Profile cover photo
Profile photo
Franklin Fibre-Lamitex Corporation
95 followers
95 followers
About
Posts

Post has attachment
‘Surface Roughness’ in Lamitex® composite materials

Quite often in the process of manufacturing & fabricating industrial laminates a specific surface roughness is indicated. Be it the purpose of reducing electrical arc tracking across the surface of the composite material, or to make sure the surface is rough enough to hold an adhesive; surface roughness can be a vital component of a machined composite part’s integrity.

A surface, as defined by Merriam-Webster is “n:the exterior or upper boundary of an object or body (1).” Essentially; for the composite world, this is the topography of the sheet or part and the area that typically comes into contact with another apparatus. The surface roughness of the material is a direct result of the manufacturing & fabrication process.

Measuring for surface roughness can be done in a number of ways. The most commonly cited on mechanical drawings is a direct measurement style using instruments consisting of a stylus that glides back and forth over a specified area(2). The peaks and valleys of the stylus are measured and an average is taken for the whole. Attached you will find a picture of one of our Lamitex ® tubes being measured in this fashion. The instrument in the photo is measuring the surface roughness in micrometers (μm), equal to 1 millionth of a meter. To give you an idea of how small this is; the average human hair is about 40-75 μm. The average surface roughness is noted on most drawings as ‘Ra’and is known to be most useful when looking at a piece of material as a whole. The Rais to be understood as an average, however, and not as representative of the visual integrity of a composite. To highlight this; see the figure attached describing three materials that have the same recorded Ra,but visually different surfaces (3).

Lamitex® NEMA grade laminates can be custom manufactured to obtain low or high Ra depending on our customers’ applications. With nearly a century in the composites business, you can trust the expert craftsmanship of our parts to meet your requirements. Contact one of our material specialists today to see how we can help solve your challenges.

ARTICLE CITED:

1.“Surface.” Merriam-Webster, Merriam-Webster, www.merriam-webster.com/dictionary/surface.
2.Xue, Huanran. “Metrology for Manufacturing: Surface Measurement.” Cutting Fluids in Machining, www.mfg.mtu.edu/cyberman/quality/metrology/surface.html.
3.Talati, Jigar. Surface Roughness – Significance and Symbol Interpretation in Drawing . Hexagon Design Centre, Vadodara, hexagon@iqara.net.
PhotoPhotoPhoto
9/25/18
3 Photos - View album
Add a comment...

Post has attachment
‘Outgassing’ in Composite Materials

Lamitex ® composites have been the chosen materials in the aerospace industry for many years due to their high material strength and dimensional stability under extreme conditions. When considering a composite material for spacecraft or aerospace applications it is often imperative that you take into account their outgassing properties. ‘Outgassing’ refers to the discharge of gaseous material (many times water vapor) as a result of an atmospheric change in the environment. For example; if the material or part is exposed to a vacuum or high heat. Due to the manufacturing process and nature of the base material of most laminate composites, trace amounts of water vapor and other gases tend to get into the finished product, making them ‘outgassers’ under extreme conditions. As you can see from the table below, different composites will vary among each other in moisture absorption due to the nature of the filaments and resins used.
Testing for a material’s outgassing percentage is typically performed to ASTM Standard E595-90. The test is executed in a vacuum oven that reaches temperatures of 125C for a period of 24 hours. The sample is placed in the oven inside a container with an adjoining container connected to it to collect the displaced vapors. After 24 hours the piece is taken out and weighed (termed ‘Total Mass Lost’ –or ‘TML), along with the moisture captured (termed ‘Collected Volatile Condensable Material’ – or ‘CVCM’). An additional test that can be completed after the vacuum bake is termed as ‘water vapor regained’ (WVR). Essentially with this test, the lab attendant will leave the piece out in relative humidity at room temperature for 24 hours and then they weigh it to see how much mass was regained due to moisture absorption.

In general, materials that have a CVCM percentage less than or equal to 0.10% and a TML percentage of less than or equal to 1.00% are acceptable for space applications. However, many applications have lower standards. If the exceptional material properties of a composite are necessary, many times the end user could put the piece in a vacuum oven to expel the CVCM and then use it for their application if the material has a low WVR rate or if future WVR is not going to be an issue
Photo
Photo
7/16/18
2 Photos - View album
Add a comment...

Post has attachment
Making Sense of Thermal Analysis of Composites

Introduction to Thermal Analysis

Thermal analysis covers a group of techniques allowing properties of a sample to be investigated as a function of temperature and/or time. The applied temperature system consists of a sequence of segments where the sample is heated or cooled at a constant rate or held at a constant temperature. In many experiments the atmosphere also plays an important role, the most common atmospheric conditions include inert and oxidizing gases.

