How Hydroentanglement Energy Changes Spunlace Strength, Softness, and Absorbency

How Hydroentanglement Energy Changes Spunlace Strength, Softness, and Absorbency

Ask a spunlace producer what makes one fabric stronger than another, and fibre choice usually comes first. Ask a process engineer, and you will hear a different answer: energy. How much water energy a fibre web receives while it is being bonded has a direct effect on how the finished fabric behaves.

For a buyer, this is worth understanding. It explains why two spunlace rolls with the same fibres and the same weight can still feel and perform differently.

How hydroentanglement works

Hydroentanglement is the bonding step that gives spunlace its name. A loose web of fibres travels on a moving belt or perforated drum while rows of fine, high-pressure water jets pass over it. The jets push fibres sideways and downwards, so they wrap around and lock into each other. No glue or heat is needed, which is one reason spunlace feels more like a textile than most other nonwovens.

Several settings decide how much energy the web receives:

• the water pressure at the jets
• the number of jet strips the web passes under
• the size and spacing of the jet holes
• the line speed
• the weight of the web being bonded

Put together, these set the total energy delivered per kilogram of fabric. More energy means more entanglement, up to a point.

What happens when the energy is too low

Under-bonded fabric looks fine on the roll and fails in use. The fibres are only loosely locked, so the fabric has low strength and tears easily. The surface can look fuzzy, and loose fibres can come off the wipe as lint. On a converting line, weak fabric breaks on unwinding or folding. In a wet wipe, it falls apart under a firm wipe.

What happens when the energy is raised

Raising the energy generally makes the fabric stronger, because more fibre crossings are locked in place. The surface also becomes cleaner and more stable. Up to a point, this is exactly what you want.

Past that point, the returns drop. The web gets compressed and dense. Some fibres can be damaged or broken by the force of the jets, which weakens the structure instead of strengthening it. The fabric can turn stiff, flat and papery. Process cost also climbs, since higher pressure and extra jet strips use more power and water.

Effect on softness

Softness depends on how open and mobile the fibres are. With moderate entanglement, fibres still have room to move, so the fabric drapes well and feels gentle on skin. Very high energy packs those fibres closer together and reduces that freedom, so the hand turns firmer. Fibre type and fineness matter as well. A soft viscose or fine polyester will feel softer than a coarse fibre at the same energy level.

Effect on absorbency

Absorbency has two parts: how much liquid the fabric can hold, and how fast it takes it up. Cellulose fibres such as viscose, cotton and pulp do most of the holding. The structure decides how much room there is for liquid and how well it travels through the fabric.

A bulkier, more open web has more space between fibres, so it holds more. Heavy compaction squeezes that space out. Over-energised fabric can therefore hold less liquid than a gentler version of the same blend. For blends that include pulp, there is another risk: strong jets can wash short pulp fibres out of the web, which hurts both absorbency and cleanliness.

The surface pattern also plays a part

The surface the web rests on during bonding leaves a mark. A smooth surface gives a plain, flat fabric. A patterned or apertured surface creates texture and open zones. Those patterns change how the wipe feels, how it picks up dirt and how liquid moves through it, without changing the fibre blend at all.

What this means for buyers

You do not need to know the machine settings, but you can ask better questions:

• How does the supplier balance strength against softness for your end use?
• Is the bonding level matched to the fibre blend, particularly if pulp is involved?
• Can they supply samples with different surface patterns so you can compare feel and pickup?
• What are the dry and wet strength results for the exact fabric on offer?

Because the effects interact, the practical route is to test samples on your own line. Our guide to fibre ratio and GSM shows how the blend shapes the same properties, and our piece on wet versus dry tensile strength explains what to ask about strength.

If you are comparing options, you can look at the SoftSpun and AbsorvSpun ranges, or contact our team to request spunlace samples for your application.