Description:
FIELD OF THE INVENTION
The present invention relates to the field of plastic bottle manufacturing, specifically to the design and production of preforms used in injection stretch blow molding (ISBM) technology. The invention focuses on the use of differential glass transition temperatures (Tg) and differential wall thicknesses in preforms to enhance the structural performance of bottles made from materials such as polyethylene terephthalate (PET), polypropylene (PP), high-density polyethylene (HDPE), polyethylene terephthalate glycol (PETG), Tritan, and other plastic materials. The invention aims to improve the mechanical strength, top load performance, and overall durability of the final bottles without the need for additional structural features.

Application of the Invention
The invention is applicable in the production of plastic bottles using ISBM technology, which is widely used in the packaging industry for beverages, personal care products, household chemicals, and other consumer goods. The method involves designing preforms with differential wall thicknesses and applying a differential temperature profile during the injection molding cycle to achieve varying glass transition temperatures (Tg) at different points of the preform. This approach allows for precise control of polymer orientation and distribution, resulting in bottles with superior mechanical properties.

The application of this invention is particularly beneficial for manufacturers seeking to produce lightweight bottles with enhanced top load strength and improved resistance to deformation, impact, and environmental stress. By optimizing the preform design and molding process, the invention enables the production of high-performance bottles with reduced material usage, improved clarity, and better recyclability. This makes the invention suitable for a wide range of applications, including but not limited to:
1. Beverage bottles, such as water, soda, and juice containers.
2. Personal care product bottles, such as shampoo, conditioner, and lotion containers.
3. Household chemical bottles, such as detergent, cleaner, and bleach containers.
4. Food packaging, such as condiment and sauce bottles.
5. Pharmaceutical and medical packaging, such as pill bottles and liquid medicine containers.

Overall, the invention provides a novel and efficient method for producing high-quality plastic bottles with enhanced performance characteristics, meeting the demands of various industries for durable and sustainable packaging solutions.

BACKGROUND OF THE INVENTION
Injection stretch blow molding (ISBM) technology is a widely used method for producing plastic bottles, particularly those made from materials such as polyethylene terephthalate (PET), polypropylene (PP), high-density polyethylene (HDPE), polyethylene terephthalate glycol (PETG), and Tritan. This technology involves the injection molding of a preform, which is then reheated and stretched to form the final bottle shape. The mechanical properties of the final bottle, such as top load strength, impact resistance, and overall durability, are critical for its performance in various applications, including beverage, personal care, household chemicals, and food packaging.

Problems of Prior Art
1. Uniform Wall Thickness: Traditional ISBM processes often produce preforms with uniform wall thickness, which can lead to suboptimal mechanical properties in the final bottle.
2. Inconsistent Mechanical Strength: Bottles produced using conventional methods may exhibit inconsistent mechanical strength, particularly in areas subjected to high stress or load.
3. Material Usage: Achieving the desired mechanical properties often requires the use of more material, leading to heavier bottles and increased production costs.
4. Limited Control Over Polymer Orientation: Conventional methods provide limited control over the orientation and distribution of polymers within the preform, affecting the final bottle's performance.
5. Environmental Stress Cracking: Bottles produced using traditional methods may be more susceptible to environmental stress cracking and other forms of degradation.

Disadvantages of Prior Art
1. Higher Material Costs: The need for thicker walls to achieve desired mechanical properties results in higher material usage and increased production costs.
2. Inconsistent Quality: Variations in mechanical strength and durability can lead to inconsistent product quality, affecting consumer satisfaction and brand reputation.
3. Limited Design Flexibility: Uniform wall thickness and limited control over polymer orientation restrict the ability to optimize bottle design for specific applications.
4. Environmental Impact: Increased material usage and susceptibility to environmental stress cracking contribute to a higher environmental footprint.

Technical Solution of the Present Invention
The present invention addresses the limitations of prior art by introducing a method for producing plastic bottles using ISBM technology that involves:
1. Designing Preforms with Differential Wall Thickness: The preform is designed with varying wall thicknesses to optimize the structural performance of the final bottle.
2. Applying a Differential Temperature Profile: During the injection molding cycle, a differential temperature profile is applied to achieve varying glass transition temperatures (Tg) at different points of the preform.
3. Correlating Differential Tg with Wall Thickness: The differential Tg is correlated with the differential wall thickness to control polymer orientation and distribution within the preform.
4. Molding the Preform into the Final Bottle Shape: The preform is then molded into the final bottle shape, resulting in enhanced mechanical strength and top load performance.

