Plastics are one of the most widely recognized materials used to manufacture products at present. From the keyboard you are using to the spaceship your great-grandkids may board in the future. Plastics are here for sure. Now what is the reason plastic which makes structures that are simple and specified can create something so complex it can withstand extreme physical and chemical actions such as heat and corrosion? The answer is Thermoset plastics.
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What are Thermoset Plastics?
In Thermoset or Thermosetting Plastics there are cross links or primary bonds between the chains. When they are heated and later cooled the Polymer chains start attaching to each other. This action is called as Cross-linking. It gives Thermoset a changeless 3 Dimensional structure which gives it protection from liquefying. If you try to heat them again at high temperatures they will burn. The bonds do not break on heating so softening does not take place and they cannot be remolded. Setting it for the first time and can’t be changed that’s why they are called Thermoset.
On the contrary, the polymer chains in the structure of Thermoplastics become fluid after rise in temperature. The chains can slide on each other which results in the ability of Thermoplastics to change in shape.
Thermoset plastics are entirely not the same as traditional plastic materials such as thermoplastics. Thermoset or Thermosetting plastics are synthetic structures that get more strength when heated. Thermoset components get set in their chemical and physical properties after the first heating process and are no longer affected by increased heat exposure up to certain limits. Thermoset plastic materials resistance to corrosion, heat and chemical reactions make them perfect for applications that require high tolerances and great strength-to-weight characteristics when exposed to elevated environments.
Another difference of Thermosets from thermoplastic materials is the process used to manufacture components. The thermoplastic formation process cools the mold for solidifying the molten plastic that is injected. The Thermosetting process keeps the mold to cause a chemical reaction that forms cross-linking bonds and does material curing. While a thermoplastic monomer just has two reactive ends a Thermoset monomer has three or more due to molecular cross-linking in 3 dimensions. After molding Thermosets have all molecules interlinked with permanent strong physical bonds.
Some popular Thermoset plastics used in Industries–
1. Fiberglass (Sheet Moulding Compound and Bulk Moulding Composite or Dough Moulding Compound)
2. Vulcanized rubber
3. Bakelite
4. Polyurethane
Some common Examples of Thermoset in daily use are Shoe sole and Dish washing Foam.
Comparison of Thermoset plastics and Thermoplastics
| Thermoset Polymers | Thermoplastic Polymers |
|---|---|
| Strong chemical bond between molecules which do not separate on heating. | Weak chemical bond between molecules that can be broken by heating. |
| High Heat and Chemical resistance | Lower Heat and Chemical resistance |
| They are hard and brittle | They are elastic and flexible. |
| They do not dissolve in organic solvents | Organic solvents can cause damage to Thermoplastics |
| On heating they will scorch and not melt | On heating they will soften and ultimately melt |
| Economical Raw material | Easy repair characteristics |
| High Durability | Low Durability |
| Highly adaptable design process with ability to thick and thin wall formation | Surface formation is less hardened due to flexible nature. |
| Good Impact Resistance | Impact resistance is very poor |
Applications of Thermoset Plastics
Thermoset components are extraordinary for applications in the automotive industry, daily appliance, electrical industry, lighting industry and energy markets because of excellent heat and chemical stability as well as superior hardness, strength and mold ability. Some Common examples of Thermoset plastic components are transmission components, motor houses, valve housings, appliance knobs and handles, circuit breakers, switch plates, relays, standoff insulators, brush holders, bases and end caps, crack balls, cement and wiper plugs, load rings and other components which are in danger of exposure to high heat and corrosion.
Replacement for Metal Components by Thermoset plastics
Apart from all above mentioned details Thermoset plastic materials have acquired popularity among most of the manufacturers switching metal components to plastic components. Benefits that Thermoset plastics have over existing metal counterparts are
1. High resistance to thermal and microwaves conduction
2. Resistance to corrosion and water
3. Available molded-in tolerances
4. Offer lower tooling costs
5. High strength for lower weights
6. Great dielectric strength
7. Better color and surface finishes
8. Cheaper Production over metal components
So what are you waiting for? Start using Thermoset Plastic products daily for safe, strong, colorful functions with low price range.
Good information. Thanks.
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