1, Phenomenon: Uneven transition and fine adjustment of joint research molds
In the process of preform manufacturing, the transition phenomenon is particularly critical, as it directly reflects the fine changes in bottle wall thickness from the shoulder to the middle or from the bottom to the middle. Regarding the issues of incomplete bottom shaping and imperfect petal bottom contour, although minor imperfections have little impact on filling, they can directly affect the stability of the bottle in severe cases. It is worth noting that even high-precision equipment such as joint research molds cannot guarantee that the products in each cavity are perfect.
Diagnosis: Given that not all cavity products have issues, we speculate that the problem may not be limited to insufficient blowing pressure, but may also be caused by insufficient blowing in specific cavities. If the temperature of the preform is too low and the blowing speed of the film bubbles slows down, the problem will become more significant. A lighter bottom often means that the material is close to its natural tensile limit before the container is fully formed.
Prescription:
Check if the high-pressure filter on the side of the joint research mold is unobstructed to ensure a stable supply of high-pressure gas.
Verify the working status of the circuit valve to ensure accurate positioning during blowing.
Adjust the air flow control component to ensure the set value is correct and there is no blockage inside, in order to achieve rapid air blowing and avoid additional cooling of PET materials.
Ensure that all ventilation holes on the joint research mold are unobstructed to promote uniform heat dissipation.
2, Phenomenon: Bottle mouth expansion and temperature control challenges of joint research molds
The problem of bottle mouth expansion and gas leakage during blowing is particularly prominent in high temperature weather, manifested as the expansion of screw areas, and even transmitted to the anti gas groove.
Diagnosis: Under high temperature conditions, the cooling effect of the oven airflow is weakened, resulting in an increase in temperature in the core rod and thread area.
Prescription:
Adjust the cooling plate position of the joint research mold and strengthen the protection of the thread area of the preform, although the preform structure may increase the difficulty of adjustment.
Introduce an external cooling system to precisely control the temperature of the threaded area and core rod when the preform passes through the oven.
Optimizing the design of the cooling plate has become one of the best strategies to solve this problem.
3, Phenomenon: Neck bending and mechanical operation optimization of joint research molds
The problem of neck curvature often leads to difficulties in filling or sealing, and the displacement of the convex ring is not perpendicular to the centerline of the bottle body.
Diagnosis: Improper mechanical operation and excessive accumulation of material in the neck are the main reasons.
Prescription:
Reduce the accumulation of material at the neck of the bottle to avoid deformation of the bottleneck caused by mold collision during mold closing.
Adjust the clamping force of the concave part of the top plate of the joint research mold on the convex ring to ensure that the size of the preform is fixed in the hot state, with a reserved 0.25mm thermal gap.
Accurately calibrate the position of the conveying arm and the blowing center to reduce neck bending caused by improper alignment.
Sections four to six (omitting specific symptom descriptions and directly proposing solutions for the joint research mold)
4, Phenomenon: Blue bottom line and wall thickness control of joint research molds
Prescription: Utilize the precision design capability of the joint research mold to optimize the wall thickness distribution in the bottom area, ensure uniform material thickness on the cross section, and reduce the phenomenon of pearl stripes.
5, Phenomenon: Bottom damage and temperature management of joint research molds
Prescription: Through the temperature control system of the joint research mold, the bottom temperature of the preform is precisely controlled to avoid micro cracking problems caused by low or high temperature during the stretching process. At the same time, adjust the gap between the stretching rod and the bottom of the mold to the optimal state.
6, Phenomenon: Damage to the screw part of the bottle mouth and precise positioning of the joint mold
Prescription: Strengthen the precise positioning function of the conveying arm and blowing core in the joint research mold to ensure stable and accurate clamping and blowing of bottle preforms even in high temperature weather, reducing the risk of damage to the threaded area. At the same time, combined with external cooling measures, the temperature in the threaded area is reduced to improve overall production quality.
Foshan Heyan Precision Mould Technology Co., Ltd.'s main business is preform moulds, bottle blowing moulds, bottle cap moulds and other products. It has a strong engineering, R&D, technology and sales team, advanced processing equipment and rich project experience. If you want to know more or have special needs, please call 13318345050, or add our WhatsApp.
