1. ASTM D4894-07
  2. Wear Evolution of the Glass Fiber-Reinforced PTFE under Dry Sliding and Elevated Temperature
  3. The measurement of the surface energy of solids using a laboratory drop tower
  4. Wear Evolution of the Glass Fiber-Reinforced PTFE under Dry Sliding and Elevated Temperature

This standard is issued under the fixed designation D ; the number immediately 1 This specification is under the jurisdiction of ASTM Committee D20 on. Astm d - Download as PDF File .pdf), Text File .txt) or read online. PTFE. ASTM D - Download as PDF File .pdf), Text File .txt) or read online. ASTM D

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Astm D4894 Epub

EPUB MOBI. Page 1 Fluoropolymer Resins ASTM Teflon® PTFE Property Method Unit Granular Resin Fine Powder Tensile. Strength, 23°C (73°F) D/ MPa (psi) (4,) min. (3, min.). astm d plastic microtensile testing equipment, iso 2 en .. July 9th, - D 15 Standard Specification for Polytetrafluoroethylene PTFE Granular Molding and Ram Extrusion . [PDF] Ebooks Gratuit Gt Epub Gratuit. ePub File Size: Mb. ISBN . ID FORM PDF · ASTM D PDF · AKKA TAMMUDU KATHALU IN TELUGU PDF · THEUN MARES PDF.

The final pressure attained, if not recom- mended by the manufacturer of the particular material, shall be Hold under maximum pressure for 2 to 5 min. Release the pressure by gradually cracking the pressure release valve without an apparent movement of the press platens. Remove the top pusher and force the preform verti- cally out of the mold shell using a continuous, smooth movement. NOTE 7Remove the mold in a careful smooth movement from the die to prevent cracking. Use a saw for the rough cuts FIG. Prepare five test specimens for the determination of tensile properties from 0. Care shall be taken to avoid wedge-shaped cuts. Use the remainder of Section II to prepare tape specimens by skiving 0. Discard the initial five revolutions of skived tape before taking the test sample. Use the tape for the determination of tensile properties, as an alternative to machined disks. If electrical properties, discussed in the Appendix, are to be determined on tape, Sections II and III must be left together in order that a tape of sufficient width is obtained to allow the cutting of a Vary the billet length in accordance with the testing to be done. The test resin shall be near ambient temperature prior to molding Note 4. Add the resin to the mold, insert the top plug, and apply hand pressure.

Take care to break up all of the lumps and Type Sieve Number opening to wash the material from the sides of the sieve. B A discussion of the particular characteristics of finely divided resins is found in Appendix X1. Draw the best straight line through the points and read Air-dry the Pour each fraction into a tared beaker and Take care to prevent the resin limits based on a limited series of tests are Since there is no accepted reference Net percentage on sieve Y Size Analysis in Also, it is recommended that each manufacturing processor do an analysis to determine their own correlation.

A sample of PTFE resin of opening size or sieve number on log-probability paper as known weight is dried in a vacuum oven in a tared aluminum shown in the sample plot Fig.

The sieve numbers and weighing dish.

ASTM D4894-07

When the resin is dry, it is removed from the oven, placed in a desiccator, allowed to cool, and then reweighed. Water content is calculated from the weight lost during drying. When the acetone has evaporated from the dishes, dry them thoroughly in an oven at 50 to 80C [ to F], then store in a desiccator until ready for use. Obtain the tare weight, B, of an aluminum weighing dish, plus lid, to Sieve.

Place 35 to 40 g of PTFE resin in the tared 14 aluminum weighing dish and record the weight including lid , 18 80 A, to the nearest 0. Dry to constant weight in 25 35 90 a vacuum oven mm [25 in.

Remove the dish from the oven, replace 60 63 the lid on the weighing dish, and allow to cool in the desiccator 53 45 for at least 30 min. Reweigh the dish plus the resin and lid , 38 C, and calculate the weight loss.

If the difference between the 9 D 04 duplicate results exceeds 0. NOTE 12When a group of samples is run at the same time, it is good This as is. Also, Determine the tensile strength in accor- limits. Since there is no accepted reference material for dance with the procedures described in Test Method D , determining the bias in this test procedure, no statement on bias except that the initial jaw separation shall be Clamp the specimen with essentially equal lengths in Determine elongation at break from the chart, article made from a PTFE resin is affected both by the expressed as a percentage of the initial jaw separation.

