Polymer-Coated Coreless Roll for Reopenable Hollow Passageways
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Solution Overview
Problem
Coreless rolls of absorbent sheet products face issues with collapsing, lack of flexibility, and difficulty in reopening the axial hollow passageway after compression, leading to increased storage costs and potential sewage clogging.
Innovation Solution
A coreless roll with a continuous web of absorbent material coated with a specific polymer that has a low glass transition temperature and high melting point, applied only to the second end, which provides excellent resistance to collapsing and flexibility, allowing the roll to be compressed and easily reopened, and ensures disintegrability in water.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a binder is applied to the first inner turns to maintain the axial hollow passageway, then the passageway stability is improved, but the roll loses flexibility and elasticity
Solution Approach 1:
The coating composition is applied locally only to the first inner turns (the core region) of the absorbent sheet web, leaving the outer turns uncoated. This creates a gradient structure where the inner core has enhanced stability while the outer layers maintain flexibility and elasticity, resolving the contradiction between passageway stability and roll flexibility.
Solution Approach 2:
The invention uses a composite structure combining the absorbent sheet material with a polymer-based coating composition. The coating provides structural support and stability to the core region while the underlying absorbent material and uncoated outer layers preserve flexibility. This composite approach allows simultaneous achievement of stability and adaptability.
2Volume of moving object
If the roll is compressed to reduce storage space, then storage costs are reduced, but the axial hollow passageway collapses and becomes difficult to reopen
Solution Approach 1:
The coating composition is applied in advance to the first inner turns before compression. This pre-applied coating acts as a cushioning or support structure that maintains the axial hollow passageway definition during compression and facilitates easy reopening after compression, preventing permanent collapse.
Solution Approach 2:
The coating composition undergoes parameter changes - it is applied in a liquid or semi-liquid state and then dried to form a stable, flexible film. This transformation allows the coating to provide structural support during compression while maintaining the ability to flex and reopen the passageway when needed.
3Stability of the object's composition
If an aqueous adhesive is applied to the first inner turns, then the turns are cohesively maintained, but the adhesive is difficult to dry and leaves the material sticky
Solution Approach 1:
The coating composition uses water as a temporary carrier that evaporates completely during drying. The water serves its purpose during application and then disappears, leaving no residual stickiness. This approach replaces persistent aqueous adhesives with a volatile carrier that leaves no harmful residue.
Solution Approach 2:
The coating composition utilizes phase transition of water from liquid to vapor during the drying process. This phase change allows the aqueous-based composition to be applied easily in liquid form and then completely evaporate, leaving the polymer coating without residual moisture or stickiness.
4Strength
If the delamination force between first inner turns is increased by binder application, then the core structure is strengthened, but the tear strength of the absorbent material is exceeded
Solution Approach 1:
The coating composition parameters (polymer type, concentration, application amount) are optimized to achieve the right balance. The coating provides sufficient cohesion between turns while maintaining delamination forces below the tear strength threshold of the absorbent material, preventing damage during normal use.
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 solution effectively prevents collapsing, allows full-length use of the absorbent material, reduces storage costs, and prevents sewage clogging by maintaining the axial hollow passageway and ensuring the roll can be easily compressed and decompressed without damaging the material.
Implementation Method 1
a coating composition comprising a polymer having: (i) a glass transition temperature lower than 20° C., or lower than 15° C., or lower than 10° C., or lower than 5° C., or lower than 0° C., or lower than −5° C., or lower than −10° C.
Implementation Method 2
the roll must hence exhibit flexibility and a certain level of elasticity, which means that the roll can be returned to its cylindrical form while reopening the axial hollow passageway
Implementation Method 3
a coating composition comprising a polymer having: (i) a glass transition temperature lower than 20° C., or lower than 15° C., or lower than 10° C., or lower than 5° C., or lower than 0° C., or lower than −5° C., or lower than −10° C.; and (ii) a melting point greater than 20° C., or greater than 25° C., or greater than 30° C., or greater than 35° C., or greater than 40° C., or greater than 45° C.
Data Source
AI summary
A coreless roll of an absorbent sheet product, such as napkins, toilet paper, towels etc., including a spirally wound continuous web of absorbent material having a first end and a second end and a coating composition comprising a specific polymer coated onto the second end is disclosed. The coreless roll has excellent resistance to collapsing, as well as excellent flexibility and elasticity. Moreover, the coreless roll has excellent disintegrability in water and can be used along its whole length. Also disclosed is a process for the manufacture of the coreless roll.