Supply Chain Update.

It’s been a little over a year since our post on Supply Chains and an update seems timely. Tight supplies, shipping delays and steady price increases seem to be the norm. “Transitory Inflation” continues to wreak havoc on pricing and none of us are exempt from dealing with it.

From a supply chain perspective, lessons were certainly learned by all and applied by many.  In our case, we were fortunate to have been designated an essential industry and equally as fortunate to have kept most production going throughout the worst of it. As such, we built up finished goods inventory that allowed us to quickly respond when business started to rebound early in the second quarter. 

Additionally, our vertical integration strategy developed from day one of operations (way back in 1991!) continues to pay dividends.  This makes it a little easier to hold a higher-than-normal raw material inventory because many fiberglass yarn inputs can be twisted and plied into a number of different products, effectively buffering our supply chain. For example, ECBC-150 1/0 fiberglass yarn supports more than 20 styles of finished PTFE coated fiberglass sewing thread. Some of those are industry standard ASTM D4030 sizes including R753-12, 18 and 24.  Others have stainless steel wire twisted in, are available in colors, etc…  As demand fluctuates between various sizes / styles of thread, we can react quickly and cost-effectively.  Vertical integration to the rescue!  Another example is S-2 fiberglass yarn that becomes over a dozen styles of S-2 fiberglass sewing threads with pretty impressive operating characteristics.  Of course, braided PTFE coated fiberglass draw cords and PTFE coated fiberglass yarns also share inputs. 

Pursuing vertical integration for all these years means that our raw material inventory has become quite versatile.  When carrying extra inventory makes sense, we do it with no hesitancy.  Of course, PTFE is the other “main ingredient.” Maintaining multiple sources for PTFE dispersion and carrying higher inventory levels is an obvious requirement. Maintaining this level of inventory certainly comes at a cost, but uninterrupted supply beats line shutdowns every time. Keeping our customers up and running with as little delay as possible affords them a competitive advantage.  We’ve been able to stay ahead of supply issues to date, and if things don’t get any worse we should be in good shape.

Pricing, however, has become another matter entirely!  This “transitory inflation” is looking a little less transitory, but we are hoping for a much smoother 2022.  Current cost increases are real and have the potential to impact investment opportunities if not addressed.  To date, we continue to invest in process improvements, equipment upgrades and employee growth.  Things would have to get a lot worse for us to slow down on investments…continual reinvesting in our business is what got us here in the first place.

Vertical integration made sense to us years ago when we started this business (1991) and now seems more important than ever. Our capabilities are second to none and give us maximum control of quality, lead times and costs. Rest assured that when you work with W.F. Lake Corp., you are working with a company that removes as many links in the supply chain as practical  (with the majority of our raw materials coming from North America). 

Thank you, as always, for your continued support. 

Stay safe and take care!

Custom Creative Solutions

We get some interesting opportunities here at W.F. Lake Corp.! I’ve touched on many of our unique capabilities in our PTFE coated fiberglass sewing thread operation, where we can twist in wire with Kevlar* or fiberglass, make colors of fiberglass yarns, make colors of braided PTFE coated fiberglass draw cords, etc. Today we’ll take a look today at some of the interesting PTFE coated fiberglass belts we manufacture.

We sometimes refer to Custom Products as PTFE coated fiberglass belts (or commonly Teflon* coated fiberglass belts), but they really are custom fabricated combinations of materials designed for unique applications. All of this starts with a conversation, and that conversation usually begins with “can you guys make something that will ‘fill in the blank’??”. Our unique capabilities in our belt department enable us to combine materials in unique ways to solve tricky problems.

For example, we make a “Rotary Kiln Seal” that combines PTFE coated Kevlar*, PTFE coated fiberglass fabric, and PTFE coated fiberglass sewing thread into a high temperature gasket for a rotating kiln. This seal had to operate in a high temperature and high friction environment for months at a time.  The fabric provided reduced friction against the hot face of the rotating kilns while the Kevlar* worked to reinforce the outer face. Of course, our fiberglass thread held it all together at extreme temperatures.  This kiln seal did not look anything like one of our PTFE coated fiberglass mesh belts, but we used those same capabilities to make it happen.

In another case, a customer asked if we could put “cleats” on a PTFE coated fiberglass belt. Cleats? Sure, but what are we going to make those out of those? This belt had to operate at 500 deg. F in a curing oven. Operating temperatures of 500 degrees Fahrenheit rule out most belting materials, but not PTFE coated fiberglass.  Still, we had never put cleats on one of our belts. Interestingly, the cleats were needed because this belt was required to run up a slight incline and product would slip down the belt if no cleats were installed. So, we made up some samples and settled on standing cleats 2” tall made with layers of PTFE coated fiberglass laminated together (essentially a small board of PTFE coated fiberglass). We bonded and sewed those cleats to a belt material and the problem was solved!