The specific gravity of a specimen has been approved by the balloting process. Inspection and Certification specimen. Polytetrafluoroethylene PTFE Granular Molding and Ram Extrusion Materials 1 This standard is issued under the fixed designation D ; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision.

A number in parentheses indicates the year of last reapproval. A superscript epsilon e indicates an editorial change since the last revision or reapproval. Referenced Documents 1. The usual methods of processing ther- and Pourability of Plastic Materials moplastics generally are not applicable to these materials D Specification for PTFE Tubing, Miniature Beading because of their viscoelastic properties at processing tempera- and Spiral Cut Tubing tures.

The methods and properties included are D Test Method for Determining Temperatures and those required to identify the various types of resins. Addi- Heats of Transitions of Fluoropolymers by Differential tional procedures are provided in the Appendix for further Scanning Calorimetry characterization of the resins.

D Specification for Filled Compounds of Polytet- 1. Resin Produced From Dispersion 1.

Wear Evolution of the Glass Fiber-Reinforced PTFE under Dry Sliding and Elevated Temperature

See Notes 3 and 9 for specific cautionary statements. Published October Last previous edition approved in as D - Terminology 4. Generally made by measured under the conditions of the test.

Resin that has been treated specification and sintered g. Molding and 4. The system uses predefined cells to refer to specific for PTFE. For this example, the line callout would be ASTM 3. Grade in the appropriate specified properties, Tables, or both, 3. In this case there is no Class item so the of a specimen of PTFE material molded as described in this cell position for class is left blank. A comma is used as the specification and sintered using the appropriate sintering separator between Standard Number and Type.

Separators are schedule given in this specification. An example would be in Specification heated for a prolonged period of time.

The measurement of the surface energy of solids using a laboratory drop tower

When Special Notes are 4. Classification used, they shall be preceded by a comma. B Extrusions of this resin show different degrees of clarity from the others. Mechanical Properties plug height to allow the resin in the die can be leveled by 5. Insert the die in a suitable hydraulic the procedures specified herein.

Table 1 lists tests to be carried press and apply pressure gradually Note 3 until a total of Table 2 lists tests requiring specimens molded as MPa [ psi] is attained.

Hold this pressure for 3 min. Remove the disk identification on the disk at this time. NOTE 3—As a guide, increasing the pressure at a rate of 3. If they are not followed, the crystallinity of the disks and the resulting physical properties will be markedly changed.

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Therefore, the use of a programmed oven is recom- 8. Number of Tests mended for the most precise sintering cycle control so that the hood 8. Periodic tests shall being an important safety consideration.

Wear Evolution of the Glass Fiber-Reinforced PTFE under Dry Sliding and Elevated Temperature

One set of tests specimens as prescribed in Section 7 prepare the preforms. A combination of these properties results in the use of the PTFE in the tribological applications.

However, the mass loss of PTFE caused by the poor anti-wear property and abrasive resistance limits its broad utility.

In order to overcome the problem, attention has been attracted to the embedding fillers to make PTFE into composites. Up to now, various nano- and micro-meter inorganic fibers and metallic oxides, as well as other particles such as MoS2, were used at the reinforcement phase in the PTFE to enhance the friction and wear performance, and an apparent improvement has been obtained.

Among the fillers, glass fiber, owing to its low cost and light weight, as well as its good enhancement, is considered as the prevalent candidate blended in PTFE. It is commonly used in different percentages and is sometimes combined with other fillers [ 2 ]. Blanchet found that glass fibers reduce wear by interrupting subsurface deformation and crack propagation, which would otherwise lead to large wear sheets under severe sliding conditions [ 3 ].

Kim and M. Shin reported that short glass fibers with normal orientation to the sliding interface were conducive to the tribological properties of the PTFE composite [ 4 ]. Conte suggested that the use of glass fibers in a PTFE matrix would improve the tribological properties by reducing the abrasiveness [ 5 ].

On the other hand, the interfacial adhesion between the fibers and PTFE was reported to be another vital factor that affects the performance of PTFE composites [ 6 ], and researchers have found that silane and rare earth are the effective coupling agents to improve the tribological performance of the PTFE-based composites [ 6 , 7 ].

Most of the studies were performed at the room temperature with the changes of sliding velocity and loading.