Seat foam generally refers to polyurethane foam, which is made of two-component materials plus corresponding additives and other small materials, which are foamed through molds. The whole production process is divided into three processes: preparation stage, production stage and post-processing stage.
Mainly check whether the water content and viscosity of polyether meet the requirements. This item is especially important in winter in the north.
Free foam trial production is also carried out for incoming materials, mainly weighing to verify whether they meet the production status requirements.
Mixing is carried out according to the established formula, and automatic mixing equipment is currently used. FAW-Volkswagen’s seat foam system is divided into two types: composite material and self-mixing material.
Combination material:) A+B two mixed solutions are mixed directly
Self-batching: mix POLY, that is, basic polyether + POP + additives, and then mix POLY and ISO
2. Production stage – loop production
Generally, loop production is adopted, mainly through several processes such as pouring, forming, demoulding, and mold cleaning, as follows:
Among them, pouring is the key, which is mainly completed by the pouring manipulator. Different pouring procedures are used according to different positions of the seat foam, that is, foams in different regions are poured, and the process parameters are different (pressure, temperature, formula, foaming density, pouring route, response index).
3. Post-processing stage – including drilling, trimming, coding, repairing, spraying silencer wax, aging and other processes
① Hole – The purpose of opening is to prevent product deformation and increase elasticity. Divided into vacuum adsorption type and roller type.
After the foam comes out of the mold, it is necessary to open the cells as soon as possible. The shorter the time, the better, and the longest time should not exceed 50s.
②Edge trimming-foam Due to the process of mold exhaust, some foam flashes will be produced on the edge of the foam, which will affect the appearance when covering the seat and need to be removed by hand.
③ Coding – used to trace the production date and batch of foam.
④Repair – Foam will produce slight quality defects during the production process or demoulding process. Generally, glue is used to repair the defects. However, FAW-Volkswagen stipulates that surface A is not allowed to be repaired, and there are special quality standards to restrict repair operations. .
⑤Spray sound-absorbing wax – the function is to prevent the friction between the foam and the seat frame to generate noise
⑥Aging – After the foam is molded from the mold, the foaming material is generally not fully reacted, and micro-reactions are required. Generally, the foam is suspended in the air with a catenary for 6-12 hours for curing.
It is precisely because of such a complicated process that Volkswagen’s seat foam has excellent comfort and environmental protection with low odor and low emission.
Post time: Feb-17-2023