Glass Transition Temperature

Franklin Fibre reinforced composites are excellent thermal insulators. One of the most important factors when choosing a Lamitex ® composite is to determine whether or not the glass transition temperature will be affected by the heat applied during use. Often confused with the melting point, the glass transition temperature is actually a range of temperatures where softening occurs. Glass transition temperature (often referred to as ‘T sub g’) is the point when the glass or base substrate of the composite will soften, affecting the overall flexural modulus of the composite among other properties.

Thermal Conductivity

ASTM C168-15 defines thermal conductivity as; "time rate of steady state heat flow through a unit area of a material or construction induced by a unit temperature difference between the body surfaces". Essentially, the amount of heat that is able to pass through the specimen to the ‘thermometer’ (or other associated thermal probe) on the other side during a specific amount of time.

Thermogravimetric analysis (TGA)

In thermogravimetry, the mass of a sample is measured while it is subjected to a temperature sequence. The measurement is performed in a controlled atmosphere, usually in nitrogen (inert condition) or in air (or oxidizing condition). The mass is recorded with a highly sensitive electronic balance. Interfering buoyancy and drag force effects are compensated by blank curve subtraction.

Evolved gases from the sample can be analyzed (EGA, Evolved Gas Analysis) in a coupled mass spectrometer.

For more information on our composites and their material strengths contact us today!
info@franklinfibre.com
(800) 233-9739
Photo
Add a comment...

Post has attachment
Basalt is an extrusive igneous rock that is formed when lava is exhumed from a volcano and cools rapidly on the surface of the earth so that only smaller crystals are able to form. It is the most common volcanic rock on the planet; lining the oceanic crust as well as many of the volcanic islands. However, in order to turn this volcanic rock into a cloth to be made into a composite material it must go through a separation and extrusion process. Interestingly enough, it is processed much like steel. The raw material is melted, poured into a teapot shaped vessel (skimmer) where most impurities are separated by differences in specific gravity and (like slag from steel), forced out the teapot spout, and then extruded into filaments.

Known for its thermal properties, Basalt retains mechanical properties at cryogenic temperatures down to - 260°C. Exceptional mechanical properties, superior electrical resistance, resistance to corrosive chemicals and UV resistance provide a material that is phenomenal in extreme conditions.

Currently we offer a Basalt filament composite bound with an epoxy resin system. Our Lamitex® grade EB11-CR out-performs NEMA G10 & G11 in thermal conductivity, flexural strength, compressive strength, tensile strength, and dielectric permeability. Contact us today to find out more about this ingenious igneous composite!
PhotoPhotoPhoto
2/26/18
3 Photos - View album
Add a comment...

Post has attachment
Chemical Resistance of Lamitex® Industrial Laminates

Lamitex® laminated plastics are used in numerous applications where they are either submersed or are in constant contact with corrosive chemicals. The degree of chemical resistance of the laminate will depend on the nature and concentration of the chemical agent along with temperature and duration of exposure. The ease of fabrication, light-weight, and resistance to friction, light, and heat are other major advantages for Lamitex composites in these applications.

As opposed to metals; the deterioration of thermoset laminates is attributed to the dissolution of the resin by the newly introduced chemical and/or damage to the material reinforcement. The base fabric of which the thermoset laminate is composed of is considered the ‘reinforcement’. The type of reinforcement is principal in the specification of a laminate for an application. Cotton fabric (Lamitex grade CE/MFG/LE etc.) is satisfactory for weak acids, weak bases, most alkali solutions and organic solvents. Glass fabric has proven resistant to all chemicals tested, while basalt fabrics are resistant to corrosion and aggressive chemical liquids. The second area of deterioration is in the resin. Each resin used in Lamitex formulations is selected with an application in mind i.e.; wear, dielectric, compressive strengths etc. Each resin also demonstrates different chemical resistance to certain chemicals. For instance; Phenolic (CE/MFG/G3), epoxy (G10/FR4, G11, G12) and silicone (G7) resins are resistant to most chemicals while melamine resin is particularly resistant to alkalis.

Although total chemical inertness may not always be necessary, Lamitex materials are typically designated because they maintain their size, shape and strength when immersed in chemicals. More importantly, our materials are designated because they have a longer life than any other material; taking into consideration labor and materials for the original installation (and cost of replacement). Each chemical application should be considered individually based on past experience. If none exists, laboratory testing should be completed to determine the grade most practical and most economically sound for the application. Some tests may require a great deal of time, but for many applications conclusions can be reached from accelerated tests.

