1. Pangkalahatang ideya
1.1 This test method includes methods for evaluating the tensile properties of vulcanized thermosetting rubber and thermoplastic elastomers. This test method can not be used to test hard glue and materials with high hardness and low elongation. Ang pamamaraan ng pagsubok ay ang mga sumusunod:

Paraan A — Straight bar and dumbbell samples

Paraan B — Annular specimen

Magsalita 1 -the results of the two tests are incomparable.

1.2 Ang mga yunit batay sa SI o hindi SI ay itinuturing na pamantayang yunit ng pamantayang ito. Since the results of using different unit systems may be different, ang iba't ibang unit ay dapat gamitin nang hiwalay at hindi halo halong.

Seguridad

2 Mga Sanggunian
D 1349 Pagtutukoy ng goma — Standard test temperature

D 1566 Rubber related terminology

D 3182 Pagtutukoy ng goma — Mga Materyal, equipment and procedures for making standard compounds and standard vulcanization test pieces

D 3183 Pagtutukoy ng goma — Preparation of test pieces from finished products

D 4483 Standard test methods for rubber and carbon black industrial species – Specification for measurement accuracy

2.2 ASTM Annex

Paghahanda ng annular specimens, Paraan B

Mga Pamantayan sa ISO

ISO 37 – Methods for determination of tensile stress-strain properties of vulcanized or thermoplastic rubber

ASTM D412-0 “Pamamaraan ng Pagsubok ng Paghatak para sa Vulcanized Goma at Thermoplastic Elastomers”

3 Mga terminolohiya
3.1 Definitions

3.1.1 Makunat pangmatagalang pagpapapangit — The residual deformation of the sample after elongation under a certain action, when the applied force is relieved, ay ipinahayag bilang isang porsyento ng orihinal na haba.

3.1.2 Long stretching deformation — The long stretching deformation of the pulled dumbbell sample is closely pressed to the cross section.

3.1.3 Makunat na puwersa — The maximum force generated in the process of breaking the sample.

3.1.4 Lakas ng paghatak — the stress used when drawing the sample

3.1.5 Constant extension stress — the stress generated when a sample of regular section is stretched to a specific length.

3.1.6 Thermoplastic elasters — a material similar to rubber, pero di tulad ng ordinaryong vulcanized rubber, pwede itong iproseso at i recycle tulad ng plastic.

3.1.7 Pagpapahaba sa break — the elongation of the specimen when it breaks during continuous stretching.

3.1.8 Yield point — The point on the stress-strain curve where the velocity of the stress change with respect to strain becomes 0 and opposite before the final failure of the specimen.

3.1.9 Yield strain — Ang antas ng strain sa punto ng ani

3.1.10 Magbunga ng stress — Ang antas ng stress sa punto ng ani

ASTM D412-0 “Pamamaraan ng Pagsubok ng Paghatak para sa Vulcanized Goma at Thermoplastic Elastomers”

Method Description
4.1 For the test of tensile properties, samples are first cut from the sample material, including two parts: sample preparation and test. The shape of the specimen can be dumbbell, singsing o tuwid na bar, at ang hugis ng seksyon ay regular.

4.2 Pagpapasiya ng lakas ng paghila, pag aayos ng stress, ani point at paghaba sa break nang walang paunang extension ng sample. Ang determinasyon ng lakas ng paghatak, pag aayos ng stress, yield point and elongation at break for the specimen with normal section is based on the original cross-sectional area of the specimen.

4.3 Long-term deformation by stretching and long-term deformation by tearing, measure the deformation of the sample after stretching and shrinking according to the prescribed method.

ASTM D412-0 “Pamamaraan ng Pagsubok ng Paghatak para sa Vulcanized Goma at Thermoplastic Elastomers”

Key Points and Applications
5.1 Ang mga materyales o produkto na kasangkot sa pagsubok na ito ay kailangang sumailalim sa makunat na puwersa sa aktwal na proseso ng aplikasyon. This test is to determine such tensile properties. Gayunpaman, the tensile properties do not directly represent the whole situation of the final use of the product, because the product needs to cover a wide range of potential use conditions in actual use.

5.2 Tensile properties are dependent on materials and test conditions (bilis ng pag angat, pagsubok temperatura at kahalumigmigan, halimbawa ng geometry, pag aayos bago ang pagsusulit, atbp.). Kaya nga, ang mga resulta ng pagsubok ng mga materyales sa ilalim ng parehong mga kondisyon ay maihahambing.

