There are a lot of different types of plastic available today, each with its own unique set of properties and uses. The most prominent categories are defined and discussed below:
For more information, please visit Plastic Chair.
PET is one of the most produced synthetic plastic and is the most popular thermoplastic resin in the polyester family. It offers excellent chemical resistance to organic compounds and water and is easy to recycle. PET also has a high strength-to-weight ratio and is almost shatterproof. This material is found in many everyday items, including food and drink containers, and garment fibers. For more information, see our guide on Polyethylene Terephthalate (PET).
ABS is a glossy, highly processable, flexible, strong, and impact-resistant material that is made by polymerizing styrene and acrylonitrile in the presence of polybutadiene. ABS plastic sheeting is relatively cheap to manufacture and is frequently used in the automotive and refrigeration sectors, as well as in items like boxes, protective headgear, luggage, gauges, and children's toys. For more information, see our guide on Acrylonitrile Butadiene Styrene (ABS).
PVC, the third most common synthetic plastic polymer, can be made flexible or rigid. It is well known for its versatility in mixing with other materials. For example, foamed PVC sheets are ideal for store displays, exhibits, and kiosks. Rigid PVC is extensively used in construction materials, windows, bottles, doors, non-food packaging, and other products. Thanks to the addition of plasticizers like phthalates, the more flexible and softer version of PVC works well in clothing, plumbing supplies, medical tubing, and other related products.
Polypropylene is a thermoplastic polymer and also the second most produced synthetic plastic. PP is one of the most flexible thermoplastics, which contributes to its popularity. And despite this flexibility, it is stronger than PE. Polypropylene sheets are used to produce food containers, automobile components, medical devices, and laboratory equipment because they are affordable, strong, flexible, and heat- and acid-resistant. For more information, see our guide on Polypropylene (PP).
The most common plastic on the planet, polyethylene, comes in multiple densities. This results in plastics with distinct physical properties, so they function for a wide gamut of purposes. The four standard densities of polyethylene are LDPE, MDPE, HDPE (low-, medium-, and high-density polyethylene, respectively), and UHMWPE (ultra-high-molecular-weight polyethylene). The first three denote the relative number of polymer chains per unit volume and each is valuable for different purposes. MDPE is, for example, frequently used in shrink film, gas pipes, screw closures, carrier bags, and other products. UHMWPE, on the other hand, is not significantly denser than HDPE. This polyethylene plastic is significantly more abrasion-resistant than HDPE because of the unusually long polymer chains. UHMWPE goes into bearings, artificial ice skating rinks, hydraulic seals, and biomaterial for spine, knee, and hip implants due to its high density and low friction properties. For more information, see our guide on Polyethylene (PE).
Low-Density Polyethylene (LDPE) is one of the four standard densities of polyethylene. Due to its ductility, polyethylene at this density is perfect for plastic bags, disposable packaging, transparent food containers, and shopping bags. For more information, see our guide on Low-Density Polyethylene (LDPE).
High-Density Polyethylene (HDPE) is another type of PE that is more robust than both LDPE and MDPE. It is used in items like plastic bottles, water and sewer piping, boat hulls, snowboards, and folding chairs. For more information, see our guide on High-Density Polyethylene (HDPE).
Polystyrene, better known as Styrofoam, comes in both solid and foamed forms. This plastic is used in egg cartons, disposable dinnerware, insulation, and drinking cups because of its low cost per unit weight and ease of production. While common, it is extremely combustible and releases toxic compounds when heated. For more information, see our guide on Polystyrene (PS).
As a transparent thermoplastic material that is lightweight and break-resistant, acrylic is great for optical products and gadgets. Mirrors and plexiglass are typically made using sheets of acrylic. Among other things, PMMA is resilient against projectiles, resists UV rays and static electricity, and can accept bright dyes. There are countless applications for acrylic sheeting, which is seventeen times more impact-resistant than glass and polycarbonate sheeting put together. Moreover, it is easier to handle and create. For more information, see our guide on Acrylic or Polymethyl Methacrylate (PMMA).
