The corrugated cardboard

THE

CORRUGATED CARDBOARD STRUCTURAL DESIGN AND INNOVATIVE MATERIALS Teachers: Prof. Ernesto Di Maio Prof. Francesco Paolo Antonio Portioli Student Giuseppe D’Alessandro P10/16

HOW IT’S MADE? PAPER

Factory: Cartesar Machines: Papermill Sales Format: Coils of Paper

PAPER WASTE

From production process and recycling

Factory: Sabox Machines: Box Compression Cutter, Rolling Cutter, Printer Sales Format: Box Cutouts Factory: Formaperta srl Machines: CNC plotter, Printer Sales Format: Custom Furniture/ Mountings

CORRUGATED CARDBOARD

Factory: Sada Machines: Wave maker, Sheets Joiners Sales Format: Sheets

PRODUCTION CHAIN

Collect waste

Paper sheet

Paper coil

Corrugated Cardboard

Print

Cut

Paper wastage

Bend

Boiler

the PAPERMILL

Mixer

Production chain waste

Recycling waste

High quality paper class

Low quality paper class

The papermill produces various types of paper, with different weight (grams/m2) and different moistures. Paper can be used as cover or as inner filling for the corrugated cardboard.

Dryer

Flatter machine Paper Coils

the COVER PAPERS

BV - Bianco Vegetale

K -Kraft

BK - Biko

ITY

AL QU

KB -Kraft Bianco

In order to assure quality paper must have long fibers and the correct mixture of water and moisture.

Expecially for the cover papers, the surface must assure a good print quality.

XP -Patinato

L - Liner LB - Liner Bianco T - Test TB - Test Bianco

Weight and Classes

the WAVE PAPERS

SE - Semichimica

AL QU

Weight and Classes

ITY

US - Uso semichimica

M - Medium

SE, US, M F - Fluting

F

MAKING CARDBOARD SADA has machines that compress the paper with rollers, creating different typologies of waves (ripple coefficient).

Another machine, using glues, joins different layers of paper, alternating corrugated paper and flat sheets.

CARDBOARD TYPOLOGIES

inner cover

inner cover

taut sheet 1st wave wave

2nd wave external cover

external cover

SINGLE WAVE

DOUBLE WAVE

WAVE TYPOLOGIES Waves assure high resistance to compression and traction.

They are classified depending on the height and the step of the wave itself.

C

B

E

F

wave typology

wave Height (mm)

wave Lenght (mm)

number of waver per meter

ripple coefficient

Onda alta (K)

Superiore a 0,5

14,9

67

-

Onda alta (A)

Superiore a 4,5

da 8,6 a 9,1

da 110 a 116

da 1,48 a 1,52

Onda media (C)

Compreso tra 3,5 e 4,4

da 7,3 a 8,1

da 123 a 137

da 1,41 a 1,45

Onda bassa (B)

Compreso tra 2,5 e 3,4

da 6,3 a 6,6

da 152 a 159

da 1,33 a 1,36

Micro-onda (E)

Compreso tra 1,2 e 2,4

da 3,2 a 3,4

da 294 a 313

da 1,23 a 1,30

Micro-onda (F)

Compreso tra 0,7 e 0,9

da 2,3 a 2,4

da 417 a 435

-

Micro-onda (G)

Compreso tra 0,5 e 0,6

da 1,8 a 1,9

da 526 a 556

-

H

L

ripple coefficient = Cr = H/L

G

HOW TO READ CODES Single wave paper id KTM

weight classes wave 443

C

ext. cover: Kraft wave: Test int. cover: Medium

Double wave paper id KMFMK ext. cover: Kraft 1st wave: Medium taut sheet: Fluting 2nd wave: Medium int. cover: Kraft

weight classes waves 96269

BC

MAKING BOXES SABOX prints, cuts and bends corrugated cardboard sheets to produce packaging.

It has two kind of machines. The first works using a vertical pneumatic press to imprint the shape and the cordons. The second machine works using cylindrical punches to imprint ink and shape to the sheets.

Every paper wastage is aspirated, stored, compressed and sent to the papermill.

MAKING FURNITURE FORMAPERTA designs and crafts furniture from cardboard sheets, using a CNC machine with cutter and bender.

Paper can be printed with a plotter before the cutting, making furniture customiziable.

DESIGN Functions - Contain and protect objects to be delivered.

