Journal of Scientifi c & Industri al Researeh

Vol. 62. April 2003, pp 3 11 -3 18

Paper and Corrugated Boxes from Cotton Plant Stalks for Effective Packaging of Oranges

A J Shaikh and P V Varadarajan

Central Institute for Research on Cotton Technology, Adenwala Road, Matunga, Mumbai 400019

and

M S Ladaniya" and Shyam Singh

National Research Centrc for Citrus. Amravati Road , Nagpur 4400 I 0

Recei ved: 02 December 2002; accepted: 10 February 2003

Cotton plant sta lk an abund antl y ava ilable agro-waste material was successfull y tri ed out as a substitute for wood in the manufacture of co rrugated fibre board boxes for packaging of fruits. A process was stand ardi ,ed to prepare good quality kraft paper from Cotton plant stalk s. The process was worked out by conducting large-sca le tri al in a paper mill . Corrugation trials were success full y conducted on the kraft paper prepared. The co rrugated boxes of desired size and designs were prepareLi and evaluated for various properti es. Suitability o f these boxes for packaging of fru i ts li ke oranges was assessed through simulated laboratory as well as actual transport ati on tria ls. Detai ls of the laboratory and the mill tri als. simulated and actu al packaging and transportation trial s with oranges are presented and discussed in thi s paper. Results inLli ca ted that good qualit y kraft paper suitable for manufacture 01' CFB boxes can be prepared from cotton plant stalks. Uniform chipping of stalks and kraft l iquor concentrati on of 18 per cent produced kraft paper with desired properties. The techno-economic feasibil ity worked ou t by conducting large-sca le tri al in a mill indi cated that the box prepared from cott on plant stalk kraft would be cheaper than that of commerciJll y available box. Corrugated boxes were l ighter in weight than wooden boxes and hence more CFB boxes could be transported thus reducing frei ght per box. CFB boxes prepared from cotton plant sta lk kraft paper possessed des irable bursting and compress ive strength . Laminat ion of CPS box with polypropylene fil m from outer side fu rther improved strength and ability of these boxes to withstand moisture during prolonged coo l storage under high humidit y conditions. Results of the simulated and actual packaging and transportation tri als demonstrated sllit abilit y of corru gated fibre board boxes for packaging, transportation and storage of agpur-mandarin oranges.

Introduction

Abou t 15 Mt of cotton plant stalks (CPS) are produced every year in India. To a limited ex tent , these stalks are utili sed as domestic fu el in ru ral areas, whil e the bulk of it is disposed off by burning in the fi e ld itself. CPS is rich in cellulose and is much similar . to hard wood in fibre dimensions. Hence, it can be a potenti al raw material for the preparation of pulp and paper. Use of CPS in the preparation of kraft paper for the manufacture of CFB boxes for packaging of fruit s and vegetables has not been attempted earlier.

' Nagpur' mandarin (Cilrus reliculala Blanco) is a commerc iall y culti vated orange in central India as a cash crop. The production of thi s orange exceeds 5

* Corresponding author

lakh t/y. Wooden box is commerc ia lly used for packaging and transport of the orange and post­harvest losses of these frui ts in wooden packaging are fairly hi gh. These losses can be minimized to a considerable extent by adoption of better materi als . The CFS boxes are most idea l for packaging of oranges due to the ir li ghter weight , foldablility and the resu ltant ease of storage. However, CFB is cost ly due to the hi gh cost of kraft paper manu fac tured from wood pulp. The manufacturers of both the wooden boxes and CFB boxes are depend on the forest resources for the ir raw materia l requirements ' .

There ex ists, therefore, an imperative need to switch over to more viabl e non-conventional and eco­fri endl y li gno-cellulos ic raw materials li ke CPS fo r the manufacture of kraft paper.

The present stud y is aimed at development and evaluation of CFB boxes frolll kra ft paper of CPS for

3 12 J SCI IND RES VOL 62 APRIL 2003

packaging of Nagpur-mandarin oranges. These boxes were also compared with wa x coated CFB boxes made from commerc iall y ava ilable kraft paper.

