Package Evaluation Training3transversalsealing

Evaluation - Tear down Step 2: Place the sample in Check of the samples – TS accurate check the stretch pliers and gently squeeze the handles to stretch the seal.. Evaluation of the sam

2 Evaluation - Tear down method + Practical

3 Evaluation - Dissolving test method + Practical

4 Evaluation - Heat Pattern + Practical

5 Evaluation - TS integrity by red ink + Practical

6 Example of TS defect

6 Example of TS defect

Polyethylene Sealing – Microscopic Scale

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1 Principle of TS sealing

General information on TS Sealing

► The heat required to melt the sealing layer of the packaging

material is generated by induction in the aluminium foil in the

packaging material

► TPIH sealing systems can produce short pulses with sufficient heat

► The heat is transferred directly to the sealing area

Jaw System

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1 Principle of TS sealing

Definition

Thermograph of Transversal Seal

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1 Principle of TS sealing

Induction Network

TBA/19 – Sealing jaw components

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1 Principle of TS sealing

Chain – Sealing jaw components

Bushing

Principle of ridge induction heating (IH)

►The method consists of

Evaluation concept

►The method consists of pulling TS(1) apart using the stretch pliers(2) and examining how the seal separates

►Seal must be mechanically stronger than the materials

If the sealing is good, the g g ,packaging material/strip layers (plastic film, Al-foil or paperboard) break while the seal does not separate

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Seal is stronger than materials

2 Evaluation - Tear down

►Blocked seal

Definition

Blocked seals, or cold seal, is

when the inner packaging material

layers have not completely

merged Separation takes place

between the sealing layers

►Plastic lump

Plastic lump is a plastic residue

that solidifies out of the dolly area

Plastic lumps are a potential

Preparation of the samples – TS rough check

Unfold the top and bottom flaps of the packages

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2 Evaluation - Tear down

► Checking the integrity of the TS by gently

Check of the samples – TS rough check

the TS by gently squeezing the package with the fingers

► If there is product leakage, the TS has a gross defect

(most likely a dolly is missing)

St 1 C t ff th t d

Preparation of the samples – TS accurate check

Step 1: Cut off the top and bottom of the packages at a distance of about 25 – 30

mm, from the top and bottom fin creases

Rinse the samples and dry them with either compressed pair or soft tissue

Note! Use compressed air with care since it might damage the sample.

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2 Evaluation - Tear down

St 2 C t ff 1

Preparation of the samples – TS accurate check

Step 2:Cut off 1 mm max from the edges (at the corner)

Note: It is recommended to start cutting from the outside in order

to have control over that important section.

Check of the samples – TS accurate check

Step 1: Run your finger over the TS and check if there are plastic lumps or ridges

Plastic lumps show that the sealing is not correct

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2 Evaluation - Tear down

Step 2: Place the sample in Check of the samples – TS accurate check

the stretch pliers and gently squeeze the handles to stretch the seal

Good light is important when evaluation the seal quality

Step 3:Stretch by pressing

Check of the samples – TS accurate check

Step 3: Stretch by pressing the plier handles along the whole length of the sample

Stretch a little bit at a time, both ends (1) towards the LS/TS cross (3), stretch the LS/TS cross last

LS/TS cross last

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2 Evaluation - Tear down

Critical points of the transversal seal are:

1 The cross : which is the point where the TS and LS meet

2 The corners : which are

at the ends of the package

Evaluation of the samples

Defective seal

“Plastic lump”

Before pulling the seal apart, check that there are no plastic lump in the sealing Use your fingernails to detect plastic lump.

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Plastic lumps (1) are a potential danger, hard residue might punch the PM layers during distribution of the package.

2 Evaluation - Tear down

Evaluation of the samples

Evaluation of the samples

Good seal

The seal does not come apart; the plastic film stretches and breaks, leaving the paperboard uncovered.

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2 Evaluation - Tear down

Evaluation of the samples

Good seal

At the cross where TS and LS meet, the LS must be considered

as additional plastic multilayer

Below picture shows the LS which stretches and separates

Evaluation of the samples

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2 Evaluation - Tear down

Evaluation of the samples

Evaluation of the samples

2 Tear down method and practice

Evaluation of the samples

Defective seal

“Blocked seal”

The seal separates;

no rupture occurs in the material layers

The seal appears mattish or greyish mattish or greyish.