Technical Effect
The technical effect of the present invention includes:
1. Enhanced Mechanical Strength: The differential Tg and wall thickness result in improved mechanical strength and top load performance of the final bottle.
2. Optimized Material Usage: The method allows for the production of lightweight bottles with reduced material usage while maintaining structural integrity.
3. Improved Durability: Bottles produced using this method exhibit improved resistance to deformation, impact, and environmental stress.
4. Better Control Over Polymer Orientation: The method provides better control over polymer orientation and distribution, leading to consistent product quality.
5. Improved Clarity and Appearance: The differential Tg and wall thickness result in bottles with improved clarity and aesthetic appeal.

Need of the Present Invention
The present invention is needed to address the limitations and disadvantages of prior art in the production of plastic bottles using ISBM technology. By introducing a method that optimizes preform design and molding parameters, the invention provides a solution that enhances the mechanical properties, durability, and overall performance of the final bottles. This innovation is particularly important for manufacturers seeking to produce high-quality, lightweight, and sustainable packaging solutions that meet the demands of various industries and consumers.

OBJECT OF THE INVENTION
The primary object of the present invention is to provide a method for producing plastic bottles using injection stretch blow molding (ISBM) technology that significantly enhances the mechanical properties and overall performance of the final bottles. The specific objectives of the invention include:

1. To Design Preforms with Differential Wall Thickness: To create preforms with varying wall thicknesses that optimize the structural performance of the final bottle.
2. To Apply a Differential Temperature Profile: To implement a differential temperature profile during the injection molding cycle to achieve varying glass transition temperatures (Tg) at different points of the preform.
3. To Correlate Differential Tg with Wall Thickness: To correlate the differential Tg with the differential wall thickness to control polymer orientation and distribution within the preform.
4. To Enhance Mechanical Strength and Top Load Performance: To produce bottles with superior mechanical strength and top load performance, making them more durable and reliable for various applications.
5. To Optimize Material Usage: To reduce material usage while maintaining the structural integrity and performance of the final bottles, leading to cost-effective and sustainable production.
6. To Improve Resistance to Deformation and Impact: To enhance the resistance of the final bottles to deformation under load and impact, ensuring better durability and longevity.
7. To Improve Environmental Stress Resistance: To produce bottles with improved resistance to environmental stress cracking and other forms of degradation, extending their useful life.
8. To Achieve Consistent Product Quality: To provide better control over polymer orientation and distribution, resulting in consistent product quality and performance.
9. To Enhance Aesthetic Appeal: To produce bottles with improved clarity and appearance, meeting consumer expectations for high-quality packaging.
10. To Improve Recyclability and Sustainability: To create bottles that are more recyclable and environmentally friendly, contributing to sustainable packaging solutions.
11. To Provide Versatility for Various Applications: To develop a method that can be applied to produce bottles for a wide range of applications, including beverages, personal care products, household chemicals, food packaging, and pharmaceuticals.

By achieving these objectives, the present invention aims to provide a novel and efficient method for producing high-performance plastic bottles that meet the demands of various industries and consumers, while also addressing the limitations and disadvantages of prior art.

SUMMARY OF THE INVENTION
The following disclosure presents a simplified summary of the invention in order to provide a basic understanding of some aspects of the invention. This summary is not an extensive overview of the present invention. It is not intended to identify the key/critical elements of the invention or to delineate the scope of the invention. Its sole purpose is to present some concept of the invention in a simplified form as a prelude to a more detailed description of the invention presented later.

The present invention provides a novel method for producing plastic bottles using injection stretch blow molding (ISBM) technology. The method involves designing preforms with differential wall thicknesses and applying a differential temperature profile during the injection molding cycle to achieve varying glass transition temperatures (Tg) at different points of the preform. This approach allows for precise control of polymer orientation and distribution, resulting in bottles with enhanced mechanical properties, including improved top load strength, impact resistance, and overall durability. The invention is applicable to various plastic materials, including polyethylene terephthalate (PET), polypropylene (PP), high-density polyethylene (HDPE), polyethylene terephthalate glycol (PETG), and Tritan.

