Plastic Formulation and Additive Processing: 19 Guides from Recipe to Recycling

A plastic formulation is the ingredient list of a plastic compound with the level of every ingredient, written in parts per hundred resin (phr) for PVC and rubber and in weight per cent or parts per million for polyolefins and engineering plastics. A single PVC pressure-pipe recipe runs to 8 ingredients and 108.03 parts, so where does a formulator start?

A formulation answers 6 questions, in the order this page follows: what goes in, at what level, in which unit, by which route the ingredients reach the polymer, what each one does once inside it, and what the recipe decides at the end of the part's life. Every ingredient added to a base polymer is one of the plastic additives this reference catalogues, and the plastic additives root page defines what each one is and does, a predicate this formulation-focused page does not repeat.

This directory links 19 guides in 6 groups: designing the formulation, getting additives into the polymer, how additives behave once inside it, why stabilizers are needed at all, defects and troubleshooting, and end of life and sustainability. Four tables carry the numbers a formulator reaches for most: the units and conversions, the dosage bands from parts per million to tens of per cent, the 5 incorporation routes, and the defect map. A seventh guide, /formulation/additive-selection/, sits inside this directory as the reference's selection framework; this page never repeats it.

Guides marked "coming soon" publish on the date shown; the link activates automatically.

What Is a Plastic Formulation?#

A plastic formulation lists every substance in a plastic compound and the level of each one, from the base polymer at 100 parts down to a clarifier at 150 parts per million. It is not the recipe for making the polymer itself: polymerisation happens first, in a reactor, and formulation happens afterward, when the finished polymer is mixed with additives to become a usable compound. Which substances in the finished pellet are therefore not part of the formulation? Catalysts, emulsifiers and chain-transfer agents are polymer production aids, and Regulation (EU) No 10/2011 Article 3(8) defines them separately from additives; they are consumed or trapped during polymerisation and are not dosed by the formulator.

Every ingredient that is dosed by the formulator, in contrast, has a fixed chemical identity that the site tracks individually in its own plastic additives database. Every ingredient in a formulation has a CAS number, and all of them are indexed in the plastic additives database, which carries the identity, dosage and regulatory status behind every family referenced on this page.

What goes into a plastic compound?#

A plastic compound has 5 kinds of ingredient: the base polymer, stabilizers that keep it from degrading, property modifiers that change how it behaves, processing modifiers that make it shapeable, and additives that give it an appearance or a function the polymer lacks.

• Base polymer, the resin that carries every other ingredient and is always written as 100 parts in a phr recipe
• Stabilizers, such as heat stabilizers and antioxidants, that slow the degradation reactions covered later on this page
• Property modifiers, including plasticizers, impact modifiers, fillers and reinforcements, that change stiffness, softness or strength
• Processing modifiers, including lubricants and processing aids, that let the melt flow, release and fuse correctly
• Appearance and function additives, including pigments, flame retardants, slip agents and antistatic agents, that give the part a colour, a fire rating, a feel or a surface behaviour the polymer does not have on its own

The worked recipe below is the range composition published by the Plastics Pipe Institute in TR-2-2023 for a US PVC pressure pipe (cell class 12454), which uses additives for PVC as its stabilizer, lubricant and filler package.

wt% values not printed in TR-2-2023 are calculated as phr / 108.03 x 100.

The polymer carries most of the weight of this compound at 92.57 wt%, while the calcium carbonate filler and the paraffin lubricant are the next-largest ingredients at 4.63 wt% and 1.11 wt%. This is one published starting-point recipe, not a recommendation: a real formulation is adjusted against the specification in the 6-stage process described further down this page.

Compound, masterbatch, dry blend and one-pack#

The same recipe reaches the machine in 4 forms: a fully compounded pellet, a masterbatch concentrate that is diluted at the press, a PVC dry blend that is never melted before extrusion, and a one-pack that combines several additives in a single product.

