Preform Extended Finish for Lightweight Bottle Resin Reduction
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Solution Overview
Problem
The challenge lies in creating lightweight plastic bottles that minimize resin usage while maintaining mechanical performance and structural integrity, as conventional designs often struggle with heat transfer and dimensional stability during the blow-molding process, leading to inefficiencies and increased material usage.
Innovation Solution
The introduction of a preform design with a neck portion and body portion featuring varying wall thicknesses and a tapered transition, along with internal and external columns, and a beveled finish, which reduces material usage while maintaining structural integrity and allowing for efficient blow-molding, thereby minimizing heat transfer and preserving mechanical strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If conventional preform design with uniform wall thickness is used, then structural integrity is maintained, but resin consumption increases and weight increases
Solution Approach 1:
The preform employs varying wall thicknesses in different regions: the neck portion has a first wall thickness, the upper body portion has a second wall thickness similar to the neck, and the lower body portion has a third wall thickness greater than the upper portion. This local differentiation allows resin to be concentrated where structural support is needed while reducing material usage in less critical areas, directly resolving the contradiction between minimizing resin consumption and maintaining structural integrity.
2Weight of moving object
If preform wall thickness is reduced to decrease weight, then resin consumption decreases, but heat transfer control during blow-molding becomes difficult
Solution Approach 1:
The differentiated wall thickness design allows different regions of the preform to manage heat transfer differently during blow-molding. The upper body portion with thinner walls (second wall thickness similar to neck) cools faster and can be protected from excessive heat, while the lower body portion with thicker walls (third wall thickness greater than second) provides thermal mass and structural support during the heating process. This resolves the contradiction by allowing weight reduction while maintaining heat transfer control through spatial differentiation.
3Loss of substance
If preform design is optimized for lightweighting, then resin consumption decreases, but dimensional stability during processing deteriorates
Solution Approach 1:
The preform design provides dimensional stability through strategic placement of thicker walls in the lower body portion (third wall thickness greater than second wall thickness) while maintaining lighter walls in the upper portion. The support ring at the neck base provides localized reinforcement. This spatial differentiation of material distribution maintains dimensional stability during processing while achieving overall lightweighting, resolving the contradiction between resin consumption and dimensional stability.
4Ease of manufacture
If uniform wall thickness is used throughout preform, then manufacturing simplicity is maintained, but production efficiency decreases due to longer cycle times
Solution Approach 1:
The varying wall thickness design enables differential cooling rates during blow-molding: the thinner upper body portion (second wall thickness) cools faster than the thicker lower body portion (third wall thickness). This allows the upper portion to solidify and stabilize earlier in the cycle, enabling faster ejection and shorter cycle times. The design maintains manufacturing simplicity through injection molding while improving production efficiency, resolving the contradiction between ease of manufacture and productivity.
Data Source
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.