Aeroponics is a technique used for indoor cultivation in a controlled environment. There is no growing media like soil or coco and the water tanks so well known in hydroponics are eliminated. In aeroponics, plant roots are suspended in air and fed directly by a nutrient rich water mist. Because there is no media, plants do not expel energy searching for oxygen and nutrients, which means that grow faster and with higher yields than in other methods. The use of mister systems allows for reduction in water consumption of up to 95%.
Aeroponics was greatly advanced by NASA in the 19990’s for growing in space and is now extremely common for growing vegetables in urban environments. The technique has long been used in the Clone stage of cannabis cultivation and is now becoming commonplace through the Veg and Flower stages. High levels of grower control, the ability to grow vertically, and massive reductions in water consumption make aeroponics highly favorable.
Electrical insulating materials from WS Hampshire take many forms and serve a wide range of application. From polyester film used in the lighting industry, to corrugated vulcanized fiber in large transformers, to high temperature composites in the electric arc furnace of a modern steel mill. Our extensive capabilities allow us to slit, roll, punch, form or CNC machine insulating materials into parts per your specifications.
Contact us today to learn more about how our material and fabrication expertise can help you and your team.
It may be ugly, but this Ryertex bearing was NOT A FAILURE! Follow here to see how this bearing set replaced bronze and gave one mill the ability to reduce the risk of tens of thousands of dollars in lost production and damaged equipment.
Cable pulling equipment in the electric, telecommunications, and related industries use rollers to support the line being installed and for directional changes to protect the line from damage. This includes support blocks, snatch blocks, corning arrays/quadrants, and boom point roller-type sheaves on a variety of stringing equipment extensions. These rollers were initially made of steel or aluminum, but corrosion damaged lines and safety concerns due to part weight led to changes. Rubber and urethane rollers have been used, but they have limitations caused by weathering, chemical attack, and wear.
Using nylon in place of steel, rubber, or urethane allows for improved performance and operational efficiency as nylon rollers are lightweight and will not cause damage your cable due to corrosion and wear.
What applications are you working on where this may apply?
Engineering plastics are a form of polymer that are well known for their high mechanical strength, versatility, and ability to be melted and reformed into other shapes. For decades, engineers have seen plastics replace metal in applications where weight reduction, corrosion resistance or low coefficient of friction is needed to reduce wear on mating parts.
Plastics are lightweight so they are safer to maintain than steel and can reduce noise and vibration levels. Options exist to produce parts from fiber reinforced polymers as well as those that are self lubricating which can enhance the performance of plastics. These features help provide longer part life for the entire system, leading to cost savings for equipment manufacturers and end users.
For example, a significant reduction in the weight of sheaves and wear pads will increases the lifting capacity of cranes or aerial work platforms and may offer a reduction in power requirements. Additionally, the handling and assembly of these parts is made safer as most plastics are one seventh the weight of steel. Additionally, plastic materials cause very little wear on the contacted surface as seen where wire rope will last two to three times longer when plastic sheaves are used instead of steel. Scheduled maintenance for lubrication of parts is often reduced or eliminated completely when components are manufactured from plastics.
WS Hampshire supplies asbestos free thermal insulation boards for applications such as platen presses, foundries, glass handling, molding machines, fire protection, or customized applications with temperatures up to 1,800ºF.
European cast nylon producers, and injection molding resin guides, report both “dry” and “conditioned” data for nylon-based materials which are hygroscopic (absorb moisture from the air) and can absorb upwards of 8% moisture by weight at saturation (compared to 0.8% for acetal).
This is a completely reversible physical reaction as the higher the humidity, the faster nylon will absorb moisture. However, it only absorbs moisture until it is saturated and can absorb no more. Conversely, it releases moisture and dries out when exposed to dryer air.
Under normal conditions, nylon will reach equilibrium in a short period of time, though time will vary depending on thickness. However, “equilibrium” is a relative term given its environment at a given time. So, equilibrium will vary from Minnesota to Louisiana, and from winter to summer.
