Key Specifications of a PET Preform for a Water Bottle Injection Molding Machine

The production of high-quality water bottles through injection molding heavily relies on the specifications of the PET preform used. PET preforms are semi-finished products that are later blown into bottles, and their characteristics significantly influence the efficiency and outcome of the molding process. Here are the key specifications of a PET preform for a water bottle injection molding machine:

1. Material Composition

Polyethylene Terephthalate (PET):

- Purity: High-purity PET resin is essential to ensure clarity, strength, and food safety of the water bottles.

- Additives: Sometimes additives like UV blockers, colorants, or barriers are included to enhance the performance and appearance of the final product.

2. Preform Weight

Weight Range:

- Typical Weights: PET preforms for water bottles generally range from 10 grams to 50 grams, depending on the bottle size and application.

- Weight Consistency: Consistent preform weight is crucial for uniform bottle thickness and quality.

3. Neck Finish

Neck Size and Thread Design:

- Standard Sizes: Common neck finishes include 28mm, 30/25, 38mm, and 48mm, each suited for different bottle caps and applications.

- Thread Design: The thread design must match the cap specifications to ensure a secure and leak-proof seal.

4. Wall Thickness

Uniform Thickness:

- Even Distribution: Uniform wall thickness across the preform ensures consistent blowing and prevents weak spots in the bottle.

- Precision: Precise control over wall thickness is critical for maintaining bottle strength and aesthetics.

5. Length and Diameter

Dimensional Accuracy:

- Length: The length of the preform varies based on the desired bottle height and capacity.

- Diameter: The diameter must be precisely controlled to fit into the injection molding machine and ensure proper blowing.

6. Molecular Weight and IV (Intrinsic Viscosity)

Molecular Characteristics:

- Molecular Weight: Determines the flow properties of PET during injection molding and affects the final product’s mechanical properties.

- Intrinsic Viscosity (IV): Typically ranges from 0.70 to 0.85 dL/g for water bottle preforms. Higher IV indicates better strength and clarity.

Conclusion

The specifications of a PET preform for a water bottle injection molding machine play a crucial role in the production process. By adhering to precise standards in material composition, weight, neck finish, wall thickness, dimensions, molecular weight, crystallinity, color, and manufacturing tolerances, manufacturers can ensure the production of high-quality, durable, and aesthetically pleasing water bottles. Understanding these specifications helps in selecting the right preform for specific applications, ultimately leading to better product performance and customer satisfaction.