11.3.3. Removal of dirt – the cleaning process

Dirt is the term applied to grease, grime and dust jammed between the fabric structure. There are two types of dirt. One, which is held loosely onto the fabric and can be removed easily and the other, which is held tightly by means of sweat and grease.

Dirt on fabrics can be categorized into two main types: loose dirt and tightly held dirt. Loose dirt sits on the surface of the fabric and can easily be brushed off or removed by using water. Tightly held dirt, however, is trapped within the fibers due to grease or sweat, making it harder to eliminate. To properly care for fabrics, it's essential to understand these differences because they determine the methods and products we use for cleaning.

Imagine cleaning your car. Dust on the exterior can be wiped away easily, just like loose dirt on fabric. But, think of grease stains on the car seats—these are more stubborn and require specialized cleaning solutions, just like the tightly held dirt on fabrics.

There are three main methods of removing grease – by the use of solvents, absorbents or emulsifiers. When cleaning is done by solvents or absorbents it is called dry cleaning. Normal cleaning – washing is done in water with the help of soaps and detergents, which emulsify the grease (break it into very small particles). This is then rinsed with water.

To effectively clean fabrics that have grease, there are three main strategies: using solvents, absorbents, or emulsifiers. Solvents dissolve grease, while absorbents soak it up, and emulsifiers (like soaps and detergents) break grease into tiny particles that can then be washed away. Dry cleaning relies on solvents to clean fabrics without using water, which is particularly helpful for delicate textiles. In contrast, regular washing involves water, where soaps and detergents help to emulsify, or break down, the grease for easier removal.

Think of washing a greasy pan. When you soak the pan in warm water mixed with dish soap, the soap acts as an emulsifier breaking down the grease, allowing it to wash away easily. Similarly, the same principle applies to cleaning fabrics.

Water is the most valuable agent used for laundry work. During steeping, water penetrates into the fabric and causes wetting. Pedesis or the movement of water particles helps to remove the non-greasy dirt from the fabric.

Water plays a crucial role in the cleaning process by soaking into fabrics and helping to dislodge dirt particles. The process called 'pedesis' refers to the movement and action of water molecules, which helps lift non-greasy dirt from the fabric when agitated. However, while water is good for loosening dirt, it doesn't remove grease on its own—it needs the aid of soaps or detergents for that purpose, and greasy dirt can redeposit onto the fabric if not properly rinsed.

Imagine soaking a sponge in water to clean a countertop. The sponge absorbs the water, and as you scrub, the water helps lift off crumbs and dirt. Similarly, in laundry, warm water can assist in loosening grime but often needs soap to effectively tackle tougher stains.

Soaps and detergents are the most important cleansing agents used in laundry work. Both soaps and detergents share a critical chemical property – they are surface-active agents or surfactants. In other words, they reduce the surface tension of water.

Soaps and detergents are essential in the laundry process because they help break down and remove dirt and grease. They do this by acting as surfactants, which means they lower the surface tension of water making it easier to penetrate and cleanse the fabric. This enables water to wash away dirt more effectively and also helps keep dirt suspended in the wash water, preventing it from settling back onto clean fabrics.

Consider when you add dish soap to a bowl of water for washing dishes. The soap lowers the water’s surface tension, allowing it to spread and clean more effectively. Without soap, the water would have a harder time accessing food particles stuck on dishes, similar to how it affects the washing of clothes.

Once the soap or detergent has emulsified the grease holding the dirt, it has to be held in suspension till it is rinsed out. The methods of washing are classified as follows: Friction washing, Kneading and squeezing, Suction washing, Washing by machines.

After forming an emulsion with the grease, the next step in cleaning is to ensure that dirt remains suspended in the wash water until rinsed out. Different methods of washing achieve this: friction washing involves rubbing fabrics to dislodge dirt; kneading and squeezing are gentle methods useful for delicate fabrics; suction washing is used for larger items like towels; and machine washing provides agitation using various motions for efficient cleaning. Each method has its own best use depending on the fabric type and dirt level.

Think about making a smoothie. At first, the fruits and other ingredients are blended, creating a mixture. Pressing or agitating them helps to break them down further, just like friction or kneading does with fabric during washing. Similarly, a blender is like a washing machine that continuously stirs to keep everything mixed until the smoothie is smooth and ready.

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