Differences between flexible and rigid PVC compounds

PVC (polyvinyl chloride) is a thermoplastic polymer used in many fields of construction, healthcare, food packaging, car parts, raincoats, and toy manufacturing… come in a variety of shapes and sizes – not to mention they also come in a variety of hardnesses. Flexible and rigid PVC compounds are used in the manufacture of different products based on their properties and physical characteristics.

So what is the basic difference to distinguish between rigid PVC & flexible PVC compounds?

The amount of plastic content contained in rigid PVC compounds & flexible PVC compounds

Generally speaking, Rigid PVC compounds usually contain little or no plasticizer at all, while soft PVC compounds have a high concentration of plasticizers. Plasticizers are of two different types, primary plasticizers, and polymeric plasticizers. Primary plasticizers include phthalates, phosphates, and fatty acid compounds. Adipate, propylene glycol azelate, and sebacate are a few of the polymer plasticizers. To make PVC more flexible, plasticizers such as phthalates, adipates, and phosphates are used in larger quantities.

Each type comes with its own pros and cons. Rigid PVC could be stronger and more durable, while flexible PVC can be made to be resistant to chemical and liquid damage.

The physical properties of the compound

Because of the different plastic content, the physical characteristics of the two PVC compounds are also different. Rigid PVC compounds are usually denser and stiffer, which makes them strong and durable. Soft PVC in general has less utility as it cannot be preserved for long due to excessive use of softener. However, rigid PVC can be stored for a longer period of time, making it useful for many products.

Rigid PVC is denser and more resistant to gases and air pressure than flexible or soft PVC. The density of hard PVC can be measured from 1.3-1.45 g/cm3 compared to the density of soft PVC which is 1.1-1.35 g/cm3. Due to the higher density, a product made from hard PVC will last longer than a product made from soft PVC.

Rigid PVC is in greater demand in the manufacturing sector than soft PVC because of its stronger thermal, mechanical, and chemical resistance.

Practical applications of flexible and rigid PVC compounds

The application of the PVC compound will suggest the specific qualities and benefits it must have from which the PVC compound manufacturers will adjust and adhere to the proportions during the manufacturing process.

Rigid PVC compounds are used in the construction sector, which are more suitable for exterior protective uses, such as profile, window frames, roofing, and drainage pipes as they can withstand extreme weather conditions such as bad weather events. Flexible PVC can provide different uses, such as the material used to make wires & cables, gumboots, because of its flexibility and resistance to oils, greases, and chemicals.

Rigid PVC compounds that can be recycled and disposed of is less hazardous than flexible PVC compounds because they contain no added concentrations of plasticizers. Flexible PVC compounds contain higher levels of plasticizers, which are hazardous to health and difficult to recycle.

At Green PVC, we offer a full range of rigid and flexible PVC compounds for industrial extrusion & injection molding that your business is looking for. We are proud to become one of the largest PVC Compound factories in Vietnam with an output of up to 15,000 MTs/year. Currently, the PVC Compound of Nhat Huy Group has exported finished products to more than 30 countries throughout Asia, Europe, and America.