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Contact: Wang Lili
E-mail：18066002268
Phone：702461526@qq.com
Address: Lifute Industrial Park, Taizhou City, Jiangsu Province
Lift Sling Rigging Co., Ltd. manufactures the polypropylene flat sling - a PP flat woven webbing sling to EN 1492-1, made to order from 1 t to 10 t. Polypropylene is the fibre to specify where acids are present: it is unaffected by acids and by alkalis, so it is the flat woven sling for steel pipe pickling lines, acid tanks, plating and anodising shops and acid-washed steel. It is the one fibre of the three that takes up no water, absorbing below 0.1% of its own weight, so a wet polypropylene band carries the same rating as a dry one. Its limits are equally specific: keep it clear of chlorinated solvents, aromatic hydrocarbons and strong oxidising acids, and keep it below +80 C. Brown polypropylene label, 7:1 safety factor and a minimum breaking load of seven times the working load limit, EN 1492-1 colour code with one black capacity stripe per tonne, 25 mm to 250 mm webbing, single or double ply, any length from 1 m to 12 m. HS code 630790. Phone 18066002268.
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Release time：2026-09-17 08:39
Lift Sling Rigging Co., Ltd. +8618066002268 produces Polypropylene flat sling, lifting rope, acid-washed sling, lifting sling。
Polypropylene Flat Sling
Polypropylene Flat Sling — PP webbing to EN 1492-1, 1 t to 10 t, the acid-side fibre of the range, single or double ply, any length from 1 m to 12 m
What is on this page. This page covers the polypropylene flat woven webbing sling as a material choice: what the product is and what it is not, the band range, what polypropylene does that polyester and polyamide do not, which duty points to it, how a polypropylene band behaves wet, hot and in contact with each class of chemical, what the acid duty of a steel pickling line actually asks of a sling, how to inspect and retire it, and how to order it.
What the product is, and the terms that get confused with it — section 1
The polypropylene band range and the PP specification sheet — section 2
Three fibres side by side, property by property — section 3
Choosing the fibre and the band from the duty in front of you — section 4
Polypropylene under wet, hot, cold, sunlit and chemically loaded conditions — section 5
Chemical resistance in detail, by class of chemical — section 6
The acid duty: what a steel pipe pickling line asks of a sling — section 7
Endless or eye-and-eye — section 8
Inspection and retirement criteria for a PP band — section 9
Standards, marking and duties a polypropylene sling is not rated for — section 10
1. What Is a Polypropylene Flat Sling?
A polypropylene flat sling is a flat woven webbing sling woven from polypropylene and sewn into either an endless loop or an eye-and-eye form. EN 1492-1 — the European standard for these products — covers flat woven webbing slings in Type A (endless), Type B, Type C and Type D (eye-and-eye, with or without fittings), made of polyamide, polyester or polypropylene, across webbing widths of 25 mm to 450 mm, and it sets out the requirements for design, testing and marking. The polypropylene bands on this page are the same product built from the third of those three fibres, with a safety factor of 7:1.
Polypropylene, PP and PP webbing mean the same fibre on this page. Polypropylene is the polymer; PP is the abbreviation used on labels, in standards and in purchase orders. The colour that identifies it is brown on the label — the webbing colour is a separate signal, and section 2 explains the difference.
The fibre is unusual in one respect that changes how it is specified. Polypropylene is a non-polar polyolefin. It does not absorb water, it is lighter than water, and it is chemically inert towards acids and alkalis because there is nothing in the polymer chain for them to attack. That is a genuine advantage on a pickling line. It is also why the fibre has the lowest tensile strength of the three: the same inertness that frustrates acids leaves the polymer with less orientation and less tenacity than polyester or polyamide, so a polypropylene band reaches a given working load limit on more webbing, not less.
What it is not. Three products sit close to each other in the market and are routinely quoted as if they were the same thing. They are not, and the difference decides whether the sling you are offered can do the job:
Polypropylene flat sling — flat woven polypropylene webbing, sewn, Type A to D under EN 1492-1. This page.
Polypropylene round sling — a different product: a load-bearing core of parallel yarn inside a woven tubular cover, covered by EN 1492-2. Different standard, different construction, and not interchangeable with a flat woven sling.
Polypropylene webbing with fittings — still a flat woven webbing sling under EN 1492-1, but Type D: eyes with metal end fittings, or a sling built as an assembly with a master link and hooks. On acid duty the fittings matter as much as the webbing, and section 7 explains why.
Terminology: what the term in the quotation actually means
| Term you may be offered | What it actually is | Standard | Covered on this page? |
|---|---|---|---|
| Polypropylene flat sling, PP flat woven sling | Flat woven polypropylene webbing, sewn into a loop or with eyes | EN 1492-1 | Yes — this page |
| PP webbing sling, polypropylene webbing sling, PP sling | The same product, named by fibre or by abbreviation rather than by construction | EN 1492-1 | Yes — this page |
| Acid-washed sling, acid resistant flat sling | The same product named by the duty it is bought for; on this site the term is carried by the polypropylene band | EN 1492-1 | Yes — this page, section 7 |
| Endless polypropylene sling, PP ring sling | Flat woven polypropylene webbing closed into a continuous loop, no end fittings (Type A) | EN 1492-1 | Yes — section 8 |
| Eye-and-eye polypropylene sling, two-eye PP sling | Flat woven polypropylene webbing with a reinforced eye at each end (Type B, C or D) | EN 1492-1 | Yes — section 8 |
| PP braided sling, braided lifting sling | A round sling: load-bearing yarn core inside a woven tubular cover. Not a flat woven sling, and not covered by this page | EN 1492-2 | No — a different product |
| Rond sling, round sling | The same round sling as above; rond is a frequent misspelling of round | EN 1492-2 | No — a different product |
| One-way sling, single-trip sling | A lower-rated consumable flat woven sling for one known lift, often built in polypropylene — where a re-usable sling is not economic | EN 1492-1, consumable grade | On request |
2. The Polypropylene Band Range, 1 t to 10 t
Polypropylene bands are made in the same band structure as the rest of the flat woven range, because the band is set by the standard and not by the fibre. The webbing colour is the working load limit code for a straight lift, the black transverse stripes repeat that capacity one stripe per tonne, and the width grows with the band. What changes with the fibre is not the colour code but two things: the label, because the label colour states the material and a polypropylene band carries a brown label at every band from 1 t to 10 t, and the amount of webbing behind the rating, because polypropylene has the lowest tensile strength of the three fibres.
