Indentation force deflection

Impingement mixing, 200 Implants, bioresorbable, 27 Indentation force deflection (IFD) test, 244 Infrared (IR) spectroscopy, 91, 162, 300, 490. See also Fourier transform infrared (FTIR) spectrometry Ingold s classification, 60-61 Inherent viscosity, 161-162 Injection molding, of polyamides, 136,... 

IFD indentation force deflection, CS compression set, % Ct compression set expressed as a ... 

Indentation force deflection (HD) Compression force deflection (CFD) Compression set... 

Two techniques allow determination of the compressibility of foam. The methods are related and the application dictates which method better defines the quality of the product. For example, for furniture cushions, indentation force deflection (IFD) is a more common test technique than compression force deflection. Both methods determine the amount of force required to compress a foam to a percentage of its thickness. In the IFD test, the plunger that compresses the foam is smaller than the foam sample. This presumably correlates to a person sitting in the center of a chair cushion. 

Representative test methods of flexible foam properties, as defined by the ASTM D-3574 are density, IFD (indentation force deflection), CFD (compression force deflection), sag factor, compression set, tensile and tear strengths, elongation, resilience, dry-heat aging and steam autoclave aging. 

Other important properties of flexible urethane foams include indentation force deflection (IFD) or compression force deflection (CFD), compression set, and humid agiiig. 

The CFD (compression force deflection) as well as IFD (indentation force deflection) curves of these foams are relatively linear in comparison with slabstock foams, as shown in Figures 10 and 11. 

Indentation-Force Deflection (See also Compression/Deflection Properties)... 

Indentation-Force-Deflection (IFD) (ILD) Test (to Specified Deflection) ASTM D 3574 - Test Bj. This test consists in measuring the force necessary to produce 25% and 65% or other designated indentations in the flexible foam product. The results are reported in newtons required for 25% and 65% indentations. These figures are known as the 25% and 65% IFD (or ILD) values, respectively. 

Test I3 determines (1) the loss of force support at 40% IFD (indentation force deflection), (2) loss in thickness, and (3) structural breakdown as determined by visual inspection. This vocedure describes tests that deflect the material by a flat-horizontal indentation exerting a force of 750 +/- 20 N in the test specimen. Test I3 is similar to ISO 3385 and BS 4443 Method 13 and is used jximaiily to determine the loss in thickness and in hardness of flexible cellular materials intended for use in load- bearing upholstery. The test involves repeated indentation of a specimen by an indentor smaller in area than the test piece. The flexible cellular materials tested are usually latex and polyether urethanes. 

Covers density, indentation-force deflection, compressionforce deflection, constant deflection, compression set, tension, tear resistance, air-flow, resilience (ball rebound), static-force loss at constant deflection, dynamic fatigue, steam autoclave aging, and dry-heat aging. 

CuiO-treated flexible polyurethane foam were not significantly different from the comparable untreated flexible polyurethane foam. The physical properties examined were tensile strength, elongation, tear strength, resilience, indentation force deflection, support factor, compression sets, and airflow. 

The American test method for indentation force deflection (IFD). ASTM D 3574-95, de.scribes a procedure similar to the British Standard, but it differs in several ways that must be recognized if direct comparisons are to be made. D 3574- 95 is specifically for "Flexible Cellular Materials Slab. Bonded, and Molded Urethane Foams. Specimen... 

FTC measurements were conducted 90 seconds after demoulding. The foam pad was removed from the mould, weighed and placed in the FTC apparatus (Instron 4502). The force detection device is equipped with a 5.0 kN capacity pressure transducer. The actual force is shown on a digital display. This device mimics the ASTM D3574, Indentation Force Deflection Test and provides a numerical value of freshly demoulded foams initial hardness or softness. The pad was compressed to 70 percent of its original thickness at a cross head velocity of 380 mm per minute with the force necessary to achieve the highest compression cycle recorded in Newtons. Values are reported as the FTC value for the foam based on the assumption that the lower the FTC values the better the dimensional stability of the foam. 

Tables 1.36 and 1.37 provide the physical property comparison for the 46 kg/m MDl flexible monlded formnlations XXV-XXXTV. The data clearly demonstrates that physical properties are maintained, and in several cases improved, compared to the control formulations, depending on the formulation and the use of experimental cell-opening catalysts. For example, the data in Table 1.36 illustrates that at an index of 90, all physical properties are comparable to the control formulation. When the index is increased to 105, ball rebonnd and airflow are improved, with a slight decrease in indentation force deflection (IFD) properties when the non-fngitive catalyst (XXXIV) is compared to the control formnlation (XXVI). When Dabco NE1060/Dabco NE200 is used (XXIX), the physical properties are equal to the control at an index of 90. Improved Japanese wet sets (see Section 1.3.1.2f) and slightly decreased lED valnes are observed at an index of 105 compared to the control formulation (XXX).

Method A. Indentation force deflection (IFD) consists of measuring the load necessary to produce deflection (generally 25-65 percent) in the foam product. The test is carried out by pushing a flat circular indentor foot down into the foam specimen and measuring the force on the foot at various compression amounts. The test is widely used in the cushioning and bedding industry. Higher IFD values indicate a stiffer foam. 

Method C—dynamic fatigue test by constant force pounding—is conducted to determine the loss of force support at 40 percent indentation force deflection (IFD), a loss in thickness and structural breakdown as assessed by visual inspection. The test evaluates the specimen by repeatedly deflecting the material by a flat horizontal indentation exerting a specified vertical force on the test specimen. This test may be conducted by using either 8000 or 80,000 cycles. The percent loss in thickness and percent loss of 40 percent IFD and results of visual examination are reported. 

---