Dry and conditioned data
Nylons are semi-crystalline polymers, with both crystalline and amorphous regions. The tight crystalline regions give nylon much of its strength, stiffness and wear resistance.
The amorphous regions absorb the water, which then bonds to the polymer chain and force the crystalline structures apart. The result is nylon parts that swell and show diminished mechanical properties. Water actually acts as a plasticizer, making the nylon softer while increasing toughness and elongation. Since these effects happen when polyamides are exposed to moisture, they must be considered when designing a part.
What is the difference between data quoted for dry and conditioned data for plastic materials? And why is this most significant for nylons
Dry: Data with equivalent moisture content as when it was run (typically <0.2%).
Conditioned: data after absorbing environmental moisture at 50% relative humidity prior to testing.
Effect of moisture on properties
In general, as moisture content rises, impact strength and other energy absorbing characteristics increase. Some other properties decline
Variation of properties of nylon 6 as a function of humidity
When designing nylon components, it is important to consider that dimensions will be dramatically affected by temperature and humidity. This is especially so on long parts. If the dimensional change is unacceptable, you should consider acetal (POM) or polyester (PET) as alternative materials as they provide additional stability in wet environments.
At room temperature and 50% relative humidity, equilibrium moisture content for nylon tends to remain around 2%, which corresponds to an increase in size of roughly 0.5 – 0.6%. Under similar conditions, acetal absorbs roughly 0.2% moisture by weight and grow around 0.2%.
Variations between nylon grades
How much the different properties change depends a great deal on the chemistry of the polymer itself. Nylon types include 6, 6/6, 4/6, 6/12, 11, and 12 (types = number of carbon atoms in the molecule) Polyamide 12, for example, doesn’t absorb as much moisture as Polyamide 6, so Polyamide 12’s properties don’t fluctuate as much with moisture.
Absorption of Moisture by Nylons by Weight % at 50% R.H. and Saturation @ 23°C (resin data)
Additionally, as nylon absorbs moisture beyond equilibrium, its surface becomes “amorphous” (spongy), and wear resistance is lower. The addition of liquid or solid lubricants to the nylon offsets most of the decrease.
Need help deciding what to use? The experts at WS HAMSHIRE can explain this and more, so you can make the best material decisions for your needs! Call us – you’re in the right place!
Tom Connelly is a self proclaimed “Street Engineer” with over 40 years in the plastics industry.
Thank you for allowing us to do what we do. As we enter the Thanksgiving week, we are reminded again that we would not be in the amazing position that we are today without the trust, support, and commitment that we receive from you every day. Whether you are customer number one, a supplier that we only buy from sporadically, or somewhere in the middle, please know that we are thankful for all that you do in allowing us to succeed. We truly could not do it without you.
From our team to yours, have a Happy Thanksgiving!
Nylon – chemically polyamide (PA, not to be confused with polyimide, PI) was invented in 1935 by DuPont’s Wallace Carothers (PA 6/6). Nylon 6 (PA 6, extruded), or polycaprolactam, was developed by Paul Schlack at IG Farben to reproduce the properties of nylon 6/6 without violating DuPont’s patent. Initially used in fibers to replace silk in parachutes, stockings etc, these resins established the basic principles of polymer chemistry that have made plastics such a ubiquitous part of our lives today. Nylon was also injection molded into components for the automotive market with varying degrees of success…people back then disliked nylon timing chain sprockets as they constantly stripped out!
(FUN FACT – “NYLON” was originally DuPont’s tradename, but DuPont didn’t protect it and it became so commonly used that they lost the right to it – today it is “ZYTEL®”)
Generally, nylon machined parts have a robust combination of properties, including high strength-to-weight ratio, toughness and inherent wear resistance. Stock shapes in 6/6 nylon are all extruded; in type 6, it can be either extruded (Europe) or cast (worldwide). While there are slight property differences, usually the decision between PA 6/6 and 6 involves either size and/or specifically modified version availabilities.
