Device for
automatic hanging of polyethylene film bags at left foreground, loaded with bags on wickets. (Bottom) Filled bag
discharge. Worker at left is check-weighing and worker at right is attending the automatic staple-closing unit.

crease is attributable to discontinuance of fab-
ric mesh bags for citrus by the Florida Citrus
Commission (now the Department of Citrus) in
1967 (1), polyethylene net bags have been fa-
vorably received in marketing channels because
they improve package appearance and quality
maintenance of produce. Simulated shipping
and marketing tests with various kinds of cit-
rus have shown that there is less spoilage of
fruit in net bags than in film bags (3, 4, 6).
Further, the cooling response of citrus in net
bags is better (5, 8).

Manufactured polyethylene net bags cost
about twice as much as film bags. Economic
advantages would accrue to consumers and
packers alike by having bag forming incorpor-
ated into an automatic cycle of bag filling and
closing, as in the experimental machine.

Testing of the machine was confined to
packing 5-pound bags of oranges because of
their lead in shipments of Florida citrus fruit
in polyethylene net bags. The machine is adapt-
able, however, to other bag sizes, produce, and
applications.

DESIGN OF MACHINE

The bagging machine (fig. 5) is designed
to form bags from factory rolls of polyethylene
net tubing (fig. 6), fill the bags with produce,
and close and eject them in a continuous auto-
matic cycle. The machine consists of six main
parts: (1) an opening and gripping mechanism,

Figure 5.—Experimental model polyethylene net bag-
ging machine. Fruit supply conveyor and commer-
cial count-fill unit are in light tone at top. Supply
roll of polyethylene net tubing is on reel on the
floor at rear of machine. Triggering circuitry,
direct-current power supply for photoelectric con-
trol of top closing, and variable transformer are
in box on machine frame, lower right. The machine
is 65 inches high.

i

Figure 6.—A, Polyethylene net bag produced by ex-
perimental machine. B, Polyethylene film strip la-
bel attached manually for demonstration.

(2) a bottom-closing and cutting mechanism,
(3) a filling device, (4) a top-closing mechan-
ism, (5) an ejection chute, and (6) automatic
action controls.

Opening and Gripping Mechanism

At the end of the downward movement of
the gripping head, the four gripping fingers go
inside the end of the net tubing (figs. 7A and
8), which has been opened by popup action of
the spring-loaded top part of the internal
spreader inside the net tubing (fig. 9B). Simul-
taneously, the spring-loaded spreader top is
pushed downward by the gripping fingers to
a latched position. The spreader is now ready
to pop up when tripped by the solenoid-actuated
trippers in the next cycle (fig. 9A).

The gripping fingers, actuated by air cyl-
inders, open, stretch the end of the net tubing
to a rectangular shape, and press it against
nonslip inserts inside the frame of the grip-
ping head (fig. 8). The gripping head then
raises to its top position to provide the neces-
sary length for the bag and to have the open
top of the tubing in position under the chute
of the count-fill device (fig. 7B). During the
upward movement the spreader floating inside
the tubing opens it from the flattened and

4

wrinkled state in which it comes from the fac-
tory roll. The spreader floats just above the
stationary spreader guide ring and seat (figs,
7A, 9, and 10) as the upward movement of the
net tubing takes place. The weight of the
spreader in the experimental machine is 3.25
pounds (fig. 9), and the upward movement of
the gripping head is at a rate of approximate.
ly 54.7 feet per minute (21 inches in 0.032 min-
ute).

Bottom-Closing and Cutting Mechanism

The basic component of the bottom-closing
and cutting mechanism is a commercial air-
operated stapler (model HR-S Internationa]
Staple). The stapler is mounted on a swing
action arm, which moves it into position for
closing and cutting the tubing and then back to
clear the vertical movement of the gripping
head (figs. 10 and 11). Space limitations neces-
sitated positioning the stapler with the mag-
azine downward instead of in the normal up-
right position, and, lacking gravity feed, a
spring was added to push the staples upward.
An air cylinder provides power to swing the
arm. A part was made for the stapler head
with a larger V-shaped guide notch than that
originally provided, and a knife was attached
on the bottom surface (fig. 12). The knife is
powered by a separate air cylinder. A micro-
switch, actuated by the gathering arm that
moves with the knife, triggers the stapler when
the gathering action is completed and just ahead
of the cutting action. There was a tendency for
the material to slip upward and out of the
stapler before completion of stapling if cutting
was completed first.

