Plastics in Everyday Household Articles

Household adhesives can be used for gluing plastic together, with varying degrees of success, depending on the glue and the plastic. Refer to the table below, which lists the major types of plastics and how they are used in common household and industrial products.

Plastics in Everyday Household Articles
Household Article	Type of Plastic
Bottles and other containers	Polyethylene, polypropylene
Buckets	Polyethylene, polypropylene
Dishware (plastic, of course)	Melamine resin†, polystyrene
Glasses (drinking)
Clear, hard	Polystyrene
Flexible	Polyethylene
Insulated cups	Polystyrene foam (Styrofoam)
Foam cushions	Polyurethane foam
Electrical circuit boards	Laminated epoxies, phenolic
Fillers
Caulking compounds	Polyurethane, silicone, PVAc*
Patching compounds	Polyester, fiberglass
Putty	Epoxy, polyester, PVAc
Films
Audio tape	Polyester
Food wrap	Polyethylene, polypropylene
Photographic	Cellulosic
Garden hose	PVC
Insulation foam	Polystyrene, polyurethane
Plumbing pipes
Fresh water	PVC, polyethylene
Gray water, sewage	ABS
Siding and paneling	PVC
Toys
Flexible	Polyethylene, polypropylene
Rigid	Polystyrene, ABS
Tubing (clear or translucent)	Polyethylene, PVC

† Melamine resin is the fancy name for things like Formica. It’s a plastic, but it can’t be remelted into usable shapes. Gluing may be difficult with common adhesives.

* PVAc is not the same as PVC. PVAc stands for polyvinyl acetate, a kind of plastic used in common household glues, among other things.

Decoding Plastic ID Symbols

You’ve seen them on the bottoms of bottles and canisters. They’re the funny circular arrow thingamajigs with numbers inside. You know this already—these funky graphics are ID symbols designed to help consumers and recyclers tell the difference between various plastics.

If you’re building robots out of junk you find around the house, it can be darned useful to know what kind of plastic it is, in case you want to join two or more pieces with some solvent cement. Why is this important? Because different plastics require different kinds of solvent cements. A solvent for one plastic may do absolutely nothing for another.

Here’s what the ID symbols mean:

Recycle Code	Plastic Name	Common Household Items
	PET and PETE - polyethylene terephthalate	Soft-drink bottles, containers for food and other consumer products, water bottles, peanut butter jars
	HDPE- high density polyethylene	Milk and juice bottles, dishwashing and laundry detergent, grocery bags
	PVC - polyvinyl chloride	Bottles, food trays, rigid sheets used for packaging, electrical insulation, irrigation pipes
	LDPE - low-density polyethylene	Squeeze bottles, wire insulation, grocery bags, trash bags, food storage bags
	PP - polypropylene	Fruit and vegetable packages, bottle caps, drinking straws (telltale sign: cloudy appearance)
	PS - polystyrene	Packaging, CD covers, Styrofoam, egg cartons, packing “peanuts,” plastic tableware, carryout containers
	A combination of plastics, or none of the above	Items already made from recycled goods, semi-rigid food storage, drinking cups