How Does A Thin Layer Of Diaper Suck Your Baby's Urine?

The ultra-high water absorption capacity and water retention capacity of the diaper benefit from its absorbent material and structural design.


Baby's diapers generally have a four-layer structure:

Surface layer: made of non-woven fabric, directly in contact with baby skin, receiving liquid and passing to the next layer;

Conductive layer: made of non-woven fabric, which uniformly transfers the liquid received by the surface layer to the absorbing layer;

Absorbing layer: It is made of polymer water absorbing resin (SAP) and is the most important functional layer in diapers for absorbing and storing urine.

Bottom layer: made of PE film or PE film + non-woven fabric, the main function is to prevent leakage.


Water absorbing material: polymer water absorbing resin


Many mothers are naive to think that the baby's diaper is cotton inside, relying on cotton to absorb water. When you uncover the surface of the diaper, you will find that there is a small bead-like particle. Although the cotton absorbs water, the water absorption speed and water-locking ability are far less than the new polymer water-absorbent resin.


Polymer water absorbing resin (SAP) is a typical functional polymer material. SAP is similar to a small bead, only about 0.2mm in diameter, can absorb hundreds of times its own weight, or even thousands of times of water, and has a strong water retention capacity, so it is also known as super absorbent or high water retention agent.


SAP has a superior water absorption capacity because the superabsorbent resin is a low cross-linking or partially crystalline high molecular polymer having many hydrophilic groups. When the SAP particle size is 100~120mesh (ie 0.212mm~0.254mm), the absorption capacity is the best; when the pH value is 6~8, the absorption rate is the largest.


Principle of water absorption: layer by layer infiltration


Knowing the main diaper in the diaper, the baby's urine is absorbed from the outside of the body to the diaper. What is the process? Let us explore further.


Do not look at the thin diaper, there are four layers: the surface layer, the drainage layer, the SAP absorption core layer, the bottom layer.


The baby discharges the urine to the outside of the body. First, the urine is received from the surface of the diaper and penetrates downward. Then, the diversion layer receives the urine permeated by the surface layer, and a part of the urine is directly passed to the next layer of the SAP absorbent core along the gap. The body absorbs, and the remaining part of the liquid conducts and diffuses along the longitudinal direction of the flow guiding layer, which enlarges the absorption area of the SAP absorbent core. Finally, the urine diffused along the longitudinal direction of the guiding layer penetrates into the next layer to uniformly distribute the SAP absorbent core. Absorbed.


The surface layer of the diaper is in direct contact with the baby's butt, and is the first layer that receives the urine; the drainage layer guides the urine permeated from the surface to conduct and spread along the longitudinal direction of the diaper, so that the urine is evenly absorbed by the core. Absorption does not cause the diaper to locally thicken due to several kinds of liquid absorption, hindering the absorption of the urine by the absorption core; the SAP absorption core layer is a layer that finally absorbs and stores the urine; the bottom layer can effectively prevent leakage.


Water lock principle: SAP water retention


We all know that the sponge absorbs very strong, but the sponge that washes the water is slightly squeezed, and the water will seep out. The baby's urine is on the diaper, how the small butt is squeezed, and there is no urine reverse osmosis on the surface of the diaper. How does the baby's diaper lock in moisture?


The water-absorbing substance SAP of the diaper is a polymer compound with many atoms close to water. Therefore, water molecules are quite easily attracted to their molecules and squeezed between molecules, thereby expanding the SAP particles and integrating them. SAP itself is insoluble in water and can absorb hundreds of times to thousands of times its own weight without extravasation.


For example, rice has boiled ripe rice. Although the rice grains contain a lot of water, the water does not flow out; the flour and water are kneaded into dough, and the moisture inside can not be squeezed out anyway, with rice and noodles. Similarly, SAP not only has strong water absorption capacity, but also has a strong water retention capacity.


If any demands for SAP for baby diaper, please feel free to contact us.

Company name: Quanzhou Goooing Corporation

Email: sales@goooing.com

Tel/wechat/whatsapp: 86 15880766111