PP (PP stands for Polypropylane) is a hard and crystalline thermoplastic widely used in everyday items such as packaging trays, household appliances, battery boxes and medical devices…
In this article, Household Plus will help you discover and learn everything you should and need to know about this widely used PP thermoplastic.
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What Is Polypropylene (PP) Plastic & What Is It Used For?
Polypropylene (PP) plastic is a rigid thermoplastic manufactured from the monomer propene (or propylene). It is a hydrocarbon resin.
The chemical formula of polypropylene is (C3H6)n. PP is one of the cheapest plastics available today.
The formula & chemical structure of PP . resin
PP plastic is used in many applications including packaging for consumer products, plastic parts for various industries including the auto industry, special appliances, home appliances and textiles. …
Polypropylene was first polymerized in 1951 by a pair of Phillips petroleum scientists named Paul Hogan and Robert Banks and later by Italian and German scientists Natta and Rehn. It came to prominence extremely quickly, as commercial production began just three years after the Italian chemist, Professor Giulio Natta, first polymerized it.
Natta perfected and synthesized the first polypropylene resin in Spain in 1954, and polypropylene’s ability to crystallize created a lot of excitement. By 1957, its popularity had exploded and widespread commercial production began throughout Europe. Today, it is one of the most commonly produced plastics in the world.
PP belongs to the family of polyolefin polymers and is one of the top three widely used polymers today. PP has applications both as a plastic and as a fiber:
Automotive industryIndustrial applicationsConsumer goodsFurniture.
According to some reports, the current global demand for raw materials creates an annual market of about 45 million tons and it is estimated that demand will grow to about 62 million tons by 2020. The end user of polypropylene is the packaging industry. , which consumes about 30% of the total, followed by electricity and appliance production, which uses about 13% each. The home appliance and automotive industry both consume 10% each, and construction materials follow with 5% of the market. These other applications together make up the rest of the global polypropylene consumption.
One of the main benefits of Polypropylene is that it can be manufactured (via CNC or injection molding, hot pressing, or bending) into a live hinge. Live hinges are extremely thin pieces of plastic that bend without breaking (even over extreme ranges of motion near 360 degrees). They are not particularly useful for structural applications like holding a heavy door but are particularly useful for non-load bearing applications such as caps on ketchup or shampoo bottles. Polypropylene is especially good for live hinges because it doesn’t break when bent repeatedly. One of the other advantages is that polypropylene can be CNC machined to include a live hinge allowing for faster and less expensive prototype development than other prototyping methods. The innovative mechanism is unique in our ability to fabricate a living hinge from a single piece of polypropylene.
Another advantage of Polypropylene is that it can be easily copolymerized (essentially combined into a synthetic resin) with other polymers such as polyethylene. Copolymerization dramatically changes material properties, allowing for more robust engineering applications than is possible with pure polypropylene (many of which are self-produced).
The characteristics mentioned above and below mean that polypropylene is used in many applications: dishwasher-safe dishes, trays, cups, etc., chisels and many toys.
What are the Properties of Polypropylene Plastic
?Some of the most important properties of polypropylene are:
Chemical resistance: Diluted bases and acids don’t react readily with polypropylene, which makes it a good choice for containers with liquids such as detergents, first aid products, and more. and toughness: Polypropylene will behave with elasticity over a certain deflection range (like all materials), but it will also undergo plastic deformation early in the deformation process, so it is often considered a “hard” material. Toughness is a technical term that is defined as the ability of a material to deform (plastic, inelastic) without breaking.. Deformability: Polypropylene retains its shape after many twists, turns, and bends. / or bending. This property is particularly valuable for living hinges. Insulation: polypropylene has a very high resistance and is useful for electronic components. Transparency & light penetration: Although Polypropylene can be made transparent , but it is often manufactured to be naturally opaque. Polypropylene can be used for applications where some light transfer is important or where there is aesthetic value. If high transmittance is desired then resins such as Acrylic or Polycarbonate are a better choice.
Polypropylene is classified The type is a “thermoplastic” (as opposed to a “thermoplastic”) material that is related to how the plastic responds to heat. Thermoplastic materials become liquids at their melting point (about 130 degrees Celsius in the case of polypropylene). A key useful property about thermoplastics is that they can be heated to the melting point, cooled, and reheated without significant deterioration. Instead of incineration, thermoplastics like polypropylene liquefy, allowing them to be easily molded and then recycled.
