Two-Part Plastic Preform for Drug Applicator Sealing

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Solution Overview

Problem

The existing one-piece plastic design for active substance applicators complicates filling and sealing, leading to difficulties in industrial production and filling, and results in leaks during transport due to kinking of attachment elements.

Innovation Solution

A two-part plastic preform set comprising a lower part with a receiving space and a cover part, where the lower part has a one-piece application tube closed at its end with an attachment element, and both parts have sealing edges with attachment plates and energy directors for improved sealing and ultrasonic welding, allowing for precise filling and sealing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a one-piece plastic blank is used for the active substance applicator, then manufacturing cost is reduced and production is simplified, but filling and sealing become difficult due to the geometric arrangement of the application tube

Engineering Contradiction:
Improvemanufacturing cost and production simplicityVSAvoidfilling and sealing efficiency
Core Design Contradiction:
Ease of manufactureVSProductivity

Solution Approach 1:

The invention divides the one-piece plastic blank into two separate parts: a lower part containing the application tube and a cover part. This segmentation allows the filling process to access the receiving space without obstruction from the application tube, while maintaining the geometric arrangement needed for application. The two parts are subsequently sealed together to form the complete applicator.

Inventive Principle:
Principle #1Segmentation

2Strength

If a one-piece plastic blank is used, then structural integrity is improved, but the application tube covers the sealing edge, denying access for applying counter-pressure during sealing

Engineering Contradiction:
Improvestructural integrityVSAvoidsealing process accessibility
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

By separating the structure into a lower part and a cover part, the invention creates an open access path to the sealing edge during the sealing process. The counter-pressure device can apply force to the sealing edge of the lower part without obstruction from the application tube, ensuring proper sealing before the parts are joined.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention applies counter-pressure to the sealing edge before the parts are permanently joined together. This preliminary action ensures that the sealing surface is properly prepared and sealed while still accessible, preventing leakage before the final assembly is complete.

Inventive Principle:
Principle #10Preliminary action

3Productivity

If the applicator is filled and sealed fully automatically, then productivity is increased, but correct insertion of the one-piece plastic blank into filling and locking devices becomes difficult

Engineering Contradiction:
Improveautomatic filling and closing speedVSAvoidinsertion accuracy into filling device
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

The two-part design simplifies the insertion process into the filling device. Only the lower part needs to be inserted, which has a simpler geometry without the complex application tube arrangement that obstructed access in the one-piece design. This enables fully automatic filling and sealing operations with high precision and speed.

Inventive Principle:
Principle #1Segmentation

4Strength

If attachment elements have sufficient wall thickness for strength, then structural reliability is improved, but they become prone to kinking during transport

Engineering Contradiction:
Improveattachment element strengthVSAvoidleak prevention during transport
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The invention optimizes the wall thickness parameter of the attachment element to a specific range (0.1-0.5 mm) that balances structural strength with flexibility. This parameter change prevents kinking during transport while maintaining sufficient strength for the application, eliminating the leakage problem associated with thicker, more rigid attachment elements.

Inventive Principle:
Principle #35Parameter changes

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

Enables efficient, high-speed industrial production of active substance applicators with precise dosing and 100% sealing, significantly reducing production time and preventing leaks during transport by facilitating automatic filling and reliable sealing.

Implementation Method 1

counter-pressure must be applied to the sealing edge of the lower part, which pressure extends over the entire sealing surface

Methodology Applied
Scientific EffectPressure: Pressure Increase

Implementation Method 2

closed at its free end with a closure formed in one piece over an attachment element

Methodology Applied
Scientific EffectMechanical Fastening: Mechanical Fastener

Data Source

PatentEP3248646B1Two-part plastic blank set
Publication Date: 2021.02.17 MATTERN CLAUDIA
  • EP3248646B1 patent drawingFigure 1~2

AI summary

The present invention relates to a two-part plastic blank set for manufacturing a drug applicator for storing a unit dose of a drug preparation and for administering this unit dose into the human nose, wherein the plastic blank set comprises a lower part and a lid part separate from the lower part, wherein the lower part has a receiving chamber enclosed by a sealing rim and a one-piece molded application tube extends from the receiving chamber, the application tube being closed at its free end with a closure molded one-piece over an attachment element, wherein the attachment element has a wall thickness of 0.1-0.5 mm, preferably 0.2-0.3 mm, and wherein the lid part is sized to completely cover the receiving chamber when placed on the lower part and has a sealing rim that can be sealed to the sealing rim of the lower part.as well as a drug applicator that can be produced from it.