Evaluation of the samples

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Defective seal - “Overheated”

The seal is overheated; the two PE layers are burnt and the

Al-foil shows micro cracks and cuts

2 Evaluation - Tear down

Evaluation of the samples

Good Seal - At corner, seal

above the ridge

Blocked Seal - At corner, seal below the ridge

−Chemical reaction, from the multilayer structure to the

inside pouch, via acidoralkali reaction

inside pouch, via acid oralkali reaction

−Heat pattern assessment and red ink tightness of each

Dissolving packaging

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3 Dissolving method and practice

►Information gained:

Dissolving Package Purpose

−Monitor sealing components state and performance

−Control settings over time

−Monitor each sealing link over time

−Allow archiving and traceability

Evaluation of the samples

• plastic lumps

• product residue

• overheated seal

p

• channels (unsealed spots)

• cuts in the ridge area

• Bending off

• sealing symmetry

• abnormal heat pattern

Step 1:

Preparation of the sample

►Unfold all the flaps and flatten the packages Cut the package in a I shape,

as shown in the picture (app 25 – 30mm, from the top and bottom fin creases).

►Mark each sample in order

to distinguish the TOP and BOTTOM seal after dissolution

Preparation of the sample

Step 2: cont…

►Cut with a distinctive cut type (3) part of the sample to identify from which jaw pairs the package comes

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3 Dissolving method and practice

Step 3:

Preparation of the sample

►If possible, cut the top of the package using the pinking scissors for an easy identification of the top This step still remain

6 layers (1 – 6)

Step 4:

Preparation of the sample

►Peel off the external packaging (outer PE, a part of PB layer will come off) The PM layers left at the stage on the sample are the following: (2 – 6)

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3 Dissolving method and practice

Fast methods :

Use HCl acid

Alternative VERY FAST/ FAST methods : Use

HNO3acid and alkaline NaOH

Alternative – Acid &

Alkaline agent (very fast)

- HNO360-65%

- NaOH 15%

- very fast (sample ready in

20 min) Room temperature no

Alternative – Acid &

Alkaline agent (fast)

- risk of spoiling of the sample with too long immersion in solution

- Room temperature, no need water bath

- risk of spoiling of the sample with too long immersion in solution

Disadvantages

3 Dissolving method and practice

Warning ! Risk of personal injury!

Dissolving Method – Chemical Warning

Observe safety regulations when working with ACIDS Preparation

and handling of HCl, HNO3and NaOH solutions must be carried out

in a well-ventilated environment, as fumes may be given off It

should be carry out in an Exhaust cabinet Always wear protective

goggles and gloves Use heat resistant beakers for preparation and

storage Exhausted chemical must be disposed of in accordance

with current regulations

Dissolving Method – Acid 1 VERY FAST (HCl)

Step 1/6:

Immerse the samples in HCl1:1 solution one at a time for approximately 4 minutes at temperature between 55 –

60 C Use a water bath

Note! The temperature settings might need adjustments given the equipment used

Neutralizing Solution should

Step 3/6:

Dissolving Method – Acid 1 VERY FAST (HCl)

The external lamination layer should easily separate from the Al-foil by mechanical hand action

The inner plastic layers and the Al-foil are left The Al-foil will be dissolved in the next step

step

The PM layers left, at this stage, on the sample are the following (4 – 6)

Dissolving Method – Acid 1 VERY FAST (HCl)

This the most sensitive step!

Immerse the sample into HCl1:3 solution, no more than two at a time, until Al-foil is dissolved Keep the sample

in motion to reduce the temperature

The temperature of HCl 1:3 solution increase when the samples are immersed into

it, therefore there is a high risk of burning the package

! This bath is controlled at

room temperature

the dissolving are the following;

Note! Always use tongs to immerse and remove the sample from the solutionssample from the solutions, avoiding contact with hands

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3 Dissolving method and practice

Dissolving Method – Acid 2 FAST (HCl 30%)

Step 2/4:

Remove the samples from the HCl 30% solution and immerse them in

Neutralizing solution to balance acidity

The PM layers left at the end of the dissolving are the following; (5 – 6)dissolving are the following; (5 6)

