TPE for Hydrophilic seal into Construction aera Pascal Gruyer ELASTO Müller Innov Days Lyon, 27 September 2012
What is Dryflex WS?
A range of flexible materials, based on SEBS, that contain hydrophilic particles. They swell at a controlled rate and percentage when immersed in water. When there is no longer water present the compound shrinks back to its original size.
How do they work?
The active hydrophilic ingredient is compounded into the TPE at the time of manufacture Upon contact with water Dryflex WS will expand uniformly, at a controlled rate and percentage When there is no longer water present Dryflex WS shrinks back to its original size
Applications
Building & Construction Pools, Ponds & Tank Liners Tunnel Lining Waterstops Marine Cables & Optical Fibres Plumbing Automotive Seals
The Dryflex WS range
Dryflex WS Nomenclature. Grades are quoted based on hardness and percentage swell level. Recommended process techniques are included to differentiate between Moulding and Extrusion. Variations are indexed by the last 3 digits to include colour, water chemistry and variant. Dryflex WS 40M350-001.
Dryflex WS Nomenclature. WS 40E350-011 Water Swell trade name. WS 40E350-011 Hardness on Shore A scale. WS 40E350-011 Designed processing methods: M = Moulding E = Extrusion WS 40E350-011 Percentage volume swell. WS 40E350-011 Colour. WS 40E350-011 Water Chemistry: 0 = Neutral ph 1 = Saline WS 40E350-011 Variant.
Initial Development Hardness Water Swell % Comments 40 Shore A 350 / 450 / 850 Extrusion 30 Shore A 500 Moulding 25 Shore A 165 (350) Saline 73 Shore A 150 Extrusion Stage Two Hardness Water Swell % Comments 25 Shore A 950 Extrusion The Future Hardness Water Swell % 35 Shore A 550 Extrusion 25 Shore A 450 Extrusion???
Dryflex WS % Volume Swell
Processing
Extrusion Guidelines 20-30 Shore A 80-90 C 80-90 C 90-100 C 90-100 C 110-120 C 35-45 Shore A 100-110 C 100-110 C 110-120 C 110-120 C 130-140 C
Injection Moulding Guidelines 100-110 C 110-120 C 120-130 C 130-140 C 15-40 C
Test results
Dryflex WS. Long term swell characteristics.
Effect of Salt Concentration on Dryflex WS.
TPE for single-use syringe plunger seals Pascal Gruyer ELASTO Müller Innov Days Lyon, 27 September 2012
Contents Requirement profile TPE plunger seals characteristics and comparison vs rubber - Sealing and plunger movement control - Processing - Raw material * Medical grade TPE characteristics * Compounding with colour * Change control - In-house production advantages
Plunger seals for single-use syringes Requirement profile: Sealing function Consistent dosage control in siliconized barrels Low specific gravity Medical grade raw material with long-term availability In-house production = control of supply and quality Cost-efficiency Common material: butyl rubber
Sealing and plunger movement control For balance between sealing ability and sliding force in siliconized barrels: * Medical grade TPE in the hardness range 45-60 ShA Note: Low specific gravity compared with rubber
Processing aspects THERMOSET RUBBER FABRICATION GUM RUBBER FILLERS,OILS ADDITIVES, ETC MIXING SHAPING VULCANIZE FINAL PRODUCT NEED TO R/C SCRAP SCRAP SCRAP TPE FABRICATION TPE SHAPING FINAL PRODUCT Short cycle time No trimming needed Recyclable material
Medical grade TPS Raw materials High biocompatibility status requirements should be set up for the raw materials High biocompatibility status of the raw materials high biocompatibility status of the TPE The ELASTO raw material selection policy for Mediprene: - SEBS/SBS from a series of rubbers where representative grades have passed USP Class VI - Medicinal white oil, complying with EP for light liquid paraffin - Medical grade plastic that has passed USP Class VI - Medical grade colour masterbatch made from components that have passed USP Class VI or corresponding parts of ISO 10993
Medical grade TPE - Cleanliness Thorough cleaning procedures Following the material flow from mixer and feeding area to the box with finished goods Check-list to be followed and double-signed No material release without cleaning checklist properly filled-in and signed Special precautions in risk areas Closed mixers Curtain system preventing from contamination in the box Operators wear clean clothes, hairnets and gloves
Medical grade TPE - Cleanliness Cleaning procedures and precautions based on risk analysis Must be done for each specific compounding line intended for medical production Should be done by a cross-functional group including for example production operators, maintenance, development and quality staff The same level of cleanliness is required also in production of all raw materials, colour masterbatch included! Documented thorough cleandown procedures based on risk assessment required Picture: Dedicated materials and support for the medical and pharmaceutical sectors, Clariant International Ltd
Medical grade TPS - Traceability Three kinds of traceability are needed Raw material traceability Link: finished goods raw material lot numbers Production parameter traceability Link: finished goods production parameters Material properties traceability Link: finished goods material properties
Medical grade TPS - Reproducibility Reproducibility is depending on: Raw materials Variances in raw material properties, even within the specification for each individual raw material may cause unfavorable variances in the properties of the compound Production equipment Modern high precision equipment with gravimetric feeders and advanced process monitoring systems is needed
Medical grade TPS - Reproducibility Reproducibility is depending on: Strict and well documented procedures Medical standards like ISO 13485 form a rigid framework for procedures and documentation Reproducibility and biocompatibility: Every compound batch should have the same biocompatibility status Raw materials need to be thoroughly selected!
Colouring during compounding Colour masterbatch fed with high accuracy - Correct and reproducible addition level Excellent dispersion Colour measurements - Ensures colour reproducibility Compound ready for use - No additional steps for moulder or extrusion company - Compounder to ensure supply of colour masterbatch
Change control Customer requirements Always use the same raw material in the same quantities Always produce the material under the same conditions on the same line Notification in due time if the composition of a raw material is changed Notification in due time if a certain raw material will no longer be available ELASTO approach: Always use the same raw material in the same quantities Always produce the material under the same conditions on the same line Close cooperation with suppliers to solve product change notification and supply during the time required for the qualification of a replacement commpound 2-year availability of the unchanged product based on customer forecast
In-house production possibilities Easier to integrate production of TPE plunger seals in existing production of injection moulded barrels and plungers than rubber Allows the medical customer full control of all components for the 3-part single use syringe Change from rubber to TPE is a good opportunity for optimizing plunger design material saving
Thank you for your attention!! Contact details: Pascal Gruyer Commercial Manager - France Phone: +33 (0) 160 431 717 Mobile: +33 (0) 607 447 383 E-mail: pascal.gruyer@elastotpe.com