November 12, 2019 Volume 15 Issue 43

Mechanical News & Products

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ClampDisk micro fastener is new alternative for automotive and consumer electronics

Designed as a unique alternative in assemblies for the automotive and consumer electronics markets, the ClampDisk Press-on Fastener is a new offering from PennEngineering that delivers a fast, simple way to achieve sheet-to-sheet clamped attachment while replacing the use of standard screws, nuts, and adhesives. The most common challenges that can be eliminated or reduced by using ClampDisk include over installation, cross threading, stripped screw heads, broken screws, and damaged product. This fastener can be removed easily with a sharp-edged tool.
Learn more and see ClampDisk in action.


Specialty hinges expand design possibilities for opening and closing

From the simplest of hinges to multi-joint hinges with complex kinematics, the JW Winco selection has everything needed for superior door and flap solutions -- including extra functions. Popular choices include the heavy-duty stainless steel GN 237.3 with 180-degree range of motion and the GN 235, which can be mounted with socket head cap screws and -- thanks to its offset axis -- still swivels 180 degrees without collision. Additional functionality is offered by hinges with variable friction, and in another Winco-Norm part, an integrated spring ensures independent return of the hinge. This special product range, which also includes integrated damping, indexing, and locking functions, is being continually expanded by Winco. One kinematic highlight is already available from Winco: the multiple-joint hinge with either a 4x, 7x, or 10x joint mechanism, which opens flaps and shifts their position at the same time, while still offering 180 degrees of travel. Many more options.
See the full range of JW Winco hinges.


New advanced materials for production-grade 3D printing

Stratasys recently unveiled several new durable temperature- and chemical-resistant FDM thermoplastics aimed at addressing the growing demands of engineers and designers to deliver production-grade, custom 3D-printed tooling and parts. Suited for aerospace and industrial applications, the new Antero 840CN03 PEKK-based polymer with ESD properties can create strong yet lightweight parts used in frames, panels, and components. Built for highly durable tooling applications, Diran is a new nylon-based FDM thermoplastic that provides manufacturers with extreme toughness and low friction, combined with resistance to hydrocarbon-based chemicals and a smooth surface to offer low sliding resistance. Diran's toughness is able to withstand the rough handling of tools often common in a manufacturing setting.
Learn more.


Need help coupling two parallel shafts?

Electromate offers a full family of power-on clutches from Inertia Dynamics for most applications. Power-on clutches are used to couple two parallel shafts. The armature hub assembly is mounted to the same shaft as the rotor assembly. The armature hub accommodates a pulley, gear, sprocket, etc., to transmit torque to the second shaft. The field assembly is mounted on the shaft and retained by a loose-fitting pin or bracket through the anti-rotation tab. Typical applications include: packaging machinery, medical equipment, conveyors, postal sorters/readers, document feeders, textile equipment, and copiers/printers.
Learn more.


A proportional isolation valve like no other

Clippard's new patented ceramic technology is the first to provide precise proportional control combined with isolation valve attributes to meet the needs of the most stringent analytical and industrial process control applications. This valve is ideal in critical applications for liquid and gas delivery, medical, analytical, and industrial automation requiring ultra-fine resolution and excellent repeatability. In addition, the unique design allows for custom flow profiles.
Learn more.


New ball screw for machine tools

Featuring high-speed performance and load capacities that exceed existing full ball standards, THK's new Type BSM Ball Screw is ideal for use in machine tools. The Type BSM uses a newly developed circulation structure and a large lead to meet high-speed performance demands. The DN value is 170,000, contrasted with 130,000 in conventional products. The unique groove design and double groove structure improve load capacity. The Slim Nut Type BSM-B conserves space with a nut diameter up to 14 percent more compact than THK conventional ball screws. An extended overall length and increased number of loaded circuits ensure optimum rigidity.
Learn more.


How to calculate plastic injection molding shrinkage

Do you know how to calculate the shrinkage of your part ahead of time? Plastic injection molding shrinkage is the contraction of a plastic molded part as it cools after injection. Most of the part shrinkage occurs in the mold while cooling, but a small amount of shrinkage occurs after ejection, as the part continues to cool (especially for Delrin or POM). After that, the part may continue to shrink very slightly for several hours or even days until the temperature and moisture contents stabilize.
Read the ICOMold blog.


New anti-static air knife with 30% better performance

EXAIR's new Gen4 Standard Ion Air Knife eliminates static electricity 30 percent better at low inlet pressures, which saves compressed air and money. Production speeds, product quality, and surface cleanliness can improve dramatically. It eliminates static on plastics, webs, sheet stock, and other product surfaces where tearing, jamming, or hazardous shocks are a problem. The unique amplified airflow carries the ions to the target, making it possible to eliminate static charges in less than a half second. Air volume and velocity are infinitely controllable from a breeze to a blast to gently wipe or forcefully blow away debris.
Learn more.


