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Info.

Ji Zhong (季忠） Ph.D., Professor

Packaging Research Institute

Phone: 0531-88392817

Email: jizhong@sdu.edu.cn

Http://www.dplab.sdu.edu.cn

Office: RM908, Main Building (Qianfoshan Campus);

RM510, Xipeilou

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Flexible Packaging Laminates

Lesson 8

第8课 软包装复合材料

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Plasticating Extruder

Exitport

Gear reducer

Variable speed motor

Feed throatFeed hopper

Hopper throatCooling jacket

Screw

Heater bands

Fig. 10.2www.dplab.sdu.edu.cn 4/43

Adjustable Die Lips

Extrusion Die

Adjustable Pressure (Restrictor) Bar

Extruder

Cast Film and Sheet Extrusion

Fig.10.4www.dplab.sdu.edu.cn

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Extruder #1

Extruder #2

Extruder #3

Material #1Material #2

Material #3

Three-Layer Coextrusion

Fig.10.9

magnifier

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Extrusion Cast Film Line Layout

Extruder

Extrusion die Chill roll

Edge trimmer

Material roll

Fig.10.5www.dplab.sdu.edu.cn

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Machine Direction Orientation

Rotation x 1 x 3x 2 X 4

From extruder casting rolls

Fig.10.8www.dplab.sdu.edu.cn 8/43

Extruder

Casting Rolls

Annealing Zone

Extrusion Die

Tenter Clips

Cross Direction Orientation

Fig.10.8www.dplab.sdu.edu.cn

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Bubble

Blow-up air inlet

Cooling air Cooling air

Plastic from extruder

Die lip adjusting bolts

Die BodyDie core

Frost line

Bubble constantly pulled up

Blown-film Die Cross-Section

Fig.10.6www.dplab.sdu.edu.cn 10/43

Three-layer Extrusion Blow Mold

Cut-away view

material 1

material 2

material 3

film bubble

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ExtruderCircular die

Air ringInternal bubble cooling

Plastic film bubble

Collapsing frame

Upper nip rolls

SlitterDual rollwinder

Blown Film Line With Slitter

Fig.10.7www.dplab.sdu.edu.cn 12/43

Blown Film Line Showing Die & Bubble

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Why Laminate?

There is no perfect, universal普遍的 packaging material

Laminates assemble materials with indi’vidually desirable properties to create an optimum material

Laminate: A product made by bonding togethertwo or more materials

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Mechanical propertiestensile strength stiffness

coefficient of friction use temperatures

elongation formability, dead fold

puncture resistance abrasion resistance

Laminate Properties

Barrier properties as requiredoxygen barrier essential oil barrier

water vapor barrier light barrier (UV)

美音：['tɛns!]

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Laminate Properties

Sealabilitymost flexible packaging is heat sealedmost heat seals are polyethylene based

other polymers used in more critical applications

Aesthetic美学的 appearanceclarity，opacity, feel, surface glossreflective metallic luster (光辉）US: [ˈlʌstər]

brightness or shine on a smooth surface www.dplab.sdu.edu.cn

seal [si:l] n.封条, 印章n.海豹v.密封, 盖印, 明确

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美国海军海豹部队 （United States Navy Sea, Air and Land，SEAL）

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Describing Packaging Laminate

Note:！！！

Packaging laminate plies are always listed from the outside to the inside

Laminates are assembled from various combinations of paper, adhesives, plastic films, surface coatings, aluminum foils, and aluminum metallized paper.