Two colour signals therefore travel on the same sling, and it is worth separating them once:
Two colours, two different messages
| The colour you are looking at | What it tells you | Set by | The values |
|---|---|---|---|
| Webbing colour (the band itself) | The working load limit for a straight lift | EN 1492-1 band colour code | Violet 1 t, green 2 t, yellow 3 t, grey 4 t, red 5 t, brown 6 t, blue 8 t, orange 10 t |
| Black transverse stripes | The same capacity, repeated as a physical mark you can count when the colour is faded or dirty | EN 1492-1 | One stripe per tonne of working load limit |
| Label colour | The fibre the sling is woven from — not the capacity | EN 1492-1 fibre identification | Blue polyester (PES), green polyamide (PA / nylon), brown polypropylene (PP) |
| Customer colour or printed logo | Nothing about capacity | The buyer | May be added alongside the band colour, never instead of it |
Read together, a 3 t polypropylene band is therefore yellow webbing with three black stripes and a brown label. Note what the code does not tell you: it says nothing about the fibre. A yellow 3 t band is a 3 t band whether it is woven from polypropylene, polyester or polyamide, and only the label distinguishes them — which is why a quotation that specifies a colour but not a fibre has not specified the product.
The table below is the polypropylene band specification as we build it. Capacity figures for hitches other than a straight lift are calculated with the standard mode factors, which are explained in section 4.
Polypropylene flat sling: band specification, 1 t to 10 t
| Band | Webbing colour and stripes | Working load limit, straight lift | Minimum breaking load at 7:1 | Choked hitch (0.8) | Basket, parts parallel (2.0) | Two-leg assembly (1.4) |
|---|---|---|---|---|---|---|
| 1 t | Violet, 1 black stripe | 1 t / 1,000 kg / 2,205 lb | 7 t | 0.8 t | 2 t | 1.4 t |
| 2 t | Green, 2 black stripes | 2 t / 2,000 kg / 4,409 lb | 14 t | 1.6 t | 4 t | 2.8 t |
| 3 t | Yellow, 3 black stripes | 3 t / 3,000 kg / 6,614 lb | 21 t | 2.4 t | 6 t | 4.2 t |
| 4 t | Grey, 4 black stripes | 4 t / 4,000 kg / 8,818 lb | 28 t | 3.2 t | 8 t | 5.6 t |
| 5 t | Red, 5 black stripes | 5 t / 5,000 kg / 11,023 lb | 35 t | 4.0 t | 10 t | 7.0 t |
| 6 t | Brown, 6 black stripes | 6 t / 6,000 kg / 13,228 lb | 42 t | 4.8 t | 12 t | 8.4 t |
| 8 t | Blue, 8 black stripes | 8 t / 8,000 kg / 17,637 lb | 56 t | 6.4 t | 16 t | 11.2 t |
| 10 t | Orange, 10 black stripes | 10 t / 10,000 kg / 22,046 lb | 70 t | 8.0 t | 20 t | 14.0 t |
How to read the polypropylene band table.
The rating is the rating, however wet the sling is. This is the one row that differs from the polyamide bands in the same range. Polypropylene takes up below 0.1% of its own weight in water, so a band that has been in a rinse tank or left out in the rain still carries the figure in this table. On a pickling line that is a working advantage rather than a footnote — the sling is damp for most of its life, and the rating does not move.
Width is a construction figure, not a rating. Polypropylene has the lowest tenacity of the three fibres, so the same band arrives on a wider, heavier band of webbing than a polyester or polyamide sling of the same rating. That is the honest cost of the chemistry: you buy the band you need and then you accommodate a larger, heavier sling, and on a cramped pickling line hook that matters. Confirm width against ply on the quotation rather than assuming a width from this table.
The breaking load is a destruction figure. 7 t at the 1 t band and 70 t at the 10 t band are minimum breaking loads at the EN 1492-1 factor of 7:1. They are never working capacities, and they are not a margin to be spent.
Above 10 t. Heavier flat woven webbing slings are made to order, and for very heavy lifts we would normally quote a different product — a round sling, a wire rope sling or a lifting beam. Tell us the load and we will say which one the number points to.
Order by band, fibre and length together. A band on its own does not describe a deliverable product: 2 t tells you the colour and the rating, but the fibre, the ply and the length still have to be specified, and on a polypropylene band the fibre also decides which chemicals the sling may never meet.
3. Three Fibres Side by Side: What Polypropylene Does That the Others Do Not
EN 1492-1 covers three man-made fibres, and the choice between them is decided by the environment rather than by capacity. The table below puts published fibre data for the three side by side, with polypropylene first because it is the fibre this page is about. Where a figure is a range rather than a single number, that is because it is a range in the fibre data itself.
