Fundamentals of Water Repellency Testing.ppsx
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Water Repellency testing
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Fundamentals of Water Repellency Testing.ppsx
- 1. 1 Fundamentals of Water Repellency Testing The webinar will start shortly
- 2. 2 Presenters Alex Mitchell Presenter Kathryn Hawkes Organizer Sara Williams Technical Specialist
- 3. 3 Presenters Alex Mitchell Presenter Charlotte Law Organizer Sara Williams Technical Specialist
- 4. Housekeeping Your microphone will be muted Use the questions box A copy of the webinar will be sent to you
- 5. In this webinar… • What is water repellency testing and why is it important? • The role of water repellency in the layer system • A general overview of the test • How water repellency is measured • Issues that can impact your results • Using a more sustainable approach
- 6. What is water repellency testing and why is it important?
- 8. 8 The Great Outdoors More and more of us are heading outdoors for exercise
- 9. 9 Comfort Performance textiles and clothing keep the wearer comfortable in a range of different activities
- 10. 10 Safety Performance textiles and clothing keep the wearer safe in a range of different environments
- 11. 11 It’s not just garments We have higher expectations for other items to keep water out
- 12. The role of water repellency in the layer system
- 13. 13 • Base layer • Mid layer • Outer protective shell layer A three layer system is often used for outerwear
- 14. 14 For ultimate comfort, an outer layer must have a high level of water resistance and a high level of water vapour permeability
- 15. 15 The outer layer itself can use a layered construction for maximum performance
- 16. 16 Outer layer performance testing Water repellency Water resistance Wet abrasion Breathability Air permeability UV resistance
- 17. • Tests for water resistance/repellency: • Static repellency tests: • Water contact angle – Goniometer system – sessile drop method and contact angle hysteresis method • BS EN ISO 23232 Aqueous liquid repellency. Water/alcohol solution resistance test • AATCC 193 Aqueous liquid repellency. Water/alcohol solution resistance test • BS EN ISO 14419 Textiles – Oil repellency. Hydrocarbon resistance test • AATCC 118 Oil repellency: Hydrocarbon resistance test. • Dynamic repellency tests: • BS EN ISO 4920 Textile fabrics – Determination of resistance to surface wetting (spray test) • AATCC 22 Water repellency – Spray test • BS EN ISO 29865 Determination water repellency of fabrics by the Bundesmann rain-shower test • Water resistance tests: • ISO 22958 Textiles – Water resistance – Rain tests: exposure to horizontal water spray • BS EN ISO 18695 Textiles – Determination of resistance to water penetration. Impact penetration test • AATCC 42 Water resistance: Impact penetration test • BS EN 20811 ISO 811 Textiles – Determination of resistance to water penetration – Hydrostatic pressure test • AATCC 127 Water resistance: Hydrostatic pressure test • AATCC 35 Water resistance: Rain test • NWSP 80.6 Water resistance (hydrostatic pressure) • Tests for water vapour permeability: • ASTM E96 Standard test method for water vapour transmission of materials • ASTM F1868 Standard test method for thermal and evaporative resistance of clothing using a sweating hot plate • BS EN ISO 15496 Textiles – Measurement of water vapour permeability of textiles for the purpose of quality control • BS EN ISO 11092 Textiles – Physiological effects – Measurement of thermal and water-vapour resistance under steady-state conditions (sweating guarded-hotplate test) • AATCC 204 Water vapor transmission of textiles: Method overview and recommended applications • Hohenstein Watson method • EMPA Sweating cylinder method • Manikin methods for water vapour permeability: • ASTM F 2370 Evaporative resistance of clothing using a sweating manikin • Tests for air permeability: • BS EN ISO 9237 Textiles – Determination of permeability of fabrics to air • ASTM D 737 Standard test method for air permeability of textile fabrics Testing the Outer Layer: Relevant Standards
- 18. A general overview of the ISO 9865 Bundesmann Test
- 19. 19 Preparation is required for both the instrument and your specimen fabric
- 20. 20 Clamp your specimen and ensure the drainage valves are closed
- 21. 21 The test takes 10 minutes and aims to simulate rainfall and real life use
- 22. 22 Once 10 minutes has passed, you can move onto the assessment part of the test
- 23. How water repellency is measured
- 24. 24 Surface water repellency is visually assessed
- 25. 25 Grade 4/5
- 26. 26 Grade 3
- 27. 27 Surface water repellency is visually assessed Grade 1
- 28. 28 Resistance to water absorption is evaluated by weighing the fabric