A compound is fully formulated and pelletised: every ingredient in the table above is already melt-mixed into the polymer before the pellet leaves the compounder, so the converter processes it exactly as received. A masterbatch is the opposite of a finished compound: it is a concentrate of pigment or additive in a carrier resin, typically 40 to 65 wt% active (15 to 80 wt% in extreme cases), that the converter dilutes into natural polymer at 1 to 5% at the press itself.

A dry blend is a free-flowing PVC powder mix made in a hot and cold mixer, never melted before it reaches the extruder, and is either extruded directly or pelletised first. A one-pack is a pre-blended multi-component additive system, such as the PVC stabilizer and lubricant packages sold by Baerlocher or the polyolefin blends sold by Songwon under its one-pack system, that combines several functions into a single product to cut the number of weighing steps at the compounder.

How Are Additive Levels Written? phr, wt%, ppm and Let-Down Ratio#

Additive levels are written in 4 units: phr for PVC and rubber, weight per cent for most thermoplastics, parts per million for trace additives, and let-down ratio for masterbatch.

The unit matters because the basis changes what a number means. A limit written as wt% of the polymer is not the same basis as wt% of the compound once a filler is present, since the filler dilutes every other ingredient's share of the total weight without changing the polymer's own weight. Let-down ratio compounds this ambiguity further: the industry writes the same ratio both ways, so "1:50" and "50:1" both describe one part of masterbatch diluted into fifty parts of base polymer, and a formulator has to read the order from context rather than assume it. The let-down ratio calculator converts a masterbatch percentage into both ratio conventions and the reverse.

How do you convert phr to weight percent?#

Weight per cent equals the ingredient's phr divided by the sum of all parts in the recipe, multiplied by 100, so 5.00 phr of calcium carbonate in a 108.03-part PVC pipe compound is 4.63 wt%.

wt%_i = phr_i / (sum of all phr) x 100

5.00 / 108.03 x 100 = 4.63 wt%

The polymer itself works the same way: 100 phr of PVC in that same 108.03-part recipe is 92.57 wt% of the finished compound, not 100 wt%, because every added ingredient dilutes the polymer's own share once the total is renormalised to the compound rather than to the resin. The PHR to weight percent calculator runs this conversion in both directions for a full recipe rather than one ingredient at a time.

How much additive does a plastic carry?#

The additive content of a plastic ranges from 0.001 wt% for a biocide to about 70 wt% for plasticizer in very soft PVC, and the band an additive falls into decides whether it is weighed in, dosed as a masterbatch or blended into a one-pack.

Additive content falls into 4 bands:

• Parts-per-million level: clarifiers at 150 to 200 ppm, acid scavengers up to 1,000 ppm, slip agents at 500 to 1,200 ppm
• Tenths of a per cent: 0.05 to 1%, where most stabilizer packages sit
• Phr level: 1 to 10 phr, covering PVC stabilizers, lubricants and impact modifiers
• Tens of per cent: 10 to 70%, covering plasticizers, fillers and mineral flame retardants

The ranges below come from the review by John Hahladakis and colleagues at the University of Leeds (Journal of Hazardous Materials, 2018), as tabulated by Chea and colleagues in 2025.

Ranges describe finished products, not recommended dosages. Curing agents (0.1 to 2 wt%) and residual catalysts (0.1 to 0.3 wt%) appear in the source table but are not additives in the EU sense.

Accuracy at the low end of these bands needs equipment, not just a smaller scoop: gravimetric loss-in-weight feeders are needed for ppm-level accuracy, which is why the lowest-dosed additives arrive as masterbatch or one-pack rather than as neat powder at the hopper. A legal maximum is a different thing from a dosage band: the FDA food contact rules cap azodicarbonamide at 5 wt% in foamed polyethylene under 21 CFR 178.3010, and that ceiling describes what is allowed, not what a formulator normally uses.

How Is a Plastic Formulation Built? 6 Stages from Polymer to Trial#

A plastic formulation is built in 6 stages: write the specification, fix the base polymer, choose the additive families, set the levels, choose the incorporation route, then compound a trial and measure it.