Mater'ials and Methods

Dry CPS of Hybri d-4 cotton procured from Central Institute for Cotton Resea rch, Nagpur were used. All the che mi cals Ll sed in the laboratory scale trials wen: of analytica l reagent grade, while the commerci;.:1 grade chemica ls were used in the mill trial. All amdyses were done as per TAPPI standard test meth ods".

S f{/I/.dordisot ion o{ ,oil /ping Conditions

Laboratory scale trials were conducted :0 standardise cook ing condi tions Cor the preparation of kraft pulp from CPS. Oven dr ied (00 ) 300 g chips of CPS were digested in a rotary di gester with 14, 16, 18 or 20 per cent kraft li quor as Na/J based on OD we ight of the raw materia l, at a materia l:liquor rat io of I :3, at 160 DC fo r 3 h (including I h to raise the temperature of the digester contents to the cooking temperature, 160 "C) . The di ges ted mate ri al was dis integrated and washed thoroughl y to remove bl <1c k liquor and unreacted chemi cals. The pulps were then beaten in a va lley beater to get the pulp of required freeness [250 CSF (Canad ian Standard Free ness)] and then si eved through a Somervill e fl at screen to re move the uncooked material s and fibre bu ndl es.

Shee t Making {lnd Tes ting

Standard pape r sheets of 60± I g/m2 were prepared from the pu lp on a Briti sh standard sheet ma king machine. The paper sheets were dried in air and then tes ted fo r va ri ol.l s propert ies I.Isi ng TAPPI standard tes t meth ods under specified conditi on s ~ .

Lo rge 5co/(' Trio ls in 0 Paper Mill

Subsequent to the laboratory trial s, one large sca le trial was conducted ill a paper mill at selected concentrati on of kraft liquor where better pulp yi eld as we ll as bett er properties of paper were obtained.

PlIlping

About 15 t chips of CPS were converted into kraft pulp in four batch diges ti ons, the detail s of wh ich are gi veil below:

About 3 t of 00 chips of CPS were di gested ill a rotary di gester (29 m3 ca pacity) with 18 per cent kraft

liquor as Na20 on 00 CPS weight bas is at 20 per cent sulphidity, at 160 "c for a total peri od of 4 h, including 2 h spent in raising the temperature of the c1i gester from room temperature to the cooking temperature of 160 "c. The material to liqu or rati o was I :2.5. The cooking co nditions in the miil trial had to be 11l0dified as in the laboratory scale trials the material was cooked with electricall y heated system whil e steam was used for cooking in mil l trial s. The cooked material was re fin ed in a di sc refin er in two passes at 1St hou and 5 th ou clearances ( I th ou= I/I OOO in) and was hed thoroughl y in mechanica l washers and then beaten in a valley beater to obtain pu lp of des ired freeness (250 CSF). Subsequently, the beaten pulp was screened to remove the uncooked CPS chips and fibre bund les and then transferred to the storage tank .

Preparation of Kraft Paper

The pulp was transferred from the storage tank to the stock preparati on chest where it was mixed with 2 per cent ros in, 2 per cent alul1l and J per cent dye. The stock was su bjected to furth er screening to remove uncooked chips, if any, which escaped in the initi al screening. Kraft paper of 100 and 120 g/m2 was prepared on a Pourdrinier paper makin g machine. The kraft was eva luated fo r va ri ous strengt h properties empl oy ing standard test methods2

. ~

Corm galiol1 Trials, /vIanujclclllre olld Spec!licatiolls (~l Corm gafed Boxes

Corrugation tri als on the kraft: paper thus obta ined were carri ed out sati sfactoril y in a local fac tory on a Mini Make Corrugating 1achine. The corrugated fibre boards of 5 ply were prepared and converted to te lescop ic type CFB boxes . Some CPB boxes were laminated on the ex ternal surface with po lypropylene film . These CFB boxes a long with wax coated te lescopic type boxes made from commercially used kraft paper were evaluated for van ous properti es such as bursting strength , compression strength , cobb test, etc.

