“Will plastic rollers or cam followers last in my application?”

Together with a leading university we developed a roller life calculation, to reassure our customers of the reliability of Intech Power-Core™ rollers. This formula includes calculation of flat development and number of expected life cycles.

The roller life calculation is based on experimental data collected in tests over a period of three years. We can say with confidence that the calculation has become a reliable predictive tool for durability of plastic rollers.

Frequently we get asked about the durability of our plastic rollers and cam followers. We thought it would be good to give readers a quick link from our blog to the Roller Card, which you can download, edit and then send to us with data pertinent to your application:
http://www.intechpower.com/Roller_Calculation.html

Example of Sketch and Input Data for Roller Durability Calculation

Happy Holidays from Intech Corporation

Thank you for your interest in our company. We wish you a peaceful holiday and a prosperous year in 2010.

Happy Holidays

Effects of Moisture on the Tensile Strength of Nylon

Continuing the theme of our last blog entry, moisture absorption is also a factor in determining the tensile strength of nylon, as shown by this chart:

Moisture Absorption vs Tensile Strength

You can learn more by reading a complete article on this topic that appeared in Machine Design at: http://www.intechpower.com/Machine%20Design%20Nylon%20Article.pdf

Moisture Absorption Causes Swelling in Nylon (Polyamides)

Moisture absorption is a key factor to consider during nylon material selection. Design engineers need to take account of the application and tolerances because, machined component dimensions for a particular nylon grade will change if they were originally designed for a dry environment but are then used in a humid location. Moisture is absorbed by the part, and at some point when it reaches equilibrium, swelling can occur, and the fact that the dimensions of the part are subsequently altered increases the likelihood of premature part failure.

Injection molding, extrusion, and casting can all be used to form nylon, and the process used will influence material properties. In the case of injection molding, nylon is subjected to high compression and decompression within a short period of time. Correct mold design, timing, and precise pressure control are vital, and accurate thermal history for the part when both inside and outside of the mold should be maintained.

If water is present where extrusion is used in forming a part, severe problems can result. Therefore, moisture content and cooling rates should be monitored rigorously as they will both influence the physical properties of the extrusion.

Extruded rods or slabs can also be susceptible to shrinkage voids that are caused while the inside is in a molten state but the exterior surface begins to solidify. While the interior cools and shrinks under thermal contraction and crystallization, a void forms as the exterior no longer contracts. One solution is for extruders to use controlled water or vacuum quenching to cool formed parts. Note that even where forming processes can be precisely controlled, physical properties and dimensions may change over time when exposed to changing transport and storage conditions.

Dimensional change polyamides versus moisture

The diagram shows moisture absorption causes swelling which results in up to 3.3% dimensional change in the nylon 6 family. When designing with nylon 6 or 6/6, this has to be taken into consideration, for example, when calculating backlash in gears, or when storing precision parts for prolonged periods of time in changing environments. For cast nylon 12 such change is negligible, even when permanently immersed in fuels, oils, and chemicals.

Self-Lubricating cam followers replace steel and stainless steel wheels in aerospace, refrigeration, and outdoor applications such as ski lifts.

Our customers have been asking us to help them with components for machines that will operate in ever harsher conditions. Intech iCam Followers® and Power-Core™ guide rollers feature a unique crystalline structure that is resistant to flow under static load, and provides long-wearing, non-lubricated performance. The devices do not wear out the rail, do not absorb moisture and, when fitted with stainless steel bearings, are suitable for wash downs and harsh and corrosive environments.

Unlike other plastic material, Power-Core™ does not become brittle in low temperatures. iCam Followers® and Power-Core guide rollers reduce maintenance and down time by retaining good bearing fit from -40° to 160° F, retaining elasticity, and absorbing shock and vibration in sub-zero temperatures. The devices are not only quiet and easy rolling, they do not generate metal particles, which can further increase down time potential.

Intech Rollers for High Security Door

Intech Power-Core rollers, cam followers, and trolleys are assembled from precision machined high performance, self lubricating engineered plastic tires and quality roller bearings. The plastic part of the roller fully envelopes and embraces the bearing outer racer which in turn provides high capacity to carry side loads.

The Power-Core rollers and iCam Followers® are available in stock sizes with load capacity from 60 to 500 lbs. Trolley assemblies feature aluminum track and trolley systems with attachments. Custom sizes and dimensions and tire shapes can be developed to meet specific applications.