1. Write the specification: property targets, the process the compound will run on, the end use, and any fire, food-contact or electrical requirements the part must meet
2. Fix the base polymer and grade against additives by polymer, since the same additive family behaves differently in PVC, polyolefins and engineering plastics
3. Choose the additive families that close each gap between the polymer's natural properties and the specification; each family is chosen against the polymer, the process temperature, the end use named in plastic additives by application and the regulation, which the additive-selection guide works through step by step
4. Set the level and the unit for every ingredient, using the phr, wt%, ppm and let-down ratio rules above
5. Choose the incorporation route and the product form from the 5 routes covered next
6. Compound a trial, measure it and iterate

Every stage in this sequence should end at a measurement, not an assumption, because plastics are processed at 150 to 320 degrees Celsius, and engineering polymers run at the top of that range, around 240 to 320 degrees Celsius, which is enough heat history to change what a trial batch actually delivers compared with the paper recipe. Testing plastic additives covers the standard tests a trial is checked against: melt flow rate for chain scission and oxidative induction time for the remaining stabilizer level are the two most common confirmation tests after a first compounding trial.

How Do Additives Get Into the Polymer? 5 Routes#

Additives reach the polymer by 5 routes: melt compounding into a finished pellet, masterbatch let down at the processing machine, PVC dry blending, direct dosing of neat powder or liquid, and a pre-blended one-pack.

Melt compounding, dispersion and distribution on a twin-screw extruder#

Melt compounding mixes polymer and additives above the melting point and pellets the result, in 5 steps: feeding, conveying, melting in the barrel zones, cooling the strands, and granulating.

The equipment for this ranges from co-kneaders and internal batch mixers, such as the Banbury mixer named after Fernley H. Banbury and dating to 1916, to co-rotating and counter-rotating twin-screw extruders. For an equal cross-section and intermeshing, the axial velocity and the degree of mixing are higher in a co-rotating machine, while pressure build-up is higher in a counter-rotating one, and the twin-screw extruder is all but mandatory for compounding because adequate mixing is essential to a usable compound.

Compounding needs both dispersive mixing, which breaks agglomerates apart, and distributive mixing, which spreads them evenly through the melt, together with careful heat management so the additive package survives the barrel without degrading. Pigments fed by a twin-screw side feeder downstream of the melting zone are wetted gently, with fewer agglomerates than a pigment added at the main throat, and the resulting dispersion quality is confirmed by dispersion testing of pigments and masterbatch rather than by visual inspection alone.

Masterbatch and the let-down ratio#

A masterbatch is a concentrate of pigment or additive in a carrier resin, typically 40 to 65 wt% active, that the converter dilutes into natural polymer at 1 to 5%.

25 kg of masterbatch per tonne of polymer is 2.5% let-down, and the same figure can be written as 1:40 or 40:1 depending on which convention the supplier uses. Black polyethylene pressure pipe is a worked example of the range this covers: a 35% carbon-black masterbatch let down at 5 to 6.5% gives a finished part 1.75 to 2.3% carbon black, while coloured pipe masterbatch runs lower, at 2 to 4% let-down (49:1 to 24:1). An antioxidant masterbatch dosed at 2.5% delivers about 1,000 ppm of active antioxidant into the finished part, which illustrates why masterbatch exists at all: it lets a converter dose an expensive, ppm-level additive with the same simple percentage feeder used for colour.

PVC dry blending#

PVC is the one polymer that is usually formulated without melting first: a hot and cold mixer turns resin, stabilizer, lubricants, filler and, in flexible grades, plasticizer into a free-flowing dry blend that goes straight to the extruder.

In this process, the resin grains absorb plasticizer while stabilizers and lubricants coat the outside of the grain, and the resulting blend is either extruded directly or pelletised for later use. Rigid PVC needs a balanced internal and external lubricant package to make this work: the PPI TR-2-2023 ranges are paraffin at 0.6 to 1.5 phr and calcium stearate at 0.4 to 1.5 phr as the external and internal lubricants, PE wax at up to 0.3 phr, plus an acrylic processing aid at 0.5 to 2.0 phr to help the melt fuse once it reaches the die. The PVC hub above already carries this page's one link to that polymer's additive package.