The design specifi cations of the boxes were suppiied by the National Research Center for Citrus , -agpur. Two piece wax coated te k~scopic boxes,

from commercia l kraft paper were designed and gOI manufactured by National Research Center for Citrus at Nagpuf. The comparati ve specificati ons of corrugated boxes are given in Table I.

SHAIKH c/ al. : PAPER & CORR UGATED BOXES FROM COTION PLA NT STALKS 3 13

Packaging and tests of the boxes

Packaging

Mature Nagpur-mandarin fruits were packed in CFS boxes made from (i) CPS kraft paper (220 un­laminated and 55 laminated boxes), and ( ii ) commerc ia ll y used kraft paper (220 wax coated boxes) In layers separated by 3 pl y CFS vented dividers which prov ided cushi oning to fruits . After c los ing the polyethylene line rs at the top , the upper flaps of boxes were c losed with 50 mm wide synthetic tape . Vented polyethylene line r was placed before packaging fruits JI1 boxes. Thirty one wax coated boxes were packed with fruits In the conven tiona l way using rice straw as the cush ion ing mate ri a l in stead of CFS dividers and polyethylene liner.

Simulated Lahoratory Transportatioll Tests

To evaluate transport worth iness, the packed CFB boxes of a ll types were su bjected to vibration , inclined impact and drop tests at the Indi an Institute of Packaging, Mumbai. After comp leti on of a ll the tes ts, observations on the condition of the CFS boxes and packed rrui ts were recorded.

TrWlsporta ti(J/! and Evaluation

CFS boxes packed with fruits as above were arranged in a truck , the dimensions of the deck be ing

5 10 cm x 210 cm x 2 10 cm (stack he ight was about 240 cm) . In a ll , 506 boxes, weighing more than 9 1

were transported from Nagpur to New Mumbai covering a tota l di stance of about 800 Km in 48 h. The physical condition of the boxes and fruits were evaluated at the destination .

Performance of CFR Boxes in cool storage

Seven boxes of each type packed with fruits were stored by stacking up to a he ight of 2 10 cm in a coo l chamber at 6-7 "c and 85-90 per cent relative humidity (RH). The damage to the CFS boxes due 10

bu lgi ng and compression was noted.

Ecol1omicfeasibility of box manufacture and econolllics of t ransporlat ion

For producti on o f one tonne kraft pape r from CPS, the economics was worked out. The cos t of CFB boxes obtained from one tonne kraft paper was calculated and cos t per piece (box) was worked out. The cost 01" commerc ia ll y avail ab le CFS box of

Tabl e 1- Comparative speci fi calions of corruga ted boxes

Specificalion

I Box slyle

2 Number or

ply

3 Flute or cor-

ruga ti on

4 Inner dimen­

sio ns (cm)

5 Outer dimen­

s ions (cm)

b Aeration

vents

7 Lamination/

coating ror

waterproo ling

8 Fru it ho lding

capaci ty

S) Weight or

e mpty box at

27 "C, 65 per

cenl RI-I, kg

10 Gross

wei ght , kg

I I Graillmage

or kraft paper

used for various

plies o r the box

Boxes made rrom kraft paper rrom

C PS , non - CPS, poly- Comlllerci;]1

laill inated

Two piece,

telescopic

5

B Ilute, ve;1i­

ca l

48.5 x 2R.S x2.8. S

50.0 x 30.0 x

30.0

3.93 per cent

on sides (4

long sl it s, 8.5

cm x 1.75

em); 1.65 per

cent on ends

( I sli t, 8 cm x

1.7 cm)

propylene

II I III lami ­

nated

Two piece .

te lescopic

5

B Ilute. ver-

tical

4B.5 x 2X.5

x28 .S

50.0 x 30.0 x

30.0

3.93 per cent

on sides (4

long ~; Iit s, 8.5

cm x 1.75

cm); 1.65 per

cent on ends

(I s lit; 8 cm

x 1.7 Clll)

Two piece.

te lescopic

5

13 Il ute.

verti cal

48.5 x 28 .5

x28.5

50.0 x 30.0

x 30.0

4.53 per

cen t on

sides (3

long sl it s.