5.3 Test temperature and tensile speed have significant effects on tensile properties, na dapat mahigpit na kontrolin. And the effect varies with different materials.

5.4 Tensile pangmatagalang pagpapapangit ay kumakatawan sa natitirang pagpapapangit ng sample. Ito ay kumakatawan sa pangmatagalang pagpapapangit at bahagyang pagbawi ng sample pagkatapos ng kahabaan at pag urong. Kaya nga, ang mga proseso ng pag angat at pag urong (at iba pang mga kondisyon ng pagsubok) need to be tightly controlled to ensure comparable results.

ASTM D412-0 “Pamamaraan ng Pagsubok ng Paghatak para sa Vulcanized Goma at Thermoplastic Elastomers”

6 Mga Kagamitan
6.1 Makunat na makina — The tensile testing machine shall have an electric drive mechanism to ensure that the separation speed of the sample chuck is constant 500±50mm/min, and the minimum stroke is 750mm(tingnan sa Tala 1). The testing machine should have a suitable dynamometer and reading recording system to ensure that the measured force deviation is within ±2%. Kung ang hanay ng mga pagsubok machine ay hindi maaaring baguhin (halimbawa na lang, ang dynamometer ng pendulum), then the deviation of the measured force when the sample is broken is ±2% of the full range of the dynamometer, and the accuracy of the measured minimum force is 10%. If the dynamometer has an automatic compensation function in the direct measurement of tensile stress, then the compensation function for the cross-sectional area of the specimen should be turned off during the measurement. The recording device should be fast enough to measure the force and ensure the required accuracy during the whole process of specimen failure. If the testing machine does not have a recording device, there should be an indicator to indicate the maximum force value during stretching. Pagpapahaba ay dapat na sinusukat sa sistema ng pagsubok na may isang minimum na increment ng 10%.

Tala 1 — Kung ang bilis ng paghatak na ginamit ay 1000±100mm / min, dapat itong ipahiwatig sa ulat ng pagsubok. In case of doubt, the test should be repeated at a speed of 500mm/min.

6.2 High and low temperature test box — the test box should meet the following requirements:

6.2.1 Sa silid ng pagsubok, there should be a heat flow around the position of the chuck and the shaft, ang bilis ng palibutan ay 1 sa 2m/s, and the temperature is kept within the range of 2 ° C of the required temperature deviation.

6.2.2 Use the calibrated temperature measuring device to measure the actual temperature near the chuck and shaft.

6.2.3 The test chamber shall have an exhaust ventilation device to discharge the gas released in high temperature (sample na lang) into the atmosphere.

6.2.4 Bago ang pagsusulit, ang sample ay dapat ilagay nang patayo malapit sa chuck at shaft para sa pagsasaayos. Specimens should not be in contact with each other or with the walls of the test chamber except for transient contact caused by agitation of the surrounding air.

6.2.5 Place the chuck appropriately to facilitate operation in high and low temperature environments. Sa ganitong paraan, the dumbbell or straight strip specimens are placed into the chuck for as short a time as possible to reduce the temperature change of the test chamber.

6.2.6 The dynamometer should be suitable for working at the test temperature, or have good insulation with the test chamber.

6.2.7 Elongation measuring device shall be provided in the test chamber. If a ruler is used to measure the elongation of the specimen scale, the ruler should be placed parallel to the scale close to the path of the chuck movement and can be controlled from outside the test chamber.

6.3 Thickness gauges — Thickness gauges shall meet the requirements of Specification D 3767(Paraan A). Para sa annular specimens, tingnan sa Artikulo 14.10 ng paraan ng pagsusulit na ito.

6.4 Pagsukat ng makunat pangmatagalang pagpapapangit — Use test equipment as described in 6.1 o tulad ng makikita sa Figure 1. The stopwatch or other timing device should have a range greater than 30min, and the measuring accuracy of the ruler or other measuring device for elongation should be within 1%.

ASTM D412-0 “Pamamaraan ng Pagsubok ng Paghatak para sa Vulcanized Goma at Thermoplastic Elastomers”

7 Pagpili ng mga sample
7.1 The following points should be considered when selecting samples

7.1.1 The anisotropy and orientation of the material caused by the flow during preparation and treatment can affect the tensile properties. Kaya nga, in the preparation of dumbbell or straight bar specimens, under the premise of knowing the calendering direction, Ang direksyon ng sample cutting ay dapat na parallel sa direksyon ng calendering. Para sa annular specimens, the orientation characteristics are usually averaged to a certain extent.