Polycarbonate is a good engineering plastic that is strong, stable, and transparent. Its strength-to-weight ratio is 250 times better than steels and it has glass-like clarity. Transparent polycarbonate sheets are 30 times stronger than acrylic and are easy to work with, mold, and thermo- or cold-form. Polycarbonate plastic's intrinsic design flexibility enables incredibly strong and impact-resistant construction. Unlike acrylic or glass, PC plastic sheets can be cold-formed or cut right away without needing to be pre-formed and manufactured. Polycarbonate plastic is used to make a variety of products, including greenhouses, CDs, sunglasses, police riot gear, and more. For more information, see our guide on Polycarbonate (PC).
Plastics can have a wide range of physical and chemical properties, depending on their chemical structures and how they are processed. However, some general physical and chemical properties are common to most plastics. These properties are given below:
The physical properties of plastic include:
Here are some common chemical properties of plastic:
Plastic has many different applications. Some of the most common uses of plastic are listed below:
Plastics are often used in the production of toys because they can be molded into various shapes and colors. Plastic toys are durable and lightweight, so they withstand wear and tear.
Plastics are non-conductive, meaning they can protect electronic components and allow for easy assembly. This is why you find plastic in computer and cases and as the insulation on wires.
Plastics are used in various parts of automobiles, including dashboards, bumpers, engine parts, and interior panels. Since theyre both lightweight and durable, they reduce the vehicles weight and improve fuel efficiency.
In the construction sector, plastics are used in a growing array of applications. Plastics are economically appealing thanks to their outstanding strength-to-weight ratio, cost effectiveness, durability, low maintenance requirements, and corrosion resistance. Plastics are used in, among other things, pipes, insulation, roofing materials, and windows.
Plastics can be turned into synthetic fibers and fabrics for textiles. Modern clothing and upholstery commonly include plastics.
Plastic is an ideal material to use for product packaging. Plastics are adaptable, hygienic, light, flexible, and durable. Packaging is thus responsible for the majority of the plastics used globally, coming in the form of vending packaging, baby products, protective packaging, containers, bottles, drums, trays, boxes, cups, and much more.
Plastics are used extensively in the medical industry, including, but not limited to, disposable syringes, IV and blood bags, prosthetic limbs, implantable devices, dialysis machines, heart valves, tubing, and wound dressing. Medical-grade plastics are sterile and biocompatible and can be easily molded into complex shapes. Plus, theyre often less expensive than traditional medical materials.
Plastics have become so widespread because of their numerous advantages, including:
While plastics offer some distinct advantages, they also have several disadvantages. Here are some of the most significant ones:
Plastic is harmful for several reasons. Firstly, most plastic is not biodegradable and can remain in the environment for hundreds of years, causing plastic pollution.
Secondly, some plastic contains toxic chemicals such as bisphenol A (BPA) and phthalates that can leach out into the environment or contaminate food and water sources, posing health risks to humans and wildlife. Although research on the health effects of plastics is far from complete, current scientific findings do show that plastic causes diseases, disabilities, and early death at every stage of its life cycle. Beyond that, animals can become entangled in plastic debris or ingest it, leading to injury, suffocation, and death. Additionally, plastic pollution can alter habitats and food sources, leading to ecosystem disruptions.
The production of plastic uses non-renewable resources such as petroleum, contributing to resource depletion and dependency on fossil fuels. And finally, the production, transportation, and disposal of plastic can contribute to greenhouse gas emissions and climate change, further adding to the harmful effects.
Plastic waste is caused by improper disposal of used plastics. Faulty part designs can also result in plastic waste especially when the part cannot be used as planned.
The short answer here is that it depends. Sometimes there are no alternatives that are viable, economical, and accessible. In many cases, though, plastic can be replaced with more sustainable materials such as paper, glass, or metal. However, in some industries, such as medical devices, plastics unique properties are what make it useful. It is important to assess the need for plastic on a case-by-case basis and consider its environmental and health impacts before deciding whether it is truly necessary.
Several alternatives to plastic are often viable depending on the items purpose. Here are some examples:
Plastics and polymers are closely related concepts, but they are not the same thing. A polymer is a large molecule made up of repeating subunits called monomers, while plastic is a material made from polymers that can be molded into various shapes.
In short, plastics are made up of polymers, but not all polymers can be turned into plastics. Polymers can be natural or synthetic and take on many different forms including proteins, DNA, and cellulose. When the right polymers are chemically treated and processed, they can be turned into plastic.
