PAPER OR PLASTIC?Kate Pinter

vs.

Outline

Consumption Production Pollution Recycling Biodegradable? Negatives of both What should we do? Discussion

Consumption - Paper

Americans use over 10 billion paper bags per year

14 million trees cut down annually for paper bag production

Consumption - Plastic

Americans use 100 billion plastic bags annually Equivalent to 12

million barrels of oil Worldwide, 4

billion plastic bags per year end up as waste Enough to circle the

Earth 63 times

Production - Paper

Paper comes from trees

Logs are stripped of bark and chipped into small squares in debarker

Chips are placed in a pressure cooker with water and other chemicals and digested into pulp

Pulp is washed, refined and cleaned

Production - Paper

Pulp is placed in a beater and turned to slush

Slush moves down wire screen where water is drained and recycled

Crude paper sheet is squeezed between rollers to remove remaining water

Paper runs through heater dryer rollers

Paper is cut, printed, packaged, and shipped

Production - Plastic

Plastic bags are made from polyethylene

Polyethylene comes from oil refineries as small resin pellets

Plastic resin is extruded, forming a thin tube

Production - Plastic

Air enters into the tube and causes it to expand

Tube moves upward on nip rollers, which flatten the bag into double-layered film

Film is cut into sheets/rolled up

Production

It takes more than four times as much energy to manufacture a paper bag than a plastic bag.

Safeway bag Energy to produce bag (BTU)Paper 2,500 BTUPlastic 600 BTU

Pollution - Paper

Paper production involves toxic chemicals Air and water

pollution Take up more space

in landfills than plastic

Production of plastic bags requires fewer pollutants than paper bags

Pollution - Plastic

5 of the top 6 chemicals that generate the most waste are commonly used in the industry

Thousands of marine animals die annually from eating plastic bags

Recycling - Paper

Paper bags have higher recycle rate than plastic

Paper must be returned to pulp Requires bleach and

other chemicals Recycled bags

often turn into corrugated cardboard

Recycling - Plastic

Recycling involves re-melting and reforming Bags must first be

separated into type of plastic they’re made from Time consuming and

expensive $4,000 per ton

Bags collected for recycling are often not recycled Sent to other

countries for incineration

Recycling

Takes 98% less energy to recycle 1 lb of plastic than 1 lb of paper

Recycling rates are low!

Type of bag Energy to recycle bag (BTU) % of bags recycledPaper 1,400 10 to 15Plastic 20 1 to 3

Biodegradable? - Paper

Paper is biodegradable Does not

completely break down in landfills

Biodegradable? - Plastic

Petroleum-based plastics are non-biodegradable

Plastic bags take up less space in the landfill than paper 2,000 plastic bags

= 30 lbs 2,000 paper bags

= 280 lbs

Biodegradable? - Plastic

Some stores use biodegradable plastic bags

Do not break down as quickly as believed

Require oxygen to degrade

Additives in the bags are potentially harmful to the natural world

Generate greenhouse gas emissions

Negatives of each

Paper: Causes more

pollution Consumes more

energy Produces more

waste

Plastic: Contributes to

litter Danger to wildlife Recycling

difficulties Not

biodegradable (most)

What should we do?

Invest in reusable bags Eliminate the use of

~1,000 disposable bags in their lifetime

Not convenient for everyone

Don’t take a bag for 1-2 items

Reuse bags to line trash cans, litter boxes, etc.

Discussion

Which bag has more negative effects? What are other materials bags could be

made from? Other thoughts…

References

http://www.madehow.com/Volume-2/Paper.html

http://www.projectgreenbag.com/paper-bag-are-no-better-than-plastic/

http://www.washingtonpost.com/wp-dyn/content/graphic/2007/10/03/GR2007100301385.html

http://science.howstuffworks.com/environmental/green-science/paper-plastic1.htm

http://www.msnbc.msn.com/id/18538484/

http://www.telegraph.co.uk/earth/earthnews/7422006/Biodegradable-plastic-bags-may-not-be-as-eco-friendly-as-thought.html

http://www.thomasnet.com/articles/plastics-rubber/designing-plastic-bags

http://www.aza.org/uploadedFiles/Member_Resource_Center/Green_Practices/paper_plastic.pdf?n=8191