Aspects of the Invention
1. Designing Preforms with Differential Wall Thickness:
o The preform is designed with varying wall thicknesses to optimize the structural performance of the final bottle.
o Thicker walls are provided at points requiring higher mechanical strength, while thinner walls are used at points requiring flexibility.
2. Applying a Differential Temperature Profile:
o A differential temperature profile is applied during the injection molding cycle to achieve varying glass transition temperatures (Tg) at different points of the preform.
o The temperature profile is controlled by varying the cooling rates at different points of the preform.
3. Correlating Differential Tg with Wall Thickness:
o The differential Tg is correlated with the differential wall thickness to control polymer orientation and distribution within the preform.
o This correlation ensures that the mechanical properties of the final bottle are optimized.
4. Molding the Preform into the Final Bottle Shape:
o The preform is molded into the final bottle shape using ISBM technology.
o The differential Tg and wall thickness result in enhanced mechanical strength and top load performance of the final bottle.

Implementation of the Invention
1. Material Selection:
o The method is applicable to various plastic materials, including PET, PP, HDPE, PETG, and Tritan.
o The choice of material depends on the specific application and desired properties of the final bottle.
2. Preform Design:
o The preform is designed with differential wall thicknesses to optimize the structural performance of the final bottle.
o Computer-aided design (CAD) software can be used to create precise preform designs.
3. Injection Molding Cycle:
o During the injection molding cycle, a differential temperature profile is applied to achieve varying Tg at different points of the preform.
o The temperature profile is controlled by adjusting the cooling rates at different points of the preform.
4. Correlation of Tg and Wall Thickness:
o The differential Tg is correlated with the differential wall thickness to control polymer orientation and distribution within the preform.
o This correlation is achieved by adjusting the injection molding parameters, including injection speed, pressure, and cooling time.

5. Molding the Final Bottle:
o The preform is reheated and stretched to form the final bottle shape using ISBM technology.
o The differential Tg and wall thickness result in bottles with enhanced mechanical properties, including improved top load strength, impact resistance, and overall durability.

Other aspects, advantages, and salient features of the invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses exemplary embodiments of the invention.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Figure 1: Core
This figure illustrates the core component used in the injection molding process, highlighting its structure and design.

Figure 2: Preform Design
This figure shows the detailed design of the preform, including dimensions and varying wall thicknesses, essential for optimizing the final bottle's structural performance.

Figure 3: Preform and Core Assembly
This figure depicts the assembly of the preform and core within the cavity, demonstrating the initial setup for the molding process.

Figure 4: Final Bottle
This figure presents the final bottle shape, showcasing the result of the injection stretch blow molding process.

Figure 5: Preform and Bottle
This figure illustrates the relationship between the preform and the final bottle, emphasizing the transformation during the molding process.

Figure 6: Preform, Core, and Bottle
This figure provides a cross-sectional view of the preform, core, and bottle, highlighting the alignment and interaction of these components.

Figure 7: Cavity Cross Section
This figure shows a cross-sectional view of the cavity used in the molding process, detailing its internal structure.

Figure 8: Preform, Core, and Bottle Cross Section
This figure offers a detailed cross-sectional view of the preform, core, and bottle, illustrating the internal configuration and material distribution.

DETAILED DESCRIPTION OF THE INVENTION
The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of various embodiments of the present disclosure as defined by the claims and their equivalents. It includes various specific details to assist in that understanding, but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the various embodiments described herein can be made without departing from the scope and spirit of the present disclosure. In addition, descriptions of well-known functions and constructions may be omitted for clarity and conciseness.

All terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which various embodiments belong. Further, the meaning of terms or words used in the specification and the claims should not be limited to the literal or commonly employed sense but should be construed in accordance with the spirit of the disclosure to most properly describe the present disclosure.

The terminology used herein is for the purpose of describing particular various embodiments only and is not intended to be limiting of various embodiments. As used herein, the singular forms "a," "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising" used herein specify the presence of stated features, integers, steps, operations, members, components, and/or groups thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, members, components, and/or groups thereof.

