What are the knowledge about the bottle blows of the (bottle blowing machine)?
2017-11-07Announcementfont+font-
The bottle billet of the bottle blowing machine is also called the billet. It is the injection molding of PET granules. It requires that the proportion of the recycled material can not exceed 10%, and the number of recovery can not exceed two times.
Bottle blank after injection molding preform or heating and then cooling must be above 48h, and the bottle blank use storage time should not exceed 6 months, different production date, especially the bottle blank can not mix the interval is too long, the main reason is two times the proportion of the material residual preform the raw material type, mixed and bottle the compact inner stress caused by the different, and these factors on the forming of bottle blowing technology have a great impact, should be treated according to the actual situation of the specific. Because PET has very strong water absorption, so in storage must pay special attention to moisture, and before processing must be effective dehumidification drying conditions, usually 150 to 180 DEG C for 4 hours, but also to prevent the plastic grain moisture again, must be at a temperature above 140 DEG C insulation, shutdown to prevent the plastic Huang, dehumidifying dryer cooling to 100 DEG C, not only heat dehumidification.
In addition, PET injection molding material if the temperature is too high, the shear force is too large or too fast speed are easy to produce acetaldehyde due to acidification, PET bottle molding after the acetaldehyde content usually must be less than 3ppm, require a certain moisture bottle before the crystallization, the general requirements of around 1000 ppm, at least in 900ppm therefore, in the above, the preform injection requires a period of time, the water content reaches the requirements before crystallization.
