The design of EPS moulding Control of key processes
The production process of EPS moulded prodects is as follows:
Raw material → prefoaming → ripening → molding → cutting → drying → finishing → delivery
Prefoaming process is the key the process in production process.In the pre-foam process should attention:
1.Select different pre-shipment capacity according to the requirements of different products,which is usually expressed by multiplying rate.The multiplier is the inverse of the weight of the blister particles per unit volume,which is a dimensionless unit.Since the specific gravity of water is “1”,it can also be expressed by the following formula:
Ratio = weight of water per unit volume/weight of blister particles per unit volume
EPS foaming rate is too low,can increase the FRP products consumption,increase the cost of production,and is too high,will shrivel to pretest foam grain,influence forming quality.Therefore,each batch of materials should be advanced and small-batch preshipment.In the pre-trial delivery,according to the quality of raw materials,reasonable selection of pre-trial multiplier.For raw materials that have never been used,start from low multiplier.For raw materials that have never been used,start from low multiplier rate,and increase gradually according to precast and molding conditions until ideal effect.
What should be attention especially here is,when the manufacturer of bubble model product processing signs processing contract with client,buffer bubble model product is valued by sample weight commonly,and raw material,namely sheet is valued by volume however,so bubble model product processing manufacturer wants to increase profit,can reduce product material consumption through raising precast multiplier appropriately to achieve.
2.Separate common materials and self-extinguishing materials in the production process,and avoid mixing the materials when pre-foaming pr feeding,so as to avoid fire.
3.Avoid sudden change of vapor pressure,keep the schedule,proper time for material retention,uniform feeding and discharging speed,and appropriate particle size specification.
There is sufficient maturation time during the maturation process,generally about 8 to 48 hours.The basic process of forming process is : Mold closing → feeding → heating → cooling → mold opening → mold release. What should be attention is,according to the specification of different product, dimension, thickness controls heating,the length of water cooling time,in general processing molding process,water cooling time takes up half of the total cycle time of processing molding.