PP Spunbond Nonwoven Production Lines: S vs SS vs SMS vs SSS

PP spunbond nonwoven production lines are sold in four configurations, and the letters in the name are the whole story: S, SS, SMS and SSS describe how many web-forming beams the line has and whether one of them is a meltblown beam. This guide explains what each configuration produces, who buys it, and how to specify a line, so that a packaging, hygiene or agricultural-fabric maker can ask us for the right machine. In short: choose an S or SS line for shopping bags, covers and general packaging fabric, an SMS line when the product must block liquids or filter particles, and an SSS line when you need a heavier, very even fabric without a meltblown barrier. Yanfeng Group offers all four configurations; the definitions and applications below describe the configurations as the nonwoven industry generally understands them, not the specification of a particular line.

Key definitions

• Spunbond (S): molten polypropylene is extruded through a spinneret into continuous filaments, drawn by air, laid onto a moving belt and thermally bonded into a fabric.
• Meltblown (M): polymer is blown through fine nozzles with hot high-speed air into very fine, short fibres that form a dense, soft web with a high barrier to liquids and small particles.
• Beam: one web-forming station in the line; each letter in S, SS, SMS or SSS is one beam laying its own layer.
• Layer structure: the sequence of spunbond and meltblown layers, from the belt upward, that the calender bonds into one fabric.
• Barrier: the fabric's resistance to liquid penetration and its ability to hold back particles; it comes mainly from the meltblown layer.
• Hand and coverage: the softness of the fabric and how evenly the filaments hide the surface; both improve with more spunbond layers.

Comparison table

The table describes the layer structures and their usual applications as they are understood across the nonwoven industry; it is not a specification sheet. Sizes and outputs for our lines are quoted per project.

Line	Layer structure	Barrier / filtration property	Typical end-use
S	One spunbond layer	Basic; no fine-fibre barrier	Shopping and promotional bags, packaging, furniture and mattress lining, agricultural covers
SS	Two spunbond layers	Better coverage and uniformity than S; no fine-fibre barrier	Heavier bags, bedding and upholstery components, crop and ground covers, industrial packaging
SMS	Spunbond, meltblown, spunbond	Liquid-repellent and particle-filtering thanks to the meltblown core	Surgical gowns and drapes, mask layers, protective apparel, hygiene-product components
SSS	Three spunbond layers	Most even coverage of the spunbond-only lines; no fine-fibre barrier	Heavier packaging and cover fabric, furniture, agricultural and construction covers

S line: one spunbond layer

The single-beam line is the simplest configuration: one spinning beam, one belt, one calender. It makes the light, breathable fabric that goes into shopping bags, gift and promotional bags, dust covers, garment bags and the lining fabric inside sofas and mattresses. Because there is one beam, the line has the smallest footprint and the fewest parts to maintain, which suits a plant entering nonwovens for the first time or a woven-bag maker adding a nonwoven bag range. It is the configuration to choose when the customer specifies the fabric by weight and colour rather than by barrier performance. See the S line product page.

SS line: two spunbond layers

Adding a second spunbond beam lays two webs on top of each other before bonding. The filaments of the second layer fill the gaps left by the first, so the fabric covers more evenly, looks more opaque and tears less easily at the same weight. That makes the SS line the general-purpose choice for heavier bag fabric, bedding and upholstery components, agricultural crop covers and ground fabric, and industrial wrapping. See the SS line product page.

SMS line: spunbond, meltblown, spunbond

The SMS line replaces the middle beam with a meltblown beam. Meltblown fibres are far finer than spunbond filaments, so the core layer is dense and holds back liquids and small particles while the spunbond skins give the fabric its strength and a soft surface. This is the structure used for surgical gowns and drapes, the barrier layers in face masks, protective coveralls and the leak-guard components of hygiene products. An SMS line is the most demanding of the four to run, because meltblown output depends on close control of polymer, air and temperature, and it should be specified by a buyer whose customers test the fabric for barrier performance. See the SMS line product page.

SSS line: three spunbond layers

Three spunbond beams give the most uniform coverage of the spunbond-only configurations, without the process sensitivity of meltblown. The SSS line is chosen for heavier packaging and cover fabrics, furniture and bedding components, construction and agricultural covers, and any product where evenness and strength matter more than liquid barrier. See the SSS line product page.

How to choose

1. Name the end product first. Bags, covers and linings point to S or SS; medical, hygiene and protective fabric point to SMS; heavy, even cover fabric points to SSS.
2. Ask whether the customer tests for barrier. If the fabric must resist liquid penetration or filter particles, only the SMS structure delivers that; if not, a spunbond-only line is simpler to run and maintain.
3. Decide the weight range you need to cover. A single product weight suits S; a range of weights across several products favours SS or SSS, which keep coverage even at the heavier end.
4. Set the working width from the widest product, allowing for edge trim, and tell us the target output per shift; both fix the beam width and the line speed we propose.
5. Plan the downstream steps. If the fabric will be printed, our roll-to-roll flexographic printing machine is listed for non-woven cloth as well as woven cloth and film, so printing can come from the same supplier.
6. Check power and site conditions. Give us the available electrical supply, the hall dimensions and the ambient conditions, so that the line and any chilling and air-handling equipment it needs are sized together.

Model sizes, widths and outputs for our nonwoven lines are quoted per project, so send your product, weight range and target output through the enquiry form and we return a line specification. If your plant also makes woven sacks, note that the nonwoven line is a separate family from the flat-yarn and loom chain described in our PP woven bag machine guide, and the two can share a site and a sales channel. Learn more about our factory on the production capacity page.