Thermocol Balls

Thermocol balls, also known as polystyrene in general chemistry, are synthetic aromatic polymers. Polystyrene is a benzene derivative as it contains a 6-carbon benzene ring in its chemical structure. The monomer unit of this polymer is styrene, that is, polystyrene is made up of multiple units of styrene monomer that are chemically bound in the form of a long chain. Since polystyrene is a polymer, it contains a large number of monomer units. It is generally synthesised artificially in two major types: solid or foam (styrofoam). 

Thermocol is one of the most widely used plastics in the world as it is an inexpensive resin. Several million tons of polystyrene are produced every year in the world. These are used for several purposes and can be found everywhere.

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History of Thermocol or Polystyrene

• Polystyrene was initially discovered by a medical professional, Eduard Simon, in 1839. Simon extracted an oily resin called storax from the oriental sweetgum tree and distilled it to make the monomer styrol. A few days later, Simon noticed that the monomer he extracted was changed into a semi-solid substance, which he named styrol oxide.

• Later in 1845, German chemist August Wilhelm von Hofman and a Jamaican chemist John Buddle Blyth claimed that the Styrol oxide is not made by oxidation of styrol monomer and changed its name as meta-styrol. As research over meta-styrol continued, Marcellin Berthelot, in 1866, finally identified that polystyrene is formed by polymerization of Styrol in the form of long chains. However, the present name of the polymer polystyrene was given by Hermann Staudinger 80 years after its discovery. Polystyrene became famous when industrial manufacturers in Germany began their mass production around 1931. From there on, it received its common Thermocol name. Since then, Polystyrene has gone through several changes till now.

Properties of Thermocol Balls

Polystyrene balls have a relatively low melting point, and they act as a poor barrier for oxygen and water vapour. Polystyrene balls are naturally transparent but can be dyed with different colours. The physical state of Polystyrene balls is affected by temperature as they are a type of thermoplastic polymer (polymers that change their physical form when exposed to elevated temperature).

Polystyrene balls generally remain in a solid or glassy state at room temperature. Still, when exposed to a temperature higher than 100-degree Celsius, it begins to melt and flow like a semi-solid substance. This temperature is called the glass transition temperature of Polystyrene. In a counter process, the polystyrene begins to resolidify and becomes solid again when the temperature is lowered.

Due to polystyrene’s unique behaviour against temperature, it becomes easy to use polystyrene in processes like extrusion, vacuum forming, and moulding. It can be moulded in any shape and with fine details. Moulding styrofoam makes it possible to produce a thermocol box or a thermocol fort without starting from the polymerization of the monomer.

Under the general temperature and pressure conditions, polystyrene is considered non-biodegradable. It means that polystyrene products cannot be degraded entirely using natural methods, and they can accumulate as litter in the environment. This makes the overuse of polystyrene an issue for environmentalists as it contributes to pollution, mainly of rivers and oceans.

How are Thermocol Balls made?

Generally, thermocol balls are manufactured in industries, but they can also be made at home. There are several step-by-step guides available on how to make thermocol balls at home. The process of making Thermocol or polystyrene balls at the industrial level involves the following three steps.

• Pre-expansion

The method of pre-expansion involves expanding polystyrene to achieve the desired density. The polystyrene is heated with either hot air or steam to make it expand. Generally, tiny round beads of polystyrene are used during pre-expansion. An agitator is used to avoid the fusing of polystyrene beads due to high temperatures during this process. After the expansion process, the density of polystyrene decreases to only 3 percent from its initial density and becomes ideal for moulding.

• Maturing

Maturing, also called ageing, is the process in which the expanded polystyrene beads are left in mesh storage for at least 24 hours. The maturing process allows air to flow through the beads and makes air gaps. The method also cools down the pre-expanded polystyrene and makes it slightly harder.

• Moulding

Once the ageing process is complete, the polystyrene beads are fed into the           desired shape and size mould. To ensure that the beads expand inside the mould, low-pressure steam is blown inside and in between the beads. Once the desired shape is formed inside the mould, it is cooled by passing water inside the mould or spraying water on the outer surface. Generally, moulds of smaller sizes are used to speed up the process.

Uses of Thermocol Balls

Thermocol or polystyrene balls are used widely for several purposes. This includes both general uses and industrial uses. Several industries around the globe use thermocol mainly as a packaging material. Polystyrene or styrofoam is used for packing fragile items such as glass and ceramics as it is lightweight, durable, and easy to handle.

Due to their moulding properties, thermocol sheets are used to make disposable items like bottles, trays, lids, tumblers, containers, and several other general-use products. Nowadays, custom-designed moulds are being made to create 3D models using styrofoam balls. Thermocol sheets can be moulded in different sizes as per the requirement. 

Thermocol balls and sheets are cheaper and can be easily manufactured, making them ideal for roofing insulation and shipping food products. Due to the high density and low heat conductivity, polystyrene balls are used as an insulating material. They are used for the refrigeration of medicines and chemicals. Also, a thermocol box can carry hot and cool food products.

Some other uses of thermocol or polystyrene balls are as follows.

• Thermocol sheets and balls are used for decoration items.

• Thermocol boxes are used for packing fragile products.

• Thermocol sheets and balls are used for art and craft.

• Thermocol blocks are used for designing models and projects.