While polymers exist in many forms, plastic is a specific type of polymer that is designed to be easily molded and shaped. Plastic is often used in packaging, consumer goods, automotive parts, and construction materials because it is lightweight, durable, and versatile.
So, in summary, polymers are large molecules made up of repeating subunits called monomers, while plastic is a material made from polymers that can be molded into various shapes.
This article presented plastic, explained what it is, and discussed the various types of plastic and how they are used. To learn more about plastic, contact a Xometry representative.
Xometry provides a wide range of manufacturing capabilities and other value-added services for all of your prototyping and production needs. Visit our website to learn more or to request a free, no-obligation quote.
The content appearing on this webpage is for informational purposes only. Xometry makes no representation or warranty of any kind, be it expressed or implied, as to the accuracy, completeness, or validity of the information. Any performance parameters, geometric tolerances, specific design features, quality and types of materials, or processes should not be inferred to represent what will be delivered by third-party suppliers or manufacturers through Xometrys network. Buyers seeking quotes for parts are responsible for defining the specific requirements for those parts. Please refer to our terms and conditions for more information.
Furnishing a home can be a complex and time-consuming process. With so many styles, materials, and brands to choose from, it can be difficult to know where to start and what to consider. In this comprehensive furniture analysis, we will explore the pros and cons of different types of furniture and help you choose the right pieces for your home.
WOOD FURNITURE: DURABLE AND TIMELESS
Wood furniture has been a staple in homes for centuries and good reason. This natural material is durable, timeless, and versatile, making it a great choice for any room in your home.
PROS OF WOOD FURNITURE
CONS OF WOOD FURNITURE
SOLUTION:
As a furniture supplier, we understand that wood furniture can be more expensive and high maintenance than other materials. However, we believe that the benefits of wood furniture far outweigh the cons, such as durability, natural beauty, and eco-friendliness.
There are a lot of different types of plastic available today, each with its own unique set of properties and uses. The most prominent categories are defined and discussed below:
PET is one of the most produced synthetic plastic and is the most popular thermoplastic resin in the polyester family. It offers excellent chemical resistance to organic compounds and water and is easy to recycle. PET also has a high strength-to-weight ratio and is almost shatterproof. This material is found in many everyday items, including food and drink containers, and garment fibers. For more information, see our guide on Polyethylene Terephthalate (PET).
ABS is a glossy, highly processable, flexible, strong, and impact-resistant material that is made by polymerizing styrene and acrylonitrile in the presence of polybutadiene. ABS plastic sheeting is relatively cheap to manufacture and is frequently used in the automotive and refrigeration sectors, as well as in items like boxes, protective headgear, luggage, gauges, and children's toys. For more information, see our guide on Acrylonitrile Butadiene Styrene (ABS).
PVC, the third most common synthetic plastic polymer, can be made flexible or rigid. It is well known for its versatility in mixing with other materials. For example, foamed PVC sheets are ideal for store displays, exhibits, and kiosks. Rigid PVC is extensively used in construction materials, windows, bottles, doors, non-food packaging, and other products. Thanks to the addition of plasticizers like phthalates, the more flexible and softer version of PVC works well in clothing, plumbing supplies, medical tubing, and other related products.
Polypropylene is a thermoplastic polymer and also the second most produced synthetic plastic. PP is one of the most flexible thermoplastics, which contributes to its popularity. And despite this flexibility, it is stronger than PE. Polypropylene sheets are used to produce food containers, automobile components, medical devices, and laboratory equipment because they are affordable, strong, flexible, and heat- and acid-resistant. For more information, see our guide on Polypropylene (PP).
The most common plastic on the planet, polyethylene, comes in multiple densities. This results in plastics with distinct physical properties, so they function for a wide gamut of purposes. The four standard densities of polyethylene are LDPE, MDPE, HDPE (low-, medium-, and high-density polyethylene, respectively), and UHMWPE (ultra-high-molecular-weight polyethylene). The first three denote the relative number of polymer chains per unit volume and each is valuable for different purposes. MDPE is, for example, frequently used in shrink film, gas pipes, screw closures, carrier bags, and other products. UHMWPE, on the other hand, is not significantly denser than HDPE. This polyethylene plastic is significantly more abrasion-resistant than HDPE because of the unusually long polymer chains. UHMWPE goes into bearings, artificial ice skating rinks, hydraulic seals, and biomaterial for spine, knee, and hip implants due to its high density and low friction properties. For more information, see our guide on Polyethylene (PE).