Filling Device

A commercially made count-fill device (Pac-
Rite patented count bagger) was used to fill the
bags. The count type, which measures a preset
number of fruit into the bag, is generally famil-
iar in the Florida citrus industry, but various
commercial filling units could be used. An inter-
connection must provide a pulse to start the fill-
ing action when the gripping head is in the top
position holding the open bag and the bottom
closing has been completed. When filling is com-
plete, a pulse is needed from the filling machine
to continue the cycle.

(Continued on p. 10)

Vertical-action
gripping head
(opening and grip-
ping mechanism)

Commercial
count-fill
mechanism

Bottom-closing
and cutting
B mechanism

: Spreader guide

A ring and seat;
stationary (shown
only in one view)

Transfer belts
open Transfer belts

closed

Hinged
retarder flap

Figure 7.—Machine action sequence.

Gripping contact;
grooved fingers

Entry position
of fingers

Figure 8.—Opening and gripping mechanism. A, Pictorial view. B, Top view.

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LMA YY Y BRE
See eens Beene, Winer

Solenoid

Ye = Stationary
ress. guide ring
hi and seat

SUBASSEMBLY

Internal spreader, details and subassembly.

Figure 9.

0 ONO.

Electric motor, chain drive to trans-
fer belts

. Mechanism to swing transfer belt

arms open and closed

Magazine of top stapler; top-closing
mechanism not visible

Chute with retarder flap

Guide ring and seat for internal
stock spreader

Internal stock spreader
Trippers for spreader
Opening and gripping mechanism

Guide rods for vertical action of
gripping head

Bottom stapler; swing-action mount-
ing

Specially made V-notch guide plate;

gathering arm and stapler micro-
switch on top; knife underneath

Air cylinders

Figure 10.—Top and bottom parts of machine. Bottom shown in partially exploded view.

TOP-CLOSING SUBASSEMBLY

Actuates resistance-
wire carrier

; Open
Photoelectric cell position
light source
V-notch;
stapling

Hold-
transfer
position

Transfer belt arms; top view

Transfer
belt arms

Gathering arm

BOTTOM-CLOSING SUBASSEMBLY

Swing mounting
and air stapler

Figure 11.—Top-closing and bottom-closing subassemblies.

Wess. 2 :

Figure 12.—Bottom-closing stapler head. (1) Gather-
ing arm and microswitch on top of the specially
made V-shaped guide notch. (2) Knife on bottom
surface.

Top-Closing Mechanism

Transferring the filled bag from the grip-
ping head into a closing mechanism, obtaining
consistently satisfactory closure, and discharg-
ing the filled bag from the machine were the most
complex series of actions to incorporate into a
working mechanism. A commercially made air
stapler identical to the one used in the bottom-
closing mechanism, but mounted in a fixed po-
sition, is used as a basic component in the top-
closing mechanism. In addition, the mechanism
consists of transfer belts, a gathering arm to
push the material into the stapler notch, a photo-
electric cell control, and resistance wires (figs. 7,
11,and 18).

When the preset number of fruit are in the
bag, a pulse from the count-fill device causes the
transfer belts to swing together, pressing the net
material between them and moving the two re-
sistance wires into contact with the material at
each side. They then transfer the bag top from
the gripping head into the stapler (fig. 7D-F).
The gathering arm is triggered by the photoelec-
tric cell responding to the passing of the bag. The
movement of the gathering arm actuates the mi-
croswitch that operates the stapler (fig. 13).

Although the gripping fingers are released

10

when movement of the transfer belts starts, the
resistance wires melt the net material just below
the gripping fingers, thereby preventing the bag

from hanging on the fingers and hampering ac-
tion of the transfer belts. Transfer belts of more —

rugged construction and more powerful gripping
action might pull free material hanging on the
gripping fingers after they are released, thereby
eliminating the need for the hot wires.

Some difficulties in the top-closing mechan- |
ism were the result of improvising with equip-

ment not especially designed for this application.
One of the most persistent problems was lack of
consistent gathering of the net into the small
space required to have all the material encircled

in a staple. Timing was critical. The net hada ©

tendency to slide down if stapling did not take —
place within an instant after the material had —

been moved into the stapler by the transfer belts.
After attempting to trigger the action of the
gathering arm by a microswitch arranged for

actuation by pressure of the material as it was —
gathered into the stapler notch, the photoelec- |
tric cell and triggering circuitry were installed —
to provide better control. A commercially made

machine would not necessarily require a photo-
electric control for the top-closing mechanism.
Redesign of the transfer belts and gathering arm
and more tolerance in gathering all the bag top

Figure 13.—Top-closing mechanism (right) and open-
ing and gripping mechanism in raised position
(left), looking upward. (1) Resistance wires. (2) |
Gathering arm. (3) Special V-notch attachment on
stapler with slot to accommodate gathering arm |
movement. (4) Light source. (5) Photoelectric cell.

for catching in the staple (or whatever closing
means may be used) could allow the use of a
microswitch, a simpler and less expensive con-
trol than a photoelectric cell.