I could go on, but the point is that when it comes to PTFE coated fiberglass belts (or custom fabricated products) we are able to combine our unique processing capabilities with the wide range of materials we manufacture and come up with some pretty creative solutions. Since we perform all these operations in-house, ideas turn into samples quickly. The best of those ideas and samples often become unique products to solve your most demanding application needs. Give us a shout or zing us a note and we’ll get the ball rolling!

High Temperature Sewing Thread

What qualifies as high temperature sewing thread? In our industry, we typically consider a high temperature sewing thread to operate above 400 deg. F ( 200 C). Lower temperature threads abound and are used in great volume in your everyday life. The thread in your cotton shirt can handle over 200 deg. F. However, that does not qualify as “High Temperature Thread” from an industrial standpoint. While 200 degrees is certainly hot to the touch and dangerous, for industrial sewing threads, 200 F (93 C) is considered low temperature.

As noted above, our industry considers high temperature sewing thread to be a thread that operates above 400 deg. F (200 C). At that point, your choice in materials, sizes, colors, and finishes begins to diminish rapidly. With colors, for example, we manufacture Red, Orange, Yellow, Green, among others, but we do not offer shamrock green, fern green and seaweed green!  Additionally, as temperature increases, your material choices and color options diminish even further. ”Sewability” typically decreases as well. The high temperature sewing thread we manufacture includes PTFE coated Para-aramids (Kevlar by DuPont), E-glass and S-2 glass fiberglass, Quartz and combinations of steel or Inconel wire with each of these fibers. Para-aramids require the least number of changes in the sewing process versus fiberglass or quartz but limit out in continuous operating temperature to about 450 F (204 C). The maximum temperature limit of any thread we manufacture is PTFE coated Quartz thread at 2,000 deg. F (1100 deg. C). As previously noted, we can twist into the thread up to 10 strands of stainless steel or Inconel wire to enhance the “fail-safe” working limit of the thread or to enhance static dissipation.


Of course, sewing with these threads demands adjustments to equipment and to your expectations of throughput! Slower sewing machine speeds are required along with other adjustments and accommodations. Some sewing tips for high temperature sewing threads can be found HERE. In the case of fiberglass and quartz sewing thread, PTFE coating enhances sewability and reduces the potential for breakage. It also enhances chemical resistance and the buildup of contaminates. We modify our PTFE coating to make colors and enhance UV resistance of Para-aramid threads.

We manufacture the industry’s widest range of high temperature PTFE coated fiberglass sewing threads and PTFE coated para-aramid sewing threads. If our wide variety of products do not meet your unique needs, then remember that we have some unique capabilities that allow us to create all kinds of different combinations of materials to produce a specialty thread that meets your application parameters.

Of course, extreme operating temperatures also often come with extreme chemical exposures. In that case, our PTFE coating capabilities offer definite advantages to uncoated threads beyond enhancing sewability and reduced breakage. We’ll take a look at those advantages in another post.

When it comes to high temperature sewing thread, think of W.F. Lake Corp. first.  In the unlikely event we don’t currently manufacture the thread you need, we can quickly and cost effectively develop something to solve your most demanding high temperature sewing needs!

New Product Development

What drives new product development for a relatively small manufacturing business? In our experience, the bulk of new product development flows from existing customers’ needs.  In the case of W.F. Lake Corp., our ability to bring our many and diverse capabilities to bear are what lead to our successes with new product development (and therefore future growth). Equally important is the ability and desire to get samples into engineer’s hands as quickly and cost effectively as possible. In some cases, these new products are developed for a single application and remain in limited use.  In other cases, those unique properties required for a specific application are useful in a wide variety of other areas and, voila! We have a new product in our standard offering.  Many of our PTFE coated fiberglass sewing threads and PTFE coated Kevlar sewing threads came about in this fashion.

But how did we come to have these capabilities in house?  For W.F. Lake Corp., it started early on with the philosophy that sensible vertical integration not only cuts down on supply chain issues, but also leads to synergies across many disciplines.  It gives us the unique ability to control scheduling of trials, use the varied raw material in our inventory and adjust processing parameters quickly. 

Of course, keeping the lines of communication open with customers and letting them know of your capabilities and willingness to work on development ideas is of utmost importance.  Customers must also feel that finding a solution to their needs is as important to us as it is to them!

