Definition
PVC (polyvinyl chloride) is a thermoplastic obtained by polymerisation of vinyl chloride (VCM), supplied to processors as powder or granulate with a density of about 1.2–1.45 g/cm³, occurring in a rigid variant (PVC-U) and a flexible one (PVC-P with plasticisers), used above all for pipes, window profiles, cables, films and flooring.
Polyvinyl chloride is the third-largest commodity plastic in the world by production volume — after polyethylene and polypropylene. It differs from them fundamentally, however: it is not a polyolefin, it contains chlorine in the chain (about 57% by mass), it is heavier than water and it is very rarely used “pure” — only a formulation with stabilisers and additives turns the base polymer into a usable material. From the terminal’s perspective this distinctiveness has concrete consequences: a different density, a different delivery form and — in the case of powder — different transloading requirements.
What PVC is — chemistry in brief
The starting point is vinyl chloride (VCM, vinyl chloride monomer) — a gaseous monomer that, in the polymerisation process, joins into long chains of poly(vinyl chloride). VCM itself is a hazardous substance and is subject to strict control at the production stage, but the finished PVC polymer — powder or granulate — is an inert material, safe in trade. This distinction is important: in logistics we do not trade the monomer but the finished polymer, which we treat like any other bulk plastic not covered by ADR.
The base polyvinyl chloride practically never goes into a product in pure form. A range of ingredients is added to the formulation: thermal stabilisers (protecting against degradation in processing), plasticisers (softeners — deciding whether the material will be rigid or flexible), fillers (e.g. chalk), pigments, impact modifiers and lubricants. It is precisely thanks to this formulation flexibility that one polymer yields materials as different as a rigid sewage pipe and a soft garden hose.
Hence two basic divisions that must be known when talking about PVC: hardness (PVC-U versus PVC-P) and polymerisation method (suspension S-PVC versus emulsion E-PVC). The first speaks of the properties of the finished material, the second — of the form and purpose of the base polymer.
Rigid and flexible PVC — PVC-U and PVC-P
| Variant | Characteristics | Typical application |
|---|---|---|
| PVC-U (rigid, unplasticised) | stiff, durable, without plasticisers | pressure and sewage pipes, window profiles, panels, sheets |
| PVC-P (flexible, plasticised) | flexible thanks to plasticisers | cables, films, flooring, hoses, synthetic leather |
PVC-U (unplasticised PVC, i.e. “without softeners”) is a hard and rigid material. It is what white window profiles, water and sewage pipes, window sills, panels and sheets are made of. Its advantages are chemical resistance, rigidity, non-flammability (PVC is self-extinguishing thanks to its chlorine content) and durability — a PVC-U window profile works for decades.
PVC-P (plasticised PVC) is created by adding plasticisers — compounds that push apart the polymer chains and give it flexibility. The more softener, the more pliable the material: from semi-flexible flooring to soft films and hoses. PVC-P is what cable insulation, floor coverings, waterproofing membranes, synthetic leather and medical products (e.g. drains) are made of. The same polymer, yet completely different in use thanks to the formulation — and this is the key feature distinguishing PVC from the polyolefins, where the properties are determined above all by the chain structure itself.
S-PVC and E-PVC — polymerisation method and form
The second division concerns the way the base polymer is produced, which translates into its physical form:
| Type | Polymerisation | Form | Application |
|---|---|---|---|
| S-PVC (suspension) | suspension | powder with larger grains | pipes, profiles, rigid and flexible products |
| E-PVC (emulsion) | emulsion | very fine powder | pastes, plastisols, coatings, flooring |
S-PVC (suspension PVC) is the market-dominant form — the majority of production. It is created by suspension polymerisation, has the form of a porous powder with relatively large grains (tens to over a hundred micrometres), which absorbs plasticisers and additives well. It is the basic raw material for pipes, profiles and most PVC products.
E-PVC (emulsion PVC) has much finer particles and is intended where a paste form is needed — plastisols, i.e. suspensions of PVC powder in plasticiser, used for coatings, flooring, synthetic leather, printing and dip coating. From the transloading perspective E-PVC, as a very fine material, dusts the most and requires the most caution.
It is also necessary to distinguish the base polymer, the dry blend and the compound (granulate). The base polymer and dry blend (PVC powder mixed with stabilisers and additives, ready for extrusion) are powdery. PVC granulate is created only after compounding and extrusion — and mainly for flexible PVC and ready compounds. This difference in form — powder versus granulate — is more important for the terminal than the chemical nuances, because it determines the transloading method.
Properties
The most important features distinguishing PVC from the polyolefins are density and thermal sensitivity.
PVC is clearly heavier — the polymer density is about 1.2–1.45 g/cm³ depending on the formulation (rigid PVC-U closer to the lower limit, flexible and filled closer to the upper). This is significantly more than PE (0.91–0.96) or PP (about 0.90). The practical consequence: PVC sinks in water, while the polyolefins float — which is, incidentally, the simplest way to tell the plastics apart in field conditions. In bulk transport this means a reversal of the logic known from the polyolefins: whereas PE/PP granulate fills a silo tanker by volume before it reaches the weight limit, with PVC it is easier to hit the permissible combination weight before the tank fills up.