7.1.2 Maliban kung iba ang tinukoy, for thermoplastic rubbers or elasteers, specimens shall be cut from injection molded specimens with a thickness of 3.0±0.3mm, and the test results obtained from specimens of other thicknesses shall be comparable. The samples should be two sets of perpendicular and parallel forming flow directions. The size of the test piece or test plate should be able to meet the test requirements.

7.1.3 The elongation of the annular specimen can be measured by the separation of the collet, but the elongation distribution on the radius width of the specimen is inconsistent. Upang mabawasan ang epektong ito, the sample width should be smaller than the diameter of the annular sample.

7.1.4 When the sample is used for ordinary tensile test, the failure of the sample generally occurs in the chuck. Kaya nga, the straight bar specimen is used only when the sample cannot be made of other shapes. For non-destructive stress-strain or material modulus experiments, straight strip specimens should be used.

7.1.4 Ang laki ng sample ay depende sa mga kinakailangan ng materyal, ang mga kagamitan sa pagsubok at ang sample na ginamit para sa pagsubok. Para sa mga materyales na may mababang paghaba sa break, longer specimens can be used to improve the accuracy of elongation measurement.

ASTM D412-0 “Pamamaraan ng Pagsubok ng Paghatak para sa Vulcanized Goma at Thermoplastic Elastomers”

Pag calibrate ng mga kagamitan sa pagsubok
8.1 Calibrate the test machine according to Procedure A of Specification E 4 for dynamometers of measuring precision type, and calibrate one or more force points according to the 7 at 18 test of specification E 4. For pendulum dynamometers, sundin ang mga sumusunod na hakbang upang mag calibrate:

8.1.1 Ilagay ang isang dulo ng sample ng dumbbell sa chuck ng test machine.

8.1.2 Alisin ang mas mababang chuck mula sa machine ng pagsubok, na ang ibig sabihin ay, the clamping mechanism of the sample is on the upper chuck of the testing machine.

8.1.3 Mag install ng isang hook sa mas mababang chuck upang i hold ang mas mababang dulo ng sample

8.1.4 Hang a weight with a known weight on the hook, so that a certain mass can be temporarily applied to the lower fixture of the sample (tingnan sa Tala 2).

8.1.5 Turn on the fixture movement monitoring device and keep it running until the weight is free to hang on the sample in the ordinary test.

8.1.6 If a disc or ruler (or equivalent tester for stress compensation) does not indicate force values within the specified accuracy, the equipment should be effectively checked for faults (e.g. friction on shafts or other moving parts). Dapat itong matukoy na ang masa ng mas mababang chuck at hook ay isinasaalang alang din.

8.1.7 Matapos ang alitan at iba pang mga faults ng pagsubok machine ay eliminated, the testing machine is calibrated to know that the weight is measured at three points at about 10, 20 at 50% ng buong scale ng testing machine. If ratchets and spines are used in normal testing, they should also be used in calibration. Friction is checked by mounting a ratchet.

Tala 3 — There should be a device to prevent weights from falling from the test machine.

8.2 Ang isang spring ay maaaring gamitin para sa tinatayang mabilis na pag calibrate.

ASTM D412-0 “Pamamaraan ng Pagsubok ng Paghatak para sa Vulcanized Goma at Thermoplastic Elastomers”

9 Temperatura ng pagsubok
9.1 Maliban kung iba ang tinukoy, ang standard test temperature ay 23±2°C. Ang sample ay dapat na nababagay sa 23 ° C para sa hindi bababa sa 3 mga oras. Kung ang materyal ay apektado ng kahalumigmigan, ang specimen ay dapat na kondisyon sa 50±5%R.H. para sa higit sa 24 ilang oras bago ang pagsusulit. Kung susubukan sa iba pang mga temperatura, ang temperatura na nakalista sa Specification D 1349 ay gagamitin.

9.2 If the test is carried out at A temperature higher than 23℃, ang sample ng method A ay dapat na preheated para sa 10±2min; Method B should be preheated for 6±2min. Bago ang bawat agwat ng pagsubok, the specimens are placed in the test chamber separately, so that all specimens are continuously subjected to the same warm-up time. Preheating tests at high temperatures should be strictly limited to prevent persulphation and thermal aging.

