Instron, Model

Characterization Methods. Stress-strain experiments were carried out with an Instron model 1122. Dogbone samples of 10mm in length were used, and the initial strain rate was 2 mm/min. Dynamic mechanical data were obtained utilizing a DDV-IIC Rheovibron Dynamic Viscoelastometer. Most samples were tested within the temperature range of -100°C to 220°C with a heating rate of 2-3°C/min. A frequency of 11 Hz was selected for all the dynamic mechanical experiments. 

The light intensity of the 3000 A lamps was determined as previously described ( ). Yarn samples were knit on a Lawson Fiber Analysis Knitter (FAK), and yarn tensile testing was performed on an Instron Model 1101 (TM-M) constant rate of extension testing machine. 

Dielectric constant and dissipation factor measurements were conducted according to the procedures of ASTM D-150-87. Tensile strength and modulus and percent elongation were measured on an Instron model 1125 according to the procedures of ASTM-D-882-83. 

Mechanical Properties. Mechanical properties obtained on the cured resins included tensile strength and fracture toughness. Tensile tests were run on an Instron model 1122 Universal Tester with a crosshead speed of 0.02 /minute. Tests were run on dry and saturated samples in air. Fracture toughness (K ) values have been obtained using a MTS 610 Materials Testing System at 0.02 /minute at ambient and elevated temperatures in air. The compact tensile specimens tested were 0.5 x 0.5 x 0.125 in dimension. Mechanical properties data are based on the results from four or more tests run at each condition. 

The instrument consists of a steel sphere (2.063 cm. in diameter) attached by a length of thin steel wire to a load cell. The slurry sample rests on a horizontal cross arm which can be raised or lowered at controlled speeds. The load cell and cross arm which are part of an Instron Model TT-C testing instrument may be used. The sphere is placed in the lower third of the slurry sample, and the cross arm is lowered at a constant speed (8.5 X 10"4 cm./sec.). The resulting force on the load... 

Mechanical Tests. These were determined on an Instron model TM using thin films. 

Property Measurements. All silk samples were conditioned prior to testing at 65% RH and 21°C according to ASTM Test Method D 1776-79, "Standard Practice for Conditioning Textiles for Testing." (8) Tensile properties were determined on an Instron Model 4201 Universal Testing Instrument. Tensile test data were recorded and stored for reanalysis using Instron software, "General Tensile Test, Revision D."... 

Time-dependent stress-strain behavior of the neat resins was studied using an Instron (Model 1122) tensile tester. Dog-boneshaped epoxy specimens were prepared in accordance to ASTM D1708-66. Strain-rate used was 5x 10 5 s 1. 

Lap shear strength of the pieces of wood with plastic injection molded to them was tested on a Instron Model 4200 universal testing instrument. Experimental conditions were as follows room temperature, 23°C room relative humidity 50% crosshead speed, 2.54 mm/min with the sample in hand-fastened grips and an aluminum specimen holder. The lap shear strengths of the wood-plastic samples are summarized in Table 9. The copolymer samples were fractionated by benzene extraction. The reaction product was labeled product A. The benzene extract of the product became ben. ex. Whereas the benzene-insoluble portion of the product was labeled product B. 

Tenacity, initial modulus and elongation to break were obtained on fiber samples with an Instron Model 1123 tester using an extension rate of 50.8 cm/min. and a guage length of 2.54 cm at 25°C and 65% relative humidity. 

Uniaxial tensile tests were carried out to determine the stress-strain curves and document the damage growth on a computer-controlled Instron model 8516 servo hydraulic testing machine operating at a strain rate of 5% min . The macroscopic tensile yield stress was considered equal to the maximum stress on the loading curve. The Young s modulus was determined as the plateau value of a plot of the secant modulus as a function of the strain. 

Initial moduli at room temperature were obtained with an Instron Model 4206 at a strain rate of 2/min ASTM D638 type V specimens were used. The Instron was also used in the creep experiments, in which deformation under a 1 NPa tensile load was continuously monitored for 10 sec, followed by measurement of the recovered length 48 h after load removal. Strain dependence of the elastic modulus was determined by deforming specimens to successively larger tensile strains and, at each strain level, measuring the stress after relaxation after it had become invariant for 30 min. 

An Instron Model 1130 was employed to run samples at 50% relative humidity at 25 C with a crosshead speed of 5 cm/min. 

Tensile testing was done using an Instron Model 1122 load frame and an Instron 1000 lb. maximum combination tension/com-presslon load cell. Samples were cut from films using ASTM 1822 Type D standard cutter for tensile samples. Crosshead speed was 5 Inches per minute for all samples. Prior to tensile testing, polystyrene homopolymer tensile samples were annealled at 85 C for 4 days in order to remove any additional Internal stresses introduced during the specimen cutting procedure. 

Evaluation of Fiber and Fabric Properties. Breaking strengths of the control and treated fabrics were determined according to ASTM D 1682, ravelled strip method (24) using an Instron model 1130 equipped with a 1,000 pound load cell and a gear ratio of 1 1. Five conditioned warp strips from each of two replicates were tested for each experimental condition. 

The oriented film specimens were mounted on aluminum frames and exposed on an Atlas Weather-Ometer, Model 65WR. An 18 minute spray cycle together with an 102 minute cycle at 55% relative humidity and approximately 65°C was used. At regular intervals, the test specimens were removed from exposure and their tensile strength measured on an Instron Model 1102. A decrease in tensile strength, expressed as tenacity, over the tensile strength of the same formulation before exposure, is a measure of the deterioration of the physical properties of the polymer. "Failure" in this test is defined as a loss of 50% or more of the initial sample tenacity. 

IR spectra were recorded with a Perkin Elmer 1500 Fourier Transform IR spectrophotometer with a TGS detector. Typically 200 scans were averaged for each sample to improve the signal-to-noise ratio and allow spectral subtraction at high sensitivities. Spectral subtraction was performed using the 973 cm-1 PP band (which is largely insensitive to variations in helical content) as the reference band to be suppressed to zero. Iodometric analysis of oxidized films were performed as described previously (8). Stress-strain measurements were performed on 4 mm film strips on an Instron Model 1123 at 500 % min-1. 

Two aspects of texture were considered firmness of the intact segment and toughness of the carpellary membrane. Both were measured on stored segments with an Instron model 1011 Universal Tester (Instron Corp., Canton MA 02021) set on compression mode. Firmness was determined by crushing a pair of segments in an Ottowa Texture Measurement System to 3 mm final thickness. Crushed segments were then transferred to a Kramer Shear Cell and the force necessary to shear the membranes determined. 

Rotational Rheometry. Two instruments were used for these measurements. An Instron model 3250 rheometer was used for measuring rotational viscometry and forced oscillation as a function of frequency with strains in the region of 0.5. A Bohlin VOR rheometer was used for dynamic measurements at smaller strains (i.e., 0.1). 

An InsTron model 1122 was used for the stress relaxation experiments. Dog-bone-shaped specimens v/ere prepared in accordance to ASTM D1708-66, The specimens v/ere 22,25 mm long (linear section of the dog-bone-shaped specimen), 4.75 mm wide, and ca,... 

Mechanical properties were obtained on 4 inch by 0,5 inch strips of cured film using an Instron Model 4201 with the initial jaw separation distance of 2 inch at a strain rate of l /min. 

Mechcmical testing was carried out in triplicate with an Instron model 4032 universal testing machine. A1 kN load cell was used and the crosshead speed was 500 nun/min. 

---