Preform Neck Finish Extension for Lightweight Bottle Resin Reduction
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Solution Overview
Problem
Current plastic bottle preforms require more resin than necessary, leading to heavier bottles and increased petroleum usage, while existing designs face challenges in achieving both lightweighting and maintaining structural integrity during the blow-molding process.
Innovation Solution
A preform design featuring a neck portion with a support ring, an elongated body portion with varying wall thicknesses, and internal and external columns to reduce material usage while maintaining structural integrity, allowing for efficient blow-molding into lightweight bottles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conventional preform design with uniform wall thickness is used, then structural integrity is maintained, but resin usage increases and bottle weight increases
Solution Approach 1:
The preform employs varying wall thicknesses in different regions: the neck portion has a first wall thickness, the upper segment of the body portion has a second wall thickness similar to the neck, and the lower segment has a third wall thickness greater than the second. This local differentiation allows resin to be concentrated where structurally necessary while reducing it where less critical, thereby reducing overall resin usage while maintaining structural integrity.
Solution Approach 2:
The preform is divided into distinct segments (neck portion, upper segment, lower segment) with different wall thickness characteristics. The support ring at the lowermost point of the neck portion further segments the structure to provide localized reinforcement. This segmentation enables optimized material distribution across different functional zones of the preform.
2Weight of moving object
If preform wall thickness is reduced to decrease bottle weight, then resin usage decreases, but dimensional stability during blow-molding deteriorates
Solution Approach 1:
The preform maintains thicker walls in the lower segment (third wall thickness greater than second) where dimensional stability is critical during blow-molding, while using thinner walls in the upper segment (second wall thickness similar to neck) where less structural support is needed. This local quality differentiation achieves lightweighting without compromising dimensional stability in critical areas.
Solution Approach 2:
The support ring is positioned at the lowermost point of the neck portion to provide preliminary structural reinforcement before the blow-molding process begins. This preliminary action ensures that the neck portion maintains its dimensional stability during the subsequent blowing operation, even though overall wall thickness is reduced in other areas.
3Strength
If more resin is used in preform, then mechanical performance improves, but environmental sustainability deteriorates due to increased petroleum usage
Solution Approach 1:
The preform concentrates resin in the lower segment where it provides maximum mechanical benefit (third wall thickness greater than second), while minimizing resin in the upper segment and neck (second wall thickness similar to first). This optimized distribution achieves suitable mechanical performance with reduced overall resin content, thereby reducing petroleum usage and improving environmental sustainability.
Solution Approach 2:
The invention changes the wall thickness parameter across different segments of the preform rather than using a uniform thickness. By varying this critical parameter (first wall thickness in neck, second wall thickness in upper segment, third wall thickness in lower segment), the design achieves optimal mechanical performance with minimized material consumption, reducing the harmful environmental impact of petroleum-based resin production.
Data Source
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AI summary
Disclosed are preforms which incorporate improvements in the region of the neck and upper segment of the body to allow the production of lightweight containers, such as bottles suitable for containing water or other beverages. In accordance with certain embodiments, the improvements include a thinner neck finish area than conventional bottles, where the thinner area is extended into the upper segment of the body portion below the support ring. Reducing the thickness in these areas of the bottle allows for less resin to be used in forming the preform and bottle.