packaging & laminates aims – to understand environmental issues associated with paper &...

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Packaging & laminates Aims – To understand environmental issues associated with paper & board packaging.

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Packaging & laminates Aims – • To understand environmental issues associated with paper & board packaging.

Environmental issues of paper & board use in packaging

Paper and board are produced primarily from hard and softwoods. Wood is made up of cellulose fibres bound together by lignin. To produce paper, these fibres must be separated to form a mass of individual fibres called wood pulp.

Softwood fibres are longer, offering greater strength; hardwood fibres are shorter, offering a smoother, opaque finish. Wood pulp is produced by one of three methods: mechanical, chemical or waste pulping.

Environmental issues of paper & board use in packagingToxic PollutionMany toxic chemicals are used in paper making, especially toxic solvents and chlorine compounds used to bleach and remove the, lignin from pulp. Many pulp and paper mills have made reductions in chemical use over the years, but these benefits may be countered by increased production.

Air PollutionPulp and paper mills are major sources of air pollutants, such as carbon dioxide. These gases contribute to the depletion of the ozone layer, global warming, acid rain and respiratory problems in the local area.

Environmental issues of paper & board use in packagingWater and energy consumptionPaper making is energy-intensive, using large amounts of electricity. It also uses a great deal of water from local supplies, which can cause problems such as increased sedimentation, increased water temperature, a reduction in the number of wildlife species in local habitats, possible concentration of toxic material and lowering of water tables.

Environmental issues of paper & board use in packagingSolid WastePaper fibres can only be recycled a limited number of times before they become too short or weak to make high-quality paper. The broken, low-quality fibres are separated out to become waste sludge filling large areas of landfill space each year. Some companies may burn their sludge in incinerators.

DeforestationWorldwide, enormous areas of virgin forest are being felled for paper pulp production, contributing to the destruction of the world’s forests or deforestation. Many UK paper mills import their pulp, some of which may come from endangered forests.

Environmental issues of paper & board use in packagingPossible SolutionsMechanical pulping is arguably the least environmentally damaging process for producing virgin wood pulp, and has the advantage of producing a high pulp yield compared to other processes. Newsprint quality, mechanically-pulped paper contains few additives, can be recycled up to four times and is adequate for many purposes for which chemically pulped products are currently used.One solution would be greater use of recycled fibre pulp rather than virgin pulp. The UK currently imports large quantities of virgin pulp, so needs to expand its recycling industry as an alternative. Using alternative fibres, such as hemp and straw, can reduce pressure on forests, and have great potential for being produced in the UK.

Environmental issues of paper & board use in packagingPractice Questions

1. Why is recycled pulp used for newspapers? Explain your answer.

2. Why would virgin pulp be used to make a glossy fashion magazine? Explain your answer.

Packaging LaminatesA polyethylene, aluminium foil and paperboard packaging laminate combines the characteristics of all three materials into a single package. Developed by Tetra Pak in the 1950s, this innovation has changed the way food is packaged and distributed around the world.

Tetra Pak’s strength is in the area of hygienic processing and packaging of drinks. When packaging laminate is combined with ultra-high-temperature processing (UHT), products can be packaged and stored under room temperature conditions for up to a year. This allows for perishable goods to be saved and distributed over greater distances.

Packaging Laminates

Packaging Laminates

Packaging Laminates

Packaging Laminates

Task - Create a model of a section of Tetra Pak using layers of materials. Label the layers & what they do.

Layer (out to in)

Material Reason for use

1 Polyethylene External layer, protects against outside moisture, glossy finish.

2 Paperboard Provides shape and stiffness. Good print surface.

3 Polyethylene Helps bond the paperboard to the aluminium.

4 Aluminium Foil

Provides a good barrier against air and light (which can damage the contents).

5 Polyethylene helps bond the internal layer with the aluminium foil.

6 Polyethylene Internal layer in contact with the drink. Seals in the liquid.

Packaging LaminatesPractice Question (5 marks)

Q. Explain how a packaging laminate such as a Tetra Pak carton keeps the liquid inside fresh?

Tip - Before you answer the question ask yourself...•What do I know about packaging laminates?

And•Which things are relevant?