15 cm )( 1.5

elll ) I .D

per cent on

ends (I slit:

ISclllxl.5

Clll )

No la lllin <l- Polypropyl- PararIln

tion ene outer wax coated

Side on the ou te r

s idc

112 large si7.e I 12 large I 12 large

rruils (28 cm size rruit s si7.e rruits

x 4) 160 (28 ("m x 4) (28 Clll x 4)

medium ~ ize 160 Illedium 160 IllC-

rruit s (32 CI11 size fruits diulll si7.e

x 5) (32 Cill x 5) rruib (32

em x 5)

I. 06 l. I 0 I .40

20.00 20.00 20.00

120- I 00- 120- 120- 100- 100-80-

100- I 20 120- 100- I 20 100-80- 100

12 Cost of box , 15.72 17.72 27.0D Rs

s imilar s ize was a lso obtained fo r comparison. In oruer to compare the economics of t ransport~ti on of

314 J SCI INO RES VOL 62 APR IL 2003

CFB boxes from CPS kraft vis-a-v is conventional wooden box , prevai ling costs were taken into account. O n the basis of lOt load in the truck, number of boxes transported and freight per box was

al so worked out.

Results and Discussion

Properties (?f pulp

T otal yie ld of pulp decreased from 59.2-45.3 per cent with the increase in the che mica ls charged ( 14-20 per cent , Tab le 2) . However, the screen rejects, an important quality parameter of pu lp showed a reverse trend . The 14 per cent kraft pulp recorded the hi ghest rejec ts ( 10.8 pe r cent) fo llowed by 6 .3 pe r cent for 16 per cent kraft pulp and then almost nil rejects for 18 and 20 per cent kraft pulps . The quality of pu lps obta ined using 18 and 20 per cent kraft liquor was superi or as indicated by nil rej ects and hi gher bri ghtness leve l. The .rejects were probabl y due to the non-uniform cooking on account of variati on in the chip s ize. There fore, by ensuring uniform chip size it may be possibl e to o btain kraft pu lp o f fa irly good

quality.

Properties (~l Paper Sheets

Physical properti es o f the paper as prepared from pu lps detailed abo ve showed a gradual improvement with the increasing kraft liquor concentration employed (Table 3) . The tre nd was seen up to 18 per cent kraft liquor onl y and thereafte r a downward trend was observed. Thi s could probabl y be attributed to the degradati ve action of c hemical s on the fibres at hi g her chemi cal concentration .

Tahl e 2 - Propert ies o r kra ft pul ps at dillerent chemi cal

concentratio ns

Propert y Pul p, per cent

14 16 I ~ 20

Tota l yie ld , per cent 59.2 53. 1 50.6 45.3

Screened yie ld , per 45.6 46 . ~ 50. 3 45 .3

cent

Rejects, per cent 10.X 6.3 0 .3 Nil

Ini ti al CSF 579 506 435 370

Final CSF 250 250 250 250

f ree Alf.. ali, giL T races 1.7 7 . ~ 10.9

Kappa No. 4 1.2 33.3 29.5 2 1.0

Brightness. per cent 43 54 59 62

However, the overa ll qua lity of the paper produced re mai ned satisfactory .

