Filler (materials)

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Plastic consumption uses by field Plastics applications en.svg
Plastic consumption uses by field

Filler materials are particles added to resin or binders (plastics, composites, concrete) that can improve specific properties, make the product cheaper, or a mixture of both. [1] The two largest segments for filler material use is elastomers and plastics. [2] Worldwide, more than 53 million tons of fillers (with a total sum of approximately US$18 billion) are used every year in application areas such as paper, plastics, rubber, paints, coatings, adhesives, and sealants. As such, fillers, produced by more than 700 companies, rank among the world's major raw materials and are contained in a variety of goods for daily consumer needs. The top filler materials used are ground calcium carbonate (GCC), precipitated calcium carbonate (PCC), kaolin, talc, and carbon black. [3] Filler materials can affect the tensile strength, toughness, heat resistance, color, clarity, etc. A good example of this is the addition of talc to polypropylene. [4] Most of the filler materials used in plastics are mineral or glass based filler materials. [4] Particulates and fibers are the main subgroups of filler materials. Particulates are small particles of filler that are mixed in the matrix where size and aspect ratio are important. Fibers are small circular strands that can be very long and have very high aspect ratios. [5]

Contents

Types

Powder calcium carbonate CaCO3 used widely as a filler material. Calcium carbonate.jpg
Powder calcium carbonate CaCO3 used widely as a filler material.

Calcium carbonate (CaCO3)

Referred to as "chalk" in the plastic industry, calcium carbonate is derived from limestone and marble. It is used in many applications including PVC's and unsaturated polyesters. As much as 90% CaCO3 can be used to make a composite. These additions can improve molding productivity by decreasing the cooling rate. They can also increase the operating temperatures of materials and provide insulation for electrical wiring. [6]

CaCO3 is used in filler masterbatch as a base with a large percentage in composition. Calcium carbonate powder accounts for 97% of the composition will bring white/opaque products more whiteness. So manufacturers can reduce the usage of white masterbatch. With a smaller percentage, calcium carbonate powder can be used for color products. In addition, it brings final plastic products a more bright and more glossy surface. [7]

Kaolin

Kaolin is mainly used in plastics for its anti-blocking characteristics as well as an infrared absorber in laser marking. [6] It increases impact strength and heat resistance. Metakolinite is used to stabilize PVC. [6] Kaolin has also been shown to increase the abrasion resistance and can replace carbon black as a filler material and improve the flow properties of glass-reinforced substances. [6]

Magnesium hydroxide (talc)

Block of talc. Talc block.jpg
Block of talc.

Talc, a soft mineral and generally more expensive than calcium carbonate. It is derived from layering sheets of magnesium hydroxide with silica. In the plastic industry, it is used for packaging and food applications due to its long-term thermal stability. [6] [5]

Wollastonite (CaSiO3)

Wollastonite has an acicular structure with a relatively high specific gravity and high hardness. This filler can improve moisture content, wear resistance, thermal stability, and high dielectric strength. Wollastonite competes with platy filler substances like mica and talc and also can be used to replace glass fibers when creating thermoplastics and thermosets. [5]

Glass

Glass microsphere filler (left) and fiber fillers (right) Glass fillers.jpg
Glass microsphere filler (left) and fiber fillers (right)

Glass filler materials come in a few diverse forms: glass beads, short glass fibers, and long glass fibers. in plastics by tonnage. [5] Glass fibers are used to increase the mechanical properties of the thermoplastic or thermoset such as flexural modulus and tensile strength, There is normally not an economic benefit for adding glass as a filler material. Some disadvantages of having glass in the matrix include low surface quality, high viscosity when melted, poor weldability, and warpage. [5] The addition of glass beads will help with oil absorption and chemical resistance. [6]

Fly ashes

Coal and shale oil fly ashes have been used as a filler for thermoplastics that could be used for injection molding applications. [8]

