Plastic Raschig Ring

Plastic Raschig ring is the plastic version of the oldest and simplest random packing: a plain hollow cylinder with a thin wall and no windows. It is light, corrosion-resistant and low-cost, and because the moulded wall is thin it keeps a high free volume — around 92 to 95 percent — with a low pressure drop and good liquid distribution. We mould it in the full range of packing plastics: polypropylene for everyday warm corrosive duty, PVC and CPVC, PVDF, and PTFE for the most aggressive chemicals and the highest temperatures. It suits absorption, adsorption, scrubbing and reaction towers where the stream is corrosive but within reach of the chosen plastic. We make it in sizes from 20 to 76 mm.

The plastic form of the classic hollow-cylinder Raschig ring — simple and low-cost.
Light and corrosion-resistant, with high free volume (about 92 to 95 percent) and low pressure drop.
Available in PP, PVC, CPVC, PVDF and PTFE to match the chemistry and temperature.
Good for absorption, scrubbing and reaction towers in corrosive service.
PTFE grade resists nearly all chemicals; sizes 20, 25, 38, 50, 65 and 76 mm.

Technial Parameters

Size (mm)	Surface area (m²/m³)	Free volume (%)	Pieces per m³	Bulk density (kg/m³)*
20×20×2	267	92.8	125,000	550
25×25×2	219	93.4	60,000	450
38×38×2.5	165	94.6	15,800	420
50×50×4	108	94.5	6,800	450
65×65×5	84	94.8	4,600	500
76×76×4	73	92	2,000	300

*Bulk density is indicative; it varies with the resin — fluoropolymers such as PTFE are the heaviest, polyolefins such as PP much lighter.

Property	Value
Product Type	Plastic random packing (Raschig ring)
Material	PP / PE / PVC / CPVC / PVDF / PTFE (chosen by chemistry and temperature)
Model NO.	RJ-603
Colour	White or natural (by resin)
Standard Sizes	20, 25, 38, 50, 65, 76 mm
Shape	Thin-wall hollow cylinder, height ≈ diameter
Free Volume	About 92–95%
Max Service Temperature	~60°C (PVC) up to ~260°C (PTFE), by material
Chemical Resistance	Good to excellent by resin; PTFE near-universal
Strengths	Light, corrosion-resistant, low-cost, simple, high void
Limitations	Lower temperature and strength than metal or ceramic; lower capacity than a Pall ring
Applications	Absorption, adsorption, scrubbing and reaction towers; acid / alkali fume treatment
Trademark	RONGJIAN
Origin	China
HS Code	8419909000
Transport Package	Carton box / ton bag / steel drum

FAQs

What is a plastic Raschig ring used for?

Plastic Raschig ring is used in packed columns for gas-liquid contact — absorption, adsorption, scrubbing and reaction — where the stream is corrosive and the temperature is within reach of the chosen plastic. Being light and chemically resistant, it is common in acid and alkali fume scrubbing, waste-gas treatment, fine-chemical and environmental plants, and wherever a low-cost, corrosion-proof packing is wanted. Its thin wall gives a high void and a low pressure drop, so it moves gas and liquid freely and spreads liquid well. For cool-to-moderate corrosive duty, or for the harshest chemistry when made in PTFE, the plastic Raschig ring is a simple, economical choice.

Which plastic should I choose, and what can each handle?

The plastic is chosen to match the chemistry and, above all, the temperature, and the range runs from cheap and mild to costly and nearly indestructible. Polypropylene is the everyday choice — inexpensive, resistant to acids, alkalis and salts, and good to about 100 degrees. PVC and CPVC are strong on chlorine and acids, PVC to around 60 degrees and the chlorinated CPVC to about 95. PVDF takes hotter and more oxidising streams, to roughly 150 degrees. PTFE stands at the top, shrugging off almost every chemical, hydrofluoric acid included, and running to about 260 degrees, though it costs the most. The sensible approach is to start with polypropylene and move up only as far as the heat or the chemistry actually needs. Tell us the fluid and its temperature and we will point to the right plastic.

How does a plastic Raschig ring compare with a plastic Pall ring?

A Raschig ring is a plain plastic tube; a Pall ring is the same tube with slots cut in its side and the flaps turned inward. Those slots give the Pall ring more open volume, a lower pressure drop and more even liquid spreading, so at the same size a plastic Pall ring has more capacity and efficiency. The plastic Raschig ring trades that away for a simpler, stiffer, cheaper piece with an unbroken wall, and it works well as a support layer or a budget packing. In short, choose a plastic Pall ring when you want the most performance from the column, and a plastic Raschig ring when simplicity, rigidity and cost come first.

When is plastic the right material, rather than ceramic or metal?

Plastic wins on three counts: it is the lightest packing, so it loads a tower with little weight; it resists specific corrosives, such as hydrofluoric acid or strong chlorides, better than most metals; and it costs less than metal. Where it loses is heat and strength — even PTFE stops around 260 degrees, far below ceramic or metal, and plastic is softer, so very deep or high-pressure beds are better in metal. So choose plastic for cool-to-warm corrosive duty on a budget, ceramic for hot strongly acidic gas, and metal for high temperature, high pressure or maximum efficiency. For the many towers that run corrosive but not especially hot, a plastic Raschig ring is the economical answer.

The Raschig ring is the simplest random packing there is — a plain hollow cylinder, as tall as it is wide, with no cut openings — and in plastic it becomes light, corrosion-resistant and cheap. A moulded plastic wall is thin, so the ring holds a high free volume, roughly 92 to 95 percent, which keeps the pressure drop low and lets liquid spread evenly through the bed. What a plastic Raschig ring cannot do is take much heat, and it has less mechanical strength than metal, so it is a packing for corrosive service at modest temperatures rather than for hot or high-pressure towers. Its real advantage is the choice of resin: the same simple shape can be moulded in a cheap polyolefin or in a premium fluoropolymer, so its chemistry and temperature limits are set by the plastic you pick.

The usual grades, from everyday to extreme, line up like this:

Plastic	Max temperature	Best for
PP (polypropylene)	~100°C	General acid, alkali and salt duty at low cost
PVC / CPVC	~60°C / ~95°C	Chlorine and acid service, cool or warm
PVDF	~150°C	Hotter and oxidising streams
PTFE	~260°C	Almost any chemical, including HF; highest cost

Chosen well, a plastic Raschig ring gives long, corrosion-free service in absorption, scrubbing, adsorption and reaction towers, and in acid or alkali fume treatment. Set beside the alternatives, it is lighter and cheaper than metal and often more resistant to particular corrosives, and it is far easier to handle than brittle ceramic; against that, ceramic and metal reach temperatures no plastic can, so genuinely hot duty belongs to them. And next to a plastic Pall ring, the Raschig ring gives up some capacity and efficiency in exchange for a simpler, stiffer, lower-cost piece. Tell us the medium, its temperature and the tower size and we will recommend the resin and the ring size.