Plastics have become synonymous with everyday life in our modern era. They’re so common, we rarely give a moment’s notice to the many items with plastic in them we use multiple times a day. Whether it’s keeping our food fresh or keeping our kids’ heads safe when playing, life without plastics would be remarkably different when you stop and think about it.
The use of plastics isn’t limited to everyday household items either. Piping for homes and industry are one example, and molded prosthetic limbs help those with devastating injuries lead productive lives.
Plastic can be defined as “…a material consisting of any of a wide range of synthetic or semi-synthetic organics that are malleable and can be molded into solid objects of diverse shapes.”
While the early plastics were derived from natural materials like rubber, egg and blood proteins and even cattle horns, modern synthetic (i.e. man-made) materials became more prominent in the 19th century during the Industrial Revolution. Today, more advanced molding methods and durability have made plastics an integral part of modern life. Most modern plastics are derived from oil and natural gas.
Continue reading to learn more about the specific type of plastic used to manufacture a round boat.
While the round boat has technically been around for centuries, modern synthetic plastic has transformed it into a light-weight, yet incredibly durable craft…
Plastic isn’t just one generic material, but rather a broad term for describing the material. There are several different types of plastic, including:
- Polyethylene terephthalate (PETE or PET) – containers for sodas, medications, combs, etc.
- High-density polyethylene (HDPE) – containers for milk, motor oil, shampoo and many toys.
- Polyvinyl chloride (PVC) – most commonly used in plumbing pipes, but also flooring and skirting for trailers and mobile homes.
- Low-density polyethylene (LDPE) – commonly used material for plastic wrap, sandwich bags, squeeze bottles, playground slides, computer disk drives and more. LDPE is the type of plastic used to manufacture a round boat.
- Polypropylene (PP) – commonly used for Tupperware, prescription bottles and cups. Considered more durable and able to withstand higher temperatures over other plastics.
- Polystyrene (PS) – commonly known as Styrofoam, this type of plastic is used for packing material, food boxes and disposable cups.
Low-density polyethylene, or LDPE, is the type of plastic used to manufacture a round boat. LDPE is derived from the monomer “ethylene” via a high pressure process using what’s known as free radical polymerization. It has a density range of 0.910-0.940 g/cm3. LDPE was first developed by Imperial Chemical Industries in 1933.
While its density is lower than HDPE, low-density polyethylene provides a light-weight, impervious material ideal for a round boat.
Once manufacturers have the material, they then “mold” it into the final product using one of several methods.
Rotational molding (a.k.a. rotomolding or rational casting) is the method used to make a round boat…
First developed in the early 20th century, rotational molding has grown to become the fastest growing method for processing plastics. Besides the round boat, rotational molding is used to manufacture trash cans, large storage tanks, playground equipment, auto parts, baby cribs and even immobilizer boards used by paramedics. Low-density polyethylene for rotational molding was developed in the late 1970s and ‘80s.
Rotational molding takes powdered plastic material in a heated mold and rotates it “…simultaneously in two planes perpendicular to each other” to create a rigid and durable final product. These powdered plastic particles melt on the inner surfaces between the two planes and fuse together until a desired thickness is reached.
Unlike other manufacturing methods, rotational molding produces virtually zero waste. Other reasons round boat manufacturers prefer rotational molding include:
- Costs for molds and tools are low when compared to other methods
- Wall thickness can be easily controlled
- Produces pieces with better surface finishing and detail
- Capable of producing both hollow and solid item
- Any sized piece large or small can be rotationally molded
Although it is possible to rotationally mold a wide variety of resins, polyethylene is by far the most common according to industry data.
It’s incredible to think about the history of the round boat and how it has evolved from simple willow or bamboo to an advanced plastic material that is the best of all worlds – light weight, durable and stable.
Click here for more information about the round boat from Round About Watercrafts, including how it can be an ideal craft for hunting, fishing or general leisure out on the water.