The present invention provides a method for producing plastic bottles using injection stretch blow molding (ISBM) technology. The method involves designing preforms with differential wall thicknesses and applying a differential temperature profile during the injection molding cycle to achieve varying glass transition temperatures (Tg) at different points of the preform. This approach allows for precise control of polymer orientation and distribution, resulting in bottles with enhanced mechanical properties, including improved top load strength, impact resistance, and overall durability. The invention is applicable to various plastic materials, including polyethylene terephthalate (PET), polypropylene (PP), high-density polyethylene (HDPE), polyethylene terephthalate glycol (PETG), and Tritan.

Embodiments of the Invention
Embodiment 1: Material Selection
The method is applicable to various plastic materials, including:
• Polyethylene Terephthalate (PET): Commonly used for beverage bottles due to its clarity and strength.

• Polypropylene (PP): Known for its chemical resistance and flexibility.
• High-Density Polyethylene (HDPE): Used for its durability and impact resistance.
• Polyethylene Terephthalate Glycol (PETG): Offers improved clarity and toughness.
• Tritan: A copolyester known for its clarity, toughness, and chemical resistance.

Embodiment 2: Preform Design
The preform is designed with differential wall thicknesses to optimize the structural performance of the final bottle. The design process involves:
• Thicker Walls: Provided at points requiring higher mechanical strength, such as the base and shoulder of the bottle.
• Thinner Walls: Used at points requiring flexibility, such as the body of the bottle.
• Computer-Aided Design (CAD): Software is used to create precise preform designs that meet the desired specifications.

Embodiment 3: Injection Molding Cycle
During the injection molding cycle, a differential temperature profile is applied to achieve varying glass transition temperatures (Tg) at different points of the preform. The process includes:
• Injection Molding Machine Setup: The machine is set up with the designed preform mold.
• Differential Temperature Profile: Achieved by varying the cooling rates at different points of the preform.
• Injection Parameters: Adjusted to control injection speed, pressure, and cooling time, ensuring the desired differential Tg and wall thickness.

Embodiment 4: Correlation of Tg and Wall Thickness
The differential Tg is correlated with the differential wall thickness to control polymer orientation and distribution within the preform. This correlation ensures that the mechanical properties of the final bottle are optimized. The process includes:
• Adjusting Injection Parameters: Fine-tuning the injection speed, pressure, and cooling time to achieve the desired correlation.
• Polymer Orientation and Distribution: Controlled to enhance the mechanical strength and durability of the final bottle.

Embodiment 5: Molding the Final Bottle
The preform is molded into the final bottle shape using ISBM technology. The process includes:
• Reheating the Preform: The preform is reheated to the appropriate temperature for stretch blow molding.
• Stretch Blow Molding: The preform is axially stretched and inflated within the mold to form the final bottle shape.
o Axial Stretching: Orients the polymer chains to improve mechanical properties.
o Blowing: Inflates the preform to form the final bottle shape.

Process Flow for Producing Plastic Bottles Using Differential Glass Transition Temperature (Tg) and Wall Thickness in ISBM Technology
Step 1: Material Selection
• Select Plastic Material: Choose the appropriate plastic material for the preform, such as PET, PP, HDPE, PETG, or Tritan, based on the desired properties of the final bottle.
Step 2: Preform Design
• Design Preform with Differential Wall Thickness: Use computer-aided design (CAD) software to create a preform design with varying wall thicknesses. Thicker walls are provided at points requiring higher mechanical strength, while thinner walls are used at points requiring flexibility.
Step 3: Injection Molding Cycle
• Prepare Injection Molding Machine: Set up the injection molding machine with the designed preform mold.
• Apply Differential Temperature Profile: During the injection molding cycle, apply a differential temperature profile to achieve varying glass transition temperatures (Tg) at different points of the preform. This is achieved by varying the cooling rates at different points of the preform.
o Control Injection Parameters: Adjust injection speed, pressure, and cooling time to achieve the desired differential Tg and wall thickness.
Step 4: Correlation of Tg and Wall Thickness
• Correlate Differential Tg with Wall Thickness: Ensure that the differential Tg is correlated with the differential wall thickness to control polymer orientation and distribution within the preform. This correlation optimizes the mechanical properties of the final bottle.
Step 5: Molding the Final Bottle
• Reheat Preform: Reheat the preform to the appropriate temperature for stretch blow molding.
• Stretch Blow Molding: Use the ISBM technology to stretch and blow mold the preform into the final bottle shape.
o Stretching: Axially stretch the preform to orient the polymer chains and improve mechanical properties.
o Blowing: Inflate the preform within the mold to form the final bottle shape.
Step 6: Quality Control and Inspection
• Inspect Final Bottle: Perform quality control checks to ensure that the final bottle meets the desired specifications and performance criteria.
o Mechanical Strength Testing: Test the top load strength, impact resistance, and overall durability of the bottle.
o Visual Inspection: Check for clarity, appearance, and any defects in the bottle.
Step 7: Packaging and Distribution
• Package Bottles: Package the finished bottles for distribution.
• Distribute to Market: Distribute the bottles to various industries, including beverages, personal care products, household chemicals, food packaging, and pharmaceuticals.
Process Flow
Material Selection
↓
Preform Design
↓
Injection Molding Cycle
↓
Correlation of Tg and Wall Thickness
↓
Molding the Final Bottle
↓
Quality Control and Inspection
↓
Packaging and Distribution

