Dual-Side Molding for Packaging Opening Devices
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Solution Overview
Problem
Current methods for forming opening devices on sheet packaging material for pourable food products are limited in increasing output rate and reducing machine footprint, necessitating improvements in the injection molding process.
Innovation Solution
An apparatus and method that utilize a molding unit with first and second molds to form a one-piece opening device comprising a confetti portion and pouring element, where the molten plastic material is fed and pressed to fill a mold cavity, allowing for better control and flexibility in the process, reducing the need for high pressure and enabling more efficient production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional injection molding operations are used to form opening devices on packaging material, then the opening devices can be produced and applied, but the output rate is limited and the machine footprint is large
Solution Approach 1:
The mold is divided into two separate molds (first mold and second mold) positioned on opposite sides of the packaging material. This segmentation allows each mold to operate independently and simultaneously form different portions of the opening device, thereby increasing output rate while keeping each individual mold compact in size.
Solution Approach 2:
The molding operation is transitioned from a single-sided vertical injection approach to a dual-sided horizontal arrangement where molds are positioned on opposite sides of the packaging material web. This dimensional change allows for more efficient use of space and enables simultaneous molding operations without requiring a large single-sided mold structure.
2Manufacturing precision
If high pressure is used in the injection molding process to fill the mold cavity, then the molten plastic material can be forced to flow and fill the cavity, but the process requires more energy and creates higher stress on the packaging material
Solution Approach 1:
A dose of molten plastic material is fed into the mold cavity before the molds are closed. This intermediary step allows the plastic material to be pre-positioned in the cavity, reducing the pressure required to fill the mold. The plastic material acts as a mediator that facilitates easier flow and distribution within the cavity during the molding process.
Solution Approach 2:
The molten plastic material is fed and pressed to fill the mold cavity in a controlled sequence before the molds are fully closed. This preliminary action allows the plastic material to distribute itself more evenly and reduces the peak pressure required during the final molding stage, thereby reducing stress on the packaging material.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances the efficiency and quality of forming opening devices, allowing for higher output rates and reduced machine footprint, while maintaining the integrity of the packaging material.
Implementation Method 1
molten plastic material is fed and pressed to fill a mold cavity
Data Source
AI summary
An apparatus for forming an opening device on a receiving portion of a sheet packaging material for packaging pourable food products comprises a molding unit having a first and a second mold selectively set in an open configuration, in which they are spaced from one another to allow feed of the packaging material therebetween, and in a closed configuration, in which they cooperate with faces of the packaging material and delimit a closed mold cavity housing the receiving portion of the packaging material and adapted to be filled with molten plastic material to define, when the plastic material sets, the opening device. The apparatus further comprises feeding device to feed molten plastic material to the molding zone in the open configuration of the first and second mold, and pressing device exerting pressure on the dose to force it to fill the mold cavity and to form the opening device.