The second feature is thermal sensitivity. Heated PVC splits off hydrogen chloride (HCl) in a dehydrochlorination process, which leads to discolouration and chain degradation. That is why the PVC formulation always contains thermal stabilisers — formerly commonly lead-based, today in Europe almost exclusively calcium-zinc (Ca-Zn), in line with the industry’s voluntary withdrawal of lead stabilisers. This sensitivity concerns processing, not transport — powder and granulate are carried at ambient temperature, where the problem does not occur.
A third feature important for the terminal: PVC powder dusts. The fine-grained material easily rises into the air during pouring, which requires tight packaging and installations that limit dust emission. This is the basic difference between handling powder and handling granulate and the main reason why the delivery form is the first thing we ask about when accepting a PVC load.
Otherwise, PVC is characterised by good chemical resistance, non-flammability (self-extinguishing thanks to chlorine), good electrical insulation and a low price, which makes it one of the most versatile structural and construction plastics.
Applications
Polyvinyl chloride is a plastic above all for construction — most production goes into construction and infrastructure:
- Pipes and fittings — water supply, sewage, drainage, installation. PVC-U is the number-one material here because of its durability and chemical resistance.
- Window and door profiles — white PVC-U profiles are the most popular material for windows and doors in Central Europe.
- Panels, sheets, window sills, soffits — rigid PVC-U products.
- Cables and wires — PVC-P insulation and sheathing, one of the largest applications of flexible PVC.
- Films and flooring — waterproofing membranes, floor coverings (PVC-P), packaging films, banners.
- Technical and medical products — hoses, synthetic leather, upholstery, medical drains and bags (PVC-P).
This duality — rigid PVC-U in infrastructure and flexible PVC-P in cables, films and flooring — means that under the single name “PVC” hide materials with extremely different properties. For the logistics operator this means above all a diversity of delivery forms: from base powder, through dry blends, to ready compound granulates.
Transport and transloading of PVC
The transloading method for PVC depends directly on the form of the material — and this is the most important difference from the polyolefins, which always travel as granulate.
PVC powder (base polymer, dry blend, E-PVC) requires special caution: it dusts, so it needs tight packaging, dust-emission control and dedusting at the transfer station. It is transferred carefully from big bags, with care for tightness, to limit material loss and dust formation. Fine dust is also a nuisance for the surroundings and installations, so a closed transfer path between packaging and tank is key.
PVC granulate (compound, mainly flexible PVC and ready compounds), on the other hand, is handled like any other bulk plastic — by the method of pneumatics-free transloading, i.e. by gravity, without accelerating the grain in pipes. For PVC compound, often coloured and formulated for a specific product, the key here is not so much dust as the absence of mixing with a foreign batch — a gentle flow through a sieve makes maintaining this separation easier.
The terminal in Chorula — with a buffer of 2000 big bags and a throughput of 200 tonnes per day — receives PVC from containers and transfers it into silo tankers, but unlike with the polyolefins there is no single default scenario here: with PVC we always start by asking about the form — powder or granulate — because it determines both the choice of transfer station and dust control. The material, as a finished polymer, is not a dangerous good (it is not subject to ADR), so it fits into the standard stream of bulk materials we handle: PE, PP, ABS, PS, PA, PVC, PET and others — everything that pours well and is not ADR.
Because of PVC’s higher density, the limit in bulk transport is sometimes the combination weight, not the tank volume — which distinguishes its logistics from the light polyolefins and affects the choice of trailer and the degree of filling.
PVC producers
The largest producers of polyvinyl chloride in Europe include, among others, INEOS, Vinnolit, Kem One and Vestolit. Globally, a significant part of supply is covered by plants in Asia (especially in China) and in North America.
In Poland, polyvinyl chloride is made by ANWIL of the Orlen group in Włocławek — the largest domestic PVC producer and at the same time one of the significant plants in the region. This connection has a practical dimension for us: in granulate logistics we cooperate with, among others, Orlen, and among the network’s regular customers in plastics trading are also LG Chem, Borealis and Synthos. Domestic PVC production means shorter supply chains in Central Europe and a regular stream of material that an inland terminal can efficiently handle on the last leg to the processor.
The importance of PVC recyclate is also growing — recovered mainly from window profiles, pipes and films within industry initiatives (such as VinylPlus). Recyclate is transported the same way as virgin material, but it sets higher cleanliness and batch-traceability requirements.
Related topics
PVC is best understood in comparison with the polyolefins — the lighter, floating polyethylene and polypropylene — from which it differs in density, chemistry and delivery form. The method of pneumatics-free transloading is key for dusting PVC powders, and the basic packaging for bulk transport remains the big bag (FIBC). The full big-bag transloading offering can be found on the big bag to silo tanker transloading page, and a broader context of bulk material transport — on the PHS Magnum portal.
Sources
- ISO 1163 / ISO 1183 standards — classification of PVC and determination of the density of plastics.
- PVC producers’ technical materials (data sheets for powders and compounds).
- Industry guidelines on PVC cleanliness and recycling (VinylPlus, Operation Clean Sweep).
- Operational practice of the SMIALA terminal, Chorula — Aleksy Pasternak.
