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
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