PET plastic bottle is so blow

Author: mgg-Plastic bottle manufacturer

The PET plastic bottle is such a blow-out hollow blow molding in placing extrusion or injection molding in the mold, and blows it into compressed air in the tube blank to make it close to the walls of the cavity. The molding method of the hollow article is obtained by cooling and demolding. This forming method can produce various packaging containers such as bottles, pots, barrels, daily necessities and children's toys. Hollow blow molding 1, according to different extrusion - blow molding: production method is simple, high yield, low precision, and more applications.

Injection molding - blow molding: high precision, good quality, high price, suitable for large quantities. 2, depending on the molding process, different ordinary blow molding; tensile blow molding: product is tensile, high strength, and good airtightness. Extrusion-stretch-blow molding - stretch-blow 3, depending on the number of single-layer blow molds according to the number of tube layers; multi-layer blow molding: comprehensive performance, complex production, suitable for product packaging with high packaging requirements.

Blowing device 1, pin blowing process: closed-wear billet-blown-inflated-blown retraction-melting characteristics: suitable for continuous rotary blow molding, small container, with handle. 2, top blowing process: closed-bottom clamping - top opening - core ventilation - inflation - rotating tool resection 01. In blowing pressure blow molding, compressed air has two functions, one is to cause the tube blast to be large and close to the cavity wall, form the needed shape; second, cooling. According to the variety of plastic varieties and the temperature of the seat, the air pressure is different. Generally, between 0.2-0.7 MPa, it is most suitable to make the article clear the article after forming shape, pattern, etc.

02. In order to shorten the blow time, the inflation speed is to facilitate the product to obtain a more uniform thickness and a good surface, the inflation velocity (air volume flowing through the unit time) should be as large as possible, but it should not be too large, otherwise it will A adverse effect on the article. 03. Blowing ratio is typically called the size of the product and the ratio of the size of the vehicle. When the size and weight of the boundary, the larger the size of the article, the greater the blow ratio of the blank.

The size of the blow is determined based on the variety of plastics, the shape, and size of the article and the size of the parison. It is usually controlled by 2 or 4 times. 04, mode temperature to ensure product quality, the temperature of the mold should be uniform, and the mold temperature is generally maintained at 20-50 ° C.

The temperature is too low, which will reduce the elongation of the plastic at the junction, not easy to blow, and thicken the article in this portion, while the molding is difficult, the contour of the product is unclear. The mold is too high, the cooling time is prolonged, and the production cycle is long. The product is demolded deformation, and the contraction is increased.

The high low of the mold is depends on the variety of plastics. When the plastic has a high glass transition temperature, a high mold temperature can be used; in turn, it will reduce the mold temperature as much as possible. 05, the cycle of the molding cycle blow mold includes an extruded type blank, an interceptable blank. Cutoff, blow, cooling, deflation, opening, removal of the article (subsequent trimming, supporting, packaging).