Tala 3 — Babala: Kabilang sa iba pang mga babala, use insulated, cold gloves to protect hands from high and low temperatures. Ang isang mask ay dapat gamitin sa panahon ng mga eksperimento sa mataas na temperatura upang maiwasan ang paglanghap ng mga nakakalason na gas kapag ang pinto ng kahon ng eksperimento ay binuksan.

9.3 Para sa mababang temperatura test, ang sample ay dapat na pre cooled para sa hindi bababa sa 10min.

Pamamaraan ng pagsubok A — Straight bar and dumbbell specimens

ASTM D412-0 “Pamamaraan ng Pagsubok ng Paghatak para sa Vulcanized Goma at Thermoplastic Elastomers”

10 Mga Kagamitan
10.1 Cutting Knife — The shape and dimensions of the cutting knife shall be as shown in Figure 2. The inside of the narrow part of the cutter shall be perpendicular to the cutter end face and at least 5mm from the cutter end face shall be polished. The shape of the cutter should remain unchanged without defects. (Tingnan sa Tala 4)

Tala 4 — Ang kondisyon ng tool sa pagputol ay maaaring matukoy sa pamamagitan ng pagmamasid sa punto ng pagbasag ng sample. The fractured sample was removed from the chuck and spliced along the fracture surface to observe whether the sample failure occurred at the same location. Kung ang kabiguan ay nangyayari sa parehong lokasyon, it means that the cutter may become blunt, may depekto, o baluktot sa lokasyong ito.

10.2 Marking lines — Two marking lines drawn on the sample to measure elongation and strain are called marking lines (tingnan sa Tala 5). The marker shall include a flat plate with two bumps parallel to each other. Ang nakataas na ibabaw (parallel sa ibabaw ng plato) dapat mahaba at makitid ang eroplano, at ang dalawang mukha ay dapat panatilihin sa iisang eroplano. Ang nakataas na eroplano ay 0.05 sa 0.08mm ang lapad at hindi bababa sa 15mm ang haba. The Angle between the plate and the bulge was at least 75º. Ang distansya sa pagitan ng mga sentro ng dalawang nakataas na eroplano ay dapat na panatilihin sa loob 1% of the required or target distance deviation. A handle shall be included on the back or top of the marker.

Tala 4 — No marking is required if contact extensionometers are used.

10.3 Ink Marks — Gumamit ng isang flat, matigas na ibabaw (matigas na kahoy, metal, o plastik) to make ink or toner marks. The ink or toner should be firmly bonded to the sample, not corroding the sample, and contrast with the color of the sample.

10.4 Chuck — Ang metro ng pagsubok ay may dalawang collet, isa na kung saan ay konektado sa dynamometer.

10.4.1 The chuck of the test dumbbell sample should have a self-tightening device to generate constant pressure on the surface of the chuck, and the clamping force should increase with the increase of elongation to prevent sliding and make the failure occur in the narrow part of the sample. A constant pneumatic chuck is also applicable. There is a special part in the broken part of the fixture so that the sample can be inserted into the fixture with the same length and the stress distribution is uniform.

10.4.2 The fixture used for testing straight strip samples shall have pneumatic fixture, clamp ang bibig o bolt buckle, so that the clamping force of the fixture can be applied evenly to the entire width of the sample.

ASTM D412-0 “Pamamaraan ng Pagsubok ng Paghatak para sa Vulcanized Goma at Thermoplastic Elastomers”

11 Sample
11.1 Mga specimen ng Dumbbell — Hangga't maaari, specimens should be injection molded or cut from specimens 1.3 sa 3.3mm makapal. The thickness and size of the specimen can be cut by one test method (see Specification D 3182). Ang piraso ng pagsubok ay maaaring gawin nang direkta o gupitin at makintab mula sa tapos na produkto. If the test piece is prepared directly from the finished product, ang ibabaw ay hindi dapat matigas na katad o tela. According to the requirements of specification D 3183. All specimens shall be cut parallel to the length of the specimen, maliban kung iba ang tinukoy. Kung ang specimen ay inihanda ayon sa pagtutukoy D 3182, ang kapal nito ay dapat na 2.0±0.2mm at gupitin kasama ang orientation ng materyal. Use C type cutter (FIG. 2), use a simple stamping device, and ensure the smoothness of the cut surface. .