Which product form: powder, granules, pastilles or liquid?#

The same antioxidant is sold in at least 3 physical forms, and the choice changes the feeder rather than the chemistry: powder, free-flowing or dust-free granules, and liquid.

The same additive range is generally sold in 6 product forms:

• Powder, the fastest to disperse but the dustiest to feed
• Free-flowing granules, a compacted form that feeds cleanly through a standard hopper
• Dust-free granules, a further-compacted form for operators working without local extraction
• Pastilles, a moulded drop form used for waxes and some stabilizer packages
• Flakes, a thin, brittle form used mainly for lubricants
• Liquid or molten, dosed by pump rather than by weight feeder

Songwon's physical-form codes describe this same spread for a typical additive range: PW (powder), FF (free flow), DF (dust-free flow), FG (fine grind), SB (semi-beads), DW (dispersion), CP (crystalline powder), SL (solid), LQ (liquid or molten) and GR (granules), 10 codes in total. Phosphite antioxidants ship in aluminium-coated bags because they are moisture sensitive, which is a packaging choice rather than a dosing one. Powders disperse fastest once they reach the melt but dust and feed poorly at the hopper; compacted and melt-processed forms trade some of that dispersion speed for cleaner handling; and liquids need pumps and heated delivery lines rather than a simple gravimetric feeder.

Why a Formulation Needs Stabilizers: 6 Degradation Mechanisms#

Plastics degrade by 6 mechanisms: heat, oxygen, light, water, shear and deliberate pro-oxidants, and every stabilizer in a formulation answers one of them.

What Happens to an Additive Inside the Plastic?#

An additive does one of 3 things after the pellet cools: it stays dissolved in the polymer, it diffuses to the surface, or it leaves the article altogether by evaporation or extraction.

Migration is movement of an additive through the polymer by diffusion, usually toward a contacting food, liquid or surface. Blooming is accumulation of that same additive at the surface once its concentration exceeds its solubility limit in the polymer. Volatility and extraction are physical loss of the additive from the article entirely, by evaporation into the air or by dissolving into a contacting solvent.

Migration: Fick's law, the Piringer model and EU 10/2011 screening#

Additive migration follows Fick's laws, reported by Adolf Fick in 1855, so the amount that has left the polymer rises with the square root of the contact time. For a semi-infinite medium, the concentration at depth x and time t is c(x,t) = c0 x erfc(x / (2 x sqrt(Dt))), which means early migration testing and migration modelling both scale predictably even before a system reaches equilibrium.

The diffusion coefficient D in that equation is not measured for every substance and polymer pair; instead, the European screening model is the one set out in the Joint Research Centre guideline on migration modelling (EUR 27529, 2015), which gives an upper-bound diffusion coefficient D_P* = exp(A_P* minus 0.1351 x Mr^(2/3) plus 0.003 x Mr minus 10454/T), where A_P* = A_P'* minus tau/T, D is in m2/s and T is in kelvin. The constants A_P'* and tau are published for 5 polymers: LDPE at 11.5 and 0 K, HDPE at 14.5 and 1577 K, PP homopolymer and random copolymer at 13.1 and 1577 K, PET at 6.4 and 1577 K, and rigid PVC at minus 1.0 and 0 K. The resulting activation energy is 86.92 kJ/mol for LDPE, close to the published literature mean of 87 kJ/mol, and about 100 kJ/mol for HDPE and PET. Where the partition coefficient between the polymer and the food is unknown, the model uses a worst-case value of K_P,F = 1, or 1,000 when the migrant is only sparingly soluble in the food, so the model never underestimates migration for lack of that data point.

