3) HDPE: Provides stiffness and strength, but poor machining performance

1. Firstly, the definition, properties, crystallinity and molecular structure differences of the three resins are introduced
2. Further explain why three resin blends are used in the production of flow casting, such as machining performance, strength, elongation, stiffness, etc.
HDPE longitudinal tear resistance is good, transverse poor, LDPE on the other hand
LLDPE product non-toxic, tasteless, odorless, milky white particles.
Compared with LDPE, it has high strength, good toughness, strong rigidity, heat resistance, cold resistance and other advantages, and also has good environmental stress cracking resistance, tear resistance and other properties

4.
How to identify breathable film and non-breathable film
The main differences are in ventilation: methods such as blowing, covering the glass with a permeable membrane and so on.
More in-depth method: air permeability detection of transverse and longitudinal tensile differences, etc
Appearance comparison (with certain difficulty) : The appearance of breathable film is inferior to matte, and the surface layer of flow film is bright and waxy.
5.
Production process of permeable film, how to control the amount of permeable film
Metering, mixing, drying, feeding, screw melting - the - stretch film cooling - preheating, stretching, finalize the design - cooling - corona - (embossing), printing, cutting and winding
There are many factors affecting the permeability of breathable film:
1. Equipment process: equipment tensile ratio, equipment stability, processing conditions (temperature), etc
2. Raw materials: stability of breathable particles, type and ratio of breathable particles, etc
Hengfeng advantage: imported equipment of breathable film and self-produced breathable particles
6.
The development course and future trend of disposable sanitary products used in the industry
Development history of bottom film: in the early stage, it was a fluid-extension non-permeable film
With the development of breathable film technology, high-weight breathable film (35g of sanitary towel and 32g of diaper) partially replaces flowable film, which is only used in high-end products.
During this period, breathable films were mainly imported.
With the rapid development of sanitary products industry, domestic production line of breathable film is gradually introduced, and domestic production technology of breathable particles is increasingly mature, making breathable film can replace cost permeable film for sanitary products.
Development trend: 1. Replace casting film; 2. Thin (low gram weight); 3
7.
The technological process and characteristics of the compounding of bottom film and non-woven cloth
1;
Spray adhesive composite
Using melt glue, hot melt adhesive, using random fiber rubber type spray to the basement membrane and non-woven composite winding roll type, the technology is there a difference in the production of urine trousers compound, its relatively high to the requirement of spray adhesive, the process requires the uniformity of spray adhesive and atomization effect is better, not allowed to exist a glue and glue, otherwise easy to cause the product seep.
The advantage of this process is that the production speed is fast, easy to operate, its disadvantage is that the material (non-woven, hot melt glue) requirements are higher!
2;
Scratch glue (currently our company has two ways)
A. Wiper glue coating compound
The design principle of the process is almost the same as that of the printing process, that is, using the reticulated glue plate roller to transfer the glue to coat the bottom film and compound with the non-woven cloth, and then drying through the drying path.
This process has relatively simple requirements for glue. As long as the glue depth of anilicon roller is properly controlled, the appropriate water glue is selected and the glue concentration is properly controlled. The process is characterized by slower production speed and more complicated operation, but the product stability of this process is better
B, scraping hot melt adhesive coating compound
The principle of this process is similar to that of wiper glue. The difference lies in that it is melted by hot melt glue and transferred to non-woven cloth and then combined with the bottom film. The advantage is that it does not need to be dried, and the reason why it is transferred to non-woven cloth instead of the bottom film is that the temperature of glue transfer is above 130 degrees and the bottom film will be broken.
The same with water glue is the use of aniline glue plate roller transfer glue composite, its main characteristics of the production speed is relatively fast and the stability of the product