11.1.1 Pag label ng Dumbbell Specimens — Dumbbell specimens shall be marked as described in 10.2, and the specimens shall not be subjected to tension when marked. The marking line should be drawn on the narrow part, at the same distance from the center of the sample and perpendicular to the vertical axis. The distance between the two marks is 25.00±0.25mm for type C and type D samples. The other is 50.00±0.5mm

11.1.2 dumbbell sample thickness measurement — The thickness of the sample should be measured at three points, one at the center and two at the ends of the narrow part. The median of the three values is used to calculate the cross-sectional area. Kung ang hanay ng mga sample kapal ay mas malaki kaysa sa 0.08, the sample is rejected. Ang lapad ng sample ay maaaring kalkulahin ayon sa lapad ng nagtatrabaho bahagi ng cutter.

11.2 Tuwid na strip specimens — If dumbbells or annular specimens cannot be cut from the sample, tuwid na strip specimens (e.g., narrow strips, maliit na tubo, or fine electrical insulation) can be cut. Ang specimen ay dapat na sapat na mahaba upang magkasya sa fixture. The marking is made as 11.1.1. Upang makalkula ang pagsubok cross-sectional area mula sa tubo, ang masa, haba at density ng tubo ay dapat gamitin. Ang cross sectional area ay kinakalkula tulad ng sumusunod:

A=M/DL(1)(1)

Saan:

A= lugar na pantawid seksyon,cm2

M= masa,g

D= densidad,g/ cm3

L= haba,cm

ASTM D412-0 “Pamamaraan ng Pagsubok ng Paghatak para sa Vulcanized Goma at Thermoplastic Elastomers”

12 Mga Hakbang
12.1 Pagpapasiya ng makunat stress, makunat na lakas at punto ng ani — I load ang dumbbell sample sa fixture ng testing machine, pay attention to adjust the gripping symmetry of the sample, upang ang makunat na puwersa ay pantay pantay na ipinamamahagi sa seksyon ng sample. Ito ay maiiwasan ang labis na pagtatantya ng makunat na puwersa ng specimen. The test speed is 500±50mm/min(tingnan sa Tala 7) unless special requirements are required. Start the testing machine and pay attention to the marking to prevent the influence of parallax. The force values at special elongation and at fracture of the sample were recorded. Elongation can be measured using extensionmeters, automated plotting, or optical tracking systems. Ang katumpakan ng pagsukat ng pagpapahaba sa bali ay nasa loob 10%. The calculation is given in 13.

Tala 8 — Kung ang punto ng ani ng sample ay nasa ibaba 20% pagpapahaba kapag ang bilis ng pagsubok ay 500±50mm / min, ang bilis ng pagsubok ay maaaring mabawasan sa 50±5mm / min. Kung ang punto ng ani ng sample ay nasa ibaba pa rin 20% pagpapahaba ng panahon, ang bilis ng pagsubok ay maaaring mabawasan sa 5±0.5mm / min. Sample speed should be recorded.

12.2 Pagpapasiya ng makunat pangmatagalang pagpapapangit — The sample is loaded into the testing machine or device described in 6.1 tulad ng makikita sa Figure 1. Care should be taken to adjust the gripping symmetry of the sample so that the tensile force is evenly distributed on the sample cross section. The speed of the chuck separation should be as constant as possible, so that the time to reach the prescribed elongation is 15s, and this elongation is maintained for 10min. Pagkatapos ng 10min, the load was released immediately and allowed to return freely for 10min. Pagkatapos nun, the residual deformation within the standard distance was measured, and the measurement accuracy was 1% ng orihinal na distansya. Use a stopwatch to track the time. Tingnan sa 13 para sa kalkulasyon.

12.3 Measurement of long-term fracture deformation — Pagkatapos ng sample ay nasira para sa 10min, the sample should be carefully spliced together to measure the residual deformation within the standard distance, and the calculation is shown in 13

ASTM D412-0 “Pamamaraan ng Pagsubok ng Paghatak para sa Vulcanized Goma at Thermoplastic Elastomers”

13 Pagkalkula
13.1 Lakas ng pagkalkula sa anumang pagpapahaba:

where

T(XXX)= lakas sa paghaba (XXX)%,MPa

F(XXX)= stress sa tiyak na pagpapahaba,MN

A= cross-sectional area of the sample,m2

13.2 Pagkalkula ng lakas ng ani

where

Y(stress na stress)= ani lakas,MPa

F(y)= yield force,MN

A= cross-sectional area of the sample,m2

13.3 The yield point is evaluated as the point on the stress-strain curve where the velocity of the stress change with respect to strain becomes zero and opposite before the final failure of the specimen.

