Laser-based welding system improves packaging seals

Laser-based welding system improves packaging seals Robert Parkin, Wolfson School of Mechanics & Manufacturing Loughborough University, Loughborough, UK

Engineering,

Plastic welding As well

as demonstrating

multi-layer

This brief feature describes a laser-welding technique that can seal plastic packaging materials at a high speed. Its developers claim that it is flexible and it could permit multiple package-shapes to be made on a single production line, providing a major advantage over conventional heat-sealing and pressure-sealing systems. The

integrity

flexible,

plastic

importance.

giving or even

products, of

seals

on

leakage

can

rise

to

contaminant

that failure becomes

felt

sealing

techniques

that

adopted

contacting

& Manufacturing

investigated

a laser-welding

While

may be carried

it is ofcenat

more

needed

reliable

and

prove was

to help

conditions.

seal packages Funded

Affairs’

robust

beneficial.

to

maintain

use

nonaseptic

University’s

the

(DEFRA)

ot bagged

the

Engineering,

UK

indicator

of package

The UK-based

has

machinery;

scheme,

& Rural the

rotational

The concept with

untreated

University;

and RPC

was to

(Figure

1).

Examples strength industry

Gaussian profile

that

using nature

gives

tapers

the entire

containers

The

peelability

standard

weld-strength that

a

of an

a strong

off at the edges

using

techniques.

proved

material

adjacent

therefore

tended rather

a range

of

In most cases the

to be as great

of the partially

A

system

or greater

heat-affected

parent

to the weld seam.

The

peel

to take place along the edges of than

could

process,

giving

inspected

of food-

by separation

developed

be tested a

Seal at later

months a

was

integrity

Gains-

across

the

whereby

during

high

level

integrity stages

of

also -

weld

the welding product could

even

be

weeks

or

after sealing.

When

a

containers

small

sample

was tested

using industry-standard number

R (mm)

the

of these welds have been tested for

and

acceptance.

Containers,

circular

around

laser-beam

in this

food containers.

of

weld-area

of laser

weld zone.

a fail-safe

collaborating

welding

central

possibility

by infrared

work has also indicated

of

stage.

the weld,

work

of semi-rigid

a manufacturer

of thermoplastic

periphery

the

welding

the research

feasibility

than

health.

partners

Craftsmen,

packaging

of

that can

Food

system,

were Loughborough

manufacturer

at

Government’s

handling

products.

a zero-defect

borough

run

School

technique,

LINK

on

achieve

project

Wolfson

of Environment,

concentrated

was

at a very high speed. by

Department

trayed

would

approach

methods

a later date

apparent.

sealing techniques

It was

which

Mechanical

a major perceived

microorganisms.

production,

a project,

be

the growth

of some description

UK,

Loughborough

that favour

inspection

In the

is of critical

poor

out during

The

or

in the case of high-moisture

environments

Reliable

semi-rigid

food-packaging

Seal

problem, quality

of

beam,

plastic

of

welded-tray

for oxygen

penetration,

techniques,

a significant

passed the test.

Potential The

3

I

(w.cni*)

sealing

system

could

permit

made

on

product

a single

change-over

the sealing advantage sealing

proved

multiple

to be flexible

production without

machinery.

systems,

This

Real-time

line,

or

provides

a major

hours

to accommodate

a

The system also can be applied

that may be complex control

to

in shape.

of the process

for zero-

defects will result in a high level of integrity,

Sealing Technology May 2002

fast

heat and pressure

may take several

and line changes

new product. packaging

which

to be

the need to reset

over conventional

for tooling

and

package-shapes

and

A 0

the embedding smart health

signature

provides

explore

can guarantee

package

the laser process outlined

the sealing

process).

of a process

packaging,

which

(even weeks

after

This means that the practice product

quarantine

with significant

(in certain

and re-inspection

different

materials,

A continuation

areas) of

is avoided,

cost savings.

to take advantage

and public domain

toughborough, Leicestershire LEll 3TU, UK. Tel: +44 1509 227505, Fax: +44 1509 223934, Web:

results will be published

University

website,

is located

which

Mechatronics

on the

Further development work

at www.mechatronics.(This article is based on a feature which was

envelopes

needed

is necessary

or

to

parameters

of

published

operation

Cosmetics and Drug Packaging newsletter, Val. 25

and

Parkin, Wolfson School of Mechanical and

No. 1)

random

orientation,

a large

number

and with the formation of contact

points

of

Publication date: 6 November

Polymers

describes

UV-curable

Inventors: S. Chandra,

M. Cadi, J.-A. Ducros,

R.

Thibeau

Research

laminating

BV, The

Publication date: 1 November

polydiene

polymer

fibres

The

of the polymer

the

isoprene

and

group

is attached

a hydroxyl

molecule.

hydrogenated

process

or

involves

the group

consisting

conditions

in

high-speed

This

process

in

may

more

(or

at

a

suited

for

have

0

been

material

to adhesives, to effect

2001

industry

and

Co Inc, USA

a paste

has been

elastomer

of conductive

particles

in which

the fibres

embedded

in

for

developed.

one

and

the It is

on an

in the form

are flexible

the

a container

(the metal

periodic

table)

and a reactive,

finely-

comprising and/or

a

obtained

silica,

silicates,

aluminates.

