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Syntactic foam as a mold material?

Though syntactic foam is most widely recognized for top performance as a plug assist or pusher inside a mold, a recent study found high performance when used as a mold.  Andrew Sneeringer, a recent graduate of Pennsylvania College of Technology in Williamsport, PA, compared the performance of MDF board to HYTAC-C, a unique syntactic foam resin system that may be cast to shape at a customer facility.  Performance was compared for mold cost, mold integrity/usable life and part quality produced.  The results, as published in Thermoforming Quarterly Magazine (second quarter 2012), provide beneficial details for all.  Full articles become available over time for download at or contact CMT to discuss your immediate application needs.

CMT Hires International Sales Manager in Response to Market Demand


April 8, 2013 – Attleboro, MA

CMT Materials announced today that Conor Carlin has joined the firm as International Sales Manager. “I am looking forward to working with the team at CMT, a company that is deservedly recognized as a leader in its field.” Carlin, who worked for a decade in thermoforming machinery sales in the US and Europe, returns to plastics after completing an MBA program at Babson College in Wellesley, MA where he focused on entrepreneurship and sustainability. “With increasing demand for plastic packaging around the world, the production benefits provided by HYTAC® Syntactic Plug Assist Foams have resulted in increased time and resource requests from CMT. Conor will help us grow in those areas where we are seeing increased demand for our materials,” said Terrence Woldorf, General Manager at CMT. Carlin is the Editor of Thermoforming Quarterly, a Technical Journal of the Society of Plastics Engineers.

CMT Hires Int’l Sales Manager

CMT Materials, Inc. Awarded Grant for Continuous Improvement Program

Attleboro, MA – April 16, 2013

CMT Materials, Inc. Awarded Grant for Continuous Improvement Program

CMT Materials, Inc. has been awarded a grant to implement a Continuous Improvement through Lean Manufacturing program.  The funds support training over a two-year period in an ongoing effort to improve products, services and processes.

The firm, which designs and develops specialized syntactic foam materials for use in plastics and oceanographic industries, will focus on creating a work environment where all employees strive for perfection by removing successive layers of waste, reducing of lead times and costs, and improving efficiency, productivity and quality.  “Along with immediate benefits to today’s production, this program will allow us to continue our steady growth through the effective use of existing resources. It will also enable us to welcome new employees into a culture of personal and professional excellence,” says Terrence Woldorf, General Manager.

The project is funded by a Workforce Training Fund grant through the Commonwealth of Massachusetts, Executive Office of Labor and Workforce Development.  The grant program is administered by the Commonwealth Corporation.  For more information on the program, visit

CMT Receives Grant for Continuous Improvement Program

The World’s Toughest Syntactic Foam – HYTAC® XTL

HYTAC®-XTL is the first material to combine the machined surface quality of an epoxy syntactic with the durability and dust free machining of a thermoplastic syntactic foam. Thermoformers and toolmakers report excellent performance when using XTL for plug assist.

HYTAC®-XTL was developed to offer an improved surface quality after machining when compared to our popular HYTAC-B1X.  This is particularly important when working with sticky or transparent plastics due to the challenge of polishing any thermoplastic syntactic material.

In addition to enhanced surface quality, HYTAC®-XTL has these outstanding attributes:

  • The highest toughness ratings for any syntactic foam
  • Superb machinability with no dust
  • Excellent where edge definition and detail are required
  • Low thermal conductivity
  • Low coefficient of thermal expansion
  • Excellent material distribution

CMT Materials will be promoting its new line of XTL thermoplastic syntactic foam at several major tradeshows this year including Chinaplas in May, SPE Thermoforming Conference in September and K in October.

How to Choose the Right Plug-Assist Material

A question that we get asked a lot is, “What type of syntactic plug material should I use for my application?” Like most things in thermoforming, the answer is, “It depends.” However, we recognize that thermoformers and toolmakers want some degree of certainty when choosing plug materials. That’s why we have created a selector guide to help processors make an informed choice.