Nanofillers

Nanofiller have a particle size of less than 100 nanometres. They have a high aspect ratio and are mainly used as scratch resistant and fire-resistant fillers. [4] Nanofillers can be broken out into three groups nanoplates, nanofibers, and nanoparticles. Nanoparticles are more widely used than nanoplates and nanofibers but nanoplates are starting to become more widely used. Nanoplates are like conventional platy fillers like talc and mica except the thickness is much smaller. The advantages of adding nanofillers include creating a gas barrier and their flame-retardant properties. [5]

Polymer foam beads

Polymer Foam Beads can have a bulk density as low as 0.011 g/cc and range in size from 45 microns to over 8 mm. Common drawbacks to using Polymer Foam Beads in formulated systems include static, temperature, and chemical resistance limitations and difficulty achieving a homogenous blend within a formulated system due to their extremely low bulk density. However, these limitations can be mostly if not entirely overcome through the use of formulation modifications, additives, and other surface treatments. Despite these potential challenges, Polymer Foam Beads can be added to formulated systems when weight or cost savings in a finished good are required.

Masonry filler

Masonry filler is used to repair cracks and holes in exterior walls and is typically made using cement and hydrated lime. Manufacturers include Toupret. [9]

Other fillers

Concrete filler materials include gravel, stone, sand, and rebar. Gravel, stone, and sand are used to reduce the cost of concrete. Rebars are used to strengthen the concrete. [10]

Table Of Filler Materials and Physical Properties [11]
Filler TypeDensity

(g/cm3)

Mohs HardnessMean Size

(Microns)

Aspect Ratio/Shape
Calcium Carbonate2.73-40.02-301-3 Blocky
Talc2.7-2.810.5-205-40 Plate
Wollastonite2.94.51-5005-30 Fiber
Mica2.8-2.92.5-45-100020-100 Plate
Kaolin2.620.2-810-30 Plate
Silica (Precipitated)1.9-2.15.50.005-0.1~1 Round
Carbon Black1.7-1.92-30.014-0.25~1 Round
Dolomite2.853.5-41-30~1 Round
Barium Sulfate4.0-4.53-3.50.1-30~1 Round
ATH Al(OH)32.422.5-35-801-10 Plate
MDH Mg(OH)22.42.5-30.5-81-10 Plate
Diatomaceous earth2-2.55.5-64-302-10 Disc
Magnetite/Hematite5.25.5-61-50~1 Blocky
Halloysite2.542.51-205-20 Tube
Zinc Oxide5.64.50.05-101 Round
Titanium Dioxide4.2360.1-101 Round

Mechanical properties

Tensile strength

Tensile strength is the most used method to evaluate filler materials. The tensile strength of the composite can be calculated using the equation

σc= σp(1-aΦbf +cΦfd) [12]

where

σc = tensile strength of composite
σp = tensile strength of polymer matrix
Φf = volume fraction of filler
a, b, c, d are constants depending on the type of filler. "a" relates to stress concentration and is based on adhesion characteristics of the filler material. "b" is normally 0.67. c and d are constants that are inversely related to particle size. [12]

Elastic modulus

The elastic modulus (Young's modulus) of a filled polymer can be found using the equation below:

E = E0 (1 + 2.5Φ + 14.1Φ2) [12]

where:

E0 = Modulus of unfilled resin or binder
Φ = Filler concentration

Polymers with smaller additions of filler follow this equation closely. In general addition of filler materials will increase the modulus. The additions of calcium carbonate and talc will increase the elastic modulus, while the addition of elastic filler materials can reduce the value slightly. Filler materials increase the modulus due to their rigidity or stiffness and good adhesion with the polymeric matrix. [12]

Impact resistance (toughness)

In general fillers will increase impact resistance. The contributing factors that improve impact resistance is particle size, particle shape and particle rigidity. Fibers improve impact resistance the most due to their large aspect ratio. Low hardness fillers will decrease impact strength. Particle size, within a specific range can increase the impact strengths based on the filler material. [12]

Wear resistance

The wear volume (Ws) for plastic materials can be calculated:

Ws = KμPDW/(EIs) [12]

where:

K = Proportionality constant
P = force
E = Modulus
D = Sliding distance
W = load
Is= Interlaminar shear strength

Matrix and filler both contribute to wear resistance. In general a filler is selected to decrease the friction coefficient of the material. Particle size and shape are contributing factors. Smaller particle size increase wear resistance because they cause less debris. silica, alumina, molybdenum disulfide, and graphite powder are common fillers that improve wear resistance. [12]

Fatigue resistance

Filler can have a negative or positive effect on fatigue resistance depending on the filler type and shape. In general fillers create small discontinuities in the matrix. This can contribute to crack initiation point. If the filler is brittle fatigue resistance will be low, whereas if the filler is very ductile the composite will be fatigue resistant. Adhesion is also an important factor influencing fatigue resistance. If stress is higher than the particles adhesion a crack will form/propagate. Fiber ends are areas where cracks initiate most often due to the high stress on fiber ends with lower adhesion. Talc is a filler that can be used to increase fatigue resistance. [12]

Thermal deformation

Filler materials have a large influence on thermal deformation in crystalline polymers. Amorphous polymers are negligibly affected by filler material. Glass fiber additions are used the most to deflect the most heat. Carbon fibers have been shown to do better than glass in some base materials. In general fibrous materials are better at deflecting heat than particle fillers. [12]

Creep

Creep resistance is heavily impacted by filler materials. The equation below shows the creep strain of a filled material: [12]

εc(t)/εm(t) = Em/Ec

where:

εc(t) = is strain of filled polymer
εm(t) = is strain of matrix or unfilled polymer
Em = is Young's Modulus of matrix
Ec =is the Young's Modulus of filled polymer

The better the filler bonds with the matrix the better creep resistance will be. Many interactions will have a positive influence. Glass beads and fibers both have been shown to improve creep resistance in some materials. Aluminum oxide also has a positive effect on creep resistance. Water absorption will decrease the creep resistance of a filled material. [12]

Weldability of plastic fillers

Additions of filler materials can drastically affect the weldability of the plastic. This also depends on the type of welding process used. For ultrasonic welding, fillers like calcium carbonate and kaolin can increase the resin's ability to transmit ultrasonic waves. [13] For electromagnetic welding and hot plate welding additions of talc and glass will reduce the weld strength by as much as 32%. [14] The strength of the plastic after welding would decrease with an increasing amount of fillers in the matrix compared to the bulk material. [15] Use of abrasive fillers can affect the tool used for welding. Abrasive fillers will degrade the welding tools faster, for example, the surface of the ultrasonic horn in contact with the plastic. The best way to test the weldability of filler material is to compare weld strength to resin strength. [16] This can be hard to do since many filler materials contain different level of additives that change the mechanical behavior. [16]

Applications of filler in plastic industry

Filler is widely used in the production process of plastic products. Filler is used to changing the properties of the original plastic. By using plastic filler, manufacturers can save production costs as well as raw materials.

Undeniably the importance of filler masterbatch in improving the physical properties of plastics, especially minimizing cost and production efficiency. With the advantage of price and stability, plastic filler supports the production of:

See also

Related Research Articles

<span class="mw-page-title-main">Composite material</span> Material made from a combination of two or more unlike substances

A composite material is a material which is produced from two or more constituent materials. These constituent materials have notably dissimilar chemical or physical properties and are merged to create a material with properties unlike the individual elements. Within the finished structure, the individual elements remain separate and distinct, distinguishing composites from mixtures and solid solutions. Composite materials with more than one distinct layer are called composite laminates.

<span class="mw-page-title-main">Carbon fibers</span> Material fibers about 5–10 μm in diameter composed of carbon

Carbon fibers or carbon fibres are fibers about 5 to 10 micrometers (0.00020–0.00039 in) in diameter and composed mostly of carbon atoms. Carbon fibers have several advantages: high stiffness, high tensile strength, high strength to weight ratio, high chemical resistance, high-temperature tolerance, and low thermal expansion. These properties have made carbon fiber very popular in aerospace, civil engineering, military, motorsports, and other competition sports. However, they are relatively expensive compared to similar fibers, such as glass fiber, basalt fibers, or plastic fibers.