Polypropylene, polyester and polyamide compared, property by property
| Property | Polypropylene (PP) | Polyester (PES) | Polyamide (PA / nylon) |
|---|---|---|---|
| EN 1492-1 label colour | Brown | Blue | Green |
| Behaviour in acids (pickling, plating, mineral acids) | Unaffected — this is the reason the fibre is bought | Resists most mineral acids | Attacked. Dilute hydrochloric or sulfuric acid at 10% concentration at room temperature causes significant strength loss in 10 hours |
| Behaviour in alkalis (caustic, lime, cement slurry) | Unaffected | Attacked | Essentially immune to alkali damage |
| Strong oxidising acids (nitric, chromic) | Attacked. The polypropylene limitation that catches out buyers who move a PP sling from a hydrochloric pickling bath to a stainless pickling bath | Concentrated sulfuric acid at 95% at room temperature disintegrates polyester | Attacked |
| Chlorinated solvents (chloroform, carbon tetrachloride) | Softens or swells. This is the fibre's real chemical weakness | Not significantly affected | Not significantly affected |
| Aromatic hydrocarbons (benzene, toluene, xylene) | Attacked; at elevated temperature the polymer can be dissolved by non-polar solvents such as xylene | Subject to degradation in the presence of ketones and aromatics | Not significantly affected |
| Other organic solvents (acetone, ethanol, dry-cleaning solvents) | Resisted | Not significantly affected | Not significantly affected |
| Water absorption, published fibre data | Below 0.1% of its own weight — the fibre takes up no water | About 1% of its own weight | About 9% of its own weight |
| Strength while wet | No derating. A wet polypropylene band carries its dry rating | Does not lose strength as a result of moisture absorption | Up to 15% below its dry rating while wet; the strength returns once the sling dries completely |
| Density and flotation | 0.90 to 0.92 g/cm3, lighter than water, so the band floats | Heavier than water | Heavier than water |
| Elongation at the working load limit, published values | About 5% | 3% to 4% | 6% to 10% |
| Elongation at break, published values | 15% to 25% | 10% to 12% | 16% to 20% |
| Tensile strength | The lowest of the three, so a given band needs more webbing behind it | Intermediate | The highest of the three |
| Temperature range for use and storage under EN 1492-1 | −40 °C to +80 °C | −40 °C to +100 °C | −40 °C to +100 °C |
| US regulatory temperature ceiling, OSHA 1910.184(i)(7) | Not above 200 °F (93 °C) | Not above 180 °F (82 °C) | Not above 180 °F (82 °C) |
| Abrasion resistance | The poorest of the three in published sling-industry comparisons, though one webbing source rates it as good for its weight class. Either way it is not the fibre to choose where abrasion governs wear | Good | Good |
| Sunlight and UV | The poorest of the three. Polypropylene must be supplied UV-stabilised; unstabilised fibre degrades in sunlight | The most UV-stable of the three, which is why polyester is the default fibre for outdoor and yard duty | Good, but the most UV-sensitive of the three in sling service; published guidance recommends annual proof load and inspection for UV-exposed bands |
| Softening and melting | Softening near 150 °C, melting around 160 °C to 170 °C — the lowest of the three | Higher than polypropylene | Higher than polypropylene |
| Best property | Chemical inertness: no acid and no alkali touches it | Low stretch and UV stability | Shock absorption and alkali immunity |
| Where it is the right choice | Acid duty: steel pipe pickling, acid tanks, plating and anodising, acid-washed steel, and any duty where acids and alkalis both appear in the same area | General purpose, outdoor and yard duty, and any lift where a stable, low-stretch sling matters | Alkaline and wet-alkaline duty: cement, mortar, lime, concrete washdown, caustic cleaning, plus lifts where extra stretch is wanted |
| Where it must not be used | Chlorinated solvent, aromatic and strong oxidising acid contact; hot loads above +80 °C; and any duty where its lower strength or its abrasion performance is the binding constraint | Caustic and strongly alkaline duty; it is the fibre alkalis attack | Acid, bleach and phenolic contact; a maximum-capacity lift on a permanently wet sling |
Read the two temperature scales honestly. The two regimes that govern this product rank the fibres in opposite order, and quoting one as if it were the other is a common and quiet mistake. Under EN 1492-1, a polypropylene band is rated to +80 °C and the polyester and polyamide bands beside it to +100 °C — the polypropylene band is the lower of the three. Under the US web sling rule, OSHA 1910.184(i)(7), polyester and polyamide web slings must not be used above 180 °F (82 °C) while polypropylene web slings must not be used above 200 °F (93 °C) — the polypropylene band is the higher of the three. Neither figure is wrong. They are different rules for different markets, and if your lift plan is written against one of them, tell us which, because the answer decides how close to the ceiling you are allowed to work.
4. Choosing the Fibre and the Band from the Duty in Front of You
Two decisions are being made at once when a flat woven sling is specified: which fibre, which is decided by the environment, and which band, which is decided by the load and the hitch. The table below is organised the way enquiries actually arrive — by the process, not by the chemistry.
Fibre selection by the duty in front of you
| The duty in front of you | What the sling meets | Fibre we would quote | Why that fibre | Where to go |
|---|---|---|---|---|
| Steel pipe pickling, hydrochloric or sulfuric acid bath | Mineral acid, warm, acid mist above the tank | Polypropylene | Unaffected by acids. This is the duty the fibre exists for | This page, section 7 |
| Acid-washed steel, pickled coil and plate, scale-free sheet | Acid residue on the load, wet | Polypropylene | The chemistry decides the fibre; the band is decided by the load and the edge | This page, section 7 |
| Plating, anodising and electroplating shops | Acid drips and acid mist, not immersion | Polypropylene | Mist and drips are exposure. A sling that is only ever damp with dilute acid is still a sling on acid duty | This page, section 6 |
| Stainless pickling and passivation, nitric or nitric-hydrofluoric baths | Strong oxidising acid, with fluoride | Not polypropylene — ask us first | Strong oxidising acids are the one acid family that attacks polypropylene. The fibre that resists hydrochloric acid is not automatically right here | This page, section 7 |
| Chromic acid, conversion coating, pickling of light metals | Strong oxidising acid | Not polypropylene — ask us first | Same reason as above; chromic acid is an oxidiser, not a mineral acid | This page, section 7 |
| Pickling line that also runs a caustic degrease stage | Acid and alkali in one line | The white acid- and alkali-resistant sling | Built for a whole line cycle rather than for one tank; keep separate slings per stage if you prefer | White acid-resistant and alkali-resistant sling |
| Caustic cleaning, cement, lime and concrete | Alkalis | Read the market rule before you buy polypropylene | The fibre is unaffected by alkali, but the US web sling rule prohibits polyester and polypropylene web slings where caustics are present — section 10 explains it | Nylon woven flat sling |
| Marine, dockside, jetty and dredging duty | Water, salt, sunlight, and a real chance of losing the sling overboard | Polypropylene | It does not absorb water and it is lighter than water, so the band floats; salt is not the problem, sunlight and abrasion are | This page, sections 5 and 9 |
| Acid tank farms, bunded areas and outdoor pickling yards | Acid plus rain plus continuous sunlight | Polypropylene, UV-stabilised | The chemistry says polypropylene and the exposure says UV-stabilised — the worst combination for this fibre is the one the yard creates | This page, sections 5 and 9 |
| General purpose lifting, outdoor yards, plant installation | Weather, sunlight, no specific chemistry | Polyester | The lower elongation and better UV stability of polyester suit general duty better, and it reaches the band on narrower webbing | Endless webbing sling range |
| Mixed chemical exposure you are not certain about | Unknown, or more than one chemical | Ask before you order | Chemical resistance is not a property of the product; it is a property of a fibre against a named chemical at a named concentration and temperature | This page, section 6 |
Five rules that decide the band, once the fibre is settled.
