What makes polystyrene hard

Polystyrene is an inexpensive and hard plastic , and probably only polyethylene is more common in your everyday life. The outside housing of the computer you're using now is probably made of polystyrene, as well as the housings of things like hairdryers, TVs and kitchen appliances.

Model cars and airplanes are made from polystyrene, as well as many other toys. There's also foam packaging and insulation, and a lot of the molded parts on the inside of your car, like the radio knobs.

Polystyrene is also used to make drinking cups - the hard plastic ones and also the soft foamy ones. A popular brand of polystyrene foam is called Styrofoam TM. Would you believe all three of these cups are made from polystyrene?! Here's a molecule of polystyrene. You can see it in this 3-D model on the right or in the diagram below. Click the 3-D picture to see an interactive version. The difference between polystyrene and polyethylene is that each repeat unit in styrene has a big pendant group instead of one of the H's.

In this diagram the little "n" means that this group of atoms is repeated over and over to make the large polystyrene molecule you see on the right and below. What, you guys again?! The difference is chemistry. Styrene is a liquid that can be chemically linked to create polystyrene, a solid plastic that displays different properties. Polystyrene is used to make a variety of consumer products, such as foodservice containers, cushioning for shipping delicate electronics and insulation.

Extruded polystyrene XPS foam is a rigid insulation that has also formed with polystyrene polymer, but manufactured using an extrusion process. Plastics Foodservice Packaging Group. Tweets by AmChemistry. Home Polystyrene Polystyrene. Polystyrene in Automotive Polystyrene solid and foam is used to make many car parts, including knobs, instrument panels, trim, energy absorbing door panels and sound dampening foam.

Polystyrene in Electronics Polystyrene is used for the housing and other parts for televisions, computers and all types of IT equipment, where the combination of form, function and aesthetics are essential. Polystyrene in Foodservice Polystyrene foodservice packaging typically insulates better, keeps food fresher longer and costs less than alternatives.

Polystyrene in Insulation Lightweight polystyrene foam provides excellent thermal insulation in numerous applications, such as building walls and roofing, refrigerators and freezers, and industrial cold storage facilities.

Polystyrene in Medical Due to its clarity and ease of sterilization, polystyrene is used for a wide range of medical applications, including tissue culture trays, test tubes, petri dishes, diagnostic components, housings for test kits and medical devices. Polystyrene in Packaging Polystyrene solid and foam is widely used to protect consumer products. Back to Top. Polystyrene Safety in Food Packaging FDA has for decades stated that polystyrene is safe for use in contact with food.

Polystyrene foodservice packaging can help reduce food-borne illness in homes, hospitals, schools, nursing homes, cafeterias and restaurants.

Polystyrene foodservice packaging is preferred by the foodservice industry because it works better than alternatives. Of course, all data must meet the standards for EPF. EPF can safely be incinerated and will yield only carbon dioxide and water if the procedure is handled correctly, but the trend has been to recycle it wherever possible.

EPF can be recycled into concrete, egg cartons, office products, foam insulation, and garbage cans. Unfortunately, only one percent of the 11 billion kilograms of EPF thrown away each year is being recycled. The National Polystyrene Recycling Company, which consists of seven major corporations, including Amoco, Dow, and Mobil, plans to increase this to 25 percent by by focusing on big users of EPF—fast food outlets and college dining establishments.

Since the Montreal Protocol of , new research has focused on ways to reduce CFC use, and on developing alternative blowing agents that will not harm the ozone layer. Recent developments include a process that uses pressurized carbon dioxide to produce smaller, more uniform cells.

These in turn provide a foam that is stronger and smoother than earlier foams. Beck, Ronald D. Plastic Product Design. Van Nostrand Reinhold Company, Concise Encyclopedia of Chemical Technology.

Kaufman, Morris. Doubleday and Company, Inc. Modern Plastics Encyclopedia, McGraw-Hill, Richardson, Terry A. Industrial Plastics: Theory and Application. South-Western Publishing Co. Wolf, Nancy and Ellen Feldman. Plastics: America's Packaging Dilemma.

Island Press, Bak, David J. January 23, , p. November 20, , p. Kirkman, Angela and Charles H. October, , pp. Powell, Corey S. There are clear disposable PS containers e. The hinge in this case is a little different than your traditional PP living hinge. Typically the PS hinge is more of a series of bends that allow the clamshell to flex and open up. Whether it is technically a living hinge or not, it still works very well and can be easily thermoformed.

Three major types of polystyrene include polystyrene foam, regular polystyrene plastic, and polystyrene film. EPS includes the most well-known and common types of polystyrene to include styrofoam and packing peanuts. XPS is a higher density foam typically used in applications like architectural building models.

Some types of polystyrene plastic are copolymers. Oftentimes homopolymer PS is fairly brittle and can be made more impact resistant if combined with other materials known in this form as the copolymer High Impact Polystyrene, or HIPS.

Polystyrene film can also be vacuum formed and used in packaging applications. Films can be stretched into oriented polystyrene OPS that is cheaper to produce albeit more brittle than alternatives like PP. Yo u can read about the process in more depth here. Polystyrene is available in sheet stock, rod stock, and in various shapes.

It is a great candidate for subtractive machining processes on a CNC machine.