<span class="mw-page-title-main">Thermoplastic</span> Plastic that softens with heat and hardens on cooling

A thermoplastic, or thermosoftening plastic, is any plastic polymer material that becomes pliable or moldable at a certain elevated temperature and solidifies upon cooling.

<span class="mw-page-title-main">Polypropylene</span> Thermoplastic polymer

Polypropylene (PP), also known as polypropene, is a thermoplastic polymer used in a wide variety of applications. It is produced via chain-growth polymerization from the monomer propylene.

<span class="mw-page-title-main">Thermosetting polymer</span> Polymer obtained by irreversibly hardening (curing) a resin

In materials science, a thermosetting polymer, often called a thermoset, is a polymer that is obtained by irreversibly hardening ("curing") a soft solid or viscous liquid prepolymer (resin). Curing is induced by heat or suitable radiation and may be promoted by high pressure or mixing with a catalyst. Heat is not necessarily applied externally, and is often generated by the reaction of the resin with a curing agent. Curing results in chemical reactions that create extensive cross-linking between polymer chains to produce an infusible and insoluble polymer network.

<span class="mw-page-title-main">Plastic welding</span> Welding of semi-finished plastic materials

Plastic welding is welding for semi-finished plastic materials, and is described in ISO 472 as a process of uniting softened surfaces of materials, generally with the aid of heat. Welding of thermoplastics is accomplished in three sequential stages, namely surface preparation, application of heat and pressure, and cooling. Numerous welding methods have been developed for the joining of semi-finished plastic materials. Based on the mechanism of heat generation at the welding interface, welding methods for thermoplastics can be classified as external and internal heating methods, as shown in Fig 1.

<span class="mw-page-title-main">Wollastonite</span> Single chain calcium inosilicate (CaSiO3)

Wollastonite is a calcium inosilicate mineral (CaSiO3) that may contain small amounts of iron, magnesium, and manganese substituting for calcium. It is usually white. It forms when impure limestone or dolomite is subjected to high temperature and pressure, which sometimes occurs in the presence of silica-bearing fluids as in skarns or in contact with metamorphic rocks. Associated minerals include garnets, vesuvianite, diopside, tremolite, epidote, plagioclase feldspar, pyroxene and calcite. It is named after the English chemist and mineralogist William Hyde Wollaston (1766–1828).

Fibre-reinforced plastic is a composite material made of a polymer matrix reinforced with fibres. The fibres are usually glass, carbon, aramid, or basalt. Rarely, other fibres such as paper, wood, boron, or asbestos have been used. The polymer is usually an epoxy, vinyl ester, or polyester thermosetting plastic, though phenol formaldehyde resins are still in use.

Polymer engineering is generally an engineering field that designs, analyses, and modifies polymer materials. Polymer engineering covers aspects of the petrochemical industry, polymerization, structure and characterization of polymers, properties of polymers, compounding and processing of polymers and description of major polymers, structure property relations and applications.

Methods have been devised to modify the yield strength, ductility, and toughness of both crystalline and amorphous materials. These strengthening mechanisms give engineers the ability to tailor the mechanical properties of materials to suit a variety of different applications. For example, the favorable properties of steel result from interstitial incorporation of carbon into the iron lattice. Brass, a binary alloy of copper and zinc, has superior mechanical properties compared to its constituent metals due to solution strengthening. Work hardening has also been used for centuries by blacksmiths to introduce dislocations into materials, increasing their yield strengths.