Helical bevel gearboxes with cast-iron frames

The new IronHorse HBR series of helical bevel gearboxes combines the helical gearset with a bevel gearset to create an output that is perpendicular to the input. All HBR series gearboxes are hollow shaft output and accept double or single shafts. Dual and single output shaft kits are available. Helical gears offer a smoother, quieter operation than most other gear types. The universally interchangeable compact design ensures easy OEM replacement and provides flexible installation with C-face and TC-face inputs, perpendicular output, and six mounting positions. Five gearbox sizes support 56C up to 254/6TC NEMA motor frames, and 6 ratios are available from 10:1 to 120:1. The helical bevel gearboxes are sized to handle from 1- to 24-hp motors.
Learn more from AutomationDirect.


Cool Tools: Understanding portable measurement arms

Coordinate measuring machines (CMMs) were introduced in the 1960s to capture those complex geometries with a much higher rate of accuracy using a measurement bed, a probe, a computer, and software to operate the probe. The technology has progressed markedly since then, and portability has made these precise systems even more powerful and flexible. FARO Technologies runs through the basics of its portable CMM offerings like its FaroArm and ScanArm products, and provides a nice selection of supporting videos and articles for those newly interested in portable articulated CMM tech.
Read the FARO article.


Allite Super Magnesium is now award winner

Weighing 33 percent less than aluminum, while also being stiffer and stronger pound for pound, the new Allite Super Magnesium alloy has shown its mettle in classified defense and aerospace applications. Now it's available for wider use. Less expensive than carbon fiber, its applications include home improvement, sporting goods, aerospace, automotive, biking, and more. Three alloy variants are available to suit welding, forming/forging, or casting. These alloys feature excellent shock-absorption properties, good electromagnetic shielding performance, good heat dissipation, and recyclability. Allite received the Award of Excellence under the Process category by the International Magnesium Association in May 2019.
Learn more.


New electrically conductive flame-retardant plastic

Electrically conductive plastics continue to provide reliable EMI shielding in a wide variety of applications. Thermoplastics provide a good alternative to bulky metal enclosures due to their superior weight, EMI shielding capabilities, and simpler manufacturing process. However, before purchasing any thermoplastic, it is important to consider performance capabilities. Paige Ludl from the Chomerics Division at Parker runs through the basics of what you need to know about these materials.
Read this informative Parker blog.


Speed up design of bearing arrangements

Designers can now design complex bearing arrangements more quickly and easily, thanks to simplified software called SimPro Quick. This in-house software from SKF has the same core as more advanced products such as SimPro Expert and SimPro Spindle -- and retains many of their advanced features -- but is far easier to use. SimPro Quick is a single-shaft bearing simulation tool that was developed to quickly evaluate the design of bearing arrangements and their field performance based on relevant application requirements and conditions. This software also ties in with SKF's new online Roller Bearing Catalog, which is a live database of products.
Learn more.


Specialty hinges expand design possibilities for opening and closing

You might think that when it comes to opening and closing, all the possibilities of hinges have already been exhausted. Not even close. From the simplest designs to multi-joint hinges with complex kinematics, the Winco selection has everything needed for superior door and flap solutions -- including extra functions. Examples include hinges with 180° range of motion for heavy-duty applications, multiple-joint hinges, hinges with variable friction, locking and adjustable hinges, and units with an integrated spring that ensures independent return of the hinge. Huge selection available.
Learn more.


A new way to tie one on

The 4ZERO Cuff is the most advanced flexible polymer hand-cuff on the market and is used by select police and law enforcement agencies that demand the strongest and most durable product available. Now, the same material used to manufacture the 4ZERO Cuff is available from Micro Plastics in the line of extremely durable 4ZERO Cable Ties. The ties are designed to perform and hold their strength in extremely dry environments and in temp extremes from -30 to 400 F -- conditions that can leave normal nylon cable ties brittle and broken. Available sizes include: 8 in. (50 lb), 14 1/2 in. (50 lb), and 11 in. (120 lb).
Learn more.


Using a newly developed adhesive, a double-sided tape for tissues could replace surgical sutures

MIT engineers have devised a double-sided adhesive that can be used to seal tissues together. [Image: Felice Frankel, Christine Daniloff, MIT]

 

 

By Anne Trafton, MIT

Inspired by a sticky substance that spiders use to catch their prey, MIT engineers have designed a double-sided tape that can rapidly seal tissues together.

In tests in rats and pig tissues, the researchers showed that their new tape can tightly bind tissues such as the lungs and intestines within just 5 seconds. They hope that this tape could eventually be used in place of surgical sutures, which don't work well in all tissues and can cause complications in some patients.

"There are over 230 million major surgeries all around the world per year, and many of them require sutures to close the wound, which can actually cause stress on the tissues and can cause infections, pain, and scars. We are proposing a fundamentally different approach to sealing tissue," says Xuanhe Zhao, an associate professor of mechanical engineering and of civil and environmental engineering at MIT and the senior author of the study.