Choking costs you 20% of the rating. A choked lift uses a mode factor of 0.8, so a 3 t band gives 2.4 t choked — that is 20% below its 3 t straight-lift figure, not roughly the same. Choose the band on the choked figure when the load has to be choked, and on a pickling line a coil or a bundle of pipe almost always has to be choked.
An assembly is never the sum of its slings. Two legs within 45 degrees of vertical are rated at 1.4 times the single rating — a pair of 3 t slings gives 4.2 t, which is 40% more than one sling, not 100% more. A four-leg assembly uses a factor of 2.1, because a four-leg assembly is rated as if only three legs carry the load.
An off-centre load puts more on one sling. Two slings share equally only when the centre of gravity sits exactly halfway between the pick points. Move it a third of the way towards one pick point and that sling carries 67% of the load.
On acid duty the fittings have to be chosen as carefully as the fibre. An alloy lifting fitting designed for strength is not designed for a pickling shop: published industrial guidance is consistent that high-strength alloy fittings are susceptible to hydrogen embrittlement when exposed to acidic conditions, which is why fittings made from these grades are kept out of pickling and galvanising lines altogether. On acid duty we would normally quote an endless or soft-eye band with no metal fittings in the load path, and where the rig needs fittings we quote the fitting material that suits the bath rather than the strongest one on the shelf.
What the load will tolerate can overrule the capacity. On a finished, painted, polished or pickled surface, the width of the band is the binding constraint rather than its rating, and the answer is more pick points or a sleeve, not a heavier band. This bites harder on polypropylene than on the other two fibres, because a polypropylene band of a given rating is already the widest of the three.
5. Polypropylene Under Load: Wet, Hot, Cold, Sunlit and Chemically Loaded
This is the section that decides whether a polypropylene sling is right for a particular job. The fibre's profile is unusual: it is the most chemically inert of the three, and at the same time the most sensitive to heat, to sunlight and to abrasion. Each condition below has a practical answer, and the answer is rarely a heavier band.
Polypropylene in service: what the condition does, and what to do about it
| Condition | What it does to a polypropylene band | What we recommend |
|---|---|---|
| Wet: rain, hose-down, rinse tank, acid line | Nothing. Polypropylene takes up below 0.1% of its own weight in water, so a wet polypropylene band carries its dry rating. There is no wet figure to derate against | Plan the lift on the figure on the label, wet or dry. Dry the band before storage anyway, not for strength but so that dried chemistry and grit are visible at inspection |
| Continuous immersion or permanently damp service | The fibre does not absorb water and it is lighter than water, so it floats. Immersion is not a strength problem for polypropylene, but it hides the two things that do matter: surface abrasion and contact with solvents or oxidising agents | Specify the duty as permanent immersion on the enquiry. On a pickling line, say whether the sling is dipped into the tank or only crosses above it — the two are different exposures |
| Stored wet, or returned to the rack wet | A storage failure rather than a lifting failure. Damp webbing with no airflow masks contamination and holds abrasive grit | Dry naturally, away from direct heat, before storage. Do not machine dry, heat dry or store a damp sling in a closed bag |
| Heat and hot loads | EN 1492-1 gives polypropylene a use and storage range of −40 °C to +80 °C, the lowest ceiling in the flat woven range; the fibre's softening point is near 150 °C and its melting point around 160 °C to 170 °C | Keep the band clear of heat sources, welding spatter and hot surfaces. A pickling line is often warm — measure the tank, rinse and dryer temperatures the sling actually sees, not the air temperature, because +80 °C arrives sooner than it sounds |
| Cold and frost | Polypropylene remains serviceable to the low end of its range, but it is the most prone of the three to becoming stiff and more brittle as it cools | −40 °C is the lower bound. Inspect a frozen or frosted band for stiffness and surface cracking rather than assuming it is unchanged, and clear ice from it: ice is a cutting and abrasive agent |
| Sunlight and UV | The poorest UV resistance of the three fibres. Published webbing data describes baseline polypropylene as having moderate UV tolerance and significantly better service life with UV stabilisers added; the degradation is cumulative | Buy UV-stabilised polypropylene, store and park slings out of direct sun, and put UV-exposed bands into a documented periodic inspection programme. An outdoor acid tank farm is the worst case this fibre meets |
| Acid splash, drip and tank mist | The fibre is unaffected. What is not unaffected is everything else on the assembly: the stitching, the label and the fittings | This is the duty polypropylene is chosen for. Rinse and dry after contact, and inspect the fittings rather than the webbing — section 7 explains why the fittings, not the fibre, are what fails on an acid line |
| Strong oxidising acid or chromic contact | Attacked. Oxidisers are the exception to the sentence polypropylene resists acid | Withdraw the sling immediately, and check the whole assembly. If the line runs both a hydrochloric bath and a nitric or chromic stage, the two stages need different slings |
| Chlorinated solvent, aromatic or tar contact | Softens or swells. Published fibre data is consistent that polypropylene should not be used in contact with chlorinated hydrocarbons and aromatics, and that it softens in chlorinated solvents such as carbon tetrachloride | Keep the band away from degreasing solvents, paint, tar and solvent vapour in a closed workshop. Clean with mild soap and water only, and never with a solvent — a solvent-cleaned sling has no reliable rating left |
