PET Preform Mold

The PET preform mold adopts an advanced needle valve hot runner system, which precisely controls the opening and closing of each cavity gate through mechanical actuation during the injection molding process. This ensures minimal gate marks-comparable to ejector traces-significantly improving surface quality over conventional hot runner systems and reducing the need for post-processing. The mold features a large-diameter gate design to accelerate melt flow, enabling faster cavity filling and shorter cycle times. At the same time, it allows accurate control of holding time and pressure distribution, resulting in uniform material density, reduced shrinkage and deformation, and improved overall strength and stability of the preform. In addition, the hot runner system eliminates cold runner waste, lowering raw material costs, while the reliable needle valve design prevents stringing and material backflow during mold opening, ensuring stable and continuous production.

Quality first, Reliable quality

 

Due S136 mold steel contains metal components such as Si, Cr, and Mn, an oxide protective layer forms on its outer surface, isolating it from water in the air, acid, and alkali oxidation reactions, thereby maintaining the smoothness and stability of the material. Its high-temperature stability prevents the mold from deforming in the high-temperature production process of PET bottle preform injection molding, ensuring high strength and hardness, and maintaining long-term stable operation of the mold.

Efficiency leap, Precision stability

 

The PET preform mold adopts a single-cavity self-locking structure. It ensure each cavity remains independently locked during the injection molding process in the multi-cavity PET preform injection molding process. This design enables high precision and a low defect rate in final preform production. The design can significantly reduce the wall thickness difference of the preform, ensuring consistency and high quality of the product.

PET preform injection molding is used food-grade polyethylene terephthalate (PET) resin pellets. These pellets possess high transparency, excellent mechanical strength, and gas barrier properties. Due to the high hygroscopicity of PET resin, the PET pellets must be dried in a dehumidifying dryer before feeding, with the temperature controlled at 150-180℃ for approximately 4-6 hours, ensuring the resin moisture content is reduced to a acceptable range. This prevents impact on the product's mechanical properties and appearance. If recycled materials (such as clean, crushed preforms) are added during production, their proportion should be controlled below 10% to avoid performance degradation. The degree of dryness during pretreatment directly determines the stability of the PET preform product and is fundamental to ensuring a high finished product yield.

Engineers need to use CAD software to complete the 3D structural design based on the preform sample's structure, wall thickness, thread specifications, and other usage requirements. They use CAE software for mold flow analysis and cooling simulation to optimize the runner layout and heat exchange efficiency. The design must focus on the number of cavities (typically 8-96 cavities), the gate type (mainly hot runner needle valve type/point gate), and the cooling channel layout to ensure uniform filling and rapid cooling of the plastic during injection molding. The material selection for the PET needle valve preform mold is crucial. The mold core/cavity are mostly made of corrosion-resistant, highly wear-resistant high-quality stainless steel (such as S136, AISI422), while the mold plate uses pre-hardened steel (such as P20, 4Cr13). After the engineering drawings are output, the processing route must be planned simultaneously, and strict tolerance standards (typically ±0.01mm) must be established to lay the technical foundation for subsequent manufacturing.

Younce is a manufacturer of PET preform molds in China for bottled water, food, and edible oil packaging. Welcome to inquire.

Bottled water

Food

Edible oil

Cosmetic

Medicine

Handwashing Fluid

1, What is the PET preform mold?

PET preform mold is a fundamental production tool in the packaging industries of beverages, edible oils, condiments, and daily chemicals, and its market demand is closely linked to the consumer goods sector. The economic efficiency of molds lies in their "one-time investment, long-term output" characteristic. Although the initial investment in more cavities precision of mold is substantial, by fully leveraging the injection weight, space between tie bars, and other properties of the matching injection molding machine, the production cost of a single PET preform can be significantly reduced. Mold design directly affects the utilization rate of raw materials (PET particles); optimized casting and cooling designs can reduce material waste and energy consumption. Mold maintenance costs and the ease of replacing vulnerable parts are important factors in measuring their life-cycle economics.

2,What are the different types of PET preform molds?

PET preform molds can be classified into common PET preform molds (non-self-locking), self-locking PET preform molds, and pin valve self-locking PET preform molds based on factors such as structure, material, hot runner, etc.

3,What is the common PET preform mold (non-self-locking)?

Common PET preform mold (non-self-locking type) is the most ordinary and relatively simple in structure. Its advantages include low initial investment, fast cost recovery, and simple maintenance. The core/cavity typically uses materials such as 38Cr13 and 3Cr13. However, due to the susceptibility of 38Cr13 to oxidation and corrosion from prolonged operation or improper maintenance, it has been abandoned by most manufacturers. Its disadvantages include a shorter design life (1 million molding cycles), although proper maintenance by preform manufacturers can extend this lifespan.

4, What is the self-locked PET preform mold?

The self-locking PET preform mold core/cavity is made of high-quality mold steel, such as 3Cr13/S136, and the template is made of P20 mold steel. Its design life is significantly extended compared to ordinary PET preform molds, reaching 1.5 to 2 million cycles. The mold core/cavity adopts an independent self-locking structure, making maintenance and replacement convenient. In practical operation, its disadvantages are the same as common molds: in injection molding line operation, the injection molding machine cannot continuously heat and pre-plasticize.

5,What is the pin valve self-locking PET preform mold?

The pin valve self-locking PET preform mold's component cores, cavities, and sliders are machined with precision controlled within ±0.01mm. This strictly controls the preform eccentricity during injection molding. Because the mold uses needle valve's self-locking structure, the production line can simultaneously produce products and pre-plasticizing of the injection molding machine, preparing for the next injection cycle, and accelerating the production cycle. Its main advantage lies in the "point-to-point" temperature control, ensuring uniform product weight and wall thickness in each cavity, thus improving product quality.

6,Why choose Younce?

Taizhou Younce Mould Co., Ltd. is a manufacturer dedicated to the PET packaging industry. With mold and product design engineers proficient in CAD/CAE/CAM systems and Pro-E and UG software, skilled workers in assembly and CNC machine programming, and professional sales staff, we provide customers with the best service. Our company implements strict production management and adopts a complete operating system. All bottle-blowing machines and molds undergo inspection procedures before delivery to customers and provide after-sales service and warranty support. Our company can also provide customers with complete PET packaging equipment solutions, including injection molding machines, bottle-blowing machines, filling machines, and all peripheral equipment. As a pursuer of the leading supplier of plastic packaging equipment, we continuously provide high-quality plastic molds and machines at preferential prices. Continuously provide customers with better services.