Working together with Motan Colortronic Limited and technical collaboration with synthetic absorbable polymer suppliers, Fibre Extrusion Technology decided to develop this pioneering process after evaluating not just the machine and ancillary requirements but the challenges and requirements of the end product.
“A stitch in time saves nine”
Leeds based Fibre Extrusion Technology is a leading UK manufacturer and supplier of state of the art process technology and equipment for the man-made yarns and fibre extrusions industry, founded in 1998.
Flexibility is a key strength, with bespoke turn-key and standard installations provided, ranging from £25,000 to £2 Million.
In 2012 Fibre Extrusion Technology were approached by a market leader about the possibility of providing a turn-key solution for bio medical materials, such as absorbable polymers for use in sutures and medical devices.
Fibre Extrusion Technology Turn-Key Solution for Suture Manufacturing included:
- Guarantee suture manufacturing to USP or EP standards.
- From third party supply polymer through to coated braided suture materials.
- Selection of all raw materials; polymer, coating material, pigments etc.
- Specification and supply of all necessary hardware, extrusion, braiding etc.
- Supply of all ancillary equipment, drying, blending, calibration etc.
- Quality control.
- Process documentation.
- Commissioning, training and after sales technical support.
The end use of this yarn was for the manufacture of structures which is used to stitch tissue in the human body by doctors and surgeons.
The yarns used in suture production are described as multi-filament yarns; each yarn is made up of single filaments ranging from 6 to 72 depending on the final diameter. The yarns are braided together to produce the final suture. Sutures are manufactured to exacting standards according to United States Pharma copoeia and European Pharma copoeia regulations, they must achieve certain strength and diameter tolerances.
Uses include:
- Vascular implants such as vein or artery
- Soft tissue implants such as artificial corneas
- Hernia and abdominal wall repairs
- Hard tissue implants such as bone and joints
The first recorded use of fibres in medicine was mentioned in surgical papyrus nearly 4,000 years ago. A variety of materials are mentioned such as horse hair, leather strips and as more research has been completed, textiles have found their way into a variety of medical applications.
Working together with Motan Colortronic Limited and technical collaboration with synthetic absorbable polymer suppliers, Fibre Extrusion Technology decided to develop this pioneering process after evaluating not just the machine and ancillary requirements but the challenges and requirements of the end product.
The product requirements and challenges included:
- Material cost of over £2,000 per kg was to be used.
- Extreme low and consistent moisture content of material
- Special additives to be dosed consistently and accurately at 0.02% at varied extruder throughputs
- Special degradation profile to support the healing process
- Longitudinal elasticity of the product to provide strength to support the intra-abnormal pressure conditions.
- Non-toxicity, the fibre and manufacturing technique must be non toxic and free from contaminates.
- Porosity of the fibres structure, this determines the rate at which tissue will grow and encapsulate.
- Ideally, circular fibres are better encapsulated by human tissue than larger ones with irregular cross-sections.
Final production steps include:
In the latter part of 2012, after extensive R & D at the special lab unit at Fibre Extrusion Technology in Leeds, fitted with a proto-type Motan Colortronic material handling solution, a further development of the machine and material handling was required for the unique process.
Extensive discussions took place between the F.E.T. and Motan Colortronic technical teams and solutions were developed and implemented to resolve issues found during development testing and further customer requests.
These included:
- Host interface of the blender to the machine operator interface
- Further reduction on the final moisture content of the material
- Reduction in the re-absorption of material on the machine
- Improved consistency of dosing of the additive
- Reduction in energy usage of the whole process, (minimum w/kg usage)
- Automatic spin head adaption of the dosing equipment (extreme rapid changes)
How this was improved:
- Automatic dew point control and improved drying of the material via automatically controlled air flow to the hopper. This adapts to the variations of material and ambient conditions.
- Dehumidified air conveying of material from the dryer to a small machine hopper with minimum volume.
- Gravimetric loss in weight dosing which synchronously follows the extruder speed and automatically compensates for bulk density variation of the material.
- Variable speed dryer blower with a heat recovery system using return heat from the dryer back into the heater process.
- Special spin head switching software for the gravimetric loss in weight dosing unit to cope with rapid extensive changes to the machine throughput.
- Wireless interface software to the machine interface via TC/IP for complete system integration.
- In addition the FET technical team were given extensive training and documentation to enable them to support and train the customer on site as and when required.
Since this development was completed the initial line was installed and delivered to the complete satisfaction of the customer. Further lines were supplied to customers around the world with the complete Motan Colortronic range of ancillaries and are supported by the worldwide Motan Colortronic Group.