Recyclable Polyethylene Stand-Up Pouch With Two-Layer Sealant
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Solution Overview
Problem
Stand up pouches (SUPs) made from a combination of PET and PE are difficult to recycle due to the different materials of construction, and the inclusion of recycled polyethylene (r.PE) can reduce the effectiveness of the sealant layer in the film structure.
Innovation Solution
A laminated structure is developed using polyethylene webs with specific layer compositions, including HDPE, MDPE, LLDPE, and recycled polyethylene, with a two-layer sealant system to enhance seal effectiveness and ensure recyclability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a laminate of PET and PE is used to prepare SUP packages, then the structural integrity and barrier properties are improved, but the recyclability deteriorates due to the different materials of construction
Solution Approach 1:
The patent applies homogeneity by replacing the heterogeneous PET/PE laminate structure with a homogeneous polyethylene-based laminate structure. All layers are made from polyethylene materials (HDPE, LLDPE, MDPE, or recycled PE), ensuring material uniformity throughout the pouch construction. This homogeneous composition maintains the required structural integrity while enabling the entire pouch to be processed together in recycling facilities, thereby resolving the recyclability issue caused by material incompatibility in the original PET/PE laminate.
Solution Approach 2:
The patent utilizes composite materials by creating a multi-layer polyethylene laminate structure where different polyethylene types (HDPE, LLDPE, MDPE, recycled PE) are combined in specific configurations. Each layer serves a specific function: HDPE provides structural rigidity, LLDPE provides toughness and sealability, and recycled PE provides sustainability. This composite approach allows the pouch to maintain enhanced mechanical properties and barrier performance while remaining fully recyclable as a single-material construction.
2Ease of manufacture
If recycled polyethylene is used in the SUP construction, then the environmental sustainability is improved, but the sealant layer effectiveness deteriorates
Solution Approach 1:
The patent applies segmentation by dividing the sealant structure into multiple distinct layers: a primary sealant layer made from recycled polyethylene and a secondary sealant layer made from virgin polyethylene. This segmentation allows each layer to perform its specific function - the recycled layer provides sustainability and basic sealing, while the virgin layer ensures reliable seal performance. The layered segmentation resolves the contradiction by preventing the recycled material from compromising overall seal effectiveness.
Solution Approach 2:
The patent uses composite materials by creating a multi-layer sealant structure combining recycled polyethylene and virgin polyethylene in specific configurations. The sealant structure typically includes a layer of recycled PE (0.5-2.0 mils) combined with a layer of virgin PE (0.2-0.5 mils). This composite sealant design allows the pouch to achieve both environmental sustainability through recycled content and reliable seal performance through the complementary properties of virgin polyethylene, which provides consistent sealing characteristics.
3Device complexity
If a single-layer sealant structure is used, then the manufacturing complexity is reduced, but the seal effectiveness deteriorates when recycled polyethylene is present
Solution Approach 1:
The patent applies segmentation by dividing the sealant function across multiple layers rather than relying on a single-layer structure. The sealant structure is segmented into at least two layers: a recycled polyethylene layer and a virgin polyethylene layer, each with specific thickness ranges. This segmentation allows the system to achieve reliable seal performance despite the presence of recycled material, as each layer contributes specific properties that compensate for the limitations of using recycled PE alone.
Solution Approach 2:
The patent uses an intermediary approach by introducing a virgin polyethylene layer as a mediator between the recycled polyethylene layer and the sealing process. This intermediary layer of virgin PE provides consistent thermal and rheological properties that facilitate reliable seal formation, while the recycled PE layer provides sustainability benefits. The intermediary virgin layer mediates the sealing process to ensure effectiveness despite the variable properties of recycled materials.
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
The laminated structure achieves enhanced seal effectiveness while maintaining recyclability, utilizing a multilayer film design that improves rigidity, impact resistance, and optical properties, allowing for efficient use of recycled materials.
Implementation Method 1
B.3.1) a sealant skin layer including a polyethylene sealant, and B.3.2) a layer adjacent to the sealant skin layer including a polyethylene
Implementation Method 2
A laminated structure is prepared by laminating a first polyethylene web to a second polyethylene web
Data Source
AI summary
In some embodiments a Stand Up Pouch (SUP) is prepared using a polyethylene structure having a first web and a second web. The webs are laminated together to form the polyethylene structure that is used to prepare the SUP. One web contains a layer of recycled polyethylene (r.PE). In some instances, the use of r.PE has been observed to reduce the effectiveness of the sealant layer of the overall structure. In some embodiments, the SUP disclosed herein has a two layer sealant system to mitigate this problem.