Preventing Leakage In Down Filled Jackets

Transcript

Preventing Leakage in Down Filled Jackets Preventing Leakage in Down Filled Jackets This is a guide to aid with the manufacturing process of down jackets and advise on how to prevent down and feather leakage. Leakage that occurs through the fabric is a direct result of the materials used. Preventing Leakage in Down Filled Jackets Contents Introduction What is a down jacket? What are the problems associated with down jackets? Why does down leakage occur? Manufacturing process guidance for down jackets Preventing Leakage in Down Filled Jackets Introduction There is nothing better on a cold winter’s day than putting on your favourite winter jacket knowing that the materials used in its construction will offer protection from the cold. The materials that are used in the outer layer and filling of jackets vary depending on the look, fit, price point and technical specification. Some outer material will be able to block wind, allow moisture to escape and be tough enough to withstand tears and abrasions while other options may merely be wind or water resistant. The materials used for filling these jackets may consist of synthetic or natural fibres. Synthetic filling generally has the advantage that it does not leak through the fabric openings as easily, but down filling provides greater warmth. Preventing Leakage in Down Filled Jackets What is a down jacket? Down provides a higher degree of insulation. The fluffier the down inside the jacket, the more air that is trapped which in turn keeps out the cold. Most down jackets are not made of pure down but are often filled with a mix of other materials such as feathers. Preventing Leakage in Down Filled Jackets What are the problems associated with down jackets? There is, however, nothing more annoying than buying a new jacket only to have to pull out down feathers that appear for no apparent reason every few days. Leakage that occurs through the fabric is a direct result of the materials used. This could be either due to the quality of the down feather or the outer layer fabric. This outer layer material should be made in such a way to prevent penetration of down and tested accordingly prior to manufacture. Testing should conform to BS EN standards to confirm suitability. Preventing Leakage in Down Filled Jackets Why does down leakage occur? There are a number of reasons why down leakage occurs which include: • • • • • • The fabric selection is unsuitable and allows the feathers or down to penetrate through the fabric weave Additional processes that occur after final garment make up that cause agitation of the filling Needle holes caused by stitching together fabric pieces or by sewing seams to hold the down/feathers in place within the garment. This could relate to either the needle size or point or even the deflection of the needle as it penetrates through the fabric The needle or sewing machine throat plate is be larger than necessary. If a needle hole is too large it allows the fabric to flag (move up and down within the needle hole) which can pull the down or feathers through the fabric during the sewing operation The sewing thread is either too hairy or too coarse which allows the down or feather materials to attach to the thread and pull through the fabric surface during sewing Other factors such as stitch balance and static build up contribute to the down attaching itself to the needle/thread Preventing Leakage in Down Filled Jackets Manufacturing process guidance for down jackets The following can be used as a guide during the manufacturing process: • Needles should be changed on a regular basis during sewing as damage to a needle point will in turn cause damage to the fabric and increase the chance of down leakageNeedle point • Select a good quality needle as needle vibration/movement could cause the needle hole to increase in size. This vibration will also increase at higher machine speeds. A sewing machine speed of 3,500 rpm or less should be consideredNeedle selection Needle deflection may occur due to moving parts on the sewing machine brushing past or hitting the needle. The result of higher vibration or deflection will be that the needle hole will be a larger size and less neat (round) in shape allowing down or feathers to enter more easily than when not deflected. It may also be an idea to control the maximum machine speed on these types of fabrics to help reduce deflection • • Needle deflection A fine/thin needle size should be used; the finer/thinner the better. A needle point should also be chosen that allows the fabric to be pushed aside as the needle Preventing Leakage in Down Filled Jackets • • • • penetrates the fabric rather than one that has to punch through the fabric. A needle with an acute round point such as an SPI, R or RS point would be a good choice. A metric needle size of Nm 60-65 should be considered for threads that are Tkt 180-120 moving to a size Nm 70-80 for Tkt 80Needle size A lower stitch density will give less opportunity for the down/feather to pass through holes made by the needle. Ensure that the seam tear tests are acceptable and other quality requirements are met. A higher stitch density is more likely to have down leakageStitch density A smoother thread will attract less down/feathers than a hairier thread and will also look neater in the sewn seam. A suitable thread type would be a continuous filament polyester thread such as Coats Gral. Thread types Ensure the correct stitch balance is set and maintained. Try to keep the tension as low as practical to avoid thread bedding into the fabricSewing tension Joining seams prior to filling or using narrow interlinings to help prevent holes can help reduce down leakageSeam type On-site Technical Support / Training Pre-bulk can be made available along with on-site training which will help to resolve these issue of down leakage during the sewing process.