Ejection Chute

A chute tilts progressively as the transfer
belts move the bag toward the stapling mechan-
ism, reaching the fully tilted position (57°) as
stapling is completed. The bag drops clear of the
closing mechanism and slides down the chute
and onto a conveyor belt. The chute returns to
a near-horizontal position (17°) after the grip-
ping head has traveled to the top position with
the bag held open ready for filling and after the
bottom cutting and closing action has been com-
pleted. The inside end of the fully tilted chute
must clear the vertical travel of the gripping
head. As filling starts, the fruit flowing into the
bag causes the bottom of the bag to flip onto the
inside end of the chute, which provides support
as filling progresses (figs. 7 and 10).

A hinged retarder flap near the inside end of
the chute prevents movement of the bag bottom
when fruit falls into the bag and thus prevents
undesirable elongation and lateral construction
of the bag. The retarder flap is operated by a
separate, small air cylinder, and as the chute
moves toward the inclined position for discharg-
ing the filled bag, the flap drops down to make
asmooth surface (figs. 7D—F and 10).

Automatic Action Controls

Except for the previously discussed photo-
electric and microswitch controls, timing and se-
quencing of the actions in the cycle are accom-
plished by a high-torque, synchronous motor-
driven, single-cycle, multicam timer. The single-
cycle, rather than continuous, cam timer pro-
Vides a relatively simple way to connect the ma-
chine with the count-fill unit to obtain automatic
operation. A pulse from the count-fill unit starts
the timer when the preset number of fruit has
been delivered into the bag. The timer then runs
through the cycle, coming to a stop with the bag-
ging machine in readiness for filling the next
bag. The filling operation starts immediately by
a pulse from the timer to the count-fill unit.
Thus, continuous automatic action is obtained
(fig. 14).

The resistance wires in the top-closing mech-
anism are hot as long as the master switch of the

Figure 14.—Inside main control box. Cam timer at bot-
tom. Adjusting knob visible at left for variable
transformer (control of resistance wire temper-
ature) mounted in triggering circuit control box.

machine is on. A variable transformer in the cir-
cuit permits temperature regulation.

The actions of the machine are predominant-
ly powered by air cylinders. Solenoid-operated
air valves effect the necessary airflow as their re-
spective electrical circuits are energized and de-
nergized by the cam timer. Table 1 gives the
control arrangements for all actions performed
by the machine.

SUGGESTED DESIGN
MODIFICATIONS

Adjustment in Bag Length

The experimental machine cannot be ad-
justed to vary the length of the bag. In a com-
mercial machine, the length of stroke of the me-
chanism for raising and lowering the gripping
head should be adjustable to vary bag size (from
5- to 8-pound, for example).

Settling Fruit During Filling

In test operations fruit stacked up too high in
some bags and interfered with the transfer belts
and closing mechanism. A device to vibrate the
chute during filling and thus settle fruit in the
bag might overcome the problem. A small-ampli-
tude, powered vertical movement of the chute
fulcrum bar end supports, which would be made
and mounted to permit sliding action in a short-
distance range, might be used.

il

TABLE 1.—Machine actions and controls

Source of
Machine action control Actuation means
signal
Gripping fingers open and grip net tubing; Camitimenereeee sear 4-way solenoid air valve;

release tubing and close.
Raise and lower gripping head .

Swing bottom-closing mechanism: into action and

2 double-action air cylinders.
GI) coaonc ....... 4-way solenoid air valve;
2 double-action air cylinders.

CO EUTN Hs eee shed oe ae ee eter ces dOfaceaan ee 2 solenoid air valves per
cylinder; double-action
air cylinder.

Staple and cut bottom Cam timer Solenoid air valves; 1 for

Raise and lower chute

Raise and lower retarder flap .

Fill bag

Top closing:
Transfer belts swing action

Resistance wires sever net

Transfer belts operate ....
Gathering arm .

and microswitch.

Cam timer

Cam timer
(through transfer belts).