By following this process flow, manufacturers can produce high-performance plastic bottles with enhanced mechanical properties, optimized material usage, and improved durability, meeting the demands of various industries and consumers.

DETAILED DESCRIPTION OF THE FIGURES
Figure 1: Core
This figure illustrates the core component used in the injection molding process. The core is designed to shape the internal features of the preform, ensuring precise dimensions and structural integrity. It plays a crucial role in defining the internal geometry of the final bottle.

Figure 2: Preform Design
This figure presents the detailed design of the preform, highlighting its dimensions and varying wall thicknesses. The preform is engineered to optimize the structural performance of the final bottle, with thicker sections for strength and thinner areas for flexibility. The use of computer-aided design (CAD) ensures precision in the preform's geometry.

Figure 3: Preform and Core Assembly
This figure depicts the assembly of the preform and core within the cavity. It demonstrates the initial setup for the molding process, where the preform is positioned around the core, ready for the injection molding cycle. This alignment is critical for achieving the desired polymer orientation and distribution.

Figure 4: Final Bottle
This figure shows the final bottle shape, resulting from the injection stretch blow molding process. The bottle exhibits enhanced mechanical properties, including improved top load strength and impact resistance, achieved through the differential glass transition temperatures (Tg) and wall thicknesses.

Figure 5: Preform and Bottle
This figure illustrates the transformation from the preform to the final bottle. It emphasizes the changes in shape and structure that occur during the molding process, highlighting the effectiveness of the differential Tg and wall thickness in optimizing the bottle's performance.

Figure 6: Preform, Core, and Bottle
This figure provides a cross-sectional view of the preform, core, and bottle. It highlights the interaction and alignment of these components, showcasing how the core shapes the internal features while the preform expands to form the bottle's external structure.

Figure 7: Cavity Cross Section
This figure presents a cross-sectional view of the cavity used in the molding process. It details the internal structure of the cavity, which is designed to accommodate the preform and core assembly, ensuring uniform cooling and precise shaping during the injection molding cycle.

Figure 8: Preform, Core, and Bottle Cross Section
This figure offers a detailed cross-sectional view of the preform, core, and bottle. It illustrates the internal configuration and material distribution, demonstrating how the differential Tg and wall thickness contribute to the bottle's enhanced mechanical properties and durability.

Best Mode of Working the Invention
The best mode of working the invention involves the following steps:
1. Material Selection: Choose PET as the plastic material for the preform due to its clarity, strength, and widespread use in beverage bottles.
2. Preform Design: Use CAD software to design a preform with differential wall thicknesses. Provide thicker walls at the base and shoulder for higher mechanical strength and thinner walls at the body for flexibility.
3. Injection Molding Cycle:
o Set up the injection molding machine with the designed preform mold.
o Apply a differential temperature profile by varying the cooling rates at different points of the preform.
o Adjust injection parameters, including injection speed, pressure, and cooling time, to achieve the desired differential Tg and wall thickness.
4. Correlation of Tg and Wall Thickness:
o Fine-tune the injection parameters to ensure the differential Tg is correlated with the differential wall thickness.
o Control polymer orientation and distribution to enhance the mechanical strength and durability of the final bottle.
5. Molding the Final Bottle:
o Reheat the preform to the appropriate temperature for stretch blow molding.
o Axially stretch the preform to orient the polymer chains and improve mechanical properties.
o Inflate the preform within the mold to form the final bottle shape.
6. Quality Control and Inspection:
o Perform mechanical strength testing to ensure the top load strength, impact resistance, and overall durability of the bottle.
o Conduct visual inspection to check for clarity, appearance, and any defects in the bottle.
7. Packaging and Distribution:
o Package the finished bottles for distribution.
o Distribute the bottles to various industries, including beverages, personal care products, household chemicals, food packaging, and pharmaceuticals.

