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Plastic filler: What it is and how it benefits our plastic industry?

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Plastic filler has now become an indispensable part of the plastic industry. Calcium carbonate, talc, barium sulfate, sodium sulfate,…are the most well-known plastic fillers. They are added to plastic due to its various functions such as cutting cost, improving certain properties of end-products.

For a lot of people, it may seem a bit surprised when the fact that a great number of plastic products containing plastic fillers is revealed. And it is true. Up to 70% of plastic products are composed of organic or inorganic fillers. So, what exactly plastic filler is and why it is so essential that many plastic products make use of it?

1. What is plastic filler and why is it added to plastic products?

Plastic fillers are particles added to plastic products with a view to cutting production cost and improving some specific properties of the end products. As such, plastic fillers can enhance the tensile strength and toughness, boost the heat resistance and increase the quality of color together with plastic’s clarity. 

In nature, there are two groups of plastic fillers: 

  • The inorganic (also known as mineral) fillers such as calcium carbonate (limestone), magnesium silicates (talc), calcium sulfate (gypsum), mica, calcium silicate, barium sulfate and kaolin (China clay).
  • The organic plastic fillers such as tree bark flour, nut flours, chicken feathers, and rice hulls. 
Plastic filler plays a vital role in plastic products manufacture

Based on the requirements of end products, the plastic fillers used are different. Generally, the inorganic ones are more common in plastic production due to their simple chemical composition, which makes them easier and less time-consuming to be processed and mixed with other ingredients. In this article, we would like to discuss more about inorganic plastic filler, which is directly relevant to our plastic industry.

Related: 4 most common plastic filler materials in plastic industry

2. Top 4 common plastic fillers and their applications

Plastic is one of the segments which consume the largest number of filler materials. Among a wide variety of plastic fillers, these below are 4 most common matters applied in the plastic industry.

Calcium carbonate filler

This type of plastic filler must be very familiar with all plastic firms. As such, calcium carbonate filler is amongst the most popular plastic fillers. In nature, this item is the main component of living animals’ shells such as eggshells, seashells and pearls. Also, the most well-known source of calcium carbonate is quarries, limestone ores or marble. As a plastic filler, calcium carbonate may reduce overall strength but it increases tensile modulus and density. It also provides opacity and surface gloss, improves impact strength and is a processing aid, which makes the production process more efficiently. 

Calcium carbonate is the most common plastic filler worldwide

One of the most outstanding advantages of calcium carbonate filler is how it helps plastic firms reduce overall production cost. Compared to primary plastic, calcium carbonate is much more stable and reasonable as it is not affected by the fluctuation of oil and natural gas price. Besides, the vast availability of this material also gives it a leg up in the comparison with traditional plastic, as it is easily to be exploited and processed.

All things considered, calcium carbonate filler is widely applied in many resins such as polyolefin, polypropylene, polyethylene, bioplastic,…

Calcium carbonate with PolyethyleneCalcium carbonate with polypropyleneCalcium carbonate with polystyreneCalcium carbonate with bioplastic
PE – Base film (roll bags, T-shirt bags, garbage bags)PP Woven sacks Blow molding, Injection moldingBiodegradable cutleries 
Injection Moulding (houseware, tanks, toys)Extrusion, Injection/Blow MouldingRefrigerator linersBiodegradable films and bags
Extrusion (pipe, bar)PP raffiaSilk screen-printing, sign and displayBiodegradable sheets
Blow moulding (HDPE pipes, bottles, container, cans)PP non-wovenVacuum formingOther compostable applications
Calcium carbonate filler applications 

Related: Top 3 suppliers for you to buy plastic filler calcium carbonate

Talc filler

Talc (scientific name is hydrated magnesium silicate) is the softest mineral on the market. Its chemical formula is Mg3Si4O10(OH)2. Initially, talc is mostly added to polypropylene to increase rigidity. However, the use of talc has improved significantly in the last decade. It is also used in polyethylene and polyamides. Thanks to this material, plastic products are more thermal resistant, stable, well in-shape and more durable. Also, talc is relatively reasonable compared to primary plastic. Besides, it is suitable for most traditional production processes such as bag blowing, injection moulding, extrusion moulding, compression moulding,…without any requirements of equipment or production technology. 

Talc filler is widely used in plastic industry

Therefore, it is commonly mixed with polypropylene to replace many metal parts in automotive applications such as bumpers, interior plastic ductwork and fasciae. Also, this item is used in household appliances and engineered plastic hardware. Anti-block additive is also a popular application of talc in polyethylene films to make it easier to pull the two faces of a plastic bag apart.

Related: 101 things about plastic filler talc: Components, properties and applications

Barium sulfate filler

Barium sulfate is an inorganic compound that is odorless and insoluble in water. It is commonly used as a plastic filler to increase the density of the polymer in vibrational mass damping applications. In polypropylene and polystyrene plastics, it is used as a filler in proportions up to 70%. It has an effect of increasing acid and alkali resistance and opacity. Such composites are also used as X-Ray shielding materials due to their enhanced radiopacity. Composites with high weight percentage (70-80%) of barium sulfate perform better than commonly used steel shields.  

Barium Sulfate is commonly used as filler in plastic industry

Sodium sulfate filler

Sodium sulfate (also known as sodium sulphate or sulfate of soda) is a type of inorganic compound with formula Na2SO4. This material is white, non-toxic, odorless, tasteless and highly soluble in water. One outstanding advantage of sodium sulfate is its transparency (more clear than calcium carbonate) and its reasonable price (cheaper than barium sulfate). Therefore, sodium sulfate is widely used as an effective plastic filler. 

As such, sodium sulfate significantly improves the transparency and glossiness of plastic products. Also, it reinforces end-products mechanical properties with excellent dispersion, high tenacity and strong stability. Furthermore, the use of sodium sulfate as plastic filler is highly recommended thanks to its eco-friendly components, which barely pose any threats on our environment. 

Sodium sulfate filler significantly improves the transparency and glossiness of plastic products

Some common applications of sodium sulfate as plastic filler include:

  • LLDPE agricultura film, mulch film (5-30%)
  • LLDPE stretch film (5-15%)
  • HDPE translucent film (5-40%)
  • LDPE transparent film (5-15%)

Related: What is the best filler for plastic? (Update 2021)

3. Plastic filler brand EuroPlas 

Having established over 13 years, EuroPlas has become one of the leading plastic filler manufacturers in the plastic industry. We take pride in providing a wide variety of plastic fillers ranging from calcium carbonate filler to talc filler, barium filler to sodium filler, which play an indispensable role in cutting cost as well as enhancing end-products’ mechanical properties. 

EuroPlas has become one of the leading filler masterbatch manufacturers in the world

For further information and detailed consultation, contact us HERE!



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