YY/T 1703-2020Dentistry—Coiled springs for use in orthodontics (English PDF)

3.1 Inner diameter (spring inner diameter)

The maximum outer diameter of the tube that can be accommodated in the coil spring.

3.2 Outer diameter

The smallest inner diