9 Tips for Extending the Life of Your Dryer Belt!

Screen print dryer belts made from PTFE coated fiberglass mesh operate in extreme temperatures and offer release characteristics that few other materials can match…but they are not inexpensive, and care should be taken to get the maximum life from these belts.

Here are a few tips to help make your belt last a little
longer:

  1. Take a moment to be sure when ordering a new belt that you get the dimensions right. These belts are nearly impossible to modify in the field given the extreme heat and pressure required to seal edges and reinforce the “bullnose” for the alligator lacing (or other splice type).  If your mesh dryer belt is too long, it will have to come back to the factory to be shortened… if it’s too short, we will have to make a “dutchman splice” that will lengthen the belt, but you will now have 2 splices in your belt and tracking issues may result.
  2. Take time to install a new PTFE coated fiberglass mesh dryer belt correctly.  Here’s a link on how to do it right. Be sure you get it started right and you will have better shot at a long belt life.
  3. Load the belt carefully. Most screen print dryer ovens do not have automatic tracking systems installed.  They typically run slow and can often run for years with no adjustments if installed properly (#2 above).  In order to give your belt a good chance of tracking properly be sure to load it evenly.  You can load the center of the belt or alternate left and right as the dryer runs.  Avoid heavier products placed only on one side of the belt, as this can pull the belt out of square and distort the weave. 
  4. Avoid crowned pulleys. Crowned pulleys are sometimes used in belting applications, but with a Teflon coated fiberglass mesh belt, anything but the slightest of crown in the pulley can actually split the belt in two.  Remember that these are made with PTFE coated fiberglass yarns and, like anything fiberglass (imagine a fishing rod) if you repeatedly bend it over a sharp radius, you will wear it down, and possibly break it at that point.  A mesh dryer belt is constantly flexing as it travels over pulleys and deflects slightly under the load it is carrying.  If you have your heart set on installing a crowned pulley, check with us first to see how much of a crown you can safely put in place (hint: It isn’t much!).
  5.  Do not over-tension the belt. If slippage occurs, the first thing to do is to clean your drive pulley.  There should be enough friction as delivered by the factory to drive the belt without over-tensioning it. These belts are made with a woven PTFE coated fiberglass yarn and are not intended to be tensioned like a V-belt on your car!  You can easily pull the splice out of the end of the belt, tear the alligator lacing at the corners or distort the belt to the point where it does not track properly (you could also take the dryer out of square, causing tracking issues).  If you need additional friction in order to keep the belt moving, contact us and we’ll let you know what we think is the best way to get it moving. It involves applying a “lagging” tape to the drive roll, but you must do it right!
  6. Support heavy loads with a slider bed underneath the belt.  Of course, if you purchased your dryer with printing glass panels in mind, you no doubt already have a support bed of either flat panel (stainless steel) or rollers to hold all that weight.  If you are retrofitting your dryer, be sure to consult the dryer manufacturer before making significant modifications but do support the load properly one way or another because these belts are not intended to support heavy loads in free-air under tension.
  7. Do not stop your belt under a hot lamp.  If you’re using an infrared curing dryer (electric or gas fired) be sure that the belt does not stop under a lamp that is hot. High temperature heat sources can destroy the PTFE coated fiberglass substrate, effectively “burning a hole” in the belt.  If this does happen, this is one of the few repairs you can make in the field.  Contact us for a repair kit that will include materials needed to make basic repairs.
  8. Take care not to let a cart, box or other item contact your mesh dryer belt while it is running. We’ve seen a number of belts split in two when a cart or a box was allowed to rub against the belt for an extended period of time.  A short tear can sometimes be patched in the field, but long tears often ruin the belt, as there is no good, cost effective way to bond it back together.
  9. Finally, do not cut your belt off the machine in order to measure it. Use our simple guide to measure it properly. This seems obvious, but we’ve seen that happen and it can be wasteful.  In many cases, we’ve made new dryer belts for customers who then send us their old belt that is still in reasonable shape and we’ll give it a “tune-up” that allows it to be used as a spare, backup belt.

We’ve been manufacturing PTFE coated fiberglass fabrics, tapes and belts since 1991 and are ready to help in any way we can.  Just “zing us a note!”