- 29. 29 Resistance to water penetration is determined by measuring water collected in the cups
- 30. Issues that can impact your results
- 31. 31 Ensure your fabric is clamped correctly
- 32. 32 Move quickly when assessing results to stop any of the stages progressing further
- 35. A sustainable approach to water repellency testing
- 36. 36 Sustainability is one of the biggest issues facing brands and manufacturers right now
- 37. 37 Our aim: to prove re-circulating water does not impact results
- 38. 38 We tested 3 different fabrics 150 times with recirculated water
- 39. 39
- 40. Key Takeaways
- 41. The Bundesmann test is growing in popularity, mainly due to changing consumer behaviour There is a more sustainable option for this type of test, which is time, energy and resource intensive The three steps for assessment for this test method help to paint a full picture of the fabric’s performance
- 42. Further Reading • Matt Fuller and Dr MarkTaylor, members of Leeds University’s Performance Clothing Group, explore waterproof breathable fabrics in this article: https://www.ukclimbing.com/articles/features/waterproof_breathable_fab ric_-_explained-4556 • Camotrek, a website about exploring the outdoors, looks at the differences between water resistance, repellence and proof: https://camotrek.com/blogs/news/waterproof-and-water-repellent- fabrics/ • Rei, an outdoorwear co-op, shares an oversight on how rainwear works: https://www.rei.com/learn/expert-advice/rainwear-how-it-works.html • We have published a Lab Manager’s Guide to PerformanceTesting, which gives an overview into all the different elements: https://www.james-heal.co.uk/the-lab-managers-guide-to-performance- testing/
- 44. 44 Exploring what makes a good wicking fabric Wednesday 21st April 1-2pm Eastern/6-7pm GMT Thursday 22nd April 8-9am GMT
Editor's Notes
- Before we start we have a bit of housekeeping to cover. Everyone's microphone will be muted for the presentation, so if you have a question please type it into the question box. We will email you a copy of the slides, and a recording of the webinar, so you can revisit any section you need to.
- In this webinar, we will cover: What is water repellency testing and why is it important? The role of water repellency in the layer system A general overview of the test How water repellency is measured Issues that can impact your results Using a more sustainable approach Let’s start the presentation.
- First we are going to take a look at water repellency and why the need for this type of testing has grown.
- A good place to start with water repellency is defining some of the key terms, as the terms on this slide are often used interchangeably but mean different things. Described in the dictionary as ‘resisting though not entirely preventing the penetration of water’, water resistance offers a low level of protection. When a garment is described as water resistant, it is often due to the composition of the fabric rather than any special properties, as tightly woven fabrics are used to prevent water from getting through – polyester would be a good example of this. If you went camping in a water resistant tent and it rained heavily overnight, you would wake up wet in the morning. Waterproof is the other end of the scale, defined as ‘impenetrable to water’, providing the most protection from rainfall and snow. Waterproof fabrics are either inherently waterproof, or are created by adding a waterproof treatment on both sides of the fabric. Although excellent in extreme weather conditions, the nature of waterproof garments means that as water cannot get in it also cannot get out. This means that if you sweat in a waterproof garment, it is trapped, which can be uncomfortable for the wearer. Water repellency describes water beading on the surface of a material to prevent the water penetrating. This is often achieved through combining membranes or coatings with tightly woven fabrics, we commonly see the use of DWR, or Durable Water Repellent, coatings on fabrics to achieve repellency. The benefit of water repellent garments is their breathability – the fabric remains porous making them permeable to air, water vapour and liquid water - which makes them more comfortable to the wearer. This is what the bundesmann is testing – fabrics and garments that provide protection from intermittent rain. The term ‘Waterproof breathable’ is becoming more commonly used, and has some overlap with water repellency though requires a higher level of waterproofing. There is some debate as to where these terms would fall if you were to put them on a scale, and we will recommend some further reading at the end of the webinar if this is of interest to you.