A few years ago, we were asked to come up with a high temperature thread with a “fail-safe” built in for possible temperature excursions.  We came up with the idea of combining S-2 fiberglass with 3 ends of Inconel wire that would then be PTFE coated. We were already producing sewing thread with E-glass and stainless steel wire, so this wasn’t much of a reach for us.  Our ability to twist fiberglass threads in-house, and also PTFE coat them in-house, resulted in SGT-243IL being developed within a few weeks. Final approval came quickly and now this thread has become a standard item being regularly produced. 

Another example is as simple as offering a pigmented PTFE coated fiberglass sewing thread to enhance the visual appeal of a finished insulation jacket.  It happens that we run various pigments in other areas of our operation (PTFE coated fiberglass yarn and PTFE coated fiberglass fabric) and were able to choose the right pigment from our stock, enabling samples to be delivered within days. The resulting Black PTFE coated fiberglass sewing thread is also now a standard product.

We apply these same principles across all product disciplines, including  PTFE coated fiberglass fabrics and PTFE coated fiberglass belts, where we coat, slit, sew, heat seal, sheet, and fabricate a variety of products.  Combining those capabilities has resulted in some unique products that solve interesting processing requirements resulting in Custom Materials.

If you have an opportunity that requires a unique high temperature PTFE coated sewing thread, draw cord, fabric or belt or any combination thereof, zing us a note or call.  We stand ready to put our capabilities to work quickly and cost effectively for your needs.

“Green” By Design

Do you ever wonder if what you produce makes a difference in peoples’ lives or has a positive impact on the environment? Our products and your products are “green” by design. Working together with our valued customers, our products can and do have a positive impact on the environment and on the lives of others.

Here at W.F. Lake Corp. we produce a number of products that contribute to a better environmental outcome. A couple of the many examples follow:

Our PTFE coated fiberglass sewing thread used to sew filter bags used in flu gas filtration media. This is a difficult operating environment that few products are capable of handling, but our thread can take the punishment. The filter bag itself cleans particulate from the air stream before it can be released into the environment.  The PTFE coating allows for easy cleaning of the bag while enhancing chemical resistance and sewability.

Another example is in reduced energy consumption through insulation: Any time you can reduce energy consumption, the environment wins!  Our PTFE coated fiberglass sewing thread is used to sew high temperature insulation jackets for things like gas turbines, pipelines, rotary kilns, etc…. Wherever you live, you know that simple, effective insulation can dramatically reduce your energy consumption.  Imagine how much energy can be saved when properly insulating very high temperature industrial operations!  The threads we manufacture are capable of operating against the hot side facing of these items where other threads would immediately fail.  Our PTFE coated S-2 fiberglass sewing thread, for example, operates to 1400 deg. F, while our PTFE coated Quartz sewing thread withstands 2000 deg. F!  Not only can they operate at these extremes, they facilitate the reuse and repair of these same insulation jackets.  We all know that “reuse” and “repair” are far better action words than “replace” when it comes to the environment!  And by limiting heat loss, our thread contributes to longer operational life of sensors, thermocouples, instrumentation, electric motors, etc…

We are also proud to say that we manufacture products that help make life safer for others as well.  When it comes to operator safety, our PTFE coated fiberglass sewing thread and PTFE coated fiberglass draw cord is used to help protect operators from extreme temperatures and chemicals.  Insulation jackets sewn with our thread keep heat where it belongs, thus minimizing the chance of an accidental skin burn, while safety spray shields using our thread and draw cord help contain chemicals in the event of a valve or flange leak.  Our PTFE coated fiberglass threads and draw cords won’t burn or support flame, will not rot or support fungus and are virtually unaffected by most chemicals.  When our customers use our products to fabricate these products, they are helping others remain safe every day. 

We at W.F. Lake Corp. thank our customers that use our products to make life a little safer and the environment a little cleaner while providing good, meaningful jobs in their respective communities!

PTFE Coated Fiberglass Sewing Thread…what is it worth to you?

“Wow, that thread is a bargain!”… haven’t heard that in a while, but when it comes to PTFE coated fiberglass sewing threads or draw cords (or any of our other PTFE coated sewing thread products) used to fabricate insulation jackets, safety spray shields, filter bags or other high performance products, our sewing threads are almost always the least expensive component of any finished product and perform perhaps the most critical function by holding it all together.

When manufacturing a safety spray shield or an insulated valve cover, certainly the fabric cover material itself (whether it is PTFE coated fiberglass or another high-performance material) is by far the most expensive component.  Take a look at the actual weight or length of sewing thread holding all of this together and consider that a typical yield for R753-18 is in the range of 2000 yards per pound… how many pounds are in that jacket (certainly less than one).  Then look at your cost of thread used versus cost of fabric used… not even close!  The same goes for the PTFE coated fiberglass draw cord holding the cover closed… not even close!