Co Inc, USA

elastomer

and in

collector for use in an

cell is provided. The cell comprises

that generally has a closed bottom

the top and bottom materials

are

ends. Electrochemically

disposed

D.A.

electrode.

A current

collector

200 1

that

through

the

compression

Recom

developed.

A current

opening

and

bushing

into

compresses

is inserted

one

without

using it

the closure.

is

made

composition

of

of O-10

in elongation

and

spacer

is provided

which

are arranged

with

A split

cable

a manner

at predetermined

with

The split cable of seal ribs,

that

A split a hinge

are each end

which

(detachedly) joint

faces.

to

is held in the

its halves

each

other

2001

Tension rod anchor with sealing structure Ankersysteme

GmbH

may through

be

& Co

KG, Germany A rod anchor tension head

is connected

(using a thread)

rod. The rod anchor

in which

is formed

hole,

axially

an anchor

a threaded

first bore

whereby extends threaded formed

member

aligned

the threaded through

with

to the anchor

forms a second

bore

the first bore

hole,

end of the tension

the second

engagement between

to a

includes

head. The sealing

intervals.

seal base so that

Publication date: 6 November

they

the split end seal base to be pivotally

end

Patent number: US 6312850 Inventor: R.M. Janmey

hole, and a sealing nut is attached

from

split into two halves. The spacer

has been inserted

insertion

and spaced

with

stress on the upstanding collector

the opening.

Assignee: DEHA

in tensile

the cable

seal base is also provided

abutting

spacer

500-2000%

a plurality

such

Its

bushing stress and

and

rubber

kgf/cm2

along

in

joined

tape.

assemble

so as to be contacted

to each other

split

for a cable

to

of the cables.

opposite

permits

have different

casing

in hardness,

passages

other

through

vulcanized

lo-60

is arranged peripheries

a

compressive

the

any sealing

easy

tangential

of ensuring

the

the upstanding

to exert radial compressive

wall after the current

of

A polymeric

cooperate

has

is

and

wall which

collector

active components.

closure

(that

a receiving

makes

disassemble

for a cable

of cables

into

also

Ltd, Japan

It is capable

insertion

connection

for cable closure

and

non-conductive

has an upstanding

wall so that the collector and compression

End seal structure

active

conrainer

and seal assembly

includes a resilient and electrically

electrochemically

Publication date: 1 November

in the

provided to close the open end of the container

defines an opening.

S.J. Bradshaw,

end,

between

typically include a positive electrode and a negative

seal body

Turland

outer

Specialties

comprises

1 of the

Inventors: A.W. Atkinson,

which

E.M. Zimmcrmann

gasket

Group

an alkali silicate,

divided

use

gasket material

on at least

of fibres,

from

strength

Applicant: Instrument

admixture

being and/or

diameters)

to mixing

formulations

inventors: J.R. Erickson,

electrical

an alkali metal hydroxide

correct

sulphonium

photo-initiator

Publication date: 1 November

based

by reacting

been

from

UV cure.

A conductive

is a product

which

selected

Patent number: WO 01/81494

Conductive

limiter

phase,

Assignee: Japan

other

(preferably

that can be added

or sealant

gasket

An end seal structure

is highly

Ltd,

The

mixer

cationic

compression

continuous

an insoluble

25-130°C

stable

concentrations

rapid

Battery

an open top end, and side walls extending

Patent number: WO 01/81797

block

at one end

of triaryl

of

40-100°C).

coatings,

or with

electrochemical

Technology

are

is then subjected a

temperature

making

one

Federal-Mogul

aluminosilicates

polymers

that is preferably

salts. The mixture

for

the above polymer

with

limiters

epoxidized

butadiene

These

ingredients)

photo-initiator

of at least

unhydrogenated.

mixing

polymer

formulating

preferred polymers

of

A

Ar least one is

that is used as the binder

composition.

copolymers

related

It provides

monohydroxylated

monomers.

monohydroxylated

be

and

that is composed

diene

a diene monomer

which

Seal assembly for electrochemical cell Assignee: Eveready

2001

USA

plates,

films and thin parts.

two different

Applicant:

adhesives,

printing

of an epoxidized

Gasket compression

for making

gaskets,

flexible

adhesives,

compositions,

the

a process

sealants, ink,

T. Uehara 2001

Patent number: WO 0 l/8 1799

UV-

A seal assembly and current

coatings,

details

Patent number: US 63 14229 Inventors: D. Sasaki, T. Hattori,

between

Netherlands invention

issue of Food,

For more information, contact: Professor Robert

fibres.

Non-aqueous solvent-free curable sealants

This

in the ]anuary 2002

the

establish

Patents Applicant: Kraton

www.mechatronics.org.uk.

Centre’s

org.uk. Further

Manufacturing Engineering, Loughborough University,

is ready to commence,

project

Loughborough

of

above.

with

rod

bore hole and into the first.

the nut and the tension

A seal is rod.

Patent number: US 6312185 Inventor: I? Ernst Publication ahe: 6 November

2001

Sealing Technology May 2002