- Why is water repellency testing important? A big part of the answer to this is driven by a change in consumer behaviour. We have seen an increase in athleisure for many years now, the sportswear industry has influenced mainstream fashion, and innovations in technology has led to improvements in functionality. A shift to sportswear being worn day to day means that almost anyone is a potential athleisure consumer. For outdoorwear in particular, though, the onset of a global pandemic has increased demand even further. With the long term closure of gyms, swimming pools and exercise classes, more and more of us are heading outdoors to exercise. More people are holidaying in their home country as well, which for a lot of us means swapping swimwear for cagoules and walking trousers. A Market Analysis report found the waterproof breathable textiles market was valued at 1.7 billion dollars in 2019, and is expected to have a compound annual growth rate of 6.6% over the next 6 years. A combination of the necessity to exercise outdoors and an increase in awareness of the fitness benefits of sports has increased demand. Buying the right clothing and equipment to undertake new outdoor activities is viewed as an investment, and so consumer expectations are high where these garments are concerned.
- Outdoor wear can be expensive, and for many consumers this investment comes with an expectation around longevity. Functional textile testing, such as abrasion, pilling, tear strength and burst strength can play a part in this, though the garment is also expect to keep water out for its lifespan. Consumers also expect comfort from their garments. Comfort is influenced by fit factors as well as fabric properties such as stretch and recovery, and thermal and moisture management properties, but for outdoor wear in particular comfort is about finding a balance between keeping water out and letting sweat escape. The human body generates heat and is constantly trying to regulate the core temperature between 36.5 – 37.5°C . To cool, the body sweats, which evaporates from the skin taking heat away, cooling our body. The textile garment can either help or obstruct sweat evaporating directly linked to comfort.
- Safety is also a really important feature – arguably the most important feature that users can expect from their performance garments. Performance clothing can help to protect a wearer in a range of different environments and climates. This can achieved by selecting fabrics with properties such as high water resistance, good breathability, good insulation or UV protection for example. The exact combination of properties required will vary according to the demands of the environment and the activity. There are risks involved with getting the breathability of water repellent fabrics wrong, mainly that they can trap sweat and cause the wearer to overheat. This might not seem like an issue for a quick walk around the park, but for wearers on long hikes this could cause serious health risks.
- Our expectations as consumers extend beyond garments, as it is becoming more common to buy accessories such as back packs for their water repellent or water proof qualities. This is another consideration for brands and manufacturers, and can often involve additional testing to establish what role seams, zips and pockets play. The focus of this webinar is primarily garments, but some of the testing and methods used can be applied to other items.
- To understand the testing we need to undertake, it is important to understand the make up of a garment, and the role that layers play.
- In sportswear, and especially outdoor wear, a three layer clothing system is often advocated, with each layer in the system performing a different function which complements the whole for maximum comfort. A layering system typically includes: A Base layer (commonly referred to as the “second skin”) – this layer is worn directly next to the skin and should effectively manage liquid moisture from perspiration This layer is usually tested in two ways, tests for absorption/distribution of liquid moisture within a fabric; and tests for rate of drying i.e. evaporation of liquid moisture from a fabric. We have covered this layer extensively in our Wicking and Dry Rate Testing webinars, and also have some webinars coming up about wicking. Mid layer – this layer provides majority of insulation by trapping and storing warmed air For maximum thermal insulation this layer should ideally have high loft, either in the pile of the fleece or the plume of down feathers, in order to maximize the amount of air trapped within the system for retention of heat. Testing for thermal insulation is typically performed by heated hot plate or thermal manikin methods. Finally, the Outer protective shell layer – This layer must provide protection against environmental factors such as wind, rain, fire, tear and abrasion, and this is the layer we are focusing on for our water repellency testing.