Properties of Kraft Pulp and Paper Prepared ill Mill Trial

T he qua lity of pulp from large scale tria ls though satisfactory , was found to be marginally inferior as compared to the one produced in the laboratory scale tr ial s, as indicated by higher level of rejects and the high kappa number (Tab le 4) . This might be due to improper cooking of CPS on account of the variation in chip s ize. About 10- 15 per cent chips with larger ch ip size were hard cooked , resu lting in the generation of shives as rejects , and even then the yie ld of pulp was found to be higher than that in the laboratory scale trial. The strength prope rties of the kra ft paper prepared in the mill tri a l were slightly infe rior to those pre pared in the laboratory tria l using 18 per cent kraft liquor (Table 5) . It might probably be due to the non­uniform cooking due to variation in the CPS c hip size. However, as stated earlie r the use of unifo rm s ize chips could resu lt in improved quality kra ft

paper.

Tabl e 3 - Properties o f kraft pape r sheet, prepared in

laborato ry tri als Propert y Kraft Liquor, per cent

14 16 IX 20

Pulp CSF 250± 1 250± 1 250± 1 250± 1

Bas is wei ght , glm2 60± 1 60± 1 60± 1 60± 1

Breaking length , m 2670 2802 43 12 3 117

Burst ractor 15 .3 19.8 28. 3 12. 1

Tear racto r 87 .3 103.0 106.3 5 1.1

No. or double fo lds, mr r 9 2 1 42 7

Table 4 - Properti es o r I ~ per cent kra ft pu lp prepared in

mill tri al

Property Value

Total yie ld , per cent 65 .8

Screened yield , per eent 52.7

Rej cts, per cent 13. 1

Initi al CSF 725

Final CSF 250

Free Alkali , giL 9 .2

Kappa No. 41. 2

Brightness, per cent 48 .2

-f-

~

~

A

SHAIKH el al.: PAPER & CORRUGATED BOXES FROM COTrON PLANT STALKS 315

Properties of CFB boxes

The CFB boxes made from CPS (laminated or un-laminated) possessed all the des irable strength properties as specified by the Bureau of Indian Standards and they were sli ght ly supe rior as compared to the wax coated CFB boxes made from commercially available kraft paper (Tab le 6). Lamination could improve the strength properties of the CFB boxes made from CPS .

Simulated Lahoratory Transportation Trials

There was no damage to fruits and CFB boxes during inclined impact and vibration tests (Table 7). Tn drop test - the most severe of all tests used - the un-laminated boxes made from CPS kraft paper suffered no damage, although a few packed fruits were ruptured upon five drop impacts on vari ous corners, ends and bottom of the box. Laminated boxes made from CPS kraft pape r and wax coated boxes suffered s light damage at the corners due to drop impacts resulting in rupture of a few fruits.

The performance of boxes can be improved by stapling of flaps of top and bottom piece of these

Table 5 - Properti es of kraft paper prepared in mill tri al

Property 100 g/m2 120 g/nl

Pulp CSF 250±1 250±1

Breaking length , m 3210 3360

Burst factor 21.1 22.4

Tear factor 43 42

No . uf (Iouble fo lds, mfT 12 12

Cobb test va lue. g/m2 for 30 min 20 20

Table 6 - Strength properti es of corrugated boxes

Property

I. Bursting strength

5+5 pl y, kg/cm2

2. Cumpress ion

st rength , kg

3. Cobb test valuc.

g/m2 for 30 min

Box made from kraft paper

CPS ,

non­

laminated

16.50

432

106

CPS ,

polypro-

pylelle

filllllami -

nated

19.00

460

Nil

Co III Ille r-

cia ll yavail -

ablc, wax

coated on the

outs ide

12.00

345

50

te lescopic boxes for bette r grip as compared with that o f adhesive tape. The CFB box made from commerc ial kraft paper had lower bursting and

Table 7 - Simulated lransport worthiness leslS wilh Nai! pu r-manda rin ora'lges

Type of CFB

box

1'1:51

CPS kraft Inclined

(polypropylene impaci (6

film lami­

naled)

impacts one

on each face

excepltop &

bOil om)

Vibralion

( 120 cpm:

2.:;4 em)

Drop (:;

51:quential

drops from

90 cm

heighl )

CPS kraft Inclined

paper (wilhoul impaci

Iaminal ion)

Commercially

ava ilab le

(waxed out ­

side).

