There are many kinds of disposable diapers on the market. Their main function is to absorb liquid and keep dry. But there are dozens of types of subdivision. For example, some keep dry for a long time, some wear comfortable, and some even add healthy designs. If the disposable diaper is carefully excavated, its production process may be very different. Take the surface layer as an example, the main material is nonwovens, and nonwovens are mainly divided into three processes. Next, we will briefly introduce several mainstream in the market.
The main factors affecting the quality of hot-air bonding products are fiber characteristics, hot-melt fiber mixing ratio, hot-air temperature and speed, and the moving speed of the web curtain, that is, the heating time of the fiber web. Hot air temperature, hot air speed and web curtain speed play a very important role in hot air bonding products. The speed of the fiber web, that is, the moving speed of the web delivery curtain, actually reflects the heating time of the fiber web. In the production of hot air bonding, the selection is generally based on the melting point of the hot melt fiber. The hot air temperature is high, the heating time of the fiber web can be shortened, and the hot-melt fiber can still reach the required melting or softening temperature. Under the same heating time conditions, the hot air temperature is higher, the hot melt bonding points in the fiber web are more, and the product strength is increased. Of course, the temperature of the hot air cannot exceed the melting point of the fiber, otherwise the strength of the product will decrease. In the same heating time, if the hot air temperature is higher, there will be more hot melt bonding points in the fiber web, and the product strength will be higher. In order to meet the same strength requirements, the heating temperature is high and the heating time of the fiber web is short, that is, the production speed is increased.
When the proportion of hot-melt fibers increases, the strength of hot-melt fibers is also affected. If the heating temperature exceeds the melting point temperature, the hot-melt fiber will be overheated, the fiber structure will be damaged, and the fiber brittleness will lead to a decrease in the strength of the hot air nonwoven.
Although the spunlace nonwovens industry started late, it has developed rapidly since the 1990s when it started to own nonwoven equipment with independent property rights in China and began commercial production, and its application fields involve hygiene materials and supplies.
Spunlace nonwovens have the following characteristics:
(1) Wide range of raw material sources, such as polyester, nylon, adhesives, absorbent cotton fibers, microfibers, etc.
(2) The material has good performance, high strength, good moisture absorption and air permeability, soft hand feeling, good drapability, and no chemical adhesive.
(3) Product diversity, can form jacquard non-woven fabrics.
The spunlace entanglement process relies on the ultra-fine high-pressure water jet (also known as water needle) ejected by a hydraulic jet (spunlace head) to puncture the fiber web, so that the short fibers or filaments are entangled to consolidate the fiber web. The process of spunlace nonwoven fabric is: fiber forming, pre-wetting, spunlace reinforcement, drying, winding.
The spunlace fiber web can be a dry-laid fiber web, a wet-laid fiber web, a spunlaid filament web, and a melt-blown superfine fiber web. In order to make the fiber web more fully utilize the water jet energy during the spunlace process, the fiber web must be pre-humidified before entering the spunlace zone. The fiber web is pre-wetted and enters the spunlace zone, and the fibers in the fiber web are entangled under the action of high-pressure water jets to form a spunlace non-woven fabric. The hydroentanglement process can be divided into 4 stages:
(1) Multiple strands of ultra-fine high-pressure cluster water are sprayed from the small holes of the water jet spray plate of the spunlace head, and the water is shot vertically to the fiber web.
(2) The fibers in the surface layer of the fiber mesh are in contact with the high-pressure water needle and are displaced. The water jet is forced to bounce and scatter.
(3) Under the dual action of water needle impact and reflection, the fibers move, interpenetrate, entangle and cohere between fibers, forming numerous soft entanglement points, thereby consolidating the fiber web.
(4) After the fiber web is spunlaced several times on the front and back sides, a wet nonwoven fabric with a certain strength is formed, and after being dried by a drying device, a spunlace nonwoven fabric is made.
It can be seen that the manufacturing process of disposable diaper surface material is very different. Therefore, although the appearance of disposable diapers is basically the same, we should comprehensively consider its performance advantages, price advantages and disadvantages and the habits of wearers. If it is not clear, try to choose trial equipment, analyze the effect after use, and select the most suitable product after comparison.