DIRECT EXTRUSION TECHNOLOGY

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DIRECT EXTRUSION TECHNOLOGY

The making of direct expanded snacks

based on single screw extrusion, short screw

high shear and high temperature.

Presented by Trevor Campbell

For: Lalesse Extrusion company

Lalesse / Snackex 2013, slide: 2 /28

DIRECT EXTRUSION TECHNOLOGY

The making of direct expanded snacks

based on single screw extrusion, short screw

high shear and high temperature.

Presented by Trevor Campbell

For: Lalesse Extrusion company

Lalesse / Snackex 2013, slide: 2 /28

DIRECT EXTRUSION TECHNOLOGY

The making of direct expanded snacks

based on single screw extrusion, short screw

high shear and high temperature.

Presented by Trevor Campbell

For: Lalesse Extrusion company

DIRECT EXTRUSION TECHNOLOGY DIRECT EXTRUSION TECHNOLOGY

DIRECT EXTRUSION TECHNOLOGY

The making of direct expanded snacks

based on single screw extrusion, short screw

high shear and high temperature.

Presented by Trevor Campbell

For: Lalesse Extrusion company

• Extrusion

• Snacks

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• Plastics

• Animal feed / Pet food

• Pasta

• Snacks / cereals

• (bakery extruders)

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There are extruders for:

• Twin screw

• Single – long screw

• Single – short screw

• Random / spinning plate

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Type of extruders:

Twin screw extruder:

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Single screw – long screw extruder:

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Single and short screw extruder:

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Random extruder :

WHAT IS DIRECT EXTRUSION TECHNOLOGY

- HIGH SHEAR

- SHORT SCREW

- HIGH TEMPERATURE

- VERY SHORT TIME

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How is an extruder built :

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Traditional set up:

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Traditional set up:

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Traditional set up:

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Traditional set up:

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Traditional set up:

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Direct drive:

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Direct drive:

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• Extrusion

• Snacks

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Europe : hard and crunchy

Middle East: soft ‘chewing gum’

Leading to : melt in mouth snacks

Special snacks: hard and fat

E.g. Fry type (Nik Nak)

Direct expanded tortilla

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Snack characteristics:

High Pressure

High Temperature

Intermediate Plate

& Die Plate

Snacks

Corn

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The extrusion process

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Process parameters

1: Quality of corn: size / consistency / uniformity / dust / color / smell

2: Moisture of the mix: snack size / bubble size / cell structure / hard - soft bite

3: Temperature of the extruder: effect on viscosity / pressure / energy

4: Feeding rate: pressure / expansion / bite / density

5: Pressure (die plate): feeding rate / die plate/ RPM / bite

6: RPM: energy input / retention time / viscosity / bite

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The extrusion process:

screw

sleeve

Note:

- gap

- pitch

- surface

- thickness

- height

- material

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The extrusion process:

SLEEVE

SCREW

FREE FLOWBACK FLOW CAPACITY

WATER

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Mass flow in extruder :

Qflowmax

P max

die characteristic

setting of die characteristic

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Qflowmax

P max

screw characteristic

setting of screw characteristic

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Qflowmax

P max

operatingpoint

die characteristic

screw characteristic

Qa

Pa

setting of operating point

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Qflowmax

P max

operatingpoint

die characteristic

screwcharacteristic

Q1

P1

Effect of higher RPM

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Qflowmax

P max

operatingpoint

die characteristic

screw characteristic

Q2

P2

Effect of higher pressure

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Qflowmax

P max

operatingpoint

die characteristic

screw characteristic

Q4

P4

Effect of higher RPM-2

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Expansion technology

Bite

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SNACKS CHARACTERISTICS

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SNACKS CHARACTERISTICS

Bag filling: bag size vs grams inside

Does 50 grams fill the bag sufficient?

gr/lt bag size ltrs

80 50 0,6

70 50 0,7

60 50 0,8

50 50 1,0

40 50 1,3

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The effect of wear:

• The screw becomes smaller Ø

• The sleeve becomes larger Ø

• The gap between them increases

• Sharp edges are rounded off

Leading to:

• Less shear development

• Lower pressure in process

Outcome:

• Lower capacity

• Difficult shape definition

• Softer bite snacks

• Different density / SME

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The effect of wear:

Reasons why:

• Quality of raw materials

• Frequent stops / re-starts

• Too ridgid cleaning

• Use of non-genuine parts

Solution:

• Change moisture level raw materials

• Better power supply to extruder

• Use of stop mix after extrusion process

• Careful cleaning of the wear parts

• Use only genuine wear parts

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The effect of wear:

After 100 hours:

Production loss = 5 kg/hr

Average loss = 2,5 kg/hr

= 100 bags of 25 gr

Cost price / bag = € 0,05 ?

100 bags x €0,05 = € 5 /hr

In 100 hrs: € 500 !

New parts = € 2.000

2.000 / 5 = 400 hours

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The effect of wear:

Blue line:

Losses in €

As result of wear

Break even point

New set = € 2.000

= 400 hrs

Red surface:

Losses that can be

Prevented when

Changing timely

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Limitations + excells:

Single screw extruders are limited in:

• Use of raw materials

• Adding of sugar / fat in raw materials

• Transport of raw materials through process

• Energy management

Single screw extruder excells in:

• Simple operation

• Quick start up

• Simple to clean

• Easy to operate

• Good in short + long production runs

• High versatility

Various shapes can be made

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Various cutters it needs

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Complete extrusion line

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DIRECT EXTRUSION TECHNOLOGY

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THANK YOU VERY MUCH

Presented at Snackex 2013

By : Mr. Trevor Campbell

For : Snack Engineering

And : Lalesse Extrusion

www.snackengineering.com www.lalesse-extrusion.com

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