With the improvement of people's awareness of energy saving, environmental protection and safety, polyurethane foams with low atomization and low odor have been more and more required to be used in the automobile interior decoration industry, which promotes the development of new polyols and amine catalysts and the improvement of foaming technology to reduce the odor caused by the volatilization of polyurethane foams. I believe: with the development of science and technology, high-performance, safer and healthier car seat foam products will appear in people's field of vision in the near future, and polyurethane foam will be used in more fields.
1. Process materials.
Polyurethane refers to the polymer with multiple carbamate (- NHCOO--) groups on the main chain of the polymer structure, which is called polyurethane in Chinese and abbreviated to polyurethane in English. Polyurethane, is abbreviated to PU in English.
Introduction to the raw material composition of PU foaming material:
Component A (white material): polyol component referred to as POL.
a. Main materials: Polyether / polyester polyol.
b. Cross-linking agents: diethanolamine, triethanolamine.
c. Catalyst: gel, foaming catalyst.
d. Surfactant: silicone oil.
e. Foaming agent: water, 141b.
Others: antioxidants, flame retardants, etc.
Component B (black material) isocyanate referred to as ISO.
a. Toluene diisocyanate.
2. Foaming technology of automobile seat.
2.1 seat foaming equipment.
The PU ring foaming production line consists of two parts: cadres and wet-end equipment.
The cadre equipment is mainly composed of mold base car, mold closing device and hydraulic electric control system, while the wet end equipment mainly includes high pressure foaming machine, metering system, hydraulic station and so on. The elliptical circular line has the advantages of many stations and short mold changing tempo. At present, the circular production line is mostly used in seat foaming factories.
Seat foaming mold, because foaming needs to be carried out under a certain pressure, is generally made of aluminum, with good thermal conductivity, no rust and long service life (more than 300000 pieces).
2.2 seat foaming process.
1 pre-mixing of raw materials: pre-mixing highly active polyether polyols with small materials (water or physical foaming agent, stabilizer, catalyst, cross-linking agent, silicone oil) according to the formula ratio.
2 High pressure mixing: component An and component B are sent to the mixing head of the manipulator through a metering pump, and under the action of hydraulic pressure, the two components are sprayed into the mixing chamber at high pressure and high speed through the nozzle and collide with each other in order to fully mix.
3 pouring: the equipment automatically identifies the mold, raw material pressure and measurement information through the mobey card, and the evenly mixed chemical material flows out of the mixing head and into the mold cavity.
4 ripening: the cast mold is closed by a mold closure and matured under a certain pressure.
5 take out the mold: the operator takes out the product in the mold, checks the surface defect of the product, informs the upper station of the product defect in time, and puts the product on the bubble breaker to open the hole.
6 cleaning mold: the operator cleans the mold cavity, parting surface, gas trough, gas needle stains and wax deposits.
7 spray release agent: spray release agent on the surface of mold cavity with fog spray gun.
8 insert: according to the position and size of the steel wire, the correct steel wire is selected and placed in the steel wire slot of the die; corresponding to the product model, take the non-woven cloth and hang it on the surface of the upper cavity of the mold.