Each material is optimized for performance with different types of plastic sheet, temperature use, machining conditions, surface finish, durability and even pricing.  While every HYTAC® product is suitable for a wide variety of applications, making the “best” choice reduces machining costs, improves material distribution, enhances clarity, reduces plastic residue sticking to the plug and maximizes plug life.

Though some materials may initially cost more as a percentage of the overall tool price, it is important to understand the total cost of ownership. In other words, the savings generated over the life of a particular project should all be taken into consideration, from time in the machining center to set-up time, from production of initial parts to perfection of consistent parts, not to mention the cost of replacing any damaged plugs due to a production mishap.

Please refer to our CMT Material Selector Guide for more information. Of course, you can always contact us at any time and we’ll be happy to discuss your application with you.

Best Practices for Machining HYTAC® Plug-Assist Materials

Machining syntactic foam is not like machining other materials such as wood, aluminum or plastic. That’s why we have created guides to help toolmakers and thermoformers select the right tools and the right geometry for machining and cutting HYTAC® syntactic foams from CMT.

Properly machined, HYTAC® materials generally require minimal extra polish or surface preparation.  Following our guidelines will improve surface quality of the finished plug and aid consistency of plug performance.

Tools must be sharp to obtain a satisfactory surface finish when machining HYTAC® products. High helix geometry with a special point for upward chip flow, smooth sidewall and improved bottom finish is recommended. Dull cutters or incorrect geometries will result in poor surface conditions. High speed steel cutters are quickly dulled and are not suitable for use with syntactic foams. Solid carbide cutters are preferred due to the sharp edge and long life that may be obtained. Diamond coated tools may last longer, but are not required and have not been found to provide additional benefit in machining.

Once the tool is selected, dialing in an optimal feed rate on any CNC milling machine is done using the formula “Feed Rate = Chip Load x Spindle RPM x # of flutes.”  Chip load is the measure of thickness removed by each cutting edge (flute) in a single rotation.  The intended chip load for milling tools should be available from your tool supplier.  Optimal speeds, feeds and depth of cut when turning are listed on our turning guide.

If you have a new  job or just some questions about plug machining or polishing, contact us today

CMT Materials, Inc. To Expand in Europe with New Facility in Netherlands


CMT Materials, Inc. To Expand in Europe with New Facility in Netherlands

May 14, 2013 – Attleboro, MA

CMT Materials, Inc. will open a new location in The Netherlands this year. The new facility will include full inventory, sales and customer service personnel, and cut-to-size services.  “By setting up a physical presence that is centrally located in Europe, we will be better able to serve our European customer base,” says Terrence Woldorf, General Manager. “We recognize that our customers need quick turnaround times for many new thermoforming projects. This new location will allow users to get our HYTAC® products within 2-3 days.”

The new facility will provide same-day shipping within Europe, reducing lead times and shipping costs. The full inventory of HYTAC® syntactic foam products will be available in all sizes of rods and sheets. The company expects to begin shipping orders directly from the new facility on September 1. Details will be sent directly to customers over the summer.

About CMT Materials

CMT Materials is the acknowledged leader in the design and development of syntactic foams for use as plug-assist materials. The innovative HYTAC® family of products has been designed specifically for the thermoforming industry.  Plug assist technology allows plastics processors to reduce starting gauge, reduce cycle times and improve material distribution. CMT Materials will be promoting its new line of XTL thermoplastic syntactic foam at several major tradeshows this year including Chinaplas in May, SPE Thermoforming Conference in September and K in October. For more information, visit

Best Practice: Polishing HYTAC® Materials

HYTAC® materials may be polished to a smooth surface finish condition. A properly polished plug will reduce scratching and aid in plug life/reduce sheet stick to the plug.