PTFE Coated Fiberglass: Sintered versus Unsintered

The definition of “Sinter” is: “To make a powder coalesce into a solid or porous mass by heating it without liquification”.  We typically think of sintering as it relates to metal (like bronze or brass).

W.F. Lake Corp. manufactures both sintered and unsintered materials.  With sintered PTFE, we essentially have taken a PTFE powder dispersed in water and fused it using heat into a hard, slippery coating that operates at very high temperatures, is chemical resistant and very few things stick to.  These are sintered PTFE coated fiberglass products.  Unsintered products are essentially an impregnated coating of PTFE that is dried in place, but not fully fused. It has a “waxy” feel and is less abrasion resistant.

Why sintered?  Sintered PTFE coated fiberglass fabrics, tapes, belts and sewing threads are the typical form of PTFE coated textiles you see in the marketplace.  They are the work-horse products for food processing (belts and sheets), packaging (L-Sealer bars), molding (composite release sheets), flu-gas filtration (PTFE coated fiberglass sewing threads), high temperature, hot face insulation (S-2 glass, Quartz sewing threads, etc…), and many other applications.  In these cases, PTFE powder suspended in water is fused at high temperatures (sintered) to form a solid PTFE coating.

Why Unsintered?  We are unique in that we also coat many of our fiberglass yarns with unsintered PTFE.  This process requires precise temperature control to essentially “bake” the PTFE particles without fusing them together.  This leaves a waxy type coating that has both penetrated the fiber bundle and leaves a portion of the coating on the surface of the yarn. In most cases, these yarns are braided over wire conductors or made into lacing tapes and tie cords. The advantage an unsintered PTFE coating is that it allows for further processing and bonding of subsequent layers of PTFE; in the form of PTFE films, coated fiberglass fabrics or even additional PTFE dispersions.  When all of these are finally fused, or sintered, our customers form a homogeneous coating that very effectively resists chemicals, operates at high temperatures, will not burn or support flame, will not rot or support fungus and provides excellent electrical insulation.

Most of us use sintered PTFE products virtually every day.  Pots and pans, baking sheets, even breathable, water repellent rain ware (and sometimes vascular grafts!).  Unsintered PTFE products in daily use are less prevalent, but are available as Thread Seal Tape (unsintered PTFE film), packing (valve stems, shaft logs) and gaskets (valve stems), etc…  PTFE is an amazing material.  Give us a call with any questions or application opportunities… we’re here to help!

Our Magic Principle: Vertical Integration!

How is it that W.F. Lake Corp. can turn out so many variations of PTFE Coated fiberglass threads, draw cords and yarns so quickly at competitive prices regardless of quantity?

One magic principle: Vertical Integration!

When W.F. Lake Corp. started some 27 years ago, one goal was to be able to develop specialized products in relatively small runs while supplying the “standards” at competitive prices. We had lots of ideas and realized that you have to get a sample in an engineer’s hands as quickly as possible in order to remain relevant.

Ideas are one thing, bringing them to fruition is another! So we started out focusing on our strength, i.e. PTFE coating of fiberglass materials; the standards: PTFE coated fiberglass fabrics, tapes and belts, sewing threads, yarns and draw cord.

As we continued to grow, it became clear that vertical integration could make us more competitive. We certainly could have kept going without vertically integrating, but opportunities for creative new products kept coming up!

Our first move was to greatly expand our braiding operation. We had improved the basic PTFE coated fiberglass draw cord through our coating expertise, and we were buying lots of braided fiberglass. This allowed us to “become our own best customer” as well as improve innovation. Those first braiders are long gone, as they came to us in pretty rough shape and we worked them pretty hard, but they confirmed that we were going about this in the right way (“walk before you run”). We were now able to make lots of different braids with lots of coating modifications. And since we controlled the braiding itself, new products were in our customer’s hands in days, not weeks or months. Additionally, small volume runs became simple for us…no more minimum order quantities from vendors! Want to try 20 feet? No sweat! How about a braided, PTFE coated Quartz tie cord? Sure.