Regulation (EU) No 10/2011 Annex V, chapter 2.2.3, allows this kind of modelling as a screening tool rather than requiring a physical test on every article, and Article 18(3) requires any screening failure to be confirmed by verification testing before a compliance decision is made. Migration modelling entered EU law through Directive 2001/62/EC, was validated in EU project SMT-CT98-7513 and was confirmed at 95% confidence by Begley and colleagues in 2005. The overall migration limit this screening checks against is 10 mg/dm2 of contact area, or 60 mg/kg for articles intended for infants, under EU 10/2011. The constants above are printed only for the 5 polymers listed; plasticised-PVC and polyamide constants exist in the source but are informative rather than tabulated on this index.

Blooming, exudation and plate-out#

Blooming happens when an additive is present above its solubility in the polymer at the use temperature, so the excess diffuses to the surface at a rate set by its diffusion coefficient, as described by Nouman, Saunier, Jubeli and Yagoubi at Université Paris-Saclay in Polymer Degradation and Stability in 2017. The melt dissolves more additive than the solid polymer can hold, so the part is supersaturated the moment it cools, and the excess then migrates outward until the surface concentration falls back toward the solubility limit.

Some blooming is wanted: slip agents are designed to bloom, with oleamide rising fast and erucamide rising slowly, and a slow bloom is preferred for roll stock where an early, greasy surface would interfere with printing or lamination. Migrating antistatic agents and antifog additives work the same way, by design. Unwanted blooming includes antioxidant and HALS chalking, plasticizer exudation, flame-retardant whitening from AlPi and MPP in PA66 under damp heat, and dye migration in polyethylene and polypropylene. The 3 levers against unwanted blooming are a higher-molecular-weight or oligomeric grade of the same additive, a better match between the additive's solubility parameter and the polymer's, and simply a lower loading. Plate-out is a related but separate surface problem: a deposit of formulation components on hot metal tooling, driven by over-lubrication, an incompatible external lubricant, metal-soap reaction products, or pigment and filler fines building up on the die or calender rolls.

Volatility, extraction and fogging#

An additive small enough to migrate is usually small enough to evaporate, so raising the molecular weight lowers volatility and the diffusion coefficient at the same time. Irganox 1010, at a molecular weight of 1,178, replaced BHT, at a molecular weight of 220, in most polyolefin applications for exactly this reason: the larger molecule diffuses and evaporates far more slowly at the same use temperature.

Solubility in a test solvent predicts how readily an additive extracts into a contacting liquid: Songwon reports SONGNOX 1010 dissolving at less than 0.05 g per 100 g of squalane and less than 0.1 g per 100 g of ethanol, against SONGNOX 1680 dissolving at 10.0 g per 100 g of n-hexane, a difference of two orders of magnitude between two antioxidants used in the same polymer families. Thermogravimetric 5% mass-loss temperatures follow the same pattern of supplier data: SONGNOX 1010 loses 5% of its mass between 330 and 353 degrees Celsius, SONGNOX 1680 between 286 and 306 degrees Celsius, SONGNOX 9228 at 365 degrees Celsius and SONGNOX PQ at 296 degrees Celsius, values that describe relative volatility between grades rather than an absolute processing ceiling. Plasticizer migration, extraction and volatility follows the same molecular-weight logic in flexible PVC, where the plasticizer's own size is the main lever against extraction into a contacting fluid.

How Do Additives Interact in One Formulation?#

Additives in one formulation interact in 4 ways: they strengthen each other, cancel each other out, are adsorbed onto a filler or pigment, or react chemically.

An additive is never specified alone in a working formulation, and a package is re-tested whenever one component changes, because the table above shows that adding, removing or substituting a single ingredient can flip a neighbouring additive from effective to counterproductive. This is the reason additive interactions is its own guide on this reference rather than a footnote on each family page.

Which Defects Come From the Formulation?#

8 of the most common plastic defects are written into the recipe rather than caused by the machine: gels, yellowing, pinking, plate-out, zinc burning, blooming, a rising melt flow rate and drifting film friction.