Vi bralion

Drop

Inclined

impact

Vlbral ion

Drop

Ex lernal ob-

servali on

o damage to

box

In iernal obslTva-

lion

No darnage: 10

fruil

No damage: 10 No damage: I I)

box fruit

Box lorn ncar Two fr uils rup-

bollom & edge lured and eigh l

nearl y:\-4 frui ls softened

inchl:s ill iOlal oul of 160 fru ils

:; dro ps, '0

spillage of

fru it

o damage to

box and lape:

No damagl: to

box & tapl:

No damage 10

fruit

No damage 10

frui l. CFB di ­

vidl:rs slightly

damaged.

o damages 10 No major dam-

box and lapl:

No chunagc 10

box and tapl:

No damagc 10

box and lapl:

Box lorn ncar

age Fi vc fruit s

ru plured and

four fruil s sof­

lened out of 160

No damage III

fruil

No damage 10

fruit: l ply CFB

di viders slightly

cru shed

Fi ve fruil s rup-

l:nd aboul 4" lured and :;

ncar hand hole fruil s soncl1l'd

slol .No spill - out of 160

ag'; o f fruit

J SCI IND RES VOL 62 APRIL 2003

compress io n strength, as compared to CPS boxes.

The study has indicated that CFB boxes of 50 L x 30

W x ]0 H c m size with 16 kg/cm2 bursting strength and near ly 4]0 kg compress ion strength suffered the least da mage in simulated lab tests and these hoxes can w ithstand the transport hazard s.

DYllamic Transportation Trial

O ut of 506 boxes transported in a truck from Nagpur to Mumbai none of the boxes (made from C PS paper as well as commerc ia ll y used kraft paper) were found damaged due to compress ion (Table 8) . Al l the three types of w ntainers had su ffi c ient strength and stack ing stab ility to withstand impac ts, vibrati ons and bouncing which occurred during actual transportation at the rear, middle and front side. There was no load shi fting and damage to boxes as there was no gap between box stacks and also between box stacks and truck body pane l.~ on the s ides. The load was compact due to uniformity in box size and compati bi lity w ith truck dimens ions. Some

s

Tah le X - Conditi on o f CFI3 boxes and orangc fruit ancr

transport in a truck lrom Nagpur to cw Mumbai

Type of box o . o f No. of hoxes with

No hoxes COJllprcs- Slight

Fruit

rup­

ture

or

2

2

Two pi ccc,

telcscopic, 5

pl y (non­

laminatcd)

220

Two pi ccc, 55

tclcscopi c, 5

ply, (Po lypro·

pylcne li lm

laminated)

Two pi ccc,

telcscopic, 5

ply, packcd

wi th polycth­

ylenc lincr in

thc hox

Two pi ece,

telescopic 5

ply, packed

wi th ri ce

straw cush­

ioning

220

3 1

sion dam- press-

age ing

Nil 8

Ni l 4

Nil 30

Nil 5

pres

sing

Nil

Nil

Nil

Nil

of the boxe::; were found slightly pressed from the top in a stack. These boxes were pressed at the top due to the gap in top fruit layer and upper flap and also due to settling of fru it in the box during tran c it. However, no physical injury to the fruits due to ruptu re, pressi ng or crush ing was observed.

Storage Studies

All the three types o f CFB boxes stacked to a he ight of 270 cm in a re fri gerated cool c hamber with 85-90 per cent RH withstood the load and there was no collapse, breakdown or compress ion damage. Non­laminated boxes made from CPS kraft pape r we re found s lightly bulged at the bottom of the stack but there was no damage to fruits (Table 9) .

