New Opportunities For High-End Domesticization Of PET Bottle Mold Manufacturing

Company Overview

SZ-MOLDTECH (Jiaxing) Co., Ltd. is a professional manufacturer specializing in high-precision PET preform molds. The company integrates R&D, design, and precision manufacturing to provide efficient and customized mold solutions for the global plastic packaging industry.

With advanced equipment, strict quality control, and an experienced technical team, SZ-MOLDTECH delivers molds with high durability, excellent consistency, and stable performance. Its products are widely used in beverage, food, edible oil, and personal care packaging.

Committed to innovation and customer satisfaction, SZ-MOLDTECH (Jiaxing) Co., Ltd. aims to be a reliable global partner for high-performance PET mold solutions.

Industry Background

The high-end PET bottle mold market was once monopolized by international brands such as those from Europe and America. However, with the rise of Chinese mold manufacturers, the competitive landscape has changed.
Chinese mold manufacturers, through their persistent efforts and technological advancements, have continuously achieved breakthroughs in areas such as technological innovation and design manufacturing capabilities within the mold industry.
In recent years, the export volume of high-end PET bottle mold has been increasing year by year, while the import volume has been decreasing.
This fully demonstrates China's competitive edge in the global market for molds.

Application Prospect

• Beverage industry:

The largest application area of PET bottle blanks includes packaging for various beverages such as mineral water, carbonated drinks, tea beverages, and fruit juices.

• The edible oil industry:

PET bottles have excellent transparency and chemical stability, which can effectively prevent the edible oil from deteriorating. Moreover, they have a beautiful appearance and are easy for consumers to observe the quality of the oil.

• Cosmetics industry:

For some high-end cosmetics, such as lotions and essences, PET bottles are widely used due to their attractive appearance, light weight, and non-breakable nature.

• Pharmaceutical packaging industry:

In the packaging of some oral medications, health supplements, etc., PET bottles have gradually gained a certain market share, and extremely high requirements are imposed on the quality and precision of the bottle blanks.

Customer And Industry Pain Points

• Difficulty in maintaining the accuracy of the bottle blanks:

The molds can achieve high precision during their initial manufacturing. However, during long-term and high-frequency production processes, due to factors such as thermal expansion and contraction, mechanical wear, etc., it is difficult to maintain high precision continuously. This can easily lead to issues such as size deviations, uneven wall thickness, and wire drawing at the gate of the bottle blanks, which affect the stability of product quality. This will result in the bottle blanks being unable to meet the requirements of subsequent blow molding and other processes.

• Complex structure design limitations:

As the market demands for personalized and diversified PET bottles increase, the design of some special-shaped and structured bottle blanks places higher requirements on the molds. However, when designing and manufacturing molds with complex structures, problems such as the layout of internal flow channels, cooling system design, and demolding mechanisms may arise, thereby increasing the cost of bottle blank production.

• Challenges of the hot runner technology:

The hot runner system is widely used in high-end PET bottle blank molds. However, the design and maintenance of the hot runner system require a high level of technical expertise. For instance, issues such as the temperature control accuracy of the hot runner, thermal balance, wear and blockage of the flow channels, etc., can all affect the flow and filling effect of the plastic melt, thereby impacting the quality of the bottle blanks.

• Mould cooling issues:

Poor cooling effect of the cold half-mould will increase the crystallinity of PET molecules, reducing the transparency of the bottle blank and possibly causing foggy or opaque phenomena. It will also increase the adhesion between the bottle blank and the mould, making demoulding difficult and potentially damaging the bottle blank or the mould, further affecting production efficiency. At the same time, it requires a longer time for the bottle blank to cool and set, resulting in an extended forming cycle and a decrease in production efficiency, as well as an increase in production costs.

SZ-MOLDTECH New Technological BreakthroughsSz-moldtech New Technological Breakthroughs

Precision Of Preform

SZ-MOLDTECH's high-end bottle blank mold frame is made of 3Cr13H plastic mold special steel. The key forming parts are made of Swedish S136 and have undergone original factory aging treatment. After heat treatment, the hardness is HRC52. The wear resistance of the mold has been greatly improved, and the service life has been significantly enhanced. All sliding parts' contact surfaces are embedded with self-lubricating alloy copper, which is resistant to wear. The surface grinding machine accuracy reaches 0.01mm.
The processing accuracy of the key forming components of the mold reaches 0.005mm. The surface of the key parts is coated with diamond-like material and treated with titanium plating to reduce wear, ensuring consistent mold accuracy.

Complex Structure Design

Utilizing advanced three-dimensional design software: NX
Auxiliary analysis software: Moldflow, Ansys, etc.
For complex structure molds, the flow channel size is designed through professional mold flow analysis software, and the internal flow channels, cooling systems and demolding mechanisms of the molds are optimized.
Strengthen cooperation with research institutions to jointly conduct cutting-edge technology research and solve the problems in the design and manufacturing of complex structure molds.

Hot Runner Design Advantages

The hot runner features a super-balanced design with 90-degree rounded corners at every runner bend to achieve optimal filling balance.

It ensures balanced runner pressure.

The path, pressure, and injection volume to each cavity are consistent.

The hot runner template is designed according to the manifold shape, increasing production capacity, reducing energy consumption over long-term use, and optimizing maintenance.

Advances of Cold Half Die Design

SZ-MOLDTECH Mould's excellent R&D and design capabilities not only improve production efficiency but also reduce mold maintenance costs.

The mold cavity is a split type, employing a spiral circulating water channel. The screw thread uses a W-shaped water channel to quickly achieve the cooling effect on the preform. Furthermore, damage to the cavity bottom can be replaced independently, effectively reducing maintenance costs. The mold core and mounting base structure adopts a tapered positioning type, is separable, and directly forms a tapered contact positioning between the mold core and the screw thread, reducing wear, eliminating shrinkage marks at the parting line, and ensuring high-efficiency cooling of the screw thread.

SZ-MOLDTECH's high-end preform molds generally achieve a CPK value of 1.67 or higher.

CPK, or Process Capability Index, is a crucial indicator for measuring the stability of the production process and the consistency of product quality.

In high-speed PET preform injection molding, a higher CPK value means the mold can consistently produce preforms that meet quality standards.

SZ-MOLDTECH preform molds have achieved a CPK value of 1.67 through optimized mold design, improved machining precision, and strengthened production process control. This enhances the stability and reliability of product quality, meeting the stringent requirements of the high-end market for consistent product quality.