Dissolving Method – Acid & Alkaline VERY FAST /

FAST (HNO3& NaOH)

Step 1/5:

Immerse the samples in either HNO365% solution (VERY FAST) one at a time for approximately 7 minutes or HNO335%

60-solution (FAST) one at a time for approximately 30 minutes

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Note! Always use tongs to immerse and remove the sample from the solutions, avoiding contact with hands

/ 61

3 Dissolving method and practice

FAST (HNO3& NaOH)

Step 2/5:

Remove the samples

and immerse them in Neutralizing solution to Neutralizing solution to balance acidity

Dissolving Method – Acid & Alkaline VERY FAST /

FAST (HNO3& NaOH)

Step 3/5:

Rinse the samples under tap water The external lamination layer and the Al- foil should easily separate from the inner plastic layer from the inner plastic layer excepts Al-foil still is

present on sealing area

Note! Do carefully at the corners when separating

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Step 4/5:

3 Dissolving method and practice

FAST (HNO3& NaOH)

Step 4/5:

This the most sensitive step!

Immerse the sample into NaOH15% solution until Al-foil (at sealing) is dissolved, approximately 8 minutes

The temperature NaOH solution increase when the samples areincrease when the samples are immersed into it, therefore there

Dissolving Method – Acid & Alkaline VERY FAST /

FAST (HNO3& NaOH)

Note!

Leave the beaker uncovered to allow hydrogen fumes to be ventilated

If fresh, the solution should immediately start to bubble If not, prepare a new solution

The PM layers left at the end

of the dissolving are the following; (5 – 6)

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Make sure the Al-foil has dissolved

completely; if not leave the samples in

the solution a little longer or prepare a

Drying the samples

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3 Dissolving method and practice

Drying the samples

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4 Heat Pattern Evaluation

TS Heat Pattern – Identify the ridge line

Actual Inductor ridge line Inductor ridge line and

impression shadow

Measure the heat pattern from correct ridge line

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4 Heat Pattern Evaluation

Measure the heat pattern from correct ridge line

Heat pattern & type of Inductor

Sealing Technology : A loop close between two fins

Single loop

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Twin loop

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Plastic Bag Evaluation

How to measure plastic bag

• Find the ridge line and measure from the red ink penetration

0.56 mm

1 43 mm

This level must be a “STOP” for the production Defective TS Seal

the production Defective TS Seal.

This level is “Monitoring or Stop for Action” depending on type of

deviation Not defective TS seal.

This level is a “NORMAL” production

Not defective TS seal.

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Plastic Bag Evaluation

Insulated bubble in the sealing If the red ink does not pass through, the red ink does not pass through, the sealing is good It might indicate worn out inductor

“Change Inductors”

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Hint on evaluation “Teeth” or “Product

trap” toward cutting side

Not critical, bubble

Product trap, not knife problem

does not follow knife pattern

More iti l

Indication of knife movement problem

critical, as bubble

“Change Inductors”

Insulated long bubble in the sealing, close to the ridge If red ink does

not pass through, the sealing is good It indicates worn out inductor

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Inductor Condition

- Delamination or Detachment

- Sink coil, check by measuring height of the ridge

- Corrosion on coil, check by measuring height of the ridge

Insulated long bubble in the sealing If red ink does not pass through, the

sealing is good In this case, the root cause is rubber bushing

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Rubber Bushing Condition

The seal shows show channels from the cutting area toward product side It can be related to bad knifes broken spring rubber bad knifes, broken spring, rubber bushing and/or pressure related components.

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Plastic Bag Evaluation

Product side

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Plastic Bag Evaluation

The seal shows bubbles and melted spots This indicates too high setting or problem in the jaw g g p j system.

The seal shows early bend-off

Typically related to jaw pressure.

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Plastic Bag Evaluation

Plastic bag with many insulated bubbles and long & repetitive teeth

toward cutting Probably both inductors and knifes should be changed.

“Check Inductors/Knifes life time and condition,

Change Inductors and Knifes ”

Product Residue on the dog bone and knife

• If the knife slot is dirty, it will hinder the movement of the knife and

subsequently its position