The gel-source table above follows Ampacet's technical guidance, which stresses that identifying the gel source comes before any countermeasure, because the wrong fix, such as raising temperature when the true cause is a weak antioxidant package, can make a gel problem worse rather than better.

What Does the Formulation Decide at End of Life?#

The recipe, not the sorting line, decides whether a part can be recycled: a degradable additive makes a polypropylene or polyethylene package non-recyclable under the Association of Plastic Recyclers design guide, while the workhorse stabilizers, lubricants and fillers are design-preferred.

The APR Design Guide rates thermal stabilizers, UV stabilizers, nucleating agents, antistatic agents, lubricants, fillers, pigments, impact modifiers and chemical blowing agents as design-preferred additives for additives for recycled plastics, while a degradable additive in the same polymer disqualifies the package from that rating outright. Near-infrared sorting, the technology behind most automated recycling streams, struggles with black and strongly coloured plastics, and the APR colour threshold for a sortable part is an L value above 40 with average near-infrared reflectance above 10%.

Recycled content is not optional going forward. The EU Packaging and Packaging Waste Regulation (PPWR), Regulation (EU) 2025/40, applies from 12 August 2026, caps lead, cadmium, mercury and hexavalent chromium in packaging at 100 mg/kg combined, and sets minimum recycled content from 1 January 2030 at 30% for contact-sensitive PET, 10% for other contact-sensitive packaging, 30% for single-use plastic beverage bottles and 35% for other plastic packaging, rising to 50%, 25%, 65% and 65% respectively by 2040. Against that regulatory push, global plastics recycling stood at 9% in 2015, and about 1% of plastic has been recycled more than once, which is the scale of the gap the formulation-level design rules above are meant to close.

Legacy additives in recycled plastic#

A legacy additive is one that was legal when the article was made and is restricted now, and it returns through the recycling loop: 16% of 151 new PVC floorings on the Swiss market carried regulated chemicals above 0.1 wt%, mainly lead and DEHP, in a study by Wiesinger, Wang and Hellweg at ETH Zurich, published in Environmental Science and Technology in 2024. The same study found that 29% of those floorings carried other ortho-phthalates above 0.1 wt%, which shows that a legacy substance rarely travels alone.

Two regulations currently govern how far that legacy can travel. Lead in PVC, under REACH Annex XVII entry 63 (Regulation (EU) 2023/923), has been restricted below 0.1% by weight of the PVC material since 29 November 2024, though recovered rigid PVC is allowed up to 1.5% w/w in listed uses until 28 May 2033, marked "Contains >= 0,1% lead"; the parallel derogation for recovered flexible PVC expired on 28 May 2025. PBDE flame retardants face a separate, tightening limit: Delegated Regulation (EU) 2025/1482 sets an unintentional trace-contaminant limit of 10 mg/kg in mixtures and articles generally, and for recovered material specifically, 350 mg/kg from 30 December 2025, falling to 200 mg/kg from 30 December 2027. Legacy additives in recycled plastic covers the wider list of substances these two rules apply to.

Restabilizing recycled polyolefins#

Recycled polyolefins are usually not restabilized at all, even though a binary antioxidant blend at 0.1 to 0.3 wt% is enough to keep recycled polypropylene and HDPE processable. Post-consumer and post-industrial recycled polyolefins generally leave the reclaimer without a fresh antioxidant top-up, which is the gap that restabilization is designed to close; the practice was developed by Rudolf Pfaendner, first at Ciba and later at Fraunhofer LBF, who reviewed 30 years of the field in Polymer Degradation and Stability in 2022.

A closed-loop polypropylene study by Knoben and colleagues, published in Materials in 2025, measured the effect directly: dosing 500 ppm of a primary antioxidant plus 1,000 ppm of a secondary antioxidant at every recycling pass raised the phosphite level from about 650 ppm after cycle 1 to more than 1,200 ppm after cycle 5, while an un-restabilized open-loop regranulate still held more than 150 ppm of intact phosphite even without a top-up. Restabilization of recycled plastics covers the full dosing logic behind that result.

