Hytrel® was selected for the shoe’s eyelets due to its flexibility, even at low temperatures, and its suitability for stitching to the leather upper. Zytel® was chosen for the shoe’s midsole support due to its high flexural modulus, helping to stiffen the polyurethane sole and provide more protection and comfort for the wearer. By changing to polymer components, Yakupoglu is able to save weight and manufacturing cost, while prolonging the lifetime of its shoes.
For its new, non-metallic safety shoes, footwear manufacturer Yakupoglu A.S. uses flexible and stitchable DuPont™ Hytrel® thermoplastic polyester elastomer for the eyelets (top right and highlighted on shoe) and strong, stiff DuPont™ Zytel® nylon for its midsole support (pictured below, not visible on shoe as it is embedded in its sole).
The adoption of Hytrel® for the shoes’ eyelets and Zytel® for their midsole supports represented the final stage in Yakupoglu’s drive to replace metal in its safety shoes. “The availability of an all-polymer safety shoe can be of crucial significance to workers in industries where passing through metal detectors may be part and parcel of their jobs, for example luggage handlers at airports,” explains Ismail Harmandar, production manager at Yakupoglu. A reduction in the overall weight of the shoes, without impairing safety performance, and the elimination of potential corrosion sources are further benefits to the user. The manufacturing benefits of an all-polymer shoe include fewer material stocks and the deployment of cost-efficient manufacturing processes, according to Yakupoglu.
“The greatest challenge to date was finding a material to replace the steel commonly used for eyelets, where the right combination of flexibility and toughness over a wide temperature range was imperative in providing a durable component that could also be easily integrated into our overall production process. DuPont, and more specifically Hytrel®, provided that solution,” says Ismail Harmandar. Rows of four eyelets, measuring approximately eight centimetres in length and two centimetres high, are moulded in-house by Yakupoglu before being stitched to the leather upper by industrial sewing machines. “If the material is too stiff it will break during stitching, too soft and it may tear during use,” explains Ismail Harmandar further.
A 30% glass-reinforced grade of Zytel® nylon is used to produce the midsole support for the shoes, which runs under the arch of the foot above the polyurethane sole, and provides more protection and comfort for the wearer. The material was chosen for its high stiffness when flexed over multiple cycles, and processing ease. “The support provided by DuPont when determining which materials we could use for these applications was second to none. Whether material performance and analysis, processing advice or general design guidance, DuPont provided us with the best answers,” concludes Ismail Harmandar.
Part of Yakupoglu’s non-metallic range of safety footwear, the DuPont engineering thermoplastics currently feature in its UL 100 lightweight safety training shoe and the UL 110 lightweight safety boot. Both shoes are true non-metal constructions throughout, with the soles produced from a combination of polyurethane (PU) for the midsole and thermo-polyurethane (TPU) for the outsole. The non-metal toe caps of the shoes are made from thermoplastic and are resistant to 200 joules. Both models are S1 safety classified according to European Standard EN345, and have antistatic properties as well as being oil and slip resistant. They are available under Yakupoglu’s own brand of ‘YDS’ in Turkey or under national brands throughout Europe and the Middle East.
Yakupoglu is a company manufacturing various military and police footwear, garments and accesories, worker safety shoes and firemen boots. Founded in 1927, its product spectrum consists of safety footwear, uniform and tactical footwear, sport shoes, Goodyear welted and unit soled shoes, Gore-Tex breathable and water resistant boots, summer boots, winter boots and snow boots. Its ‘YDS’ branded safety footwear and equipment are produced according to norms EN ISO 20345 and EN ISO 20345.
The DuPont Engineering Polymers business manufactures and sells Crastin® PBT and Rynite® PET thermoplastic polyester resins, Delrin® acetal resins, Hytrel® thermoplastic polyester elastomers, DuPont™ ETPV engineering thermoplastic vulcanizates, Minlon® mineral reinforced nylon resins, Thermx® PCT polycyclohexylene dimethyl terephthalate, Tynex® filaments, Vespel® parts and shapes, Zenite® LCP liquid crystal polymers, Zytel® nylon resins and Zytel® HTN high-performance polyamides. These products serve global markets in the aerospace, appliance, automotive, consumer, electrical, electronic, healthcare, industrial, sporting goods and many other diversified industries.
DuPont is a science-based products and services company. Founded in 1802, DuPont puts science to work by creating sustainable solutions essential to a better, safer, healthier life for people everywhere. Operating in more than 70 countries, DuPont offers a wide range of innovative products and services for markets including agriculture and food; building and construction; communications; and transportation.
The DuPont Oval, DuPont™, The miracles of science™, Hytrel®, Zytel® and all other product names denoted with ® are registered trademarks or trademarks of E.I. du Pont de Nemours and Company or its affiliates.This press release is based on information provided by:
Horst Ulrich Reimer | Du Pont
New material could lead to erasable and rewriteable optical chips
07.12.2016 | University of Texas at Austin
Porous crystalline materials: TU Graz researcher shows method for controlled growth
07.12.2016 | Technische Universität Graz
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
07.12.2016 | Health and Medicine
07.12.2016 | Life Sciences
07.12.2016 | Health and Medicine