- The outer layer garment provides protection against the external environment. In the context of sports and outdoor wear this typically means protection against foul weather conditions namely rain, snow and wind. Anyone attending this webinar from the UK might have had a combination of all these types of weather just in the past weekend. For the outer layer to be most effective, it should demonstrate high levels of water resistance without impeding the comfort of the wearer. This is where the challenge of the outer layer comes - creating a fabric which provides good water resistance is relatively simple, but doing this while maintaining breathability is a more complex process, as these two properties have an inverse relationship in typical textiles. A completely waterproof outer layer would not be effective as it could cause excessive sweating, resulting in moisture collecting within the clothing system causing reduced insulation and comfort. An effective outer layer should have a high level of water resistance as well as a high level of water vapour permeability (or “breathability”). How this layer is constructed plays a significant part in this.
- The outer layer itself is often a layered construction, consisting of a waterproof breathable membrane laminated to a water repellent outer fabric. This is often with the addition of an inner layer which provides protection for the membrane and can also be designed to promote moisture wicking, therefore further enhancing wearer comfort. The waterproof breathable membrane is able to resist liquid water penetration whilst still permitting the transmission of water vapour. This can be achieved by a number of different mechanisms, but before we cover those lets go over some key terminology when discussing water repellency in fabrics. Hydrophobic literally means ‘the fear of water’, so hydrophobic fabrics repel water. Hydrophilic means ‘a strong affinity for water’, so hydrophilic fabrics attract water and can transfer it Using oleo at the start, so oleophobic or oleophillic, has the same definition, but the oleo part refers to oil. To apply this terminology, mechanisms for the membrane can include: A hydrophobic microporous membrane – this is a thin film containing lots of fine holes to allow passage of water vapour; A hydrophilic membrane – this is the mechanism of absorption, diffusion and desorption of water vapour; Or a bicomponent – which is a combination microporous film with additional hydrophilic/oleophobic coating.
- Outer layer testing is quite different from the other layers, and is mainly focused around protective properties. It can roughly be divided into three categories: One - water resistance/repellency tests, Two - water vapour permeability tests Three - air permeability tests. …though you can see from the slide there are some other considerations. Water repellency is tested by spray methods such as Bundesmann where water is run over the surface of the fabric and the repellency is visually graded. Water resistance is tested by forcing water under pressure through the fabric and the pressure at which water passes through is recorded. We have also done a lot of work on testing abrasion resistance of fabrics in wet conditions and we have developed a new method which can be used to test for this. As well as keeping water out, it’s important that the fabric retains breathability to ensure that the user doesn’t over heat and become uncomfortable. This can be tested by a number of different methods which are all essentially looking to measure how much water vapour is able to pass from the inside of the fabric to the outer over a given period of time. Air permeability can be important to test if the garment needs to be wind resistant, and this testing involves forcing air under pressure through the fabric and measuring how much can pass through and how much is blocked. You might also want to factor in UV resistance for the outer layer, not only for protecting the wearer from UV but also protecting the garment from UV damage (which can be accelerated by the presence of moisture). A good example of when this might be required is in high-visibility safety garments for skiing or PPE where the colour fastness to UV is an important aspect of keeping the wearer safe.
- We have compiled a list of relevant standards for testing the outer layer based on the properties we have just talked about. We won’t talk through these standards now, there are far too many words on this slide, but I will share the presentation with you after this session has finished for you to reference.
- Let’s take a brief look at the test process for ISO 9865, which is the determination of water repellency of fabrics by the Bundesmann rain-shower test.
