The Science of Shrink-Proof Wet Cleaning for Wool: From Sheep Inspiration to Laundry Practice

As laundry industry practitioners, we all know that the shrinkage of wool sweaters is one of the most common customer complaints and the most troublesome questions.
Answering the mystery of “why do sheep not shrink when exposed to the rain, and wool sweaters shrink when washed with water?” is the basis for laundries to provide professional services, build the trust of the customers, and achieve customer satisfaction.

Core Principle

Wool fibers are covered with cuticle scales that overlap like roof tiles, with directional edges. When wool fabrics face the combined effects of water, heat, and mechanical force during ordinary washing, irreversible felting shrinkage will occur.
● Water
Water causes fiber swelling, softening, and opening the wool scales.
● Heat
Heat, especially hot water, accelerates this process and makes the fibers become sticky.
● Mechanical forces
Violent tumbling in a washing drum causes numerous wet and softened fibers with opened scales to interlock with one another. Driven by the unidirectional ratchet effect, the fibers become increasingly entangled, resulting in permanent shrinkage of the fabric dimensions and a stiffened texture.
On a live sheep, wool fibers remain locked within the skin and fleece structure, with minimal movement, friction, or mechanical action. Even when wet, the scales cannot interlock freely. Because its wool roots are fixed and lubricated by natural lanolin. More importantly, there is no intense, continuous, and irregular mechanical external force like that of a washing machine in nature. This precisely enlightens us that the core of safe wet washing of wool lies in thoroughly transforming the way mechanical force acts and precisely controlling the water temperature.

Professional Design

When laundries treat customers’ wool clothes, their first professional judgment is very important. This shows us that the safe wet cleaning of wool is completely changing the way of mechanical forces and precisely controlling the water temperature.
● Dry cleaning
It is the safest choice because it perfectly avoids the water, heat, and strong mechanical forces. Dry cleaning can greatly maintain the shape of the clothes, so it is suitable for clothes like suits and coats.
● Professional wet cleaning
It is a higher-level care method. It can completely clean the water-soluble stains like sweats and restore the original loft and soft touch of premium cashmere and Merino wool garments.

Pain points of the Laundry industry

We all know the principle of gentle hand washing. But the commercial mode of the laundry shops needs standardization, scale, and high efficiency. Relying on the customers’ hand-washing experience is not reliable and cannot be mass-produced. The real solution is to find an industrial laundry equipment that can make extreme mildness standardized and repeatable.

Kingstar Solutions

This is the destination of the Kingstar industrial wet cleaning machines.
● Mechanical force
- It provides a washing speed as low as 15-20rpm. This helps simulate the force of clothes bouncing rather than pounding in the basin.
- The spin/pause ratio is intelligent. People can set the spin/pause ratio as 10s/20s. This helps relax the fibers and prevents tanglement.
● Temperature
- From the pre-wash, main wash, to rinse, the water temperature can be strictly set below 30 degrees Celsius to completely remove the damage caused by heat.
● Intelligent technology with perfect wet cleaning: Kingstar solutions
For professional laundry shops, they need an intelligent washing and care system instead of ordinary washing machines. This is exactly the design mission of the Kingstar industrial wet cleaning machine.
- Core
It has extremely mild and intelligently controllable techniques to simulate professional hand washing.
- Gentle mode
The high spinning of traditional washing machines is the culprit for the damage to the clothes. Kingstar wet cleaning machine provides about 15rpm.
- Relaxation of fibers
The unique intelligent spin/pause ratio can give the fibers some time for relaxation to avoid entanglement.
- Cooling
From pre-wash to rinsing, the water temperature should be controlled under 30 degrees Celsius.
Turning the complicated science into simple programs is what Kingstar does. Our Kingstar wet cleaning machine series (SHS-2015P/SHS-2020P/SHS-2025P) is  equipped with a built-in programmable controller and supports setting up to 79 sets of washing programs. Among them, the “Full wool Wash” program, specially designed for wool and cashmere, is a perfect embodiment of the above concept.

This helps us click one button for starting the standard, safe, batch-processed wet cleaning of wool and say goodbye to the reliance on manual experience.
Understanding the science of wool melting is to transcend the experience and build the standards. Today, customers have higher requirements for clothes care. Safe wet cleaning of wool is an important measure for the laundries’ professionalism. Choosing intelligent equipment like Kingstar means laundries have the technology to solve the pain points and build a solid foundation of reputation and business value.

Q&A

● Q: When a customer asks, “Can this wool sweater be washed?", how should laundries respond professionally and provide options?
A:
1. Inspect the material label of the garment (wool/cashmere content), craftsmanship (whether the knitting is loose), accessories (lining, decoration), and the current condition on the spot.
2. Explain to the customer the home washing felting risk, the professional wet cleaning water to wash the essential difference between family and (mild procedures, special materials, finishing process).
3. Laundries can also provide options for customers.
“To ensure 100% that the pattern remains unchanged, we recommend dry cleaning, which is the safest option.”
“If you wish to achieve a fluffier and softer touch and the material of your clothes is suitable, our professional wool wet washing program, under strict parameter control, can safely and effectively complete the cleaning.”
4. The decision can be made by the customers.
● Q: What details must be noted in the operation process when conducting batch wet washing of wool?
A:
1. Sorting must be done by color, fabric thickness, and degree of dirtiness. Each piece of woolen clothing should be placed in a fine mesh laundry bag to reduce friction and prevent accidental hooking.
2. A neutral detergent specifically for wool and cashmere must be used. By using the intelligent material box of the equipment, precise dispensing is carried out at the designated low-temperature stage to avoid direct contact with the clothes.
3. Staff should strictly select the “wool” or “gentle” program preset on the equipment. Do not increase the water temperature or speed without authorization.
4. The default “wool” or “soft” programs of the equipment should be chosen.
4. Staff should take it out immediately after washing, absorb the excess water by rolling and pressing with a towel, then lay it flat on a drying rack and shape it. Place it in a well-ventilated area to air dry. Or use the low-temperature and high-volume “wool” setting of the dryer and make sure to take it out and shape it before it is completely dry.
● Q: How can laundries prove and promote our professional wool wet washing service to customers?
A:
1. Visualize your professionalism: You can display the "wool program" interface of the Kingstar wet wash machine in the store and explain to customers the principles of low-temperature, slow, and intermittent washing. Display professional detergents and laundry net bags.
2. Showcase the care effect: Retain outstanding care cases (with the customer's consent), and display the "fluffy as new" state of the wet-washed clothes through comparison pictures or physical objects.
3. Laundries can offer a quality guarantee commitment: For clothes that have been professionally wet-washed, they can provide a commitment of “no felting shrinkage will occur”, which in itself is the most powerful professional proof.
4. Knowledge marketing: Explain “Why sheep don’t shrink when they get wet in the rain” with short articles or sales pitches, link the service with scientific care, and enhance your professional image.