Economic Feasibility of CPS Kraft Paper Box Manufacture

The process of paper and box manufacture fro m CPS was technica ll y feasible, as evident from the trials conducted in the paper mill on large sca le . Process was a lso economica ll y viab le (Tabl e 10). The cost of I t kraft paper from C PS was Rs 8075/- and 800 boxes (50 x 30 x 30 c m s ize) can be made fro m this paper costing Rs IS .72/box . The lamination of po lypropy lene on outer side of the board increased the cos t by Rs O.SO/box. The cost of corrugated boxes of simil a r s ize from commerc iall y ava ilable kraft paper with paraffin wax coating on ly on the outer s ide was Rs 27. This indicates that CPS kraft paper boxes are more economical than commercia ll y avai lab le CFB boxes of si milar size and strength .

----------------Tab le l) - Condition of CFB hox tilled with Nagpur-mandarin

orange Fruits during storagc at 6-7 "c and 85-90 per cent RH

for 75 d

Type ofCFB

box

CPS kran

(polypropylene

lilm lami -

nated)

CPS kraft

(non-

laminated)

Commercial

kraft , (wax

outside)

Number

of boxes

Boxes

co llapsed

and stack- or com-

ing hcight

7 boxes,

2 10 cm

7 hoxes,

2 10 cm

7 boxes.

210 em

prcssed

Nil

Nil

Nil

Boxes Damage

hu lged to fruit s

i l Nil

2 Nil

N il Nil

SHAIKH el a l. : PAPER & CORRUGATED BOXES FROM COTTON PLANT STALKS 317

Tabl e 10 - Economic feasibilit y of paper and box from CPS

Prod ucti on cost of one tonne kraft paper

Cost of production of kraft pulp

Cost of stock preparati on

Cost of co nversion of pu lp to paper

Overheads

Cost of one ton ne kraft paper

Detail s of corrugated boxes

Two piece, telesco pi c. 5 ply, B Ilute verti cal

Inner dimensions

Outer dimensions

Aerati on vent s

Capacity of boxes

Weight of two piece telescopic box

Gross weight with fruit s

Grammage of kraft paper used, gfm2

No. 01' boxes from one tonne kraft

paper

Cost of production of corrugated boxes

Cost of one tonne kraft paper

Cost of corrugation and box mak ing (for SOO boxes)

Cost of SOD hoxes

" Appro ximalt: cost of one box

*Approximate cost of one box with

pl ypropylene lilm laminat ion

* Approximate cost of similar size commen:iall y avail ahle box with wax

coali ng

Rs 4963

Rs 534

Rs 1275

Rs 1303

Rs 8075

48 .5 x 28.5 x

2S.5 cm

50.0 x 30.0 x 30.0 cm

3.93 per cent

of side areas pu nched with

4 long slit s (S.5 cm) 1.65

per cent of area at ends

punched with one slit (S x

1.7 cm) as a handlin g slot

11 2 large size fruit s 160 medium size fruit s

1.10 kg

20 kg

120 x 100 x

120 x 100 x

120

SOO

Rs 8075

Rs 4500

Rs 12575

Rs 15.72

Rs 16.25

Rs 27.00

Economics of Packaging and Transportation.

The packaging of orange fruit s in CPS kraft paper boxes was cheaper than conventional wooden box. Be ing of lower weight , more number o f corrugated boxes can be ca rri ed in a truckl oad thus freight per box would be less than that o f wooden boxes (Tab le I I) . Another demerit o f wooden boxes is that these boxes lack dimens ional uniformity as they are manually made. Corrugated boxes are machine made and have uniformity of size and can fit into availab le space in the ex isting truck s izes , thus minimizing load shifting during actual transport. Wooden boxes are not uniform and s light variations create gaps, resulting in uneven load and collapse of these boxes. Surveys have revealed that up to 25 boxes in a truckload of 400 wooden boxes collapse

Table I 1- Comparative cost of packing and transport ation of Nagpur-mandarin fruit in wooden and CPS kraft paper boxes

from Nagpur to New Delhi

Head Wooden box wi th Corrugated box

conventional from CPS kraft

pack ing

I Cost of box includ- 24 (includes

ing mi scell aneous, Rs newspaper, nail s

fixin g, and coir)