Certainly the “work-horse” of the high temperature sewing thread market is our PTFE coated sewing thread made with E-glass fiberglass.  This is our R753-series thread.  The cost per pound certainly increases when using S-2 glass threads or Quartz sewing threads, but the performance characteristics also improve dramatically, especially when it comes to maximum operating temperatures.  Then look at our PTFE coated Kevlar* threads where the cost may seem high, especially if we’ve twisted in one or more ends of Inconel wire…but that yield is in the range of 3,000 yards per pound…a pretty good deal we like to think!

From a manufacturing standpoint, it is worth noting that when yields are in the thousands of yards per pound of thread, processing time is also great.  Twisting time, coating time and of course raw material costs add up to what may seem like an expensive thread, but this is not cotton and much is demanded of it in the field.  We perform all twisting and coating functions in-house, which allows us to react quickly to new opportunities, make small runs and control costs as much as possible, but when you consider what this thread does and how relatively little of it is a cost component in the final product, you can’t help but think “Wow, that thread is a bargain!”.

                                                                                                                *Reg. DuPont

Supply Chain Update

First, thank you for your continued support.  As an Essential Business, we have been in continuous operation since this pandemic began, following CDC guidelines with the safety of our employees and their families our #1 priority.  Now, as we continue to navigate through this pandemic response, we all may want to take another look at our operations and see what lessons can be applied to our businesses. 

Lessons have certainly been learned about supply chains at the national level concerning PPE equipment! As a manufacturing operation, consideration should certainly be given to the length of our own supply chains and the number of connecting links that hold it together. 

When it comes to PTFE coated fiberglass sewing threads, yarns, draw cords, and other products, rest assured that you are working with perhaps the shortest “supply chain” in the industry.  Our capabilities are second to none and give us maximum control of quality, lead times and costs. Our capabilities also allow for timely and cost-effective new product development.

Vertical integration has worked wonders for us.  Initially written in 2018, this blog post still applies today.  Vertical integration made sense to us years ago when we started this business (1991) and now seems more important than ever! Please take a moment to read that old post… and rest assured that when you work with W.F. Lake Corp., you are working with a company that removes as many links in the supply chain as we realistically can, with the vast majority of raw materials coming from the USA! 

So, what do you guys make?

In casual conversation it is not unusual to hear the question “So what do you do for a living?”. Whenever that question comes up, I try to gauge the interest in my initial reply before going into too much depth

My immediate response to “so, what do you do for a living?”
is that “our products are on the space station and in your local fast food
restaurant and many places in between”. If their eyes haven’t glazed over,
and if a follow up question is asked, I’ll get into more detail. We are
fortunate to run a business that crosses over many industries with many neat
applications that are interesting to anyone who is involved with manufacturing
in just about any way. The second line in my reply is that you may not have
seen or used our products, but they have played a small part in your life!

PTFE coated fiberglass products find their way into diverse
applications because of their
unique operating properties
. High temperature resistance, electrically insulating,
chemical resistant, non-stick, will not burn or support flame, excellent
tensile strength, FDA approved for direct food contact, etc. 

In industrial applications, Teflon* coated fiberglass
fabrics, tapes, belts, sewing threads, cords and yarns take advantage of one or
more of these properties and can be fabricated or further processed to make
some pretty unique items. The space station items include PTFE coated fiberglass
sewing threads
(space suits, insulation panels), PTFE coated fiberglass
braided tie cords and lacing tapes (wire bundles, draw cords) and even PTFE coated fiberglass
(insulation quilts, covers).  When it comes to your local
fast-food restaurant, our PTFE coated fiberglass fabrics end up as “baskets”
in toaster ovens, liners for clam-shell grills and cookie sheets for baking,
well, cookies
!  Some more unique applications include embroidery
threads for very high temperature exhaust gas shields (won’t fade in the high
heat and won’t burn or support flame and are not attacked by any fuels or
hydraulic fluids), dryer belts
for screen printers
(high temperature, non-stick), smoker
rack liners for smoke-house meats
(FDA approval, high temperature,
non-stick), and PTFE
Coated fiberglass sewing threads
(stitching insulation blankets for gas
turbines, exhaust manifolds, engine compartments).

If you’re still reading, then at some point you developed an
interest in manufacturing at some level. Thanks for hanging around!
Manufacturing appears to be on the rebound and many exciting applications for
PTFE coated fiberglass products are certainly still ahead…we look forward to
working with you on your unique application. Zing us a note for more information!

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

  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!