Production process

The product with the lowest impact, is the one that already exists. That is why we harvest old jeans and recycle them into new fabric. 

  1. Harvesting old jeans
    The raw materials of our jeans are worn out denims, which we collect via our unique HNST harvest campaigns. Our first harvest we did in 2017 in partnership with social economy partners. So far we’ve collected around 17 000 old denims which we’ll recycle into new HNST jeans.

  2. Extensive sorting & quality control
    The collected trousers are carefully sorted according to quality and usability. About half of all trousers are still of good quality and are resold to people in need by our social economy partners. A small part of the collected textiles are too dirty (oil stains, paint stains etc.) and would pollute our recycling process with chemicals we do not want. This fraction is downcycled into sheets, wipers or isolation for the automotive industry. The remainder is our raw material and is fed into the controlled HNST recycling process.


  3.  State-of-the-art recycling 
    Our German based specialised recycling partner first removes all hard parts and labels by using smart mechanical and magnetic separation techniques. After that, the used denims are carefully shredded into fibers through mechanical recycling. Of paramount importance in mechanical recycling, is to preserve the fiber length as much as possible, something HNST excels at. Mechanical recycling does not use any water, chemicals nor heat and only needs little energy in comparison to chemical recycling or virgin fiber production.

    Because of the mechanical braking forces, recycled cotton fibers lengths are too short to create a fabric consisting of 100% recycled fibers. To attain good quality properties, the recycled denim fibers are blended with Tencel®. Tencel® is a low-impact lyocell fiber made from sustainably harvested eucalyptus wood by the Austrian company Lenzing. 

  4. Innovative spinning
    To prepare for spinning the fibers are first carded and sometimes combed. Carding is a mechanical process that disentangles, cleans and intermixes fibres to produce a continuous web. Subsequently, combing removes too short fibres by means of a rotating ring or rectilinear row of steel pins.

    For denim yarn made out of recycled fibers, open-end spinning, also called rotor spinning, is being used. The combed fiber web coming from the card goes into the rotor and comes out twisted and wrapped up on a bobbin. The principle is comparable to pulling out a sheet from a rapidly twisting clothing dryer, the sheet would spin together as you pull it out.

    The yarns for our HNST collection are made out of 50% recycled old denim (cotton) and 50% Tencel®. This is the highest percentage of recycled fibers technically possible to date.

  5. Yarn preparation, weaving & detox dyeing with clean energy
    In order to properly weave denim fabric, yarns have to be pre-treated. Normally, this is done by using low-cost Poly Vinyl Alcohol (PVA), which is nothing less than a plastic polymer. The residues of this PVA are microplastics being released during industrial and domestic (yes at your home) washing. Luckily, our Italian denim mill PureDenim came up with their NaturalReco finishing solution. Instead of PVA, they use a film made of industrial vegetable waste to protect the yarn during processing and to favor its bonding. 

    Any woven fabric consists of two distinct sets of yarns that are interlaced at right angles. The longitudinal yarns are called the warp and the lateral threads are known as the weft. All denim is woven according to the twill pattern, which can be identified by its pattern of diagonal lines and is known for creating strong fabrics.

    Weaving small quantities is not simple. When you want to install a new warp loom, minimum production quantities are quite high (more than 7000 meters). Given the start-up scale of HNST, we decided to use the existing recycled warp yarn of our Italian weaving. This warp yarn consists of 60% pre-consumer recycled denim (fabric waste from pattern cutting) and 40% Greek cotton (which is not genetically modified). Combining 60% of this warp yarn with 40% of the HNST weft yarn, consisting of 50% post-consumer recycled denim and 50% Tencel®, lead into the creation of the iconic HNST fabric containing 56% recycled denim, 23% Greek cotton and 21% Tencel®.

    In denim fabric, only the warp yarn is being dyed. Take a look at your blue jeans and you’ll see that the inside is white or -in case of recycled fabric- grey/blue instead of dark indigo blue. For dying the warp yarn, our weaving partner has invested in in-house production of indigo. For this, they are using their unique patented technology called SmartIndigo. 

    On top, our Italian denim mill PureDenim has been on a journey towards ecology for over 12 years. They have invested in a cogeneration plant that, in addition to making themselves self-sufficient in the supply of clean energy, has allowed the recovery of thermal energy with an equivalent reduction of carbon dioxide. Since the commissioning of the new plant, they avoided more than 9,8 million kilograms of carbon dioxide, thus saving 570 000 trees. Today, thanks to their continuous research since 2008, for each meter of denim they averaged 70-80% less water with 60% less pollution than other manufacturers. Last but not least, PureDenim was the first denim manufacturer to have the Greenpeace Detox patent in 2014, having eliminated the 12 most polluting and harmful elements from their production process. 

  6. Sewing to last
    HNST jeans stands for timeless quality made in Europe to the highest environmental and social standards. We do not use any metal rivets, nor polyester labels or leather back patches to avoid problems at the end of life. The customized HNST unscrewable button can be removed from the jeans to replace or reuse, unlocking an easy recycling process. Together with the embroidered rivets, the use of metals is completely omitted.

    Expert seamstresses in Portugal are dedicated to transforming the recycled denim fabric into HNST jeans. We have deliberately chosen for a European confection partner in order to guarantee the best working and safety conditions for the workers behind our HNST jeans. 

  7. Ecological washing 
    Often denim is washed to create an authentic worn out vintage look. Conventional denim washing has a very high impact on the environment and workers because the process removes the indigo dye from the fabric often with quite aggressive techniques (imported stones that cannot be reused or sandblasting that exposes workers to silica dust causing severe illnesses).

    At HNST, we use three certified ecological washing methods: laser, ozone and enzyme washing. Enzymes occur naturally in nature and for example break down the sugars in your mouth. Doing this, we reduce the water footprint of our washings from 100 to only 10 liters per jeans while using zero toxic chemicals.

  8. Circular customer service
    For all online orders, we use RePack which is a reusable and returnable delivery packaging designed with reuse in mind. The reusable packaging is made from recycled material and designed for at least 40 use cycles. Best of all, RePack reduces CO2 emissions from packaging production by up to 80% and there is no trash.

    In addition, we developed the Morning After Spray. No need to put your jeans in the washing machine or freezer to freshen them up or to remove the bad odors. Our Morning After Spray contains active probiotics that naturally freshen up your jeans. This way you can reduce washing your jeans with 50% which - on a yearly basis- enables you to save about 1365 liters of water.

    On top, we offer our clients a free repair service in order to keep our products as long as possible into their circular life cycle. 

    Every story comes to an end, but not that of HNST. When our customers cannot wear their HNST jeans anymore for whatever reason, we motivate them to bring them back to us for recycling by offering a 15 euro discount on their next purchase.