It is most important when organizing such a test to have a complete understanding of the actual chemicals involved along with concentration, time and temperature of immersion. When there is a sequence of operations the entire procedure must be investigated. For example, in some metal plating operations, the racks are exposed to hot concentrated acids which would destroy the laminate if it were exposed to continuous immersion: however, laminates would perform admirably in metal plating lines where racks are immersed in hot acid solutions for short periods of time and then exposed to neutralizing baths and rinsing with water.
Photo
Photo
1/23/18
2 Photos - View album
Add a comment...

Post has attachment
Moisture Absorption Effects on Industrial Laminates

Water or moisture absorption is important in determining the value of industrial laminates as a control of the uniformity of the product, affects the mechanical, electrical and chemical properties of the laminate and has a bearing on a laminate’s appearance and dimensional stability.

Water absorption is tested according to ASTM D 570-57T. A 1” x 3” x thickness test specimen is immersed in water 24 hours @ 23°C. It is weighed before, after the test period and the water absorption rate recorded as a percent of the sample’s original weight.
This method of recording water absorption can lead to false interpretations. Various laminate formulations of different specific gravities will differ in weight and actually represent a considerable difference in percentage increase by weight. An absorption of 1 gram for a test specimen of Lamitex G5 glass melamine weighing 100 grams would be recorded as 1% absorption. A same size test specimen of Lamitex CE weighing 66.5 grams and absorbing the same amount by weight of water, 1 gram, would be reported as a 1.5%.
There are a number of water absorption factors that should be considered. While water absorption measurement is based on 24 hours immersion at 23°C, none of the laminates become fully saturated in that time. Saturation may require immersion for as long as 6 months. Also, the thicker the test specimen, the less water is absorbed in 24 hours as a % by weight and raising the water temperature will increase the rate of absorption but not the quantity of water absorbed.
The thicker the wall of a tube or the larger the diameter of a rod, the less water will be absorbed in 24 hours as a % by weight. Therefore, material dimensions and thickness greatly influence the rate of water absorption.
Low or the minimal moisture absorption rate for each laminate formulation, a key property in the material selection process, is accomplished with strict manufacturing process controls. Established resin content, volatile content and % of flow, times, pressures and process temperatures are audited for all laminate productions to ensure they meet published performance expectations.
Low water absorption rates are essential in mechanical applications to insure the lowest possible dimensional changes and least possible insulation degradation for electrical application in high humidity conditions.
Low moisture absorption is equally important to chemical resistance. Generally speaking, the lower the water absorption, the better chemical resistance to acids and alkalizes.
Photo
Add a comment...

Post has attachment
In an effort to develop a more cost-effective #coolingduct  and barrier insulation for #transformers , Franklin has developed its special corrugated insulation. For more info please contact us or visit our web page at www.franklinfibre.com #transformerinsulation   #frp   #corrugated  
Photo
Add a comment...

Post has attachment
Lamitex® PF-30 material is a jute-fibre based phenolic laminate with a graphite filler. This material is your superior option when choosing a material for a wear surface application. The jute fibres combined with a phenolic resin matrix make this product strong, and the graphite filler provides a natural self-lubricant for the material. #wearstrip   #wearpad   #Lamitex  
Photo
Add a comment...

Post has attachment
The question “What is the difference between NEMA grade #G-10 (Mil-I-24768/2 Type GEE) and NEMA Grade #FR-4 (Mil-I-24768/27 Type GEE-F)?” has been raised many times. Although they are typically made from the same base material (E-Glass), the epoxy resin matrix used for binding each material is inherently different. For more information on #Lamitex  composites please visit out website at www.franklinfibre.com or give us a call at 1 (302) 652-3621.
Photo
Add a comment...

Post has shared content
Lamitex® Glass Epoxy composite tubes and sheets, formulated to meet NEMA G10 (MIL-P-18177/ Mil-I-24768/2 type GEE) applications are a multipurpose thermoset material that is frequently specified for its mechanical strength and/ or electrical insulation. Its compressive strength (68,000 psi), temperature index (electrical =130C / mechanical =140C), arc resistance, and ability to keep these strengths in dry and humid conditions make it suitable for transformer, cryogenic, and load bearing applications among many others. This grade of material has excellent machining characteristics and can take on a greenish and/or black physiognomy. Some of the historical applications of G10 include printed circuit boards, arc chutes, and switchgear insulation. With our technical expertise and wherewithal from many years of being in this business, we are confident in our ability to work with engineers on their designs and produce exactly what they are looking for. Franklin Fibre Lamitex® glass epoxy G10 is manufactured in sheets, round tubes (convolute wound and/or filament wound), molded channel, angle, square and rectangular tubes, and custom fabricated parts.
PhotoPhotoPhoto
2015-05-21
3 Photos - View album
Add a comment...
Wait while more posts are being loaded