Gear Train Design For Zipper Pouch Packaging Machine

During the developmental stage of a new zipper pouch packaging machine, Hayssen, a division of Barry-Wehmiller, the largest packaging automation group in the Western Hemisphere asked us to devise a Power-Core™ non-lubricated gear solution to replace a structure of timing belts and pulleys that required frequent, lengthy machine shut-downs for maintenance and replacement service.

Hayssen’s Lead Developer for the integrated transverse zipper applicator noticed that the original timing belt and pulley design had significant problems with precision feed length, cut, placement and seal of thicker, higher profile zipper tapes. In addition, the difficult-to-reach timing belt and pulley assemblies stretched around tight radii and became prone to breakage and frequent maintenance.

Intech’s engineering team were able to determine a non-lubricated solution to the power train design using our gear system that capitalized on a truly unique power train design and resultant production uptime.

A pouch/pillow bag with integrated zipper is formed on the Hayssen vertical form/fill/seal machine using an exact amount of zipper material by applying it to the film before it is formed into the finished bag. Intech engineers responded to mechanical design issues that included overall clearance and tight-quarters required by the zipper tape pathway and a minimal backlash by designing small pitch diameter Power-Core gears for the gear train. In addition, concerns for USDA-3A compatibility mandated the use of stainless steel and non-corrosive gear materials.

Using proprietary gear life calculations and a special gear tooth modification to accommodate the set center distances and speed ratios of the rubber rollers, Intech was able to overcome the tight center distances and frequent stop and go requirements with a design solution that Intech calculated to last a minimum of 4 years in continuous operation without lubrication.

Geared Roller Assembly

“Green” Manufacturing Initiative from Power-Core™

Power-Core rod with cast-in metal core for machining into gears

As manufacturers, transport operators, processors and service providers seek to achieve more environmentally benign operations, Intech Corporation steps up to the challenge with the environmentally friendly Power-Core material and Engineering calculations to predict performance wear-life and cost-savings.

Specially formulated, self-lubricating Intech Power-Core™ composite material exhibits a characteristically tension-free crystalline-structure that provides exceptional stability, quiet performance and outstanding tensile and flexural strength. 

Power-Core material reduces wear, noise, vibration, maintenance, lubrication and contamination.  A key characteristic of the Power-Core material is its exceptional self-lubricating, long-wearing performance in demanding high temperature, sub-zero, high moisture, high voltage, high friction and weight bearing applications that often cause metal components to fail.

Lubrication-free Power-Core components eliminate the need for hand or centralized lubrication and the attendant problems they cause when lubricating pipes or lines dry out or the content becomes too viscous or runny and clogs or overflows into the machinery—resulting in unscheduled production line shut-down, emergency cleanup, product waste and damage to machinery, equipment, personnel, plant facilities and the environment.

Similarly, the environmentally friendly Intech Power-Core products avoid safety concerns related to worker exposure to noise and direct contact with the lubrication, lubricated parts, hazardous odors, spills, falls resulting from spills and seepage from stored lubricant or wastes.

In addition, Power-Core materials are perfect for long-wear, accuracy and quiet performance like those required in ski lift operations, high speed paper processing and converting, airplane cargo door hardware, packaging equipment, elevator guides, neo-natal incubators, x-y linear positioners, electrically insulated car painting robots and in-plant equipment subjected to demanding high speeds or frequent wash-down cycles.

Our Engineering team at Intech offer custom sizing and design assistance for replacing cast iron, steel, nylon and Delrin® parts with Power-Core materials.

Power-Core™ Screen Supports a Key Component in Fish Crowder for Oregon River Project

Following up on our first blog, we realized that increasingly we have become an integral part of projects that impact the environment in a positive way. Intech appreciates the trust of corporations and government organizations alike to use our Power-Core™ products for such projects.

Intech was approached by consultants working with the US Army Corps of Engineers to design special screen supports for an Adult Fish Collection Facility at the Cougar Dam and Reservoir. This facility is located on the South Fork of the McKenzie River directly downstream of the dam in Oregon.

The Fish Crowder barrier uses Intech screen supports made of machined stainless steel, these ensure safe operation and a long life in the collection facility. The crowder is used in the concrete raceway for cleaning, grading and herding fish together for loading tank trucks or pumping into other collection ponds through pipes. This fish collection facility is due for completion in May 2010.

Fish Crowder barrier with Intech Screen Supports

You can read about other related Fisheries and Wildlife Resources projects at the US Bureau of the interior web site:  http://www.usbr.gov/pmts/fish/Capabilities.html