| Alkali splash, cement, lime and caustic | The fibre is unaffected by alkalis. The regulatory position is a separate question: in the US market the web sling rule prohibits polyester and polypropylene web slings where caustics are present | On the fibre alone, polypropylene is fine. On the rulebook, tell us the destination market: section 10 sets out the difference |
| Abrasion: scale, grit, tank edges, dried solids | The wear that actually retires these bands. Polypropylene is the most vulnerable of the three in published sling comparisons, and it is already the widest band for its rating | Sleeve or pad every edge the band crosses, rotate the band between lifts, and wash dried solids out of the weave. On an acid line, budget for replacement on abrasion rather than on chemistry |
| Shock loading | Polypropylene stretches about 5% at the working load limit — more than polyester, less than polyamide. It is less forgiving of a snatch load than the fibre it is often compared with | A sling that has taken a shock load goes into inspection, not straight back on the rack. Look for a permanently elongated section and distorted stitching |
| A dropped sling in a wash or rinse tank | The band is lighter than water, so it floats rather than sinking into settled solids at the bottom of the tank | Recover it promptly, rinse it in clean water and dry it before it goes back into service. Floating is a recovery convenience on a wet line, not a substitute for cleaning the band afterwards |
6. Chemical Resistance in Detail, by Class of Chemical
Chemical resistance is quoted three different ways in this industry, and only one of them is useful: a named fibre, against a named chemical, at a named concentration and temperature. The grid below is by class of chemical, which is enough to choose a fibre and not enough to sign off a lift — for that, send us the tank chemistry.
Chemical class against fibre: the working grid
| Class of chemical | Polypropylene (PP) | Polyester (PES) | Polyamide (PA / nylon) | Practical note |
|---|---|---|---|---|
| Non-oxidising mineral acids: hydrochloric, sulfuric, phosphoric, pickling and plating baths | Unaffected | Resists most mineral acids | Attacked | This row is the reason the page exists. Where the plant talks about pickling, acid-washed steel or an acid tank, quote polypropylene |
| Strong oxidising acids: nitric, chromic, peracetic, concentrated sulfuric | Attacked | Disintegrated by concentrated sulfuric acid at 95% at room temperature | Attacked | The exception that catches buyers out. A hydrochloric pickling line says polypropylene; a nitric or chromic line does not — ask before you transfer a sling between stages |
| Alkalis: caustic soda, lime, cement and mortar slurry, soda ash, seawater | Unaffected | Attacked | Essentially immune | On the fibre, polypropylene is fine. On the rulebook in the US market, polyester and polypropylene web slings are prohibited where caustics are present — see section 10 |
| Chlorinated solvents: chloroform, carbon tetrachloride, perchloroethylene, halogenated hydrocarbons | Attacked — softens or swells | Not significantly affected | Not significantly affected | Polypropylene's signature weakness, and the one exemption in every description of the fibre. Solvent vapour in a closed workshop counts as exposure |
| Aromatic hydrocarbons: benzene, toluene, xylene | Attacked; at elevated temperature the polymer can be dissolved by non-polar solvents such as xylene | Subject to degradation in the presence of ketones and aromatics | Not significantly affected | Relevant in tank cleaning, paint and coating work, and any workshop where solvent drums are opened |
| Ketones: acetone, methyl ethyl ketone | Resisted | Subject to degradation in the presence of ketones | Not significantly affected | A point in polypropylene's favour, and worth knowing before you write the fibre off because of the row above |
| Alcohols: ethanol, methanol, dry-cleaning solvents | Resisted | Not significantly affected | Not significantly affected | All three fibres handle alcohols, so this class rarely decides the choice |
| Oils, greases and hydrocarbon fuel | Good resistance to most oils; affected by tars and many paints | Not significantly affected | Unaffected by common grease and oil; good resistance to hydrocarbons and ethers | All three are tolerant of ordinary workshop oil. Tars and paints are the problem, and they are a problem for all three |
| Bleaching agents and oxidising textile treatments | Attacked by some oxidising agents | Resists the oxidising agents and bleaching treatments ordinarily used on textiles | Not suitable — bleaching agents degrade polyamide | Polyester is the fibre of the three for bleach. On a line that bleaches, neither polypropylene nor polyamide is the answer |
| Sea water, salt spray and road salt | Unaffected | Not significantly affected | Immune to the alkaline fraction, but salt is abrasive once it dries | On marine duty, salt is a cleaning and inspection issue rather than a fibre issue — and polypropylene is the one of the three that floats |
| Sunlight and UV, which is exposure rather than a chemical | The poorest of the three; must be supplied UV-stabilised | The most UV-stable of the three | The most UV-sensitive of the three | Put UV-exposed polypropylene into a documented inspection programme rather than a longer visual interval, especially where acid and sun arrive together |
7. The Acid Duty: What a Steel Pipe Pickling Line Asks of a Sling
This section exists because acid-washed sling is how most enquiries for this product arrive, and because the answer is narrower than the search term suggests. A pickling line is not one chemical environment: it is a sequence of different ones, often under one crane, and the sling usually crosses several of them in a shift. The table below separates them, because the words acid and polypropylene are not automatically a match.
