Description

Bottle Grade PET Chip WK-821 | High Performance PET Resin for Edible Oil and Beverage Packaging

Product Overview

Bottle Grade PET Chip WK-821 is a high-quality polyethylene terephthalate (PET) resin specially designed for the production of transparent, durable, and food-contact packaging products. This grade is optimized for stretch blow molding applications, especially in the manufacturing of edible oil bottles, beverage containers, wine bottles, medical packaging, and APET sheets.

PET WK-821 combines high intrinsic viscosity, excellent molecular stability, low acetaldehyde generation, superior transparency, and strong mechanical performance. These properties make it a preferred material for manufacturers requiring reliable processing behavior and consistent bottle quality.

This grade complies with major food-contact regulations, including China GB 9685, GB 4806.6, European Regulation (EU) No. 10/2011, and US FDA 21 CFR 177.1630, making it suitable for demanding food packaging applications.

Outstanding Properties of PET Chip WK-821

1. High Intrinsic Viscosity for Strong Bottle Performance

The intrinsic viscosity (IV) of WK-821 is:

0.830 ± 0.015 dL/g

Intrinsic viscosity is one of the most important parameters in bottle-grade PET because it directly affects molecular chain length, melt strength, mechanical properties, and final bottle performance.

A higher and stable IV value provides:

✅ Better melt strength during preform production
✅ Higher mechanical strength of finished bottles
✅ Improved resistance against deformation and impact
✅ Better pressure resistance for packaging applications

The IV level of WK-821 is particularly suitable for edible oil bottles, where the container must maintain rigidity, transparency, and dimensional stability during storage and transportation.

2. Low Acetaldehyde (AA) Content for Food Safety and Product Quality

WK-821 has an acetaldehyde content of:

≤ 1.0 μg/g

Acetaldehyde is a by-product generated during PET processing at high temperatures. Excessive AA levels may affect the taste and odor of sensitive products, especially beverages and food packaging.

The low AA characteristics of WK-821 provide:

✅ Improved taste protection for packaged products
✅ Reduced risk of odor transfer
✅ Better suitability for food and beverage applications
✅ Higher consumer acceptance

This property is especially valuable in applications where packaging material directly contacts edible products.

3. Excellent Optical Properties and High Transparency

PET Chip WK-821 provides excellent clarity with:

L-value ≥ 83.0

and:

b-value ≤ -0.5

These color parameters indicate a highly transparent PET resin with low yellowness.

The optical advantages include:

✅ Crystal-clear appearance of bottles
✅ Attractive product presentation
✅ Better visual quality compared with lower-grade PET materials
✅ Suitable for premium packaging applications

For edible oil bottles, transparency is an important commercial advantage because consumers can easily observe the product inside the container.

4. Stable Molecular Weight Distribution

One of the key advantages of WK-821 is its stable molecular structure and molecular weight distribution.

A stable molecular structure ensures:

✅ Consistent melt flow behavior
✅ Reduced variation between production batches
✅ Better control during injection molding
✅ Higher production efficiency

For large-scale bottle manufacturers, material consistency is critical because even small variations in PET properties can affect preform quality, bottle thickness distribution, and production yield.

5. Excellent Processing Performance

WK-821 has been developed to provide a wide processing window, allowing manufacturers to achieve stable production under different operating conditions.

Main processing advantages:

✅ Easy drying and processing characteristics
✅ Stable injection molding performance
✅ Good compatibility with standard PET production equipment
✅ Reduced processing defects
✅ Higher production efficiency

The grade is suitable for modern high-speed bottle manufacturing systems where continuous operation and low rejection rates are important factors.

6. High Mechanical Strength and Barrier Performance

PET WK-821 produces bottles with excellent physical properties, including:

• High tensile strength
• Good impact resistance
• Strong dimensional stability
• Good gas barrier characteristics

These properties help finished containers maintain their shape and protect the packaged product throughout storage and transportation.

The combination of strength and lightweight capability allows producers to manufacture efficient packaging solutions while reducing material consumption.

PET Chip WK-821 Detailed Technical Data Sheet Explanation

Melting Temperature and Thermal Characteristics

The melting peak temperature of PET Chip WK-821 is:

245 ± 2°C

This parameter indicates the crystalline melting behavior of PET resin.

Stable melting characteristics provide:

✅ Predictable processing performance
✅ Better temperature control during production
✅ Reduced risk of incomplete melting or degradation

During processing, PET must be heated carefully because excessive thermal exposure may reduce molecular weight and affect mechanical performance.

Moisture Control and Drying Requirements

PET is a hygroscopic polymer, meaning it can absorb moisture from the environment. During processing, moisture can react with PET chains and cause hydrolysis.

Hydrolysis may lead to:

❌ Reduction in intrinsic viscosity
❌ Lower mechanical strength
❌ Reduced bottle performance
❌ Processing instability

Therefore, WK-821 should be fully dried before processing.

Recommended drying conditions:

• Temperature: 75 ± 10°C
• Drying time: 4–6 hours
• Dew point: ≤ -40°C
• Melting temperature: 280–300°C

Proper drying ensures maximum molecular stability and final product quality.

Typical Applications

Edible Oil Bottles

WK-821 is especially suitable for edible oil bottles because it provides:

✅ High transparency
✅ Good chemical resistance
✅ Strong mechanical properties
✅ Food-contact compliance
✅ Long-term storage stability

Beverage Bottles

The low acetaldehyde content makes it suitable for beverage packaging where taste preservation is important.

Medical and Pharmaceutical Packaging

The material’s stability, transparency, and controlled quality make it suitable for selected medical packaging applications.

APET Sheets

WK-821 can also be used for APET sheet production, where clarity, strength, and thermoforming performance are required.

Storage Recommendations

To maintain PET resin quality:

• Store in a dry indoor warehouse.
• Keep bags sealed until use.
• Avoid direct sunlight exposure.
• Prevent contamination during storage.
• Recommended usage period: within 2 years.

After opening the package, the material should be processed as soon as possible to prevent moisture absorption.

Conclusion

Bottle Grade PET Chip WK-821 is a high-performance PET resin designed for manufacturers who require stable processing, excellent appearance, and reliable mechanical performance.

With its combination of high intrinsic viscosity, low acetaldehyde content, superior transparency, stable molecular structure, and food-contact compliance, WK-821 provides an effective solution for producing high-quality edible oil bottles, beverage containers, and other PET packaging products.