13.4 Pagkalkula ng lakas ng makunat

where

TS= lakas ng paghatak,MPa

F(MAGING)= maximum force at fracture,MN

A= cross-sectional area of the sample,m2

13.5 Compute the elongation at any elongation;

where

E= porsyento ng pagpapahaba (distansya sa scale),%

L = naobserbahan na distansya sa loob ng sample standard distance,mm

L(0)= length of the sample’s original marking distance,mm

13.6 Elongation at break is calculated by substituting L at the time of sample fracture into Equation 5.

13.7 Formula 5 can also be used to calculate long-term deformation, as long as L in the formula is substituted by the residual deformation after 10 mga minuto.

13.8 Test Results — Ang mga resulta ng pagsubok ay ipinahayag bilang median ng mga resulta ng tatlong independiyenteng magkakasunod na sample. Sa dalawang espesyal na kaso, limang sample ang nasubok at ang median value ng limang sample ay iniulat.

13.8.1.Espesyal na Kaso 1 — When the results of one or two samples in the test do not meet the specified measurement.

13.8.2 Espesyal na Kaso 2 — For arbitral tests.

Paraan B — Annular specimen

ASTM D412-0 “Pamamaraan ng Pagsubok ng Paghatak para sa Vulcanized Goma at Thermoplastic Elastomers”

14 Mga Kagamitan
14.1 Cutter — A circular cutter is shown in Figure 3. Use a cutting knife to cut the annular sample from the flat test piece, and install a part of the upper shaft of the cutting knife into the rotary compression device, under which the test piece can be fixed in the rubber fixing device.

14.1.1 Blade lalim ng retainer — The cylindrical disk in the retainer shall be at least 0.5mm thicker than the thickness of the rubber sheet to be cut. Its diameter should be smaller than the inner diameter of the sample, upang ang protrusion ng talim ay maaaring ayusin mula sa tool ng pagputol. Tingnan sa Larawan 3

14.2 Goma pag aayos ng plato — A device for holding rubber in place during cutting, the upper and lower surfaces parallel to each other, and made of hard polymeric materials (matigas na pandikit, polyurethane at polymethyl methacrylate). Holes of about 1.5mm in diameter are distributed at intervals of 6 to 7mm through the center of the plate. All these holes shall communicate with the mold cavity inside to reduce the air pressure used to hold the test piece. Larawan 4 is used to hold the standard test piece (mga 150×150×2mm) sa panahon ng pagputol.

14.3 Pinagmulan ng presyon ng hangin — A vacuum pump can be used to maintain a suction force of 10kPa on the specimen at the center of the gripper mold cavity.

14.4 Soapy water — Use neutral soapy water to lubricate the knife.

14.5 Rotary pagputol — Use a precision rotary machine or other equipment that can provide a speed of at least 30rad/s to cut the test piece. The cutter rotating device shall be mounted on a horizontal plane with a vertical positioner to support the rotating connecting rod and the shaft used for the cutter. The eccentricity of the rotating shaft should be less than 0.01mm.

14.6 Built-in table — There shall be a table or other device that can be moved along the x-y axis respectively to hold and position the test piece so that the test piece corresponds to the axis of rotation of the rotary cutter.

14.7 Tensile testing machine — shall comply with the requirements described in 6.1.

14.8 Test Fixture — The fixture of the annular sample is shown in Figure 5. The testing machine should be calibrated according to 8 articles.

14.9 Test chambers — High and low temperature test chambers shall meet the requirements in 6.2.

14.9.1 The fixture shall not only be suitable for testing at room temperature. Gayunpaman, under special temperature, appropriate lubrication should be used to ensure the lubrication of the rotating shaft.

14.9.2 Ang dinamimetro ay dapat na angkop para sa paggamit sa temperatura ng pagpapatakbo o mahusay na insulated mula sa silid ng pagsubok.