Pickling and finishing line chemistry, stage by stage
| Stage or process | What the sling meets | Fibre that suits | What to watch |
|---|---|---|---|
| Carbon steel pickling, hydrochloric acid bath | Hydrochloric acid at working strength, warm, with acid mist above the tank | Polypropylene | The mist counts. Rinse and dry after the shift, and inspect the fittings rather than only the webbing |
| Carbon steel pickling, sulfuric acid bath | Sulfuric acid at working strength, warm | Polypropylene | As above. Rinse and neutralising stages are part of the same exposure profile, not a break from it |
| Rinse, neutralising and phosphate stages | Water, then dilute alkali or phosphate | Polypropylene | No wet derating to apply, so the band keeps its rating through the whole sequence. Dry before storage |
| Stainless steel pickling and passivation | Nitric acid, often with hydrofluoric acid — a strong oxidising bath | Not polypropylene | This is the trap. Polypropylene is the right fibre for hydrochloric pickling and the wrong fibre for a nitric or nitric-hydrofluoric bath, because oxidising acids attack it. Ask us which fibre and which fittings before you standardise on one sling for the whole shop |
| Chromic acid, conversion coating, light-metal pickling | Chromic acid and other strong oxidisers | Not polypropylene | Same reason. Colour code the stages in the rigging store so that the acid sling and the oxidising-bath sling cannot be swapped by mistake |
| Electroplating and anodising lines | Acid drips, acid mist, occasional immersion | Polypropylene | Dripping and misting are exposure, not background. Inspect the eye and stitch areas, which hold the chemistry longest |
| Acid tank farm, bunded area, outdoor pickling yard | Acid, rain and continuous sunlight at once | Polypropylene, UV-stabilised | The worst combination this fibre meets. Stabilised fibre, stored under cover, and inspection on an interval rather than on appearance |
| Caustic degrease stage on the same line | Alkali, usually hot | Ask us, and see the market rule | The fibre tolerates it; the US web sling rule does not permit polyester or polypropylene web slings where caustics are present, and hot caustic is harder on the sling than cold. Use the acid-and-alkali sling or keep separate slings per stage |
| Crane duty over pickled coil, plate and bundles | Acid-wet steel, sharp edges, abrasive scale | Polypropylene with edge protection | On these lifts the band retires on abrasion, not on chemistry. Sleeve every edge and budget on wear |
The fittings are where an acid line usually fails, not the webbing. This is the point most buyers miss. The webbing is inert to the acid it was bought for; the hardware on a lifting assembly is not. Published industrial guidance is consistent that high-strength alloy lifting fittings are susceptible to hydrogen embrittlement when exposed to acidic conditions, which is why those grades are specifically kept out of pickling, hot-dip galvanising and similar processes, and why some standards explicitly warn against using them in acidic environments. Two consequences follow for this page:
Where the rig allows it, take the metal out of the load path. An endless band or an eye-and-eye band with soft eyes carries the load on webbing alone, so there is no alloy fitting sitting in acid mist above a tank.
Where fittings are unavoidable, they are a specification item. Tell us the bath and the temperature and we will quote the fitting material for the duty rather than the strongest fitting in the catalogue. On a pickling line the correct fitting is rarely the hardest one.
The stitching, the label and the thread are part of the same question. A webbing sling is a sewn product, and the lap splice or eye reinforcement carries the whole load. If the duty is immersion rather than splash, say so: the answer may be a different construction rather than a different fibre, and it is much cheaper to settle that at the quotation stage than after a band has been in a tank.
8. Endless or Eye-and-Eye: Which Form to Order
The fibre decides what the sling can be used near; the form decides how it is used. Both forms are flat woven slings under EN 1492-1, and both are made in polypropylene.
Endless (Type A) against eye-and-eye (Type B, C or D)
| Endless polypropylene sling (Type A) | Eye-and-eye polypropylene sling (Type B, C or D) | |
|---|---|---|
| End fittings | None, by definition | None in Type B and C; metal fittings in Type D |
| Where the hook contacts | Any point on the loop | The eyes, at each end, every time |
| Wear | The loop can be rotated after each lift, so the wear, the splice and the hook contact point keep moving round the webbing | The same two eyes take every lift, so wear concentrates at the reinforcement |
| Length basis | Stated as a loop circumference | Stated bearing point to bearing point, laid flat |
| Best for | Choked, basket and multi-point picks; slings that are repositioned during the job; and duty where a contaminated or worn section needs to be moved out of the load path | Lifts that need a fixed, hookable end; assemblies with a master link and hooks; and work where the rigger needs a definite end to attach to |
| On acid duty specifically | Usually the better answer on two counts: there is no metal fitting sitting in the acid mist, and a band that has been over a tank can be rotated so that the part which held the chemistry is moved out of the load path | Where the rig needs a hookable end, quote the fitting material for the bath as well as the fibre — see section 7 |
| On abrasive duty specifically | Preferred: rotation spreads the wear that scale, grit and tank edges cause, and polypropylene is the most abrasion-prone of the three fibres | Wear concentrates in the same two eyes, which is where a polypropylene band will retire first |
| On wet duty specifically | Both forms behave identically wet. There is no wet derating on polypropylene, so the rating does not move with the weather | As for endless |
A note on the word endless. An endless sling is closed by a stitched lap splice, so it is a sewn product rather than a jointless one, and the splice is a real joint that has to be inspected. What the form genuinely gives you is a long overlap instead of a short reinforced eye, a loop that can be rotated, a usable bearing area all the way round, and one sling that covers straight, choked and basket hitches.
9. Inspection and Retirement Criteria for a Polypropylene Band
Every sling should be inspected before every use, with a documented periodic inspection on top of that. On a polypropylene band there are three things to look for that do not apply to the other two fibres: abrasion, which is the wear that actually retires these bands, UV degradation, which shows up as a faded, dry, brittle feel rather than as a cut, and solvent softening, which is the one chemical family this fibre cannot be cleaned of. The table below is the withdrawal list we work to.