Low-Density Polyethylene (LDPE) is one of the four standard densities of polyethylene. Due to its ductility, polyethylene at this density is perfect for plastic bags, disposable packaging, transparent food containers, and shopping bags. For more information, see our guide on Low-Density Polyethylene (LDPE).
High-Density Polyethylene (HDPE) is another type of PE that is more robust than both LDPE and MDPE. It is used in items like plastic bottles, water and sewer piping, boat hulls, snowboards, and folding chairs. For more information, see our guide on High-Density Polyethylene (HDPE).
Polystyrene, better known as Styrofoam, comes in both solid and foamed forms. This plastic is used in egg cartons, disposable dinnerware, insulation, and drinking cups because of its low cost per unit weight and ease of production. While common, it is extremely combustible and releases toxic compounds when heated. For more information, see our guide on Polystyrene (PS).
As a transparent thermoplastic material that is lightweight and break-resistant, acrylic is great for optical products and gadgets. Mirrors and plexiglass are typically made using sheets of acrylic. Among other things, PMMA is resilient against projectiles, resists UV rays and static electricity, and can accept bright dyes. There are countless applications for acrylic sheeting, which is seventeen times more impact-resistant than glass and polycarbonate sheeting put together. Moreover, it is easier to handle and create. For more information, see our guide on Acrylic or Polymethyl Methacrylate (PMMA).
Polycarbonate is a good engineering plastic that is strong, stable, and transparent. Its strength-to-weight ratio is 250 times better than steels and it has glass-like clarity. Transparent polycarbonate sheets are 30 times stronger than acrylic and are easy to work with, mold, and thermo- or cold-form. Polycarbonate plastic's intrinsic design flexibility enables incredibly strong and impact-resistant construction. Unlike acrylic or glass, PC plastic sheets can be cold-formed or cut right away without needing to be pre-formed and manufactured. Polycarbonate plastic is used to make a variety of products, including greenhouses, CDs, sunglasses, police riot gear, and more. For more information, see our guide on Polycarbonate (PC).
Plastics can have a wide range of physical and chemical properties, depending on their chemical structures and how they are processed. However, some general physical and chemical properties are common to most plastics. These properties are given below:
The physical properties of plastic include:
Here are some common chemical properties of plastic:
Plastic has many different applications. Some of the most common uses of plastic are listed below:
Plastics are often used in the production of toys because they can be molded into various shapes and colors. Plastic toys are durable and lightweight, so they withstand wear and tear.
Plastics are non-conductive, meaning they can protect electronic components and allow for easy assembly. This is why you find plastic in computer and cases and as the insulation on wires.
Plastics are used in various parts of automobiles, including dashboards, bumpers, engine parts, and interior panels. Since theyre both lightweight and durable, they reduce the vehicles weight and improve fuel efficiency.
In the construction sector, plastics are used in a growing array of applications. Plastics are economically appealing thanks to their outstanding strength-to-weight ratio, cost effectiveness, durability, low maintenance requirements, and corrosion resistance. Plastics are used in, among other things, pipes, insulation, roofing materials, and windows.
Plastics can be turned into synthetic fibers and fabrics for textiles. Modern clothing and upholstery commonly include plastics.
Plastic is an ideal material to use for product packaging. Plastics are adaptable, hygienic, light, flexible, and durable. Packaging is thus responsible for the majority of the plastics used globally, coming in the form of vending packaging, baby products, protective packaging, containers, bottles, drums, trays, boxes, cups, and much more.
Plastics are used extensively in the medical industry, including, but not limited to, disposable syringes, IV and blood bags, prosthetic limbs, implantable devices, dialysis machines, heart valves, tubing, and wound dressing. Medical-grade plastics are sterile and biocompatible and can be easily molded into complex shapes. Plus, theyre often less expensive than traditional medical materials.
Plastics have become so widespread because of their numerous advantages, including:
While plastics offer some distinct advantages, they also have several disadvantages. Here are some of the most significant ones:
Plastic is harmful for several reasons. Firstly, most plastic is not biodegradable and can remain in the environment for hundreds of years, causing plastic pollution.
