What is the difference between polypropylene and acrylic

This overall creation process is known as polymerization. Without getting too bogged down by the technical details, polycarbonate is produced by the reaction between bisphenol A and phosgene COCl2. On the other hand, acrylic is made by synthesizing methyl methacrylate. Methyl methacrylate is typically created by reacting acetone with sodium cyanide to produce acetone cyanohydrin. This is then reacted with methyl alcohol to finally produce methyl methacrylate. These are the most common methods for creating these polymers.

However, there are a variety of ways that polycarbonate and acrylic can be formed, especially when creating plastic sheets with special qualities such as color, non-glare, anti-static, UV-filtering, and more. Using a process known as bulk polymerization, the monomer methyl methacrylate and the catalyst typically organic peroxide are poured into a mold, which is sealed and heated to produce the reaction that forms the acrylic plastic polymer.

The molded acrylic sheets are then cured. Thinner acrylic sheets can be cured in 10 to 12 hours, but thicker sheets may require several days of cure time. The molds are then cooled, opened, and the resulting acrylic plastic sheets are either immediately used or further processed to improve the overall quality of the final product. Batch cell and continuous bulk polymerization are the two methods used to create acrylic plastic sheets. Batch cell is the most common form of bulk polymerization because it is effective at making acrylic sheets in thicknesses from 0.

The continuous method of bulk polymerization is quicker and less labor intensive because this method is specifically used for creating acrylic plastic sheets with thinner thicknesses and smaller widths than batch cell can produce. Polycarbonate can be processed and manufactured in a wide variety of ways, such as extrusion, injection molding, blow molding, thermoforming, and more.

When it comes to producing polycarbonate sheets, however, the extrusion manufacturing process is most commonly utilized.

To begin the process, raw resin polycarbonate pellets is fed into an extruder and melted to the desired temperature. The melted polycarbonate material is then forced through a die that is shaped to produce flat sheets of various lengths, widths, and thicknesses with uniform cross-sections. During this process, the polycarbonate sheet can be produced with colors, high or low glosses, smooth or textured surfaces, and in single or multiple layers.

Once the polycarbonate sheets have been fabricated through the extrusion process, they can be further processed to achieve the desired final product. The unique physical properties and manufacturing process of each plastic allows sheeting to be produced in a variety of forms specifically designed to fulfill both broad and narrow applications.

Here are the different types of polycarbonate and acrylic sheeting available:. Polycarbonate and acrylic share many of the same types of plastic sheeting options like clear, colored, mirrored, and more. While the form may be the same, you will find that a clear polycarbonate sheet and a clear acrylic sheet are vastly different due to the physical and chemical properties of the plastic. Choosing one over the other depends entirely on the specifics of your application.

If you are interested in clarity and light transmittance, acrylic sheets will outperform polycarbonate sheets. On the other hand, if you are looking for high impact resistance, polycarbonate sheeting is the obvious choice.

Even though each plastic can share the same form, they will function very differently. By contrast, thermoset plastics can only be heated once typically during the injection molding process. The first heating causes thermoset materials to set similar to a 2-part epoxy resulting in a chemical change that cannot be reversed.

If you tried to h eat a thermoset plastic to a high temperature a second time it would simply burn. This characteristic makes thermoset materials poor candidates for recycling. Polypropylene is used in both household and industrial applications. Its unique properties and ability to adapt to various fabrication techniques make it stand out as an invaluable material for a wide range of uses.

Its growth has been sustained over the years and it remains a major player in the plastic industry worldwide. At Creative Mechanisms , we have used polypropylene in a number of applications across a range of industries.

Perhaps the most interesting example includes our ability to CNC machine polypropylene to include a living hinge for prototype living hinge development. Polypropylene is a very flexible, soft material with a relatively low melting point. These factors have prevented most people from being able to properly machine the material. It gums up. It starts to melt from the heat of the CNC cutter.

It typically needs to be scraped smooth to get anything close to a finished surface. But we have been able to solve this problem which allows us to create novel prototype living hinges out of polypropylene. Take a look at the video below:. There are two main types of polypropylene available: homopolymers and copolymers. The copolymers are further divided into block copolymers and random copolymers. Each category fits certain applications better than the others.

This is usually achieved by introducing special additives to it or by manufacturing it in a very particular way. This adaptability is a vital property. Homopolymer polypropylene is a general-purpose grade. You can think of this like the default state of the polypropylene material. Ethylene improves certain properties, like impact resistance while other additives enhance other properties. Random copolymer polypropylene — as opposed to block copolymer polypropylene — has the co-monomer units arranged in irregular or random patterns along the polypropylene molecule.

Polypropylene is not readily available in filament form for 3D printing. Polypropylene is widely used as sheet stock for CNC machine manufacturing. When we prototype a small number of polypropylene parts we typically CNC machine them. Polypropylene has gained a reputation as a material that cannot be machined. In addition to being than glass and polycarbonate sheeting, acrylic is seventeen times more impact resistant than glass, easier to handle and process, and has endless applications.

Tough, stable, and transparent, polycarbonate is an excellent engineering plastic that is as clear as glass and two hundred and fifty times stronger. Thirty times stronger than acrylic, clear polycarbonate sheets are also easily worked, molded, and thermo-formed or cold-formed.

Although extremely strong and impact-resistant, polycarbonate plastic possesses inherent design flexibility. Unlike glass or acrylic, polycarbonate plastic sheets can be cut or cold-formed on site without pre-forming and fabrication.

Polycarbonate plastic is in a wide variety of products including greenhouses, DVDs, sunglasses, police riot gear, and more. The most common plastic on earth, polyethylene can be manufactured in varying densities. Each different density of polyethylene gives the final plastic unique physical properties. As a result, polyethylene is in a wide variety of products. This density of polyethylene is ductile and used to make products like shopping bags, plastic bags, clear food containers, disposable packaging, etc.

Possessing more polymer chains and, thus, greater density, MDPE is typically in gas pipes, shrink film, carrier bags, screw closures, and more. Compared to HDPE, this polyethylene plastic much more abrasion resistant due to the extreme length of its polymer chains.

Possessing high density and low friction properties, UHMWPE is in military body armor, hydraulic seals and bearings, biomaterial for hip, knee, and spine implants, and artificial ice skating rinks. Its widespread use and popularity are undoubted because polypropylene is one of the most flexible thermoplastics on the planet.

Although PP is stronger than PE, it still retains flexibility. It will not crack under repeated stress. Durable, flexible, heat resistant, acid resistance, and cheap, polypropylene sheets are used to make laboratory equipment, automotive parts, medical devices, and food containers.

Just to name a few.