- Before testing can start, the Bundesmann instrument must be primed – this involves running it for 15 minutes, measuring the water in the cups and checking that all the nozzles are dripping consistently. 140mm specimens must be prepared and conditioned in line with the standard. You can use the same sample cutter as for preparing Martindale specimens. The test specimen must be weighed prior to testing, to an accuracy off 0.01g – this measurement will be used to calculate water absorption once the test is finished.
- Ensure all the cups are empty of any water before placing your specimen. We are showing this process on the carousel in the instrument, but the cups can be removed individually if you find that easier. START VIDEO: Identify the face of the specimen to be tested and place uppermost over the cups without any particular pre-tension, smoothing manually. Place the clamp ring on top of the specimen and secure in place with spring clamps. This final step is very important – ensure each drainage valve is closed! If you don’t, any water collected during the test will drain out again, voiding your results. Repeat for up to four specimens.
- The test takes 10 minutes, and on our TruRain Bundesmann you can set alarms if you are doing visual assessment at 1 and 5 minutes. START VIDEO: This video shows what is happening underneath the specimen – wiper blades inside each cup press and rotate against the underside of the textile specimen to simulate movement during use, for example your arms moving in a jacket when walking. 300 evenly distributed nozzles produce individual raindrops to simulate a rain shower, falling on the specimen which is 1.5m below the showerhead.
- On our TruRain, we have a shower guard that activates once testing has finished, to stop any further water falling on the test and also to keep the user dry. At this point the test is finished and you move onto the assessment stage.
- Now we have been through the test process, we need to understand how water repellency is measured in the context of bundesmann testing. There are three steps to the process, starting with visual assessment.
- Surface water repellency is assessed by visually comparing the tested specimen with a photographic grading scale, similar to the spray rating tester. This assessment should be conducted while the specimen is still on the cup, immediately after testing. The standard gives the option to do this assessment at 1 minute and 5 minutes into the test as well, and although these steps aren’t necessary, they can be useful for spotting early issues with the fabric. There are 5 grades, I cannot show you these in their entirety as we aren’t allowed to reproduce the standard, but you can get an idea from this slide and we can talk through what you are looking for at each grade, and then I will show you some examples from our own testing: Grade 5: you are looking for the fast runoff of small drops Grade 4: you are looking for the formation of large drops Grade 3: is when the Drops adhere to parts of the specimen Grade 2: you would see the Specimen partly wetted Grade 1: the Specimen is wet through over complete surface The grading photographs are provided in the standard so you do not need to purchase additional photographs. They aren’t great quality, this standard is nearly 20 years old and the photographs do reflect that. I have some examples of the different grades, using photographs from our research project which we will talk more about later in the presentation. This is to show the difference between a Grade 5, excellent water repellency fabric, through to a Grade 1, which would be poor.
- This is a 3 layer fabric that has a polyester face with a DWR coating, an ePTFE membrane and a polyester tricot backing. This is an example of a layered outer layer as we talked about earlier. This specimen has been assessed as Grade 4 to 5, which the standard states is the ‘formation of large drops’ with ‘fast run off of small drops’. The reference photograph shows grade 4. This is the best example of water repellency we have to show you today.
- This black fabric is a medium to heavy weight waxed cotton fabric. Out technical specialist has graded this specimen as 3, which is “Drops adhered to part of the specimen”, and the reference photograph also shows grade 3. This is the middle option of the three example fabrics we have.
- The final example is a fire retardant fabric with splashguard. It has been visually assessed as grade 1, which means the “Specimen is wet through over the complete surface”. This is the worst example of water repellency we have, and it is actually quite difficult to see the water on the fabric as it has covered it and soaked through.
- Resistance to water absorption is evaluated by weighing the specimen before and after test. This ‘after-test’ measurement is taken after the specimen has been centrifuged for 15 seconds to remove any excess surface water – you can see the fabric on the centrifuge in this image. We have heard of customers shaking the fabric after the test before weighing it, however a centrifuge is referenced in the standard and is a more consistent way of removing excess water. It is important to remove the excess surface water because this step of measurement is concerned only with the water that has been absorbed by the fabric, so weighing surface water as well would misrepresent the measurement. The results for water absorption are worked out using a formula as stated in the standard and expressed as a percentage.