14.10 Mga Gauge ng Kapal — Thickness gauges shall meet the requirements of Specification D 3767(Paraan A).

14.10.1 The main components of the thickness gauge, isang cylindrical itaas na pagsukat ibabaw (longitudinal axis along the vertical direction) hindi bababa sa 12mm ang taas at 15.5±0.5mm ang diameter. In order to fit the small annular sample, the measuring head with diameter of 15.5mm is used to measure, at ang pagsukat ay hindi magiging sanhi ng pagpapahaba ng sample. The bottom of the cylindrical surface can be cut off half along the center so that there is no interference when measuring small samples. Maaari ring gamitin ang isang hubog na dulo ng pagsukat.

ASTM D412-0 “Pamamaraan ng Pagsubok ng Paghatak para sa Vulcanized Goma at Thermoplastic Elastomers”

15. Annular specimen

15.1 ASTM Annular specimens — May dalawang uri, generally 1-shaped specimens are used

15.1.1 Laki ng sample

Uri ng 1

The inner perimeter is 50.0±0.01mm

The inner diameter was 15.92±0.003mm

The radial width is 1.0±0.01mm

The thickness is 1.0~3.3mm

Uri ng 2

The inner perimeter is 100.0±0.2mm

The inner diameter was 29.8±0.06mm

The radial width is 2.0±0.02mm

The thickness is 1.0~3.3mm

15.2 ISO Annular specimens — Specimens are classified as normal and small according to ISO 37, which specifies their specific test procedures.

ordinary

The inner diameter is 44.6±0.2mm

The outer diameter is 52.6±0.2mm

The thickness is 4.0±0.2mm

Maliit na sukat

Inner diameter 8.0±0.1mm

Outer diameter 10.0±0.1mm

The thickness is 1.0±0.1mm

15.3 Cut the annular sample from the pipe — the diameter of the annular sample should be determined by the wall thickness of the pipe and should meet the requirements of the product.

15.4 Preparation of cutting sample — Place the blade in the holder of the cutter and adjust the depth of the blade. Ilagay ang cutter sa rotary press at ayusin ang shaft o table upang ang ilalim ng blade holder ay 13mm sa itaas ng sample holding plate. Shrink the stopper with the rotating shaft moving vertically. This allows the end of the blade retainer to penetrate the surface of the plate. The sample was placed into the gripper and the cavity pressure was reduced to 10kPa. Basa ang ibabaw ng piraso ng pagsubok na may neutral na tubig na may sabon. The cutter should be stopped after reducing the cutter at a constant speed, and the cutter gripper should not touch the test piece at this time. Adjust blade depth if necessary. Reset the shaft before the next cutting.

15.5 Preparation of a sample cut from a tube — A shaft is inserted into the tube, the diameter of which is slightly larger than the diameter of the tube. Place the shaft and tube together on the machine tool. The specimen of the required axial thickness is cut from the sample with the blade or cutter on the machine tool. For thin-walled tubes, when laid flat, a cutter with two parallel blades can be used to cut.

15.6 Annular sample:

15.6.1 Perimeter — The inner perimeter can be measured with a cone or gauge. Walang stress na maaaring gamitin upang baguhin ang ellipticity ng annular specimen sa panahon ng pagsukat. Ang median perimeter ay maaaring batay sa panloob na perimeter, meridional width, and π(3.14).

15.6.2 Lapad ng radyal — Distribute three measuring points equally on the circumference of the specimen as per the thickness gauge in 14.10.

15.6.3 Ang kapal — The thickness of the disk from the inner circle to the outer circle can be measured by a thickness meter according to specification D 3767 when cutting annular specimens.

15.6.4 Pantawid na Lugar — Cross-sectional area was calculated as the median of three measurements: radial width and thickness. Para sa manipis na pipe wall sample, the cross-sectional area was calculated using the axial length of the cutter and the wall thickness.