Gambttimena ee eee eee
Photoelectric cell! .........

single-action air cylinder
on gathering arm and knife;
1 for air stapler, which
operates on signal from
microswitch actuated from
gathering arm.

solenoid air valves per
cylinder; double-action air
cylinder.

do. _.... Double-action air cylinder
connected to chute air lines.

bo

iGO) soont oe _.... Count-fill device motor drive,

started by pulse from cam
timer, stopped by counter
and control circuitry of
count-fill device.

do _............. 2 solenoid air valves per
cylinder; double-action air
cylinder.

Transfer belts move hot wires
to action position; spring
return to clear position when
transfer belts swing open.

Electric-motor drive.

Solenoid air valve; single-action
air cylinder.

Pye Staplin pias sere: Microswitch Microswitch actuated by
gathering arm; solenoid air
valve for air stapler.

Tripping popup of internal spreader Cam timer . Solenoid with mechanical

linkage for actuating trippers
to strike spreader-latch lever.

oe ee ee ee BAe ae ees ee

1 Includes Schmidt triggering circuit.

Compensating for Twist in Factory-Roll
Tubing

The internal stock spreader occasionally
needed rotating about its vertical axis because
of the cumulative effect of twist in the polyethyl-
ene net tubing as it came from the factory roll.
Not enough tubing was used to provide reliable

information concerning the magnitude of this

=
bo

effect or whether it would be found in every roll.
When rotation of the spreader was needed, it
was done manually. A mechanism might be pro-
vided to rotate the internal spreader by action
upon the spreader guide ring and seat, which
would have to be mounted to permit turning
rather than rigidly attached as in the experi-
mental machine. The mechanism could act inter-
mittently and automatically.

Applying Label

The means to apply labels automatically will
depend upon the type of bag-closing device in-
corporated into a commercial machine. Given a
staple closure, preprinted polyethylene film strip
in rolls could be carried through the bagging
machine with the net tubing and stapled at each
end of the bag as part of the closure (fig. 6).
With the proper automatic closing unit, pre-
printed Kwik-loks could also be used.

Opening and Gripping Mechanism

To reduce the 65-inch height of the machine,
the gripping head could be made stationary; the
guide ring and internal stock spreader would be
raised and lowered instead. Popup action of the
spreader top would open the end of the tubing,
as in the present mechanism, with the tubing
moving up and around the gripping fingers, in-
stead of the fingers moving down and into the
top of the tubing. With the material opened and
held by the gripping fingers, the guide ring and
internal spreader would travel downward.

A mechanical drive to raise and lower the
gripping head might replace the air cylinders
used in the experimental machine. Cams might
be incorporated in the drive to provide sequen-
tial timing for the different actions in the cycle.
The separate motor-driven cam timer used in
the experimental machine would then be unnec-
essary.

Top-Closing Mechanism

If a staple closing mechanism is used for the
top of the bag, transfer belts should have effec-
tive gripping action on the bag top for an
appreciable distance beyond the end of the
gathering notch. This is important in respect to
catching all of the material within the staple
consistently, in addition to eliminating undesir-
able downward movement of the bag before the
stapling action takes place. These were signifi-
cant problems in the experimental machine.

Simplifying the control for triggering the
top stapler by eliminating photoelectric compo-
nents should be further considered. There ap-
pears to be a good possibility for sensing by me-
chanical action, employing a microswitch ar-
rangement, the point at which the material has
been fully gathered and pressed into position for
the stapling or other action—with adequate
clearance in the notch for the material.

ECONOMIC ASPECTS OF
AUTOMATIC BAGGING MACHINE

To compare the economics of the widely used
semiautomatic count-fill equipment and the auto-
matic bagging machine, the annual cost of bag-
ging 125,000 master cartons of oranges in 5-
pound polyethylene net bags by each method was
determined (tables 2-6). This output, represen-
tative of medium-size Florida citrus packing-
houses, is based on four semiautomatic filling
and closing stations (units) and two automatic
bagging machines.

TABLE 2.—Cost of bagging oranges in poly-
ethylene net bags and packing in master car-
tons by semiautomatic and automatic meth-
ods

{125,000 master cartons of 5-pound bags per year}

Semi-
automatic Automatic Difference
Cost item method method (saving)
Equipment ownership
and operation! $3,046.41 $9,804.31
Labor? 7,095.37 4,946.98
Bags 27,500.00 414,383.32
Staples’ 980,00 1,960.00 ae
Total 38,621.78 431,094.61 $7,527.17

1 See tables 3 and 4 for breakdown of ownership and
operating costs.

* See table 5 for breakdown of labor costs.