Next up was the twisting operation. We were chugging along with industry standard products and we had developed a few specialized PTFE Coated Fiberglass Sewing Threads. It was time to look into vertically integrating into the twisting operation. This is a bit more complicated, but we started buying and re-furbishing twister frames. Suddenly, all of those crazy ideas were easy to test out, and customer driven opportunities were addressed quickly and cost effectively. Out came PTFE Coated S-2 fiberglass threads, threads with stainless steel wire, PTFE coated threads with Inconel wire, PTFE coated Kevlar* threads with as many as 10 ends of stainless steel wire, PTFE coated Quartz sewing thread, different colors, etc…How about a PTFE coated Kevlar/Carbon Fiber Composite thread… can do! Some of these are small volume products, but that is fine with us! As a bonus, our twisting operation also feeds the braiders and the yarn coaters!

I could go on and on, (yeah, we know) but I’ll wrap it up! Suffice it to say that we continue to vertically integrate operations when it makes sense. Exploring new ideas is now simply a matter of walking out to Mark in twisters, or Fred in braiders, or Dave in the coating room, or any of a number of other employees and asking them to help out. They have, over the years, developed a keen understanding of what our equipment is capable of and they can usually get us samples very quickly, sometimes in a matter of hours!

Over the years, we have gained a good deal of knowledge about what today’s high performance materials are capable of and what combinations of materials make sense. We’ve gotten pretty good at working with customers to get them what they need in a hurry. Give us a call or zing us an email with your next development opportunity…if we don’t already have a solution, we are willing and able to give it a go and deliver samples in a hurry!

 

*Kevlar by DuPont

PTFE Coated Fiberglass Lacing Tapes and Tie Cords

W.F. Lake Corp. manufactures a wide range of PTFE coated fiberglass lacing tapes and tie cords that meet a number of military and commercial specifications.  These products are amazing in their long term performance characteristics.  Once installed, they rarely, if ever, need attention…no one wants to open up an airframe for a failed “zip tie”!  Unlike plastic zip ties, our products will not burn or support flame, will not rot or support fungus, are unaffected by virtually any chemicals including aviation fuels, diesel fuel, gasoline, oil, hydraulic fluids, etc.  They are unaffected by UV light and are highly flexible due to the nature of the PTFE coating and braiding process used in their production.

Of course, a “Lacing Tape” is a flat braid, while a “Tie Cord” is a round braid.

W.F. Lake Corp. puts extra effort into our lacing tapes and tie cords by first coating each fiberglass yarn with PTFE prior to the braiding process. This extra step of glass impregnation before braiding acts as protection against fiber-to-fiber abrasion during fatigue.  Also, when high local stresses occur, the PTFE coating allows mechanical transmission of the load within the lacing tape or tie cord to maximize load sharing between the fibers.  Typically, the PTFE coating represents 15% of the overall braided cord.

Some of our PTFE coated fiberglass lacing tapes and tie cords have been tested for outgassing properties by NASA (contact the factory for the location of this information).  Many of our products are also designed to meet military and commercial specifications including:

Military Specifications:

 

Marshall Space Flight Center

 

When it comes to high performance braided lacing tapes and tie cords, think of W.F. Lake Corp.!

 

A lesson in PTFE…what exactly is it?!

What is Teflon*? What is PTFE? W.F. Lake Corp. uses PTFE from a number of sources. Teflon* is PTFE which is polytetrafluorethylene. Is there a difference?  No.  There are different grades, of course, and some different chemistry to a point. Check it out on Wikipedia (I know… I know) but it gives a pretty accurate account of what it is, where it is used and how it was discovered. It goes by many names, but as most of us in the industry realize, the best known brand name of PTFE is Chemours’ Teflon* (Teflon* is a registered trademark of Chemours.  Chemours is the company recently spun off by DuPont).  It is an amazing material and is used in many applications including our high temperature PTFE coated fiberglass products like fabrics, tapes, yarns and sewing threads.  So when someone looks for Teflon Coated Fiberglass Sewing Thread, they will often find PTFE Coated Fiberglass Sewing Thread in the search.  While we do use some Chemours products, we don’t always use Teflon* brand.  We therefore advertise our products as “ PTFE coated fiberglass sewing thread “, or “ PTFE coated fiberglass fabric “ etcetera.

As always, give us a call or zing us a note with any questions.  We manufacture a wide range of PTFE coated fiberglass yarns, threads, fabrics, tapes and belts. We may not be the largest processor of PTFE coated fiberglass products in the world, but we may have the most diverse offering.  We’re proud of our ability to apply this amazing fluoropolymer to such a wide variety of materials, providing solutions for your most demanding applications.

*Teflon is a registered trademark of Chemours