In contrast, thermoset plastics can only be heated once (usually during injection molding). The initial heating causes the material to heat set (similar to 2-part epoxy) resulting in an irreversible chemical change. If you try to heat the thermoplastic to a high temperature a second time, it will burn. This property makes thermoset materials poor candidates for recycling.
Why is PP Plastic Commonly Used
?The plastic cups we still use often are made from PP plastic.
Polypropylene is used in both household and industrial applications. Its unique properties and adaptability to different fabrication techniques make it stand out as an invaluable material for many uses.
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Another invaluable property is polypropylene’s ability to function as both a plastic material and a fiber (like those promotional tote bags given away at events, races, etc.)
Polypropylene’s unique ability to be produced through different methods and into different applications meant that it soon began to challenge many older alternative materials, particularly in the packaging industries, yarn and injection molding. Its growth has been sustained over the years and it remains a major player in the worldwide plastics industry.
The most important is still the production cost, polypropylene plastic is the cheapest plastic currently.
On Household Plus, there are many products made from beautiful and convenient high-grade PP plastic. Including many categories such as kitchen utensils, equipment and bathroom supplies, neat utensils..
Top 3 household appliances made from PP plastic on Household Plus:
Choose smart home appliances and gadgets right away on Household Appliances Plus to make your home more convenient and life more enjoyable.
How to Produce PP Plastic
?Today, polypropylene is produced from the polymerization of propene monomer (an unsaturated organic compound – chemical formula is C3H6) by:
Ziegler-Natta polymerization Metal catalysis polymerization
After polymerization occurs, PP can form three basic chain structures depending on the position of the methyl groups:
Atactic (aPP) – Irregular arrangement of methyl groups (CH3)Isotactic (iPP) – methyl groups (CH3) arranged on one side of the carbon chainSydiotactic (sPP) – Alternating methyl group (CH3)
Types of Polypropylene & Their Benefits
There are two main types of polypropylene available: homopolymers and copolymers.
Copolymers are divided into block copolymers and random copolymers. Each category suits certain apps better than others. Polypropylene is often referred to as the “steel” of the plastics industry because of the different ways it can be modified or customized to best serve a particular purpose. This is usually achieved by introducing special additives to it or by manufacturing it in a very specific way. This adaptability is an important asset.
Homopolymer polypropylene is a kind of general purpose. You can think of this like the default state of the polypropylene material. Block copolymer polypropylene has copolymer units that are mass ordered (that is, in a regular pattern) and contain anywhere from 5% to 15% ethylene. Ethylene improves certain properties, like impact resistance, while other additives enhance other properties. Random polypropylene – as opposed to block copolymer polypropylene – has isomer units arranged in an irregular or random pattern along the polypropylene molecule. They are typically combined with anywhere from 1% to 7% ethylene and are chosen for applications where a clearer, more ductile product is desired.
What are the Advantages of PP Plastic
?PP is available and relatively inexpensive.Polypropylene has high flexural strength due to its semi-crystalline nature.Polypropylene has a relatively smooth surface.Polypropylene has very high resistance to moisture.Polypropylene has good chemical resistance to many bases and acids.Polypropylene possesses good fatigue resistance.Polypropylene has good impact strength.Polypropylene is a good electrical insulator.
What are the disadvantages of Polypropylene
?Polypropylene has a high coefficient of thermal expansion that limits high temperature applications.Polypropylene is susceptible to UV degradation.Polypropylene has poor resistance to chlorinated solvents and aromatics.Polypropylene is known to be difficult to paint because of its bonding properties poor.Polypropylene is very flammable.Polypropylene is easily oxidized.
Despite its shortcomings, polypropylene is a great material in general. It has a unique blend of qualities that aren’t found in any other material making it an ideal choice for many projects.
Is PP Plastic Toxic? Is PP Plastic Recyclable?
All plastics have a Plastic Identification Code / Plastic Recycling Code Plastics based on the type of plastic used. The PP plastic identification code is 5.
PP is 100% recyclable. Car battery covers, signal lights, battery cables, brooms, brooms, ice makers, and more, are just a few examples that can be made from recycled polypropylene (rPP).
The PP recycling process mainly consists of melting the waste plastic to 250°C to remove the contaminants then removing the remaining molecules in a vacuum and solidifying at close to 140°C. can be blended with virgin PP up to 50%. The main challenge in PP recycling is related to its consumption – currently almost 1% of PP bottles are recycled compared to 98% recycling rate of PET & HDPE bottles together.
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The use of PP is considered safe as it does not have any significant effects from an occupational health and safety point of view, in terms of chemical toxicity.