- Resistance to water penetration is determined by collecting and recording any water which passes through the test specimen into the specimen holder cups. Choosing the right measuring vessel for this step is important - the standard asks you to measure the volume in millilitres and for the best fabrics this could be a very small amount of liquid. Using a large measuring beaker could make this process much harder than it needs to be. If you have enough specimen fabric and time, it might be worth doing a test run to work out which equipment will suit you best.
- As with any testing, there are certain parts of the process to look out for which can have an impact on your results.
- Although the standard doesn’t call for any pre-tension of the specimen, how it is clamped can cause a variance in results. There are two elements that can play a part in this: 1. The first is quite simple - when you clamp the specimen, ensure it doesn’t have any bumps or wrinkles. If the specimen is fraying, cut another piece. The standard recommends not cutting specimens to close to the edge as the finish can be different to the majority of the fabric. 2. The second consideration is about the thickness of fabric, and using the correct clamp, which is demonstrated in these images. The first image shows a thin fabric with a thick fabric clamp – the clamp isn’t clamping effectively, which means the fabric is bunched in places and higher than it is supposed to be. This will impact how the fabric absorbs, as it is more likely to run off in places, and it nullifies the wipers underneath as they can’t reach the specimen. The second image shows a thick fabric, with a thin fabric clamp, and the fabric is too thick to get the clamp all the way on. As you can see there is a gap between the top of the clamp and the specimen, this can cause pooling of water around the edge, which again can impact your results. The third image shows the correct placement for everything to work correctly. Getting accurate results relies on the fabric being placed correctly and the instrument performing well, so be sure to take this into consideration.
- Timing is everything! We recommend having all your equipment for measurement ready to go and in close proximity to the test instrument, as delaying any of these stages can impact results. Centrifuge your specimen quickly to stop any further water soaking in. Weigh your specimen quickly to prevent any moisture evaporating. The aim is to halt the test and capture results at a precise moment, and repeat this for every further test that you do.
- This one sounds really obvious, but has become more of an issue as the fabrics we are testing get better at water repellency. For recent testing that we have done in our laboratory, we have found the amount of water collected in the bottom of the cups - the water penetration part of the test – is minimal, and in some cases the cup remains dry. We recommend wiping your cups with a cloth before draining the water, focusing on the spout area, so no excess water drains into your measuring device. These cups have been under rainfall for 10 minutes and will be damp, and if you collect drops from outside the cup on a fabric that hasn’t penetrated much water, your measurement could be off by 100s of percentage points.
- If you are a regular attendee of our webinars, you will know we say this all the time – control your variables, consistency is key! And that is because it is so important, and you would be surprised by the number of tickets that come through our helpdesk where one small element of the testing process has impacted multiple different results. For Water Repellency testing, things to keep an eye on include: Conditioning – all samples must be conditioned before testing, and testing must take place in a conditioned atmosphere. ISO 139 is the guide to use for atmospheres and conditioning for the bundesmann test. The temperature of water to be used is specified in the standard, this is 20 degrees with a tolerance of 3 degrees, or 27 degrees with a tolerance of 2 degrees in tropical countries, and you must measure this and record it on your test report. This is important for consistency of testing, and increased temperatures can cause your specimen to behave differently, and from a safety perspective as bacteria can grow when the temperature of the water rises too much. Calibrate your equipment – we see this step missed sometimes to save time, but it is important to calibrate at the start of the day and at regular intervals. The bundesmann must be run for 15 minutes prior to testing to ensure the instrument is performing consistently.
- I would now like to tell you a bit about research we have conducted recently relating to the bundesmann tester, and a method for testing more sustainably. First, a bit of context as to why we thought this was necessary.
