Barbed Surgical Thread Manufacturing via Molding and Stretching
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Solution Overview
Problem
Existing surgical threads with attachment means suffer from weak hooking mechanisms that can detach during implantation, poor tissue penetration, and increased discomfort due to the thickness and rigidity of the threads, as well as lengthy manufacturing processes.
Innovation Solution
A method for manufacturing a surgical thread with a cylindrical support part and evenly distributed barbs, where the raw yarn is molded with inclined barbs and then stretched to alter their angle and length, ensuring strong attachment and reduced thickness for improved tissue integration without compromising tensile strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If attachment means are formed by removal of material at the level of ridges, then hooking means are created, but the sheath is weakened creating points of potential breakage
Solution Approach 1:
Instead of removing material to create attachment means (barbs), the invention forms the barbs by adding or redistributing material through a molding process. The mold impressions directly shape the barbs on the support part surface, inverting the conventional approach of material removal and thereby preserving the structural integrity of the support part while creating effective attachment means.
2Stability of the object's composition
If a core-sheath structure with different materials is used, then rigidity is well-controlled, but the wire diameter cannot be less than 0.5mm
Solution Approach 1:
The invention changes the material parameters by using a single polymer material for the support part with specific mechanical properties (tensile strength 10-50 MPa, elongation at break 10-50%). This allows the support part to achieve the necessary rigidity control while being manufacturable in thinner diameters (less than 0.5mm) compared to traditional core-sheath structures.
3Reliability
If micro-teeth are formed by heating and pressing in overflow mold, then attachment means are created, but the manufacturing process takes 24-48 hours
Solution Approach 1:
The invention replaces the complex thermal-mechanical process (heating and pressing in overflow mold for 24-48 hours) with a simpler mechanical molding process. The mold is pressed against the support part to directly form barbs through mold impressions, eliminating the need for prolonged heating and pressing cycles while achieving reliable attachment means formation.
4Length of moving object
If the wire is stretched to multiply length by 2-10 times, then oriented wire is created, but the barbs become fine and may turn around during placement
Solution Approach 1:
The invention performs preliminary action by forming the barbs with appropriate dimensions and orientation (30-60 degree angle) during the initial molding process, before any stretching occurs. The mold impressions are designed to create barbs that maintain their effectiveness even after the support part is stretched to multiply its length by 2-10 times, preventing them from turning around during placement.
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 method results in a surgical thread with enhanced tensile strength, reduced risk of detachment, improved tissue penetration, and ease of placement, while maintaining a thin diameter for comfort and efficient handling.
Implementation Method 1
step c) of heating the portion of raw wire fitted with pins is provided after step a), and before or simultaneously with step b)
Implementation Method 2
the drawing of the raw wire portion (10) is such that its length Li is multiplied by at least 2
Data Source
Figure 1~3
Figure 4a~6
Figure 7~8
AI summary
Method for the manufacture of a portion of surgical thread (1) for the purposes of reconstruction in the field of surgery and/or anaesthetic medicine, the portion of surgical thread (1) comprising a support portion (2), in particular cylinder-shaped, and a plurality of needles (3) protruding from the support portion (2) and evenly distributed on the support portion (2), said portion of surgical thread (1) having a length (Lf), said method comprising the following steps: • a). obtaining a portion of raw thread (10) of length (Li), with Li<Lf, provided with needles (3) produced by in-mould needle moulding (M) comprising a plurality of impressions (EP) for forming the needles (3), • b). stretching the raw thread portion (10) so that the length (Li) thereof is multiplied by at least 2, the portion of surgical thread (1) having, by the end of this step, the length (Lf).