By following this best mode of working, manufacturers can produce high-performance plastic bottles with enhanced mechanical properties, optimized material usage, and improved durability, meeting the demands of various industries and consumers.

Examples to Show Technical Effect of the Present Invention
Example 1: Enhanced Top Load Strength
Objective: To demonstrate the improved top load strength of bottles produced using the present invention compared to conventional bottles.
Method:
1. Material: PET is selected as the plastic material for the preform.
2. Preform Design: A preform is designed with differential wall thicknesses, with thicker walls at the base and shoulder and thinner walls at the body.
3. Injection Molding Cycle: A differential temperature profile is applied during the injection molding cycle to achieve varying Tg at different points of the preform.
4. Molding: The preform is reheated and stretch blow molded into the final bottle shape.
Testing:
• Top Load Strength Test: The top load strength of the bottle is measured using a compression testing machine.
Results:
• Bottles produced using the present invention exhibit a top load strength of 200 kg, compared to 150 kg for conventional bottles with uniform wall thickness.
Technical Effect:
• The differential Tg and wall thickness result in enhanced top load strength, making the bottles more resistant to deformation under load.

Example 2: Optimized Material Usage
Objective: To demonstrate the reduction in material usage while maintaining structural integrity.
Method:
1. Material: PP is selected as the plastic material for the preform.
2. Preform Design: A preform is designed with differential wall thicknesses, optimizing material distribution for structural performance.
3. Injection Molding Cycle: A differential temperature profile is applied to achieve varying Tg at different points of the preform.
4. Molding: The preform is reheated and stretch blow molded into the final bottle shape.
Testing:
• Material Usage Measurement: The weight of the final bottle is measured and compared to conventional bottles.
Results:
• Bottles produced using the present invention weigh 20% less than conventional bottles while maintaining the same mechanical strength.
Technical Effect:
• The optimized material usage results in cost savings and more sustainable production practices without compromising structural integrity.

Example 3: Improved Impact Resistance
Objective: To demonstrate the improved impact resistance of bottles produced using the present invention.
Method:
1. Material: HDPE is selected as the plastic material for the preform.
2. Preform Design: A preform is designed with differential wall thicknesses, with thicker walls at points requiring higher impact resistance.
3. Injection Molding Cycle: A differential temperature profile is applied to achieve varying Tg at different points of the preform.
4. Molding: The preform is reheated and stretch blow molded into the final bottle shape.
Testing:
• Impact Resistance Test: The impact resistance of the bottle is measured using a drop test from a height of 1.5 meters.

Results:
• Bottles produced using the present invention withstand the drop test without cracking, while conventional bottles show signs of cracking and deformation.
Technical Effect:
• The differential Tg and wall thickness result in improved impact resistance, making the bottles more durable and reliable.

Example 4: Improved Clarity and Aesthetic Appeal
Objective: To demonstrate the improved clarity and aesthetic appeal of bottles produced using the present invention.
Method:
1. Material: PETG is selected as the plastic material for the preform.
2. Preform Design: A preform is designed with differential wall thicknesses to optimize clarity and appearance.
3. Injection Molding Cycle: A differential temperature profile is applied to achieve varying Tg at different points of the preform.
4. Molding: The preform is reheated and stretch blow molded into the final bottle shape.
Testing:
• Visual Inspection: The clarity and appearance of the bottle are evaluated visually and compared to conventional bottles.
Results:
• Bottles produced using the present invention exhibit higher clarity and a more uniform appearance compared to conventional bottles.
Technical Effect:
• The differential Tg and wall thickness result in improved clarity and aesthetic appeal, meeting consumer expectations for high-quality packaging.

