agricultural barrier films plast09

DSM Engineering Plastics

1

Agricultural barrier films

DSM Engineering Plastics Ted Brink | Application Development Engineer Extrusion

Living Solutions for People, Planet and Profit


Agricultural barrier films - Plast'09 - Plastics & Agriculture

Contents

• Introduction• Agricultural barrier films

- why barrier films are necessary

- barrier materials

- film compositions

- film property improvement

• Conclusions



DSM creates innovative products and services in life sciences and materials

active on 5 continents, more than 250 locations approx. 23,000 employees approx. €8.8 billion annual sales in 2007 leadership positions in ~75 % of the portfolio

DSM today

DSM Engineering Plastics€ 0.84 bn sales in 2007 and 1,500 employees worldwideAs a leading global supplier of quality engineering plastics we provide customer value through innovative solutions

Polymer Intermediates

15%

Performance Materials

29%

Nutrition28%

Base Chemicals & Materials

17%

Pharma11%



DSM EP’s product portfolio for film applications

Akulon® PA6 and PA66 barrier material

Akulon® XP extreme performance PA6

Arnitel® TPC breathable material Stanyl® high heat resistant PA46Yparex® maleic anhydride modified polyolefin



Why agricultural barrier films?

Methyl bromide is being used as a fumigant in agriculture

However, MeBr contributes to the depletion of the ozone layer

Application of a barrier film has the following effects:• reduced emission of MeBr into the atmosphere• increased effectiviness as fumigant

Methyl bromide is a neurotoxic gas• odourless• boiling point: 3.6 °C• gas density: 3.4 (air = 1)



The ozone hole in 2006

The largest Antarctic ozone hole recorded as of September 2006



Montreal protocol 1987

Reduction of methyl bromide developed countries:• 1998: 25 %• 2001: 60 %• 2003: 75 %• 2005: 100 %

Article 5 countries: 100 % reduction in 2015



Today’s reality

Objectives Montreal will not be reached

• partners granted production of 5.300 tons of methyl bromide by the USA in 2008

• environmental groups revealed stock of 10.000 tons in USA

• methyl bromide will continue to be used, but volumes will decrease as alternatives will become available

• alternative fumigants may also require barrier films to improve efficiency



Containment of emission of fumigant

• prevent emission into the atmosphere by using barrier films• injection of methyl bromide deep in the soil



Barrier materials

• EVOH• PA6.66 copolyamide• PA6 homopolymeer• PA6 nanocomposite• blend of PA6 and amorphous PA• Orgalloy

• coated film (Al, SiO2)



Properties of barrier materials

material barrier price processing mechanical

EVOH +++ -- - +/-

PA6.66 +/- - ++ +

PA6 + + + +

PA6 nano ++ - + -

PA6 AmPA ++ - + +

Orgalloy +/- - + +

coating +++ - - ?



Common film structures

6 µm10 µm

10 µm (L)LDPE/adhesive

(co)polyamide

(L)LDPE/adhesive

3-layer structure

5-layer structure (L)LDPE

adhesive

(co)polyamide

adhesive

(L)LDPE



Adhesive or tie resin (DSM Yparex)

• no adhesion between PE and PA in coextrusion• MAH-g-PE is commonly used to realise adhesion between

PA and PE• physical adhesion between MAH-g-PE and PE• chemical reaction between MAH-g-PE and PA

O

O

O+ NH2

O

O

N+ OH2



Requirements agricultural barrier films

Requirements

• British Pest Control: 1 gram MeBr per m² per hour

• French ministry of Agriculture: 0.2 gram MeBr per m² per hour



Coextrusion blown film process



Film processing

• thin film• large machines• large bubble diameter

• compromise in material use: - LDPE needed for bubble stability - PA6.66 to realise low polymer temperature

• PA6 good alternative to PA6.66 but higher melting point• rheology of PA differs from PE



LDPE and LLDPE for barrier film

property LDPE LLDPEbubble stability ++ +

impact strength + ++

puncture resistance + ++



Viscosity curves of LDPE and PA6

10

100

1000

10000

0.01 0.1 1 10 100 1000

shear rate [1/s]

mel

t vis

cosi

ty [P

a.s]

.

LDPEAkulon F132

No proper viscosity matchbetween PE and PA6



processing windowRheology mismatch PA6 and LDPE

10

100

1000

10000

0.01 0.1 1 10 100 1000

shear rate [1/s]

visc

osity

PA6LDPE

Standard materials result in interfacial instability

leads easily to problems

Poor elasticity and viscosity match creates wave effect resulting in poor optical properties and quality risk

wave lengthuniform thickness wavy interface



wide processing window

The Akulon XP solution

10

100

1000

10000

0.01 0.1 1 10 100 1000

shear rate [1/s]

visc

osity

[Pa.

s]

Minimizes differences in melt viscosity and elasticity of coextruded materials

Result: widening of processing window

Akulon XP showsshear-thinningbehaviour:• less motor power at

high rpm• higher zero shear

viscosity• lower Tpol at high

output

LDPEMFI 1.9

Akulon XP



Akulon XP for agricultural barrier film - trial

Trials in a 3-layer concept

Objective: replacement PA6.66 to reduce costs and/or improve properties

total film thickness: 25 µmCOPA layer: 6 µmPE outerlayers: 60 % LLDPE, 30 % LDPE, 10 % Yparex 9403bubble diameter: 5.8 meter (BUR 2.1)

Yparex 9403DSM’s tie resinMAH-g-PE



Akulon XP for agricultural barrier film - results

Replacement of PA6.66 with Akulon XP36-E1:

• LDPE could be omitted while maintaining bubble stability and improving mechanical properties

• bubble diameter could be increased from 5.8 to 7 meter (BUR 2.8)

• thickness PA layer could be reduced from 6 to 5 µm while maintaining mechanical and barrier properties

or

or



Conclusions

Akulon XP PA6 in agricultural barrier films results in:

• improved bubble stability

• improved mechanical properties

• improved output (larger BUR)

• cost reduction

24


Living Solutions for People, Planet and Profit

THANK YOU FOR YOUR ATTENTION

More information:Ted BrinkApplication Development ExtrusionDSM Engineering PlasticsTel: (31)464767831e-mail: [email protected]

www.dsmep.comwww.akulon.comwww.yparex.com

Visit us at Hall 20, booth D31

agricultural barrier films plast09

Technology