Secondly, some plastic contains toxic chemicals such as bisphenol A (BPA) and phthalates that can leach out into the environment or contaminate food and water sources, posing health risks to humans and wildlife. Although research on the health effects of plastics is far from complete, current scientific findings do show that plastic causes diseases, disabilities, and early death at every stage of its life cycle. Beyond that, animals can become entangled in plastic debris or ingest it, leading to injury, suffocation, and death. Additionally, plastic pollution can alter habitats and food sources, leading to ecosystem disruptions.
The production of plastic uses non-renewable resources such as petroleum, contributing to resource depletion and dependency on fossil fuels. And finally, the production, transportation, and disposal of plastic can contribute to greenhouse gas emissions and climate change, further adding to the harmful effects.
Plastic waste is caused by improper disposal of used plastics. Faulty part designs can also result in plastic waste especially when the part cannot be used as planned.
The short answer here is that it depends. Sometimes there are no alternatives that are viable, economical, and accessible. In many cases, though, plastic can be replaced with more sustainable materials such as paper, glass, or metal. However, in some industries, such as medical devices, plastics unique properties are what make it useful. It is important to assess the need for plastic on a case-by-case basis and consider its environmental and health impacts before deciding whether it is truly necessary.
Several alternatives to plastic are often viable depending on the items purpose. Here are some examples:
Plastics and polymers are closely related concepts, but they are not the same thing. A polymer is a large molecule made up of repeating subunits called monomers, while plastic is a material made from polymers that can be molded into various shapes.
In short, plastics are made up of polymers, but not all polymers can be turned into plastics. Polymers can be natural or synthetic and take on many different forms including proteins, DNA, and cellulose. When the right polymers are chemically treated and processed, they can be turned into plastic.
While polymers exist in many forms, plastic is a specific type of polymer that is designed to be easily molded and shaped. Plastic is often used in packaging, consumer goods, automotive parts, and construction materials because it is lightweight, durable, and versatile.
So, in summary, polymers are large molecules made up of repeating subunits called monomers, while plastic is a material made from polymers that can be molded into various shapes.
This article presented plastic, explained what it is, and discussed the various types of plastic and how they are used. To learn more about plastic, contact a Xometry representative.
Xometry provides a wide range of manufacturing capabilities and other value-added services for all of your prototyping and production needs. Visit our website to learn more or to request a free, no-obligation quote.
The content appearing on this webpage is for informational purposes only. Xometry makes no representation or warranty of any kind, be it expressed or implied, as to the accuracy, completeness, or validity of the information. Any performance parameters, geometric tolerances, specific design features, quality and types of materials, or processes should not be inferred to represent what will be delivered by third-party suppliers or manufacturers through Xometrys network. Buyers seeking quotes for parts are responsible for defining the specific requirements for those parts. Please refer to our terms and conditions for more information.
Furnishing a home can be a complex and time-consuming process. With so many styles, materials, and brands to choose from, it can be difficult to know where to start and what to consider. In this comprehensive furniture analysis, we will explore the pros and cons of different types of furniture and help you choose the right pieces for your home.
WOOD FURNITURE: DURABLE AND TIMELESS
Wood furniture has been a staple in homes for centuries and good reason. This natural material is durable, timeless, and versatile, making it a great choice for any room in your home.
PROS OF WOOD FURNITURE
CONS OF WOOD FURNITURE
SOLUTION:
As a furniture supplier, we understand that wood furniture can be more expensive and high maintenance than other materials. However, we believe that the benefits of wood furniture far outweigh the cons, such as durability, natural beauty, and eco-friendliness.
At Laskasas, we believe that wood furniture offers a timeless and elegant look that can add warmth and character to any home, and we are always happy to help customers find the perfect piece of furniture for their space.
METAL FURNITURE: SLEEK AND MODERN
(LessThanFive Stool by Steelcase)
Metal furniture has been rising in popularity in recent years, and it's easy to see why. It is a modern and sleek option that can complement any style. It is durable and easy to clean, and it can be used both indoors and outdoors.
PROS OF METAL FURNITURE
CONS OF METAL FURNITURE
SOLUTION:
While we acknowledge that metal furniture can have certain downsides like higher cost, maintenance requirements, and the discomfort of its cold touch, we firmly believe that it also comes with numerous advantages such as unparalleled durability, exceptional strength, and vast design flexibility.
Metal furniture is not our expertise, but we do have some recommendations that we consider a valued asset in this segment, such as Domkapa and Steelcase.