Example 5: Improved Resistance to Environmental Stress Cracking
Objective: To demonstrate the improved resistance to environmental stress cracking of bottles produced using the present invention.
Method:
1. Material: Tritan is selected as the plastic material for the preform.
2. Preform Design: A preform is designed with differential wall thicknesses to enhance resistance to environmental stress.
3. Injection Molding Cycle: A differential temperature profile is applied to achieve varying Tg at different points of the preform.
4. Molding: The preform is reheated and stretch blow molded into the final bottle shape.
Testing:
• Environmental Stress Cracking Test: The bottles are exposed to a stress-cracking agent and subjected to mechanical stress.
Results:
• Bottles produced using the present invention show no signs of environmental stress cracking, while conventional bottles exhibit cracking and degradation.
Technical Effect:
• The differential Tg and wall thickness result in improved resistance to environmental stress cracking, extending the useful life of the bottles.

By providing these examples, the technical effects of the present invention are clearly demonstrated, showcasing the significant improvements in mechanical strength, material usage, impact resistance, clarity, and resistance to environmental stress cracking. These advantages highlight the effectiveness and innovation of the present invention in producing high-performance plastic bottles.

Advantages of the Invention
The present invention offers several significant advantages over traditional methods of producing plastic bottles using injection stretch blow molding (ISBM) technology. These advantages include:

1. Enhanced Mechanical Strength:
o The method results in bottles with superior mechanical strength, including improved top load performance. This is achieved through the differential glass transition temperatures (Tg) and wall thicknesses, which optimize polymer orientation and distribution.
2. Optimized Material Usage:
o By designing preforms with differential wall thicknesses, the invention allows for the production of lightweight bottles with reduced material usage. This leads to cost savings in material costs and more sustainable production practices.
3. Improved Durability:
o Bottles produced using this method exhibit enhanced resistance to deformation under load, impact resistance, and overall durability. This makes the bottles more reliable and longer-lasting in various applications.
4. Better Control Over Polymer Orientation:
o The differential Tg and wall thickness provide better control over polymer orientation and distribution within the preform. This results in consistent product quality and performance, reducing the likelihood of defects and variations.
5. Improved Resistance to Environmental Stress:
o The method enhances the resistance of the final bottles to environmental stress cracking and other forms of degradation. This extends the useful life of the bottles and improves their performance in challenging conditions.

6. Enhanced Aesthetic Appeal:
o The differential Tg and wall thickness result in bottles with improved clarity and appearance. This meets consumer expectations for high-quality packaging and enhances the visual appeal of the final product.
7. Increased Design Flexibility:
o The ability to design preforms with differential wall thicknesses provides greater flexibility in bottle design. This allows manufacturers to tailor the bottle's structural properties to specific applications and performance requirements.
8. Improved Recyclability and Sustainability:
o The method contributes to the production of more recyclable and environmentally friendly bottles. Reduced material usage and enhanced durability lead to a lower environmental footprint and support sustainable packaging solutions.
9. Versatility for Various Applications:
o The invention is applicable to a wide range of plastic materials, including PET, PP, HDPE, PETG, and Tritan. This versatility makes it suitable for producing bottles for various industries, such as beverages, personal care products, household chemicals, food packaging, and pharmaceuticals.
10. Cost-Effective Production:
o By optimizing material usage and improving the mechanical properties of the final bottles, the method offers a cost-effective solution for manufacturers. This leads to reduced production costs and increased competitiveness in the market.
11. Consistent Product Quality:
o The method ensures consistent product quality by providing better control over polymer orientation and distribution. This reduces the likelihood of defects and variations, leading to higher consumer satisfaction and brand reputation.
12. Improved Thermal Stability:
o The differential Tg and wall thickness result in bottles with improved thermal stability. This makes the bottles more suitable for applications involving temperature variations and thermal stress.
13. Enhanced Chemical Resistance:
o The method improves the chemical resistance of the final bottles, making them more suitable for packaging products that contain aggressive chemicals or solvents.
14. Resistance to Creep and Fatigue:
o Bottles produced using this method exhibit improved resistance to creep under load and fatigue under cyclic loading. This enhances their performance in applications involving repeated use and mechanical stress.
15. Resistance to UV Degradation and Oxidation:
o The differential Tg and wall thickness result in bottles with improved resistance to UV degradation and oxidation. This extends the useful life of the bottles and maintains their performance in outdoor and high-exposure environments.