Rubber toughening is a process in which rubber nanoparticles are interspersed within a polymer matrix to increase the mechanical robustness, or toughness, of the material. By "toughening" a polymer it is meant that the ability of the polymeric substance to absorb energy and plastically deform without fracture is increased. Considering the significant advantages in mechanical properties that rubber toughening offers, most major thermoplastics are available in rubber-toughened versions; for many engineering applications, material toughness is a deciding factor in final material selection.

<span class="mw-page-title-main">Solid</span> State of matter

Solid is one of the four fundamental states of matter along with liquid, gas, and plasma. The molecules in a solid are closely packed together and contain the least amount of kinetic energy. A solid is characterized by structural rigidity and resistance to a force applied to the surface. Unlike a liquid, a solid object does not flow to take on the shape of its container, nor does it expand to fill the entire available volume like a gas. The atoms in a solid are bound to each other, either in a regular geometric lattice, or irregularly. Solids cannot be compressed with little pressure whereas gases can be compressed with little pressure because the molecules in a gas are loosely packed.

A thermoset polymer matrix is a synthetic polymer reinforcement where polymers act as binder or matrix to secure in place incorporated particulates, fibres or other reinforcements. They were first developed for structural applications, such as glass-reinforced plastic radar domes on aircraft and graphite-epoxy payload bay doors on the Space Shuttle.

Carbon fiber-reinforced polymers, carbon-fibre-reinforced polymers, carbon-fiber-reinforced plastics, carbon-fiber reinforced-thermoplastic, also known as carbon fiber, carbon composite, or just carbon, are extremely strong and light fiber-reinforced plastics that contain carbon fibers. CFRPs can be expensive to produce, but are commonly used wherever high strength-to-weight ratio and stiffness (rigidity) are required, such as aerospace, superstructures of ships, automotive, civil engineering, sports equipment, and an increasing number of consumer and technical applications.

Crystallization of polymers is a process associated with partial alignment of their molecular chains. These chains fold together and form ordered regions called lamellae, which compose larger spheroidal structures named spherulites. Polymers can crystallize upon cooling from melting, mechanical stretching or solvent evaporation. Crystallization affects optical, mechanical, thermal and chemical properties of the polymer. The degree of crystallinity is estimated by different analytical methods and it typically ranges between 10 and 80%, with crystallized polymers often called "semi-crystalline". The properties of semi-crystalline polymers are determined not only by the degree of crystallinity, but also by the size and orientation of the molecular chains.

Poly(<i>p</i>-phenylene oxide) Chemical compound

Poly(p-phenylene oxide) (PPO), poly(p-phenylene ether) (PPE), poly(oxy-2,6-dimethyl-1,4-phenylene), often referred to simply as polyphenylene oxide, is a high-temperature thermoplastic with the general formula (C8H8O)n. It is rarely used in its pure form due to difficulties in processing. It is mainly used as blend with polystyrene, high impact styrene-butadiene copolymer or polyamide. PPO is a registered trademark of SABIC Innovative Plastics B.V. under which various polyphenylene ether resins are sold.

<span class="mw-page-title-main">Paper chemicals</span> Chemicals used in paper manufacturing

Paper chemicals designate a group of chemicals that are used for paper manufacturing, or modify the properties of paper. These chemicals can be used to alter the paper in many ways, including changing its color and brightness, or by increasing its strength and resistance to water. The chemicals can be defined on basis of their usage in the process.

Novel polymeric alloy (NPA) is a polymeric alloy composed of polyolefin and thermoplastic engineering polymer with enhanced engineering properties. NPA was developed for use in geosynthetics. One of the first commercial NPA applications was in the manufacturer of polymeric strips used to form Neoloy® cellular confinement systems (geocells).

<span class="mw-page-title-main">Acrylonitrile styrene acrylate</span> Chemical compound

Acrylonitrile styrene acrylate (ASA), also called acrylic styrene acrylonitrile, is an amorphous thermoplastic developed as an alternative to acrylonitrile butadiene styrene (ABS), that has improved weather resistance. It is an acrylate rubber-modified styrene acrylonitrile copolymer. It is used for general prototyping in 3D printing, where its UV resistance and mechanical properties make it an excellent material for use in fused filament fabrication printers, particularly for outdoor applications. ASA is also widely used in the automotive industry.