Bio-based additives, and what bio-based does not mean#

A bio-based additive is one whose carbon comes from biomass, measured by radiocarbon under ASTM D6866, and it is not the same thing as a biodegradable additive. Biodegradability follows from an additive's chemical structure, such as an ester bond a microorganism can break, not from where its carbon originated, so a bio-based additive can be just as persistent as a fossil-based one, and a fossil-based additive can in principle biodegrade.

5 bio-based additive types are already covered elsewhere on this site:

• Epoxidised soybean oil and epoxidised linseed oil, used as PVC co-stabilizers and plasticizers
• Citrate plasticizers such as ATBC and TEC
• Glycerol monostearate and other fatty-acid esters and amides
• Metal stearates used as lubricants and acid scavengers
• Wood flour and natural fibres used as fillers

What Does a Formulation Cost? Cost-in-Use, Not Price per Kilogram#

Cost-in-use is the cost of getting a function into the finished part, calculated per kilogram, per litre or per part, and it is not the price per kilogram of the additive. Cost per kilogram of compound is the sum of each ingredient's weight fraction multiplied by its price, and cost per litre is that figure multiplied by the compound's density.

Converting between weight and volume is where filled compounds catch formulators out. Fillers lower the cost per kilogram of a compound, because they are usually cheaper than the polymer they displace, but they also raise the compound's density, so the cost per unit volume, which is what actually fills a part of fixed size, falls by less than the cost per kilogram alone would suggest. The additive dosage and cost-in-use calculator applies this density correction automatically rather than leaving it as a mental adjustment.

Masterbatch pricing inverts the usual intuition in a similar way. For a masterbatch, cost-in-use is the masterbatch price multiplied by the let-down fraction, so a stronger masterbatch used at a lower let-down can be cheaper per finished part while costing more per kilogram of masterbatch itself, because less of it is needed to hit the same active dose. Our sources hold no additive price figures, so every statement in this section is a method for comparing costs, never a number; current plastic additive prices are tracked separately.

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What Plastic Formulation Is Not#

Plastic formulation is the recipe of a plastic compound, which makes it a different subject from polymerisation, from part design and from the formulation of coatings, adhesives or concrete. The phrase "polymer formulation" is sometimes used for this same subject, but in live search it mostly returns results about coatings, drug-delivery and pharmaceutical formulation rather than plastics, so this page treats plastic formulation and polymer formulation as different search intents even though a reader occasionally means the same thing by both. A full glossary of the terms used across this page, from phr to restabilization, sits in the plastic additives glossary.

How is plastic made? Polymerisation is not formulation#

Making the polymer and formulating the compound are two different steps: polymerisation turns monomers into a polymer using catalysts and other polymer production aids, which Regulation (EU) No 10/2011 defines separately from additives in Article 3(8), and formulation then turns that polymer into a usable compound. The polymer producer typically adds a base stabilization package of its own before the pellet ever leaves the plant, and the formulator's own additive package, described across this page, is added on top of that base package once the polymer reaches the compounder. This reference does not cover the polymerisation step itself, including naphtha cracking or polycondensation chemistry, since that is general polymer science rather than additive formulation.

Formulations this reference does not cover#

This reference covers formulations for plastics only: thermoplastics, thermosets used as plastics, plastic compounds and masterbatch. 9 adjacent formulation disciplines share chemistry or terminology with plastics but sit outside this site's scope:

• Concrete and cement admixtures
• Paints, coatings and inks
• Adhesives and sealants
• Fuel, oil and lubricant additives
• Food and feed additives
• Cosmetics formulation
• Textile finishing chemicals
• Paper chemicals
• Pure rubber chemistry, including accelerators and vulcanising agents

Calculators for formulators: PHR to weight percent, let-down ratio and additive dosage and cost-in-use (linked above where each unit is introduced), plus the additive migration estimator (coming soon, day 48).

Request quotes for the additives in your formulation from the plastic additive supplier finder, or browse the plastic additive manufacturers and suppliers directory directly by polymer, family, volume and country.

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