ASTM D412-0 “Pamamaraan ng Pagsubok ng Paghatak para sa Vulcanized Goma at Thermoplastic Elastomers”

16 Proseso
16.1 Pagpapasiya ng makunat stress, lakas ng paghatak, pagpapahaba sa break at punto ng ani ng annular specimens – na may angkop na pagpapadulas ng mga shafts na may lubricating fixture, tulad ng mineral oil o silicone oil. Should choose to use the prescribed and have no impact on the material. Ang pagkalkula at pagsasaayos ng paunang posisyon ng shaft center ng dalawang fixtures ay ang mga sumusunod:

Saan:

IS= initial distance from the center of the jig axis,mm

C(TS)= perimeter of the sample, para sa type 1 sample ay ang panloob na diameter, para sa type 2 sample ba ang diameter,mm

C(SP)= circumference of the jig shaft,mm

The test speed was 500±50 mamms (see Notes 7 at 8), unless otherwise required. Start the test machine and record the force and the relative displacement of the two jig axes. Elongation and stress were recorded at fracture. The calculations are given in Section 17,

Tala 8 — The test speed was 100±10mm/min using small ring type samples of ISO.

16.2 Mga eksperimento sa mga hindi pamantayang temperatura — Gamitin ang test chamber tulad ng inilarawan sa 6.2 and read the warning in Note 2. For tests higher than 23 ° C, ang sample ay preheated sa temperaturang ito para sa 6±2min. Para sa mga pagsusuri sa ibaba ng temperatura ng kuwarto, ang sample ay dapat na nababagay sa temperatura na iyon para sa hindi bababa sa 10min. The test temperature in D 1349 should be used. Test pieces shall be placed in test chambers separately to meet requirement 9.2.

ASTM D412-0 “Pamamaraan ng Pagsubok ng Paghatak para sa Vulcanized Goma at Thermoplastic Elastomers”

17 Pagkalkula
17.1 Except for one important point, the stress-strain properties of the ring specimen are calculated as those of the dumbbell or straight strip specimen. When the annular specimen is stretched, the stress distribution of each edge of the annular specimen is not uniform in width (from left to right). The initial inner diameter of the sample is smaller than the initial outer diameter. Kaya nga, the stress in the inner test is greater than that in the outer test in the sample stretching, caused by the different initial size.

17.2 The following options are available for calculating tensile and breaking strengths.

17.2.1 Fixed elongation stress — The median perimeter of the annular specimen was used to calculate the elongation. The reason for using the median perimeter is that it corresponds to the average over the edges of the annular specimen.

17.2.2 Pagpapahaba sa break — The inner perimeter of the annular specimen is used as the basis for the calculation, as it corresponds to the maximum stress on each edge of the specimen. This position is also the starting position of the sample failure.

17.3 The constant extension stress is calculated according to Equation 2 in 13.1

17.3.1 The elongation used to determine the force in Equation 2 (13.1) is calculated as follows

Saan:

E= elongation,%

L= increase in the distance between fixtures,mm

MC(TS)= median perimeter of the sample,mm

17.3.2 In Equation 7, the distance between fixtures at fixed extension is calculated using the following equation:

17.4 The yield point is calculated according to Equation 3 in 13.2

17.5 Gamitin ang 13.3 to determine the yield stress. Since the yield stress is used to evaluate the overall properties of the material, the median perimeter is used to calculate.

17.6 Calculate tensile strength according to Formula 4 in 13.4.

17.7 Elongation at break is calculated according to the following formula (see Notes 9 at 10)

Saan:

E= elongation at break,%

L= the increased distance of the fixture at break,mm

IC(TS)= initial inner perimeter of the pattern,mm

17.8 The inner perimeter can be used for both types of specimens (tingnan sa 15.1.1 dimensions). The inner perimeter of type 2 annular specimens is calculated using the inner diameter.

Tala 9 — Equations 7 at 8 can only be used if the initial spacing of the fixture is adjusted according to Equation 7.

Tala 10 — Caution should be taken when using this method because stresses at elongations slightly below the elongation at break (4 sa 5%) may not be calculated when different sizes are used to calculate 1) fixed elongation stress (less than the breaking stress) at 2) elongation at break (tingnan sa 20.1 at 20.2).

ASTM D412-0 “Pamamaraan ng Pagsubok ng Paghatak para sa Vulcanized Goma at Thermoplastic Elastomers”

18 Report
18.1 The report should include the following:

18.1.1 Based on the results of Section 13 o 17

18.1.2 Sample type and description, according to the 13-section cutter type, in American, homemade or metric units

18.1.3 Date of experiment

18.1.4 Test speed

18.1.5 Laboratory temperature and humidity

18.1.6 Temperatura ng pagsubok (if not 23±2℃)

18.1.7 Date of vulcanization or (at) rubber preparation, if possible

19 Accuracy in deviation (omitted)

20 Key Words (omitted)