2 Gross weight of box, kg

25

3 Number of boxes in 400 truck (truck 540 x

210 x 210 cm size)

4 Total Cost of box and packing, Rs

5 Truck freight (Rs I 400ft), Rs

9600

14000~for lOt)

6 Freight per box , Rs 35

paper'

20 (16.25* for

box + cost of pol yethylene

lilm liner inside the box , divi d­

ers. and tape)

20

500

10000

14000 (for 10 t)

28

Price of CFB box from CPS kraft paper wit h lamina­tion rounded off to Rs 16.25 (Rs 16.22) Cost of packing in CPS kraft paper box will be fur­ther jess if instead of Polyethylene liller, rice straw is

used inside the box. Ri ce straw acts as cushion ing as

well as minimizes moisture loss from fruit. In th at case cost of pac king (including box) per hox will bc around Rs 17. Therefore, fo r 500 CPS boxes it will cust Rs 8500 agai nst Rs 9600 for 40(} wooden buxes

3 18 J SCI IND RES VOL 62 APRIL 2003

and get damaged, resulting in spill age and rupture of fruits during transportation from Nagpur to Azadpur market, New Delhi (Ladaniya, Unpublished resu lts).

Conclusions

From these experiments, it may be concluded that CPS which till recently were treated as an agro­waste can be utili sed for the production of kraft paper and corrugated boxes.

The physical properties of the CPS kraft paper such as, burst factor, tear factor and breaking length were better for the 18 per cent chemical concentrati on kraft pulp. Further, higher chemi ca l concentration (20 per cent) caused degradative effect on fibre of the pulp while lower concentration resulted in lower screened yie ld . Uniform chip size was conside red neces­sary for obtaining good quality kraft pul p.

2 Corrugated boxes from CPS kraft paper had higher bursting and compression strength than commerc ia ll y available CFB boxes . Th e cobb va lue was nil in the board laminated with polypropylene film. Lamination a lso increased bursting and compress ion strengths of the box .

3 S imulated and ac tual transportation tests showed that Corrugated boxes made from CPS kraft paper with polypropylene laminati on can withstand vibrations, inclined impacts, and drop tests . These boxes also withstood high humidity conditions during long term refrige­rated storage.

4 The estimated cost of packaging and trans­portat ion in corrugated boxes from CPS kraft paper with polypropylene laminati on and con-

ventional wooden boxes indicated that corru­gated boxes are more economical than the con­ventional wooden boxes, wh ich are heavier and cost I ier.

The results of the large scale tri a l conducted in a paper mill indicated that the process is technicall y feasible . The corrugation tria ls undertaken on the kraft paper made from CPS showed that good quality corrugated boards and boxes could be produced. The CFB boxes possessed all the des irable properti es as spec ified by the Bureau of Indian Standard s. Thus the use of CPS for the manufacture of CFB boxes will not onl y he lp in so lving the di sposal problem of cotton plant waste, but will also fetch additional income to farming community apart from minimi zing the losses to fruits and easing the pressure on the fo rest based raw material s.

Acknowledgements

The authors are thankful to the Indian Council of Agricultural Research, Kri shi Bhavan, New De lhi for their financial ass istance to undertake the above study and to Dr (Kum) I G Bhatt, Consul tant , fo r the guidance and finall y to Dr K R Kri shna Iyer, Director, Central Institute fo r Research on Cotton Technology fo r hi s kind permi ss ion to publi sh thi s paper.

References

Anonymous, Industry profi le paper packaging, Financial Express, Bombay (India), (1990) pp 4 and 7.

2 TAPP/ standa rds and suggested methods (Technical Association of the Pulp and Paper Industry, New York) 1980, pp 200-265.

3 Bureau of Indian Standards , New Delhi , IS : (19).