UPHOLSTERED FURNITURE: COMFORTABLE AND COSY
Upholstered furniture, such as sofas, chairs, and ottomans, is popular in many homes. This type of furniture is known for its comfort and cosy feel, making it a great choice for living rooms, bedrooms, and other spaces where you want to relax and unwind.
PROS OF UPHOLSTERED FURNITURE
CONS OF UPHOLSTERED FURNITURE
SOLUTION:
we understand that upholstered furniture can come with some challenges such as cost, maintenance, and comfort. However, we also believe that it offers a unique and inviting look that can add character and warmth to any space.
PLASTIC FURNITURE: AFFORDABLE AND DURABLE
(La Chaise by Charles & Ray Eames and sold by Vitra)
Plastic furniture has been popular for many years, especially in outdoor spaces. This type of furniture is known for its affordability, durability, and easy maintenance.
PROS OF PLASTIC FURNITURE
CONS OF PLASTIC FURNITURE
SOLUTION:
We recognise that plastic furniture may not be the first choice for everyone due to its limitations in style options, lack of comfort, and potential environmental impact. Despite that, we also believe that plastic furniture can offer benefits such as affordability, durability, and easy maintenance.
Plastic furniture is not our expertise, but we do have some recommendations that we consider a valued asset in this segment, such as Vitra.
CHOOSING THE RIGHT FURNITURE FOR YOUR HOME:
In conclusion, choosing the right furniture for your home requires careful consideration of your style, budget, and lifestyle. Whether you choose wood, metal, upholstery, or plastic, it's important to take the time to understand the pros and cons of each material and choose pieces that will enhance the look and feel of your home for years to come.
At Laskasas, we believe that wood furniture offers a timeless and elegant look that can add warmth and character to any home, and we are always happy to help customers find the perfect piece of furniture for their space.
METAL FURNITURE: SLEEK AND MODERN
(LessThanFive Stool by Steelcase)
Metal furniture has been rising in popularity in recent years, and it's easy to see why. It is a modern and sleek option that can complement any style. It is durable and easy to clean, and it can be used both indoors and outdoors.
PROS OF METAL FURNITURE
CONS OF METAL FURNITURE
SOLUTION:
While we acknowledge that metal furniture can have certain downsides like higher cost, maintenance requirements, and the discomfort of its cold touch, we firmly believe that it also comes with numerous advantages such as unparalleled durability, exceptional strength, and vast design flexibility.
Metal furniture is not our expertise, but we do have some recommendations that we consider a valued asset in this segment, such as Domkapa and Steelcase.
UPHOLSTERED FURNITURE: COMFORTABLE AND COSY
Upholstered furniture, such as sofas, chairs, and ottomans, is popular in many homes. This type of furniture is known for its comfort and cosy feel, making it a great choice for living rooms, bedrooms, and other spaces where you want to relax and unwind.
PROS OF UPHOLSTERED FURNITURE
CONS OF UPHOLSTERED FURNITURE
SOLUTION:
we understand that upholstered furniture can come with some challenges such as cost, maintenance, and comfort. However, we also believe that it offers a unique and inviting look that can add character and warmth to any space.
PLASTIC FURNITURE: AFFORDABLE AND DURABLE
(La Chaise by Charles & Ray Eames and sold by Vitra)
Plastic furniture has been popular for many years, especially in outdoor spaces. This type of furniture is known for its affordability, durability, and easy maintenance.
PROS OF PLASTIC FURNITURE
CONS OF PLASTIC FURNITURE
SOLUTION:
We recognise that plastic furniture may not be the first choice for everyone due to its limitations in style options, lack of comfort, and potential environmental impact. Despite that, we also believe that plastic furniture can offer benefits such as affordability, durability, and easy maintenance.
Plastic furniture is not our expertise, but we do have some recommendations that we consider a valued asset in this segment, such as Vitra.
CHOOSING THE RIGHT FURNITURE FOR YOUR HOME:
In conclusion, choosing the right furniture for your home requires careful consideration of your style, budget, and lifestyle. Whether you choose wood, metal, upholstery, or plastic, it's important to take the time to understand the pros and cons of each material and choose pieces that will enhance the look and feel of your home for years to come.
For more Tolix Chairinformation, please contact us. We will provide professional answers.