By offering these advantages, the present invention provides a novel and efficient method for producing high-performance plastic bottles that meet the demands of various industries and consumers, while also addressing the limitations and disadvantages of prior art.

The descriptions and illustrations provided in this document are intended to explain the principles of the invention and its best mode of working. They are not intended to limit the scope of the invention, which is defined by the claims. Variations and modifications to the described embodiments may be made without departing from the scope of the invention. The specific embodiments described in this document are examples of the invention and are not intended to limit the scope of the claims. The claims should be interpreted broadly to cover all equivalent structures and methods that fall within the scope of the invention. The technical specifications and details provided in this document are for illustrative purposes only. Actual implementations of the invention may vary based on specific design requirements, manufacturing processes, and application needs.

Any references to prior art documents, patents, or publications are provided for informational purposes only. The inclusion of such references does not imply that the present invention is limited by or dependent on the prior art.

The inventors and assignees reserve the right to make modifications, improvements, and updates to the invention described in this document. Such modifications and improvements may be made without notice and may not be reflected in this document.
, Claims:
1. A method for producing a plastic bottle using injection stretch blow molding (ISBM) technology, comprising:
a. designing a preform with differential wall thickness;
b. applying a differential temperature profile to the preform during the injection molding cycle to achieve differential glass transition temperatures (Tg) at various points of the preform;
c. correlating the differential Tg with the differential wall thickness to control polymer orientation and distribution within the preform;
d. molding the preform into a final bottle shape, wherein the differential Tg and wall thickness result in enhanced mechanical strength and top load performance of the final bottle.

2. The method of claim 1, wherein the plastic material used for the preform is selected from the group consisting of polyethylene terephthalate (PET), polypropylene (PP), high-density polyethylene (HDPE), polyethylene terephthalate glycol (PETG), and Tritan.

3. The method of claim 1, wherein the differential temperature profile is achieved by varying the cooling rates at different points of the preform during the injection molding cycle.

4. The method of claim 1, wherein the differential wall thickness of the preform is designed to optimize the structural performance of the final bottle.

5. The method of claim 1, wherein the differential Tg is achieved by controlling the injection molding parameters, including injection speed, pressure, and cooling time.

6. The method of claim 1, wherein the preform is designed with thicker walls at points that require higher mechanical strength in the final bottle.

7. The method of claim 1, wherein the preform is designed with thinner walls at points that require flexibility in the final bottle.

8. The method of claim 1, wherein the differential Tg and wall thickness result in improved top load strength of the final bottle.

9. The method of claim 1, wherein the differential Tg and wall thickness result in improved resistance to deformation under load in the final bottle.

10. The method of claim 1, wherein the differential Tg and wall thickness result in improved impact resistance of the final bottle.

11. The method of claim 1, wherein the differential Tg and wall thickness result in improved barrier properties of the final bottle.

12. The method of claim 1, wherein the differential Tg and wall thickness result in reduced material usage while maintaining the structural integrity of the final bottle.

13. The method of claim 1, wherein the differential Tg and wall thickness result in improved clarity and appearance of the final bottle.

14. The method of claim 1, wherein the differential Tg and wall thickness result in improved recyclability of the final bottle.

15. The method of claim 1, wherein the differential Tg and wall thickness result in improved thermal stability of the final bottle.

16. The method of claim 1, wherein the differential Tg and wall thickness result in improved chemical resistance of the final bottle.

17. The method of claim 1, wherein the differential Tg and wall thickness result in improved resistance to environmental stress cracking of the final bottle.

18. The method of claim 1, wherein the differential Tg and wall thickness result in improved resistance to creep under load of the final bottle.

19. The method of claim 1, wherein the differential Tg and wall thickness result in improved resistance to fatigue under cyclic loading of the final bottle.

20. The method of claim 1, wherein the differential Tg and wall thickness result in improved resistance to UV degradation of the final bottle.

21. The method of claim 1, wherein the differential Tg and wall thickness result in improved resistance to oxidation of the final bottle.

22. The method of claim 1, wherein the differential Tg and wall thickness result in improved resistance to hydrolysis of the final bottle.