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Aluminum Foil

Household foil is typically 17.5 m (0.0007 inches)

Available in gauges as low as 7 m (0.00028 inches)

Pin holding is present below 12 m (0.0005 inches)

Foil is susceptible（对…敏感） to flex cracking

Most foils are supported with plastic and/or paper

Unsupported foil used for some lid-stock & tablet push-through packaging 封盖

Thickness <152.4micron

[səˈseptəbəl]

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Intact完整无缺的 foil is a 100% barrier to all gases

Best deadfold properties

Easily punctured and torn (tamper evidence)

Reflective of radiant heat

Conductive (induction (感应）sealing)

‘Decorative appeal: all reflective metallics are aluminum

Excellent formability, can be molded into trays, cups…

Aluminum Foil Characteristics

请求 感染力

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• Television reality shows are losing their audience appeal in china.电视真人秀节目正在失去其对中国观众的吸引力。

appeal [əˈpi:l]n.呼吁；感染力;上诉 v.呼吁;上诉

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Foil Packaging Applications

Unsupported foil, non-sealablee.g. confection（糖果） and cheese wraps

Unsupported foil, heat sealablee.g. lidding封盖 stock, pharmaceutical tabletbacking 衬背material

Supported foil, non heat sealablee.g. decorative wraps, label stock

Supported foil, heat sealablee.g. high barrier pouches小袋 and sachetslidding stock, retort pouches

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Aluminum Vacuum Metallizing

Fig.8.1

Vacuum line

Unwind roll

Aluminum vaporCeramic boat

Rewind roll

Aluminum wire Chilled roll

Depositing of a metal layer onto a substrate底层, carried out in a vacuum

Cross section of a representative batch metallizer

真空镀敷

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batch [bætʃ]

n.一批, 一炉, 一次所制之量v.分批处理

23/43www.dplab.sdu.edu.cn 24/43Are used alone in some applications but a component in a laminated structure

Provides reflective metallic appearance

Improves moisture, a’roma香味, light and oxygen barrier

Oxygen barrier improved:up to fifty times for OPP, up to ten times for PET

OPP, PET, & PA (nylon) most common metallized packaging films

Aluminum Metallized Film

Vacuum-metallized paper gains the aesthetic,reflective AL surface, but does not gain barrier properties. But, for vacuum-metallized film,

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Gravure|| grə'vjʊr /-'vjʊə] Coating照相凹板式涂敷

Fig.8.6

刮刀

凹版圆筒

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Laminating Processes—Bonding method:Wet Bond Laminator

Fig. 8.8

夹辊展平辊

涂敷器

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Dry Bond Laminating

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Solventless Laminating不溶解的

Solventless laminating uses catalyzed催化作用or or two-part reactive adhesives

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Extrusion Laminating

Fig. 8.7

Extrusion die

Chill roll

Substrate ASubstrate B

Strip-off roll

Pressure roll

Nip roll

Extrudate Three ply laminate

底层

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Flexible Bags, Pouches and Sachets:Vertical Form-Fill-Seal (VFFS)

Fig. 8.2

Unwind

Product flow

Draw-down beltsLongitudinal sealing jaw

Cross-sealing and cut-off

Forming collar

CoF is critical!

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VFFS Pouch Seals Compared

Fig. 14.5

Fin seal Lap Seal

Seals inside surfacesUses more material

Seals outside to insideBoth surfaces need sealing medium Use less material

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Horizontal Form-Fill-Seal (HFFS)

Fig. 8.3

Unwind

Tension control

Forming plow

Top seal

Cut-off

Open pouch

Filler #1Filler #2

Filler #3Close pouch

Side seal

/‚hɒrɪ'zɒntl]

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Common HFFS Pouch Styles

Fig.8.5

Conventional pouch has three-side seal

Can be made into various stand-up designs

Some stand-up pouches are pre-made in a separateoperation

Three-side sealed pouch

Gusseted designs

'gʌsɪt]

[paʊtʃ]

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Multi-Lane Form-Fill-Seal

Fig. 8.4

Vertical heat seals Horizontal heat seals

Product dispensers

Four-sided seal pouches(separated)

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Stand-Up Pouch Examples

n. 咬碎; 扎扎地踏; 咬碎声v. 嘎吱作响地咬嚼

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Stand-Up Pouch Examples

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Film Thickness Measurement

Inch Gauge Mil Micrometre

0.001inch = 100 gauge = 1 mil = 25 m

0.0005 inch = 50 gauge = 1/2 mil = 13 m

ISO metric notes:“Micron” is a depreciated term for micrometreone inch = 25.4 millimetres and 0.001 inch = 25.4 micrometres

