YY/T 1697-2020Test method for determining strength and setting time for synthetic water-activated polyurethane fiberglass casting tape (English PDF)

Foreword

This standard was drafted in accordance with the rules given in GB/T 1.1-2009.

Please note that certain contents of this document may involve patents. The issuing agency of this document is not responsible for identifying these patents.

Introduction

Synthetic water activated polyurethane fiberglass orthopedic bandage is a representative product of polymer fixation bandage, suitable for orthopedics, plastic surgery and first The external fixation of fractures and sprains in general surgery is widely used in clinical practice.

1 Scope

This standard specifies the determination of the radial compressive strength and curing of annular specimens made of synthetic water-activated polyurethane fiberglass orthopedic bandages Time test method.

This standard applies to synthetic water activated polyurethane fiberglass orthopedic bandages.

2 Normative references

The following documents are indispensable for the application of this document. For dated reference documents, only the dated version applies to this document. For undated references, the latest version (including all amendments) applies to this document.

GB/T 6682 Analytical laboratory water specifications and test methods

3 Terms and definitions

The following terms and definitions apply to this document.

4 Method overview

4.1 Immerse the intercepted orthopedic bandage in (24±1)°C water, drain it out, and wrap it on a cylindrical shaft tube with an outer diameter of 75mm.

Wrap the bandage layer by layer to form a 5-layer ring sample. The indentation test is used to determine the curing time. After the ring sample is initially cured Remove from the shaft tube. After the specified time of 30min, 60min, and 24h, place the ring sample laterally on the two flat platforms of the testing machine The plates are compressed radially to determine their strength.

4.2 The radial compressive strength is an important indicator of the mechanical properties of solidified materials.

Note. This test method cannot be used to determine the life of the tested material, bending of the fixed material or other failure modes.

5 Apparatus and materials

6 Samples and reagents

6.1 The orthopedic bandages of the same specification are from the same batch, and at least 5 rolls of orthopedic bandages are prepared for testing; each roll shall be carried out within the specified time Ring sample preparation, each roll of orthopedic bandage can prepare 2 ring samples, and at least 9 ring samples can be prepared.

6.2 The water required to prepare the ring sample meets the requirements of GB/T 6682 tertiary water or above, and the immersion water temperature is maintained at (24 ±

1) °C, after testing 5 rolls of orthopedic bandage, change the water used.

7 Status adjustment

Place the unopened orthopedic bandage flat in an environment with a temperature of (23 ± 2) °C, and store it for at least 24h before the test.

8 Sample preparation and curing time detection

8.1 The ring sample adopts a constant tension sample preparation method, and each layer of bandage is wound on the shaft tube with a constant tension of 5.0g/mm (see Figure 1). will The counterweight load is clamped on the unfolding end of the orthopedic belt while rotating the horizontal shaft tube.

8.2 Before opening each package, record the manufacturer's name, product specifications, size (width and length) and batch number. Orthopedic bandage open It should be used immediately after packaging.

8.3 Wrap the anti-sticking lining on the shaft tube of the preparation sample and fix it with tape or other means.

8.4 Open the package, take out the orthopedic bandage, quickly unfold the orthopedic bandage, lay it flat and cut out the 1.2m~1.3m bandage, and place the intercepted orthopedic bandage.

The band is completely immersed in the water according to the instructions of the orthopedic bandage. After immersing in the water, start timing, quickly take out the soaked bandage, drain the excess water, and wrap one end on the shaft On the tube, the winding length should be less than or equal to the circumference of the shaft tube and should be able to keep the bandage from falling off. Clamp the clamp and the weight on the other orthopedic bandage.

At the end, the direction in which the bandage falls should be perpendicular to the axis of rotation of the shaft tube, adjust the winding device to 20r/min, turn on the switch to rewind, and keep Each layer completely overlaps the previous layer. When the bandage is wound to the end of the fifth layer, at ±5mm relative to the starting end of the first layer Cut off the excess bandage.

8.5 Repeat 8.4 to make a second ring sample immediately.

8.6 The winding production of multiple circular specimens can be performed at the same time. When multiple circular specimens are wound, the The belt should be soaked and taken out at the same time.

8.7 The curing time is measured by the indentation test method. A push-pull dynamometer with a wedge-shaped pusher is used for the ring sample to be perpendicular to the The indentation test is carried out on the contact surface of the ring sample, and the test is carried out every 15s until all samples are cured (no obvious indentation). Record 9 rings Calculate the curing time of the shaped sample from the time the sample is immersed in water, and record the average value as the curing time.

8.8 After the ring sample is cured, remove it from the shaft tube and avoid deformation of the sample. Remove the release liner from the inner wall of the ring sample.

8.9 Place the ring specimens vertically and keep enough space between the specimens so that air can circulate freely between the ring specimens.

9 Radial compression strength test

9.2 30min radial compression strength 9.2.1 This test shall be carried out after (30 ± 5) minutes have passed after the intercepted orthopedic bandage sample is immersed in water. Place each sample (one at a time) in Between the two flat platens of the testing machine, place it at the center of the lower platen. The length of the platen should be large enough to support the entire length sample. Adjust the direction of the ring sample so that the transition area or overlap area of the sample, that is, the part between the beginning of the first layer and the end of the fifth layer, and the lower The platen touches.

9.2.2 Make the upper platen just contact the ring sample, but do not apply any load.

9.2.3 Continue the test at a uniform rate until the ring sample is damaged or compressed after a 10mm displacement, stop the compression test.

9.2.4 If the sample is not cured within 30min, there is no need to test the 30min radial compressive strength.

9.2.5 Record the maximum load of each ring specimen, that is, the peak failure load or the maximum deflection load, whichever occurs first. 30min The radial compressive strength is the average value calculated from the test values of 3 ring specimens.

9.3 60min radial compression strength The test method is the same as the 30min radial compressive strength test, and the test is carried out at (60±5)min after the sample is immersed in water.

9.4 24h radial compression strength The test method is the same as the 30min radial compressive strength test, and the test is carried out 24h±30min after the sample is immersed in water. Sample During the 24h curing period, it should be stored at (23±2)°C and (50±10)% relative humidity.

10 Report

The test report should include at least the following.

a) Curing time in seconds (s);

b) Test speed, the loading speed of the testing machine when testing the radial compressive strength, in millimeters per minute (mm/min);

c) 30min, 60min, 24h radial compressive strength, the unit is Newton per millimeter (N/mm). Report the type of load (peak damage Load or maximum deflection load);

d) Laboratory environment temperature and humidity.