3 See table 6 for breakdown of bag and staple costs.

* Includes polyethylene film label strip.

The production rate of 37 master cartons per
man-hour or per unit (filling bags, closing, and
master-cartoning performed by operator at each
station) for the semiautomatic method ties in
with the rate for size 252 oranges* given in an
earlier report (7)—39.28 master cartons per
productive man-hour or 35.71 per total man-hour
of the crew which, in the crew organization used,
included a small amount of enforced “wait for
bags” by the bag closer and master carton pack-
ers.

For the proposed automatic form, fill, and
close machine, in a commercial production mod-
el, 60 master cartons per machine-hour (8 bags
per minute) was judged reasonable for com-
parative cost relationships. The experimental
model operated at 5 cycles per minute (1 bag per

5 Before change to size designation 125 based upon
4/5-bushel carton.

13

cycle), which is 37.5 master cartons per ma-
chine-hour. None of the research effort was
focused on increasing the speed.

A saving of $7,527 per year can be realized
with the automatic machine (table 2). This
amounts to $60.22 per 1,000 master cartons, or
19.5 percent of the total annual cost of the semi-
automatic method. On 31 million bags, the total

for citrus fruit shipped in polyethylene net bags
from Florida in the 1970-71 season, this would
amount to a saving of better than $233,000. Al-
though it costs more to own and operate and
requires twice as many staples, the automatic
machine saves on the costs of labor and bags.
Similar savings could be expected for other pro-
duce suitable for machine bagging.

TABLE 3.—Annual ownership costs for equipment?

Initial Expected
cost per life
Equipment unit (years)
Return-flow belt, 18” x 20’
and 12” x16’ $1,662 10
Semiautomatic count bagger 1,900 10
Air stapler .. PERE Ce arate 250 10
Packing stands, folding 38 15
Container takeaway conveyor, 25’ 1,550 15
Automatic net bagging machine
with count-fill device 16,000 10
Closed bag conveyor, 25’ 1,156 15
Skate-wheel conveyor, 3’ 17 10
Carton chute, 30’... ae ; 188 15

Interest? Insurance and

Depreciation (7%) taxes (4%) Total
$166.20 $63.99 $66.48 $296.67
190.00 73.15 76.00 339.15
25.00 9.62 10.00 44.62
2.53 1.42 1252 5.47
103.33 57.87 62.00 223.20
1,600.00 616.00 640.00 2,856.00
77.07 43.16 46.24 166.47
1.70 65 .68 3.03
12253 7.02 Weow 27.07

1 Costs derived by increasing the cost of items (excluding semiautomatic count baggers and air staplers) given
in an earlier report (7) by 25 percent to compensate for rising prices over approximately 10 years; ratio of ir-
crease based upon ratio of index for 1971 to index for 1960, machinery and equipment, wholesale prices, Survey of Cur-
rent Business, by U. S. Department of Commerce. Vendor prices in 1972 were used for the excluded items.

2? Computed on the average of the values at the beginning of the first and last years of estimated life.

TABLE 4.—Equipment ownership and operating costs for semiautomatic and automatic bagging
methods
{125,000 master cartons of oranges in 5-pound bags per year}

Operating cost

Ownership Mainten- Total cost No.
Equipment cost Power! ance? Total per unit units Total
SEMIAUTOMATIC COUNT-FILL METHOD

Return-flow belt, 18” x 20’
and 12” x16’ $296.67 $44.41 $43.94 $88.35 $385.02 1 $385.02
Semiautomatic count bagger 339.15 6.34 146.10 152.44 491.59 4 1,966.36
Aaristapler eastern eee ee aoe 35.00 4.22 9.22 53.84 4 215.36
Packing stand, folding ...... 5.47 4.50 4.50 9.97 4 39.88

Container takeaway

conveyor, 25’ 223.20 70.50 LAT22 187.72 410.92 1 410.92
Carton chute, 30’ 27.07 1.80 1.80 28.87 1 28.87
Totall24 reps Ts I ee tea ARRy ee REN Pg NOEL al eke nae 3,046.41

—

4

AUTOMATIC FORM, FILL, AND CLOSE METHOD

Return-flow belt, 18” x 20’

PG ee CLG! .......24en-)2'$296.67 $54.62 $54.18 $108.80 $405,47 1 $405.47
Automatic net bagging ma- 7.80
chine with count-fill device 2,856.00 34 35.00 i 1,667.20 1,710.00 4,566.00 2 9,132.00
Closed bag conveyor, 25’ 166.47 31.21 36.16 67.37 233.84 1 233.84
Skate-wheel conveyor, 3’ 3.03 offal 71 3.74 1 8.74
Carton chute, 30’ 27.07 2.19 2.19 29.26 il 29.26
Total He Se 9,804.31

1 Based on $0.03 per kilowatt-hour and ratio of 1972 hours of annual use to hours annual use in reference 7 except
for compressed air, which is based on estimate.