Polypropylene flat woven sling: what to check, and when to withdraw
| What to look at | Withdraw the sling if | Why it matters on polypropylene specifically |
|---|---|---|
| Webbing body | Any cut, snag, fraying or exposed load-bearing yarn, or damage reaching about 10% of the webbing width in any transverse section | Abrasion of surface yarns gives an unpredictable loss of strength. On a wide polypropylene band it is easy to under-read the damage: measure the transverse section rather than judging by eye |
| Abrasion and surface condition | A flattened or glazed surface, a thinned or feathered selvedge, visible loss of weave definition, or grit worked into the weave | Polypropylene is the most abrasion-prone of the three lifting fibres, and on a pickling line the band crosses tank edges, scale and dried solids every shift. This is the criterion that will retire the band, not the chemistry it was bought for |
| Colour and stripe count | The webbing colour and the black stripe count disagree | Same code as the rest of the range: one of the two capacity marks has been lost or altered, and the band can no longer be trusted |
| Stitching, eyes or lap splice | Broken or pulled stitches, loose stitching, or an open lap | The stitch is the joint that carries the whole load, and it cannot be repaired on site. On acid duty inspect the stitch line as closely as the webbing, because that is where chemistry collects |
| Stiffness and feel | A noticeable stiffening, a hard or brittle feel, or a powdery surface | Stiffening is the classic signature of heat and UV exposure, and on polypropylene it is the damage a visual check is most likely to miss |
| Discoloration and UV exposure | Bleaching or fading beyond normal soiling, a colour that no longer matches its band, or fading together with a dry, brittle feel after long outdoor service | Polypropylene has the poorest UV resistance of the three fibres and the degradation is cumulative. A band parked in the sun beside an acid tank is ageing from two directions at once |
| Solvent contact | Known contact with a chlorinated solvent, paint, tar or solvent vapour, or a band that is swollen, softened or tacky | Polypropylene softens in chlorinated solvents and is attacked by aromatics. There is no field repair and no way to clean it back to a rated condition |
| Oxidising acid contact | Known contact with nitric, chromic or other strong oxidising acid, or a band that has changed feel after working near such a bath | The one acid family that attacks polypropylene. A band that has crossed between stages in the same shop may have met it without anyone intending that |
| Acid contact on a non-oxidising bath | The webbing is usually intact — but the fittings, the label or the stitch line are not | This is the expected duty, so the inspection emphasis shifts off the webbing and onto the hardware: corrosion, pitting and any deformation at the fitting |
| Fittings on acid duty | Corrosion, pitting, cracking or deformation at any alloy fitting | High-strength alloy fittings are susceptible to hydrogen embrittlement in acidic conditions, and embrittlement does not announce itself. On an acid line, treat a pitted fitting as a failed fitting |
| Heat contact | Glazing, melting, scorch marks or weld spatter | Polypropylene has the lowest ceiling in the range at +80 °C under EN 1492-1, with softening near 150 °C, so heat damage arrives earlier than on the other two fibres |
| Labels and marks | The label is missing or illegible — the working load limit, fibre, standard reference, length or traceability code | The label is what certifies the sling, whatever the webbing looks like, and on an acid line it is also the first thing a splash destroys |
| Has the band been in a tank | The sling was dropped, dipped or immersed and has not been rinsed and dried | Immersion does not weaken polypropylene, but it concentrates chemistry inside the weave as it dries. Rinse in clean water, dry naturally, then inspect |
| Loading history | A known shock load, an overrun, or a lift taken on the wrong hitch figure | Polypropylene stretches about 5% at the working load limit — enough to leave a permanently elongated section after a snatch load, and enough to hide it |
| Whole assembly | Any one sling in the set fails, or the legs are of mixed fibre, mixed band or mixed length | An assembly is only as strong as its weakest leg, and mixing fibres mixes their limitations as well as their strengths — which on an acid line means the polyamide leg is the one being attacked |
Care rules for a polypropylene flat woven sling.
Never use a polypropylene webbing sling below −40 °C or above +80 °C.
Rotate the loop between lifts on an endless sling, and alternate the eyes on an eye-and-eye sling. On this fibre it is not a nicety: rotation is what spreads the abrasive wear that would otherwise retire the band at one point.
Do not drag a sling on the floor or across tank edges and abrasive scale, and never pull a sling out from under a load resting on it — lift the load clear first.
Do not twist, knot, shorten or lengthen a sling, and never repair one.
Fit edge protection wherever the band crosses a sharp or finished edge, at any load.
Wash with mild soap and water and dry naturally. Never clean a polypropylene band with a solvent — the fibre softens in chlorinated solvents, and a solvent-cleaned sling cannot be returned to a rated condition.
Rinse acid off with clean water after contact and dry the band before storage. On a wet line, drying is about seeing contamination at the next inspection, not about strength.
Store dry, dark and off the floor, away from oil, chemicals, solvent vapour and sharp edges. Polypropylene does not absorb water, so the reason to store it dry is contamination and UV, not moisture.
Keep the sling clear of chlorinated solvents, aromatics, tars, paints and strong oxidising acids. A polypropylene sling belongs over a hydrochloric pickling tank and not beside a degreasing bath.
Buy UV-stabilised polypropylene for anything that lives outdoors or near a window, and keep it out of direct sun when it is not working.
In an assembly, inspect every sling in the set and keep the set together.
Cut a retired sling through before disposal so that it cannot be put back into service by mistake.
10. Standards, Marking and Duties a Polypropylene Sling Is Not Rated For
What the product is built to. Polypropylene flat woven slings are made to EN 1492-1, Textile slings — Safety — Flat woven webbing slings made of man-made fibres for general purpose use. That standard covers single-leg, two-leg, three-leg, four-leg and endless sewn flat woven webbing slings, with or without fittings, made of polyamide, polyester or polypropylene, across webbing widths of 25 mm to 450 mm, and it sets out the requirements for design, testing and marking.
Why the standard reference on the label matters as much as the number beside it. A “1 t” marking means a 7 t minimum breaking load only if the sling was built to EN 1492-1 at its 7:1 factor. Under ASME B30.9, where the design factor for these slings is commonly 5:1, the same 1 t marking corresponds to 5 t. Under AS 1353 at 8:1 it corresponds to 8 t. Three slings, all marked 1 t, built to materially different margins — which is why our quotation asks for the destination market and the standard you need, not just the band.
