The defects in the process of plastic injection molding

Plastic is one of the important material of cosmetics bottles, exquisite by injection molding of plastic bottles, and then printing and packaging, in the process of injection molding is not perfect, often encounter some common defects, so perfect to understand and improve it.

a: compression deformation ( Shrink)

one of common injection molding defects, usually occurs where the plastic walls thicker, or is the place that wall thickness change, its performance for the bottle to dent external. Constitute the material because of this phenomenon, when molten embryos, not fully cooling, thicker plastic wall due to the pressure inside and outside is different, plus heat bilges cold shrink, the bottle will into recession.

improvement methods:

lower and abrasive melting temperature, increasing the pressure and the holding time.

2, injection molding flash

the bottle burrs is often encountered in the injection molding production problem, which is the most headaches, usually due to factors such as raw materials and production quantity and scale of injection molding machine, once appear, flash, the whole batch of cosmetics bottles will be big bets. Insert flash has a lot of, the cause of the physics, yield of wear and tear, mold, foreign body in it sets mold not science, etc. , and chemical factors there is too much pressure, clamping pressure is not enough, the holding time is too long, mould is too high, the loading many factors such as the cooling time is too long, want a perfect into bottles, these problems only slowly to accumulate in the normal production.

3: the bottle has bubbles and flow lines

show is inside the bottle after injection molding material or surface bubbles or flow lines of grain, it is not allowed, has seriously affected the beautiful and the smoothness of plastic bottles. Reason for the formation of many, one of the most common include feed tube temperature is high, the mold temperature is too low, the material drying time is too short, the mold imported raw materials is too small, uneven mixing, mold inside is not clean, have a jam.

4: brittle plastic body

also often see brittle plastic body, if after finished products made from brittle fracture easily, in front of the work are almost all in vain, so it's not common, is one of the key links. Causes of the plastic bottles brittle includes: material storage and the length of time a long process, raw material quality too poor, the toughness is not enough, late enough accurate temperature control, and improper disposal of cooling crack.

more than cosmetic packaging is plastic bottles in the injection molding process often encounter some of the defects and other problems, don't look so simple plastic products, industry, in other words is very good, is easy to do the PET bottle made difficult it is for this reason.