Syntactic foams are a variety of combinations of epoxy, plastic and hollow glass microspheres.  The same properties that make these foams the top choice for plug assist can create challenges in polishing.  The goal of sanding is to smooth microscopic peaks to eliminate potential scratching, prepare the plug for use and to modify surface area for different frictional performance.

Thermoset Epoxy Syntactic foams (HYTAC-W, WF, WFT, FLX, FLXT and C1R) may be wet or dry sanded using random motion. When following CMT machining/turning guidelines, most users find 220 grit sandpaper provides the appropriate roughness as a starting point. Finer and finer grits may be used for finish rubs until desired the desired surface finish is achieved.

Thermoplastic Syntactic foams (B1X and XTL) may also be polished, but a good starting surface is critical. A surface that has been damaged in the machining process cannot be fixed by sanding. After following CMT machining/turning guidelines, most users find 400 or 600 grit sandpaper provides the appropriate starting point, though many move up to 1200 and 1500 for an ultra-smooth finish. HYTAC® B1X should always be dry sanded. Download our polishing guide for details.

CMT continues to work with our partners in industry and academia to develop new techniques for polishing HYTAC®. If you have a tip to share, please let us know!

CMT International Report: Chinaplas 2013

According to official tallies from show organizers, Chinaplas 2013 drew 114,000 visitors from around the world. From the perspective of your humble correspondent, rumors of a decline in the plastics industry have been greatly exaggerated, at least on evidence of our booth traffic. We saw visitors from China, Taiwan, Indonesia, Singapore and Thailand, just to start with the Asian countries. Mexico, Brazil, Israel, Germany, Sweden, Turkey, Netherlands and India were also represented as engineers and managers from toolmakers and thermoformers all stopped at our booth to talk/learn about syntactic foam for plug assist.

New CMT booth at Chinaplas New CMT booth at Chinaplas

It would appear that the efforts of our local distributor (Melchers Trading) to educate the market about syntactic foam have paid off as many customers came to the booth with specific questions on grades of HYTAC® material and how best to machine/polish them into plug assist shapes. While some processors continue to use basic materials such as POM or nylon for low performance requirements, the level of sophistication has clearly increased over the past 2-3 years. More complex parts, multi-layer materials and demanding customers mean that thermoformers require higher performance plug assist materials. Low thermal conductivity and dimensional stability are two key reasons why the HYTAC® line of plug assist materials continues to increase in popularity in these dynamic markets. Polypropylene cups seemed to be a popular topic and several thermoformers who were running plastic at the show were extruding and forming PP.

Chinaplas 2014 will return to Shanghai and we will certainly be there again. In the meantime, our 2013 calendar is booked solid with the following events:

AMI Thin Wall Packaging Conference: June 17-19, Chicago IL

Penn College Heavy-Gauge Thermoforming Workshop: June 18-20, Williamsport, PA

Penn College Thin-Gauge Thermoforming Workshop: June 25-26, Williamsport, PA

SPE Thermoforming Conference: September 9-12, Atlanta, GA

K 2013: October 16-23, Dusseldorf, Germany

Best Practice: Threading HYTAC® Plugs

HYTAC®-B1X and XTL are thermoplastic-based syntactic foams. Due to the thermoplastic base, both B1X and XTL are extremely tough and durable. Unlike traditional syntactic foams which require inserts, B1X and XTL can be direct threaded. For all other HYTAC® materials, CMT recommends use of slotted inserts bonded into the base of the plug. We have worked with machine shops and toolmakers to develop a series of best practices for both direct threading and insert installation. Our insert installation guide offers complete details.

For direct threading, we developed a tensile test and used our in-house material testing equipment to record the results in pounds force. B1X and XTL were tested. For inserts, what we have found is that direct scored aluminum inserts work very well. Some of the key success factors for this simple process include the elimination of coolant during cutting (for proper adhesive bonding) and face milling the bottom of the plug after insert installation (to ensure a flush mating surface for the plug to the base is created).  We typically recommend Loctite 495 for bonding and our pull-out test results were based on this adhesive.