Our currency will not be depreciated.我们的货币不会贬值。 www.dplab.sdu.edu.cn 38/43

Early Universal Barriers

PVDC is original high universal barrier polymers

EVOH laminated between high moisture barrier polymers can also provide good universal barrier

But not high enough for critical applications

Metallizing also produces a high universal barrierBut aluminum metallized films are not transparent

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Recent Advances in Achieving Barrier

Monolayer polymers poly(ethylene naphthalate ) liquid crystal polymer

Multilayered constructions

PET/PA/PET

PET/EVOH/PET

PET/MXD6/PET/ MXD6/PET

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Recent Advances in Achieving Barrier

Interior coatingsSiOx (glass) coating (Glaskin)AlOx aluminum oxide coatingcarbon coating (DLC)

Exterior coatings and interior laminatesepoxy-amine(胺类) coating (Sealica and Bairocade)copolyester 共聚多脂(Amosorb: interior layer)

Nanocompositesextremely fine mineral additions

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Hot Tack

The bond strength of the seal while still hot

Critical for most form-fill-seal machines

Determines how quickly product can be dropped into a pouch

材料的热粘性（Hot Tack，热封处未冷却时的强度）

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Common Heat- Seal Materials

costbond quality

Ionomer离聚物 (e.g. Surlyn, seals through contaminants )

acid copolymer共聚物 (good foil bond, chemical resistance)

Metallocene金属茂合物 polyethylene (low temp, fast seal)

LLDPE (good hot tack, tough, wide seal temperature.)

PE/EVA (soft film, low seal temperature)

medium-density polyethylene (stiffer, better barrier)

cast polypropylene 聚丙烯(stands higher temperatures)

low-density polyethylene

Table 14.5

'aiənəmə

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Source: M. Lutterotti, DuPont

Sealing Mediums Compared

3000

2500

2000

1500

1000

500

120 125 130 135 140 150145 160 170 180LDPE

Oct. LLDPE

mPE Forceg/ inch

Temperature (degrees C)

Hot Tack Strength

Figure 14.6www.dplab.sdu.edu.cn 44/43

Heat Sealing Parameters

Fig. 14.7

Increasing Temperature

Hea

t-Sea

l Stre

ngth

High barpressure

Medium bar pressure

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foil

polyethylene

poly(ethylene terephthalate)

foilsealing medium

printed paper

sealing medium

Retort pouch Aseptic box

sealing medium

printed poly propylene

metallized polypropylene

Snack food bag

saran-coated nylon

sealing medium (Surlyn)

Luncheon meat tray

Example Laminations

See Figures 14.13 & 14.14

莎纶, 此种合成纤维的商标名丙烯

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printed polyethylene

polyethylene

Ethylene-vinyl alcohol 醇

High oxygen barrier

polyethylenepoly(ethylene terephthalate)

sealing medium (vinyl)

Over lacquer

Single-service lidding stock

printed foil

Example Laminations

See Figures 14.13, 14.14

(For barrier applicationsfoil to the inside)

surface print

paper

polyethylene

sealing medium

foil

Basic food pouch laminate

漆

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Laminateroll stock

Highbarrierinsert

Finishedtube1

Injected molded tip

Laminated Collapsible Tube Construction

Formed body

Foil

Clear LDPE

paper

Sealing medium

Printed white PE

EAA

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日常用语

• Blow one’s own horn 自吹自擂

• I can’t stand the guy-he’s always blowing his own horn about how much money he makes, how good he is at sports, even how the grass on his lawn is greener than his neighbor’s.

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• We said no questions. • she can stand it, I can.• I’m not interested in politics. The problems

of the world are not in my department.• 我们说过不准备问问题

• 。。。

• 我对政治不感兴趣，这个世界的问题不在我思考范围之内。

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• I stick my neck out for nobody.

• 我从不为任何人舍命

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