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Teens design environmentally friendly invention

Plastic grocery bags transformed into cup coasters that can be used over and over again

Members of the engineering club at Walnut Grove Secondary School are hoping to change the world, one coaster at a time.

The club members, consisting primarily of senior students with one Grade 8 in the mix, have come up with a way to liquefy environmentally unfriendly plastic grocery bags and then turn them into cup coasters.

Grade 12 William Zhang and Grade 11 Mike He have taken on leadership roles with the project.

Zhang explained the process:

“We first divide plastic bags into different grades, such as hard Nike bags, soft Save-On-Foods bags, and silky H&M bags (and) we cut them into small strips. We then put vegetable oil into a beaker, and turn on the heat for the hot plate. It will take about six minutes for the oil to reach operating temperature,” Zhang explained.

“We put the plastic bags in, and it becomes malleable in a few seconds. Finally, we press the malleable plastic in the press we made and it produces a coaster. The reason we use oil is because it does not produce toxic fumes when the oil is clean. Furthermore, the oil also retains the heat very well and does not burn the plastic.”

Studies vary, but it can take decades for a plastic grocery bag to break down in a landfill. A bylaw banning plastic bags was recently adopted in Victoria, where businesses will be restricted from charging for or providing free plastic bags, except in specific situations. Retailers must first ask customers if they need a bag, and then charge 15 cents for a paper bag, or $1 for a reusable bag.

The bylaw will be put into effect in July 2018.

WGSS science teacher Tim Stephenson sponsors the school’s engineering club and suggested to the students that they transform what he calls “non-refundable, worthless plastic” into a meaningful product, so it doesn’t end up in landfills, and then mass produce it.

“Stamp the Walnut Grove logo on it, and sell it, and who knows what you do from there and that’s what they’ve done,” Stephenson said.

Zhang and He brainstormed and presented the idea to their fellow club members.

“At first we wanted to turn the plastic into small particles,” He said. “We found it to be too challenging so we were trying to find an easier way to do this. After doing some research we found that we could turn the plastic into coasters.”

Ultimately, Zhang hopes WGSS will accept plastic bags from the public. The bags would then be pressed into coasters and other items. Zhang says the club is researching a way to melt hard plastic such as bottle caps, by using different types of oil. If successful, the hard plastic could be transformed into phone cases or pencil cases, Zhang noted.

Few of the club members take woodworking at WGSS, but they designed and then fashioned a homemade plywood device that presses the melted plastic into discs for coasters.

WGSS technology teacher Darren McKay provided the shop time and tools necessary to put the wooden press together.

“William came to me with these ideas, and he said, ‘We need to build this,’” McKay said.

“I said, ‘I can provide the tools but you guys have to provide the brainpower. I’m not going to problem solve for you, that’s the point of your club.’”

The club members wrote safety tests to ensure they could do the woodworking in the school’s shops, outside of class time.

Brainstorming began in September and the idea took flight at the end of that month. The club is starting with cup coasters but more products created by these molten plastic molds could be on the horizon.

“Phone cases was another idea we have down the road, but we’re not quite at that point yet,” Stephenson said.



troy.landreville@blackpress.ca

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The engineering club at Walnut Grove Secondary has designed a press made out of plywood. The press turns malleable plastic into cup coasters. Troy Landreville Langley Times