What every polypropylene sling has to carry. The marking is part of the product, not a finishing touch. The visible working load limit code is the webbing colour plus the black stripe count; the label carries the working load limit for the straight lift, the fibre — brown for polypropylene —, the standard reference, the manufacturer, the length and a traceability code.
The colour and the stripe count are mandatory under EN 1492-1 for the band, and they say nothing about the fibre. A polypropylene sling supplied in a colour that does not match its rating, or described as available in any colour, is not being marked to the standard.
The label is the second half of the same message. Colour tells you the band; the label tells you the fibre and the traceability. If the label is missing or illegible, the sling is out of service regardless of the condition of the webbing.
The traceability code is what makes a batch certificate possible. Keep it: it is what links a sling in service back to the batch it was tested with.
Two rulebooks, and they do not rank the fibres the same way. This matters more on a polypropylene page than on any other, because the two regimes that govern web slings disagree about this fibre — and about the fibre next to it. The table sets the two side by side, using the wording of the regulations themselves where they are quoted.
The same product under two rulebooks: EN 1492-1 and the US market rules
| Point of comparison | EN 1492-1 (Europe and most export markets) | ASME B30.9 with the US web sling rule, OSHA 1910.184 |
|---|---|---|
| Safety factor behind the marking | 7:1 for flat woven webbing slings | Commonly a 5:1 design factor, so the same nominal marking corresponds to a smaller breaking load |
| Colour code | Mandated for the band, with the black stripe count repeating the capacity | Not mandated; the identification tag is the authority, and the colour is best practice rather than a requirement |
| Temperature ceiling | Polypropylene −40 °C to +80 °C; polyester and polyamide −40 °C to +100 °C | Polyester and polyamide web slings shall not be used above 180 °F (82 °C); polypropylene web slings shall not be used above 200 °F (93 °C). The ranking of the fibres is reversed |
| Polyamide (nylon) on acid duty | The fibre is attacked by acids, so acid duty points to polypropylene on materials grounds | Nylon web slings shall not be used where fumes, vapors, sprays, mists or liquids of acids or phenolics are present — 1910.184(i)(6)(i). A prohibition, not a caution |
| Polyester and polypropylene on caustic duty | The fibre position differs between the two: polyester is attacked by alkalis, polypropylene is unaffected | Polyester and polypropylene web slings shall not be used where fumes, vapors, sprays, mists or liquids of caustics are present — 1910.184(i)(6)(ii) |
| Aluminium fittings on caustic duty | Fitting material is quoted against the duty | Web slings with aluminum fittings shall not be used where fumes, vapors, sprays, mists or liquids of caustics are present — 1910.184(i)(6)(iii) |
| Removal from service | Damage criteria including cuts, abrasion, chemical and heat damage | Acid or caustic burns are listed among the conditions that require immediate removal from service — 1910.184(i)(9)(i) |
Read the two prohibitions together, because they solve a shop problem. In the US market, nylon web slings are prohibited where acids are present, and polyester and polypropylene web slings are prohibited where caustics are present. The practical consequence is that a plant running both an acid pickling stage and a caustic degrease stage cannot cover both with one web sling material: the acid stage points to polypropylene and the caustic stage rules polypropylene out. That is exactly the case the white acid- and alkali-resistant sling exists for, and the reason we ask which market a sling is going to rather than which band.
Duties a polypropylene flat woven sling is not rated for, at any band.
Lifting or suspending a person.
Towing, recovery or vehicle pulling — the rating is a lifting rating and tow loads are shock loads.
Staying in place permanently as a tie, guy or restraint.
Being knotted or twisted to shorten it.
Lifting over an unprotected sharp edge without a sleeve.
Contact with chlorinated solvents, aromatic hydrocarbons, tars, paints or strong oxidising acids — this is the polypropylene limitation, and it is the one that catches buyers out when a band bought for an acid tank is then used to pull a load out of a degreasing bath.
Caustic duty in a market that follows the US web sling rule — the fibre is unaffected by alkali, but the rule prohibits polyester and polypropylene web slings where caustics are present. Tell us the market and we will quote the fibre the rulebook allows.
Alloy lifting fittings on acid duty — the webbing is inert to the bath, and the fittings are not. Quote the fitting material for the duty.
Working on or near live electrical conductors.
Service above +80 °C.
11. Frequently Asked Questions
Q1: What is a polypropylene flat sling?
Q2: Is a polypropylene flat sling the same as a round sling or a braided sling?
Q3: Why choose polypropylene instead of polyester or polyamide?
Q4: Can a polypropylene sling be used in acid?
Q5: Which chemicals must a polypropylene sling be kept away from?
Q6: Does a polypropylene sling lose capacity when it is wet?
Q7: What is the temperature range of a polypropylene webbing sling?
Q8: What does the brown label on the sling mean?
Q9: What is the HS code for a polypropylene webbing sling?
Q10: What do you need from me to quote a polypropylene flat sling?
Contact us — polypropylene flat slings direct from the manufacturer
Tell us the load, the rigging and the chemistry the sling will meet — including the acid, its concentration and its temperature — and we will come back with the specification and price for your polypropylene flat sling: band, fibre, ply, width, length and marking all on one sheet, with the fitting material called out if the sling is to be an assembly. Volume discounts apply. We build to order in single or double ply, in polypropylene, polyester or polyamide, in any length from 1 m to 12 m and beyond, with the EN 1492-1 colour code, one black capacity stripe per tonne and the brown polypropylene label as standard. UV-stabilised webbing for outdoor and yard duty, and matching sets for two-leg and four-leg assemblies, are supplied on request.
Contact: Wang Lili
Phone: 18066002268
E-mail: 702461526@qq.com
Address: Lifute Industrial Park, Taizhou City, Jiangsu Province, China
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