2 Based on percentage of initial cost per 100 hours of operation given in reference 7 except for automatic machine,
for which relationship was estimated.

3 Compressed air; estimated.

TABLE 5.—Labor requirements for bagging oranges by semiautomatic and automatic methods
{125,000 master cartons of 5-pound bags per year}

Avg. prod.rate Prod. man-hours
Crew-equipment per man-hour per 100 Total prod. Elapsed Hourly Total labor
arrangement (master cartons) master cartons (man-hours) hours wagel cost

SEMIAUTOMATIC COUNT-FILL METHOD

1 worker per station,
4 stations 37 2.7038 3,378.75 844.69 $2.10 $7,095.37

AUTOMATIC FORM, FILL, AND CLOSE METHOD

1 attendant per 2

machines 120 0.833 1,041.25 1,041.25 $2.65 $2,759.31

1 worker for master { 2.626 2782.50 |
eartoning 120 | 3.207 9258.75 { 1,041.25 2.10 2,187.67
Total for automatic 4,946.98

1 Based on 1972 rates.
? Based on 6.26 man-hours per 1,000 master cartons of 5-pound bags from earlier work (7).
8 Wait for bags from form, fill, and close machines.

15

TABLE 6.—Cost of bags and staples for oranges packed by
semiautomatic and automatic methods
{125,000 master cartons of 5-pound bags per year}

Amount
(millions)

Cost per

Item 1,000 Total cost

SHMIAUTOMATIC COUNT-FILL METHOD

Purchased bags . 1 $27.50 $27,500.00 |
Staples ......... il 98 980.00

Total omens a ries rete a Maer N ta oe 28,480.00 |
rr f

AUTOMATIC FORM, FILL, AND CLOSE METHOD

Net tubing in roll ie (4) 2$5.20 $9,533.32

(1)

(2)

(3)

(4)

(5)

16

Polyethylene label strip,
14%”, 22” pieces?

no eRe

4.85 4,850.00
98 1,960.00
16,343.32

1 1,833,330 ft. (22” per bag).

? Cost per 1,000 feet of net tubing.

* Price furnished by E. I. du Pont de Nemours & Co. includes print-

ing 1 color on white.

LITERATURE CITED

ON A MOVING CONVEYOR. U.S. Dept. Agr., Agr. |

FLORIDA CITRUS COMMISSION.

1967. CONTAINERS FOR CITRUS FRUITS. Reg. 105-
1038 See. (1)¢e. Amended 12/6/67.

FLORIDA DEPARTMENT OF AGRICULTURE AND CON-
SUMER SERVICES.

1971. 1970-71 SEASON ANNUAL REPORT. 88 pp.
GRIERSON, W.

1966. CONSUMER PACKAGES FOR FLORIDA CITRUS
FRUITS. Fla. State Hort. Soc. Proc. 79: 274-280.

1968. CONSUMER PACKAGING OF CITRUS FRUITS.
Presented at International Citrus Symposium,
California. 10 pp.

BENNETT, A. H., AND BOWMAN, E. K.
FORCED-AIR PRECOOLING OF CITRUS FRUIT

1970.

Res. Serv. ARS 52-40. 17 pp., illus.

(6) AND HAYWARD, F.. W.

1967.

80: 237-241.

(7) GRIZZELL, W. G.
1963. FILLING POLYETYLENE FILM BAGS WITH
CITRUS FRUIT. U.S. Dept. Agr. Agr. Marketing
Serv. AMS-503. 30 pp., illus.

(8) SouLE, J., AND GRIERSON, W.
1972. FORCED-AIR PRECOOLING OF FLORIDA OR-

ANGES, ‘TEMPLES’, AND GRAPEFRUIT IN SMALL COD- |

TAINERS. Amer. Soc. Hort. Sci. Proc. (in prep-
aration).

SIMULATED MARKETING TESTS WITH PRE- |
PACKAGED CITRUS. Fla. State Hort. Soc. Proc. |

sm