PA 6/6, sometimes referred to as Nylon 101 (old DuPont callout), is available in natural (off white), black, glass filled and specialty grades (low smoke, flame retardant, heat stabilized, impact modified). There are no enhanced wear resistant versions currently available.
NOTE: The crossover point [cost versus size] between unfilled extruded PA 6/6 and cast PA 6 is about 2.5” diameter rod, and .500” plate, over which cast PA 6 costs less to make.
PA 6 – in North America, 99+% of PA6 is cast, so we’ll stick to that technology. Cast nylon was first invented in Europe in the 1950’s and introduced in the US in the early 1960’s. Since it is made by combining two liquid feedstreams into a tool which react to become PA 6, additives are much easier to incorporate, and a wide range of sizes and shapes are readily available (from thin plate to custom castings weighing hundreds of pounds).
Here are the most popular grades of cast PA 6 currently available:
Higher cont. Temp. Use
Natural, green, others
High load / low speed
Oil & MoS2 filled
Dark blue, black
Crystallinity + lubricant
Solid lubricant filled
Red, grey, black
Highest PV rating
Solid lubricant filled
High impact resistance
There are also alloys of PA 6, such as PA 6/12, which can offer lower moisture absorption and higher impact resistance.
Again, it is nylon’s combination of properties that make it so widely used. There are many applications that have 4 or 5 key property requirements, where nylon isn’t #1 on any of them but #2 on all of them!
Too many choices? No worries – the nylon experts at WS HAMPSHIRE can guide you through the selection process. You’re in the right place!
Tom Connelly is a self proclaimed “Street Engineer” with over 40 years in the plastics industry.
Ultra High Molecular Weight Polyethylene (UHMW) is one the most widely used thermoplastic materials today. It is defined as having a minimum molecular mass (molecule length) of 3.2 million; some resins go as high as 7.5 million (for reference, HDPE = ~1MM, LDPE = ~500,000)
Like PTFE, UHMW cannot be melt processed, as this breaks down the molecular chain. It is made using compression and heat to “fuse” the material below its melting point. It is available in compression molded sheets up to 8’ x 20’, and ram-extruded rod, tubes & profile shapes.
Heat Resistance – the heat deflection temperature is 116⁰F, compared to ~200⁰F
Thermal Expansion – UHMW changes at 2X the rate of nylon with temperature changes
Compressive Strength – its compressive strength = 3000 psi, versus 15,000 psi for nylon – UHMW’s safe working load is 1000 psi maximum
Inserts – since the material is only 25%as strong as nylon, larger / specialty inserts with a foot extension on the bottom (prevents pull-through), and limited torqueing is needed
Where food contact is not an issue, reprocessed UHMW is a cost effective alternative. Using clean regrind mixed with virgin black resin yields a material with the same low friction, low moisture absorption and impact resistance of virgin at lower material cost. Due to the inclusion of the larger regrind particles, it is actually slightly harder and some OEMs prefer it over virgin.
There many modifications of UHMW available, including colors; UV stabilized; lubricant filled (solid, oil or MoS2), ceramic filled; anti-static/conductive; metal/X-ray detectable; high temperature.
This last version needs come clarification. Some mills offer an anti-oxidant filled UHMW touted to withstand 275⁰F – HOWEVER -THE HEAT DEFLECTION TEMPERATURE IS THE SAME AS VIRGIN, 116⁰F! What the 275F means is that, where pure virgin UHMW starts to oxidize (turn brown) over time @ ~175⁰F, this version adds ~100⁰F heat resistance before oxidation.
Too much information? Give us a call, the experts at WS HAMPSHIRE can walk you through all the data to find the right material for your needs – you’re in the right place!
Tom Connelly is a self proclaimed “street engineer” with over 40 years in the plastics industry.