- Sustainability is one of the biggest issues facing apparel brands and manufacturers right now, this is something a lot of you attending today will be well aware of as your businesses set sustainability goals and initiatives. Why is this? Fashion is responsible for: 10% of the worlds greenhouse gas emission 35% of the microplastics found in oceans And 20% of the world’s total waste water – in fact, it is estimated that 20,000 litres of water are used to produce 1kg of cotton Fashion is second only to oil, as the largest polluters in the word, and so there is a lot of pressure to be cleaner, more efficient and ultimately sustainable. Although testing plays a small part in the process, we have also thought about our instruments and how they can be more sustainable, and have worked on proving a solution with TruRain, our Bundesmann tester, to recirculate water.
- A typical Bundesmann water repellency tester that runs for 8 hours per day, five days per week, is consuming 3360 litres of water. It is historically plumbed into the mains and drained directly after a single fall onto the specimen. Recirculating this water might not be an entirely new concept, but the focus of our research was to ensure there were no detrimental effects to testing when doing this. For example, if the fabric sheds when being washed, and synthetic fabrics in particular shed a lot of microplastics, would this shedding stay in the water and impact the next round of testing? Would it stick to the next specimen being tested and give a false impression of water repellency for a garment that would then fail when worn? Recording what essentially would be false results for high performance garments would negatively impact brands, but could also result in the consumer purchasing another garment quickly. Wearing garments for longer is a key pillar of sustainability in fashion, garments must keep performing to the same standard for this to be possible.
- We conducted significant testing, in house and using an external laboratory, to verify that the results would be accurate regardless – the main aim of the testing was to see if there would be a variance in results between test 1 and test 150, when all other elements are controlled – the same test, the same fabric, the same environmental conditions, the same method of assessment, but the same water recirculated each time. We picked three entirely different fabrics for this testing to cover different issues that could arise, these were the fabrics we used as examples for visual assessment: A fire retardant fabric with splashguard a waxed cotton fabric and a 3 layer fabric that had a Polyester face with DWR, a ePTFE membrane & a polyester tricot backing The results for all three were consistent from start to end, and by confirming this, we were able to calculate the savings using our recirculation unit could offer.
- We saw significant cost savings: An 8-hour working day use of the TruRain recirculation system sees 83% total cost savings in energy consumption and total running costs, this is mainly due to the… Increased throughput and productivity: This method of testing is easy to use and less ‘cumbersome’ than a traditional Bundesmann, as tests can be run continuously for 8 hours/day, 5 days/week without needing to clear and refill the water. There is less waste: 99% less water is used during testing alone – if you did 150 tests a week (and we know some of our customers are doing far more), your water consumption drops from 2100 to just 23 litres! Additionally, It is accurate, safe and reliable: Through the use of an effective Water Safety Plan, health and safety can be maintained with no impact on the efficacy and reliability of test results. We also found that by using the recirculation unit, we were able to maintain the temperature of the water much easier – the percentage of water absorbed by fabrics can increase as the temperature increases, so this is important to control for consistency of results. A move towards sustainability will come from big changes and lots of little ones, and finding more efficient ways to test will be one of those.
- We have now covered all the topics we set out to, so these are the key takeaways from this presentation.
- The Bundesmann test is growing in popularity, mainly due to changing consumer behaviour. More people are heading outdoors, and outdoor wear is worn more frequently. By conducting water repellency testing, you are able to give the consumer a garment that will perform to their expectations. We have talked through the procedure for the ISO 9865 test method, and perhaps the most important part is the assessment. By measuring these three elements – visual assessment, water absorption and water penetration – you are able to build up a picture of what a fabric will behave like when subjected to the elements. Through the research we have conducted, we have shown you can take a more sustainable approach to water repellency testing and still produce consistent and accurate results. This method of recirculating water is proven to reduce water and energy consumption, and save time and resource, and also offers benefits such as maintaining a steady temperature for testing. If you would like to talk to us further about this, please get in touch.
- The technology and developments in this area of performance textiles is progressing all the time, so we can recommend some further reading to gain a good foundation of knowledge.
- If you have a question, please type it into the question box and we will try to answer some now.