Thermoplastics containing short fiber reinforcements were first introduced commercially in the 1960s. The most common type of fibers used in short fiber thermoplastics are glass fiber and carbon fiber . Adding short fibers to thermoplastic resins improves the composite performance for lightweight applications. In addition, short fiber thermoplastic composites are easier and cheaper to produce than continuous fiber reinforced composites. This compromise between cost and performance allows short fiber reinforced thermoplastics to be used in myriad applications.

References

  1. Pelzl, Bernhard; Wolf, Rainer; Kaul, Bansi Lal (2018). "Plastics, Additives". Ullmann's Encyclopedia of Industrial Chemistry . Weinheim: Wiley-VCH. pp. 1–57. doi:10.1002/14356007.a20_459.pub2. ISBN   9783527306732.
  2. "Fillers Market Report: Global Industry Analysis, 2024". www.ceresana.com. Retrieved 2019-02-14.
  3. "Market Study: Fillers (3rd edition)". Ceresana. January 2014. Retrieved 7 September 2015.
  4. 1 2 3 Shrivastava, Anshuman (2018-05-15). Introduction to Plastics Engineering. William Andrew. ISBN   9780323396196.
  5. 1 2 3 4 5 6 Gilbert, Marianne (2016-09-27). Brydson's Plastics Materials. William Andrew. ISBN   9780323370226.
  6. 1 2 3 4 5 6 Murphy, John (2001), "Modifying Specific Properties: Mechanical Properties – Fillers", Additives for Plastics Handbook, Elsevier, pp. 19–35, doi:10.1016/b978-185617370-4/50006-3, ISBN   9781856173704 , retrieved 2019-02-14
  7. European Plastic, Company (June 5, 2019). "About Calcium Carbonate in filler masterbatch".
  8. Krasnou, I. (2021). "Physical–mechanical properties and morphology of filled low-density polypropylene: Comparative study on calcium carbonate with oil shale and coal ashes". Journal of Vinyl and Additive Technology. 28: 94–103. doi: 10.1002/vnl.21869 . S2CID   244252984.
  9. Buildbase https://www.buildbase.co.uk/link/1/3434147_31669_t.pdf
  10. "Filler materials Used In Concrete". www.engineeringcivil.com. 16 March 2008. Retrieved 2019-04-03.
  11. "Functional Fillers and Specialty Minerals for Plastics". Phantom Plastics. Retrieved 2019-02-20.
  12. 1 2 3 4 5 6 7 8 9 10 11 Wypych, George. (2016). Handbook of Fillers (4th Edition) - 8. The Effect of Fillers on the Mechanical Properties of Filled Materials. ChemTec Publishing. Retrieved from https://app.knovel.com/hotlink/pdf/id:kt00CQMQQ7/handbook-fillers-4th/effect-fillers-mechanical
  13. Malloy, Robert A. (2010-10-07). "Plastic Part Design for Injection Molding". Plastic Part Design for Injection Molding: An Introduction. pp. I–XIV. doi:10.3139/9783446433748.fm. ISBN   978-3-446-40468-7.{{cite book}}: |journal= ignored (help)
  14. Stewart, Richard (March 2007). "ANTEC™ 2007 & Plastics Encounter @ ANTEC". Plastics Engineering. 63 (3): 24–38. doi:10.1002/j.1941-9635.2007.tb00070.x. ISSN   0091-9578.
  15. "ANTEC® 2011". Plastics Engineering. 67 (4): 25. April 2011. doi:10.1002/j.1941-9635.2011.tb01931.x. ISSN   0091-9578.
  16. 1 2 PDL Staff (1997), "Vibration Welding", Handbook of Plastics Joining, Elsevier, pp. 15–27, doi:10.1016/b978-188420717-4.50005-1, ISBN   9781884207174 , retrieved 2019-02-15