The double-sided tape can also be used to attach implantable medical devices to tissues, including the heart, the researchers showed. In addition, it works much faster than tissue glues, which usually take several minutes to bind tightly and can drip onto other parts of the body.

Graduate students Hyunwoo Yuk and Claudia Varela are the lead authors of the study, which appeared Oct. 30 in Nature. Other authors are MIT graduate student Xinyu Mao, MIT assistant professor of mechanical engineering Ellen Roche, Mayo Clinic critical care physician Christoph Nabzdyk, and Brigham and Women's Hospital pathologist Robert Padera.

A tight seal
Forming a tight seal between tissues is considered to be very difficult because water on the surface of the tissues interferes with adhesion. Existing tissue glues diffuse adhesive molecules through the water between two tissue surfaces to bind them together, but this process can take several minutes or even longer.

The MIT team wanted to come up with something that would work much faster. Zhao's group had previously developed other novel adhesives, including a hydrogel superglue that provides tougher adhesion than the sticky materials that occur in nature, such as those that mussels and barnacles use to cling to ships and rocks.

To create a double-sided tape that could rapidly join two wet surfaces together, the team drew inspiration from the natural world -- specifically, the sticky material that spiders use to capture their prey in wet conditions. This spider glue includes charged polysaccharides that can absorb water from the surface of an insect almost instantaneously, clearing off a small dry patch that the glue can adhere to.

To mimic this with an engineered adhesive, the researchers designed a material that first absorbs water from wet tissues and then rapidly binds two tissues together. For water absorption, they used polyacrylic acid, a very absorbent material that is used in diapers. As soon as the tape is applied, it sucks up water, allowing the polyacrylic acid to quickly form weak hydrogen bonds with both tissues.

These hydrogen bonds and other weak interactions temporarily hold the tape and tissues in place while chemical groups called NHS esters, which the researchers embedded in the polyacrylic acid, form much stronger bonds, called covalent bonds, with proteins in the tissue. This takes about 5 seconds.

To make their tape tough enough to last inside the body, the researchers incorporated either gelatin or chitosan (a hard polysaccharide found in insect shells). These polymers allow the adhesive to hold its shape for long periods of time. Depending on the application that the tape is being used for, the researchers can control how fast it breaks down inside the body by varying the ingredients that go into it. Gelatin tends to break down within a few days or weeks in the human body, while chitosan can last longer (a month or even up to a year).


VIDEO: MIT engineers led by Associate Professor Xuanhe Zhao have designed a double-sided tape that can seal tissues quickly. The tape could eventually replace surgical sutures, which don't work well in all tissues and can cause complications in some patients.

"Combining two innovative concepts, the research team succeeded in adhering quickly and effectively to the wet and soft surface of a tissue, and in maintaining good adhesion and mechanical properties for several days without causing too much inflammatory response," says Costantino Creton, a research director at ESPCI Paris, who was not involved in the research.

Rapid healing
This type of adhesive could have a major impact on surgeons' ability to seal incisions and heal wounds, Yuk says. To explore possible applications for the new double-sided tape, the researchers tested it in a few different types of pig tissue, including skin, small intestine, stomach, and liver. They also performed tests in pig lungs and trachea, showing that they could rapidly repair damage to those organs.

"It's very challenging to suture soft or fragile tissues such as the lung and trachea, but with our double-sided tape, within five seconds we can easily seal them," Yuk says.

The tape also worked well to seal damage to the gastrointestinal tract, which could be very useful in preventing leakage that sometimes occurs following surgery. This leakage can cause sepsis and other potentially fatal complications.

"I anticipate tremendous translational potential of this elegant approach into various clinical practices, as well as basic engineering applications, in particular in situations where surgical operations, such as suturing, are not straightforward," says Yu Shrike Zhang, an assistant professor of medicine at Harvard Medical School, who was not involved in the research.

Implanting medical devices within the body is another application the MIT team is exploring. Working with Roche's lab, the researchers showed that the tape could be used to firmly attach a small polyurethane patch to the hearts of living rats, which are about the size of a thumbnail. Normally, this kind of procedure is extremely complicated and requires an experienced surgeon to perform, but the research team was able to simply stick the patch on with their tape by pressing for a few seconds, and it stayed in place for several days.

In addition to the polyurethane heart patch, the researchers found that the tape could successfully attach materials such as silicone rubber, titanium, and hydrogels to tissues.

"This provides a more elegant, more straightforward, and more universally applicable way of introducing an implantable monitor or drug delivery device, because we can adhere to many different sites without causing damage or secondary complications from puncturing tissue to affix the devices," Yuk says.

The researchers are now working with doctors to identify additional applications for this kind of adhesive and to perform more tests in animal models.

Published November 2019

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