Bonds - Easy to transport: dimensions must not exceed the pallet dimensions (usually 100x120 cm) and it has to be easy to handle; - Resist to the weight of the overlying boxes; - Surface must be printable to communicate brand and infos.

Task - Mantain a competitive price, without waste material.

Free Variable - Paper quality / typology; - Cardboard thickness; - Box dimensions

Fc = overlaying boxes weight compression Fw = weight of the object Fb = breaktrough force

Fc

Fc

Fc

Fc

Fc Fb

c

Fw a

b

Corrugated carboard waves direction

Fc = overlaying boxes weight compression Fw = weight of the object Fb = breaktrough force

Rc = compression resistance

Fc

Fc

Rw = weight resistance Rb = breaktrough resistance

Fc Fc

Fc Rc Rc Fb

Rc

Fc

Rc

Rc

Rb c

Fw a Rw

Fc

b

Fb

Rb Fw

Fc

TESTING the MATERIAL Box Compression Test (BCT)

The container compression test measures the compressive strength of packages such as boxes, drums, and cans. It usually provides a plot of deformation vs compressive force.

It is commonly used to evaluate shipping containers made of corrugated fiberboard as well as wooden boxes and crates.

BCT = 5.876 x ECT x t x p t = thickness of the cardboard (mm) p = perimeter of the box (cm)

Ring Crush Test (RCT) The edgewise compression strength of corrugated board is the principal element in determining the dynamic compression strength of the container made from that board. Fiberboard shipping containers are frequently subjected to loads which are resisted by compression strength, making this property an important measure of the performance characteristics of corrugated board, and useful in controlling the manufacturing process and in measuring the quality of the finished product. Since edgewise compression strength can be estimated by a summation of the ring crush strengths of the liners and medium, this test becomes a useful one for the corrugated boxmaker.

A compression force is exerted on a specimen held in ring form in a special sample holder and placed between two platens of a compression machine, by causing the driven platen to approach the rigid platen at a uniform speed until the specimen collapses.

Edge Compression Test (ECT) The edge crush test is a laboratory test method that is used to measure the cross-direction crushing of a sample of corrugated board. It gives information on the ability of a particular board construction to resist crushing. It provides some relationship with the peak top-to-bottom compression strength of empty singlewall regular slotted containers in laboratory conditions.

BCT TEST FOR A PASTA PRODUCER

paper id CGSCFCFCFCGS ext. cover: CGS (Test) 1st wave: CF (Fluting) taut sheet: CF (Fluting) 2nd wave: CF (Fluting) int. cover: CGS (Test)

weight classes waves 31113

EB

CGS : 145g/m2 (high performance Test paper, recycled, produced with 1.2% percentage of amid instead of 0.8%) CF : fluting 105g/m2 high performance

Rc*= 3,4 x Fcb x (n°b-1)

Minumum Security Box resistance coefficient weight to assure

Number of overlaying boxes

Rc*= 3,4 x 8 kg x 7 = 190,4 kg (daN)

1 Start

2 Elastic phase

3 Maximum resistance point

4 The machine stops the compression

Tests must be repeated every 1000 boxes, identifying where the cardboard collapses.

3 2 1

4

First test - BCT1

Second test - BCT2

Third test - BCT3

Rc = 260.6 daN ΔL = 6.44 mm (3.11%)

Rc = 275.3 daN ΔL = 6.12 mm (2.95%)

Rc = 237.9 daN ΔL = 5.86 mm (2.83%)

Rcm=

BCT1 + BCT2 + ... + BCTn

n

= 260.6 +275.3 + 237.9 = 257.3 daN 3

Rc*= 3,4 x 8 kg x 7 = 190,4 kg (daN)

Rcm>Rc* Verified

WEIGHT CHANGE paper id

weight classes waves

LBUSFUSBK ext. cover: LB (Liner Bianco) 1st wave: US (Uso semichimica) taut sheet: F (Fluting) 2nd wave: US (Uso semichimica) int. cover: BK (Biko)

Rcm = 436 daN

44244

EB

Rc*= 3,4 x Fcb x (n°b-1) Minumum resistance to assure

Security coefficient

Box weight

Number of overlaying boxes

Rc*= 3,4 x 8 kg x 7 = 190,4 daN Double weight

Rc*= 3,4 x 16 kg x 7 = 380,8 daN Double weight

Rc*= 3,4 x 16 kg x 7 = 380,8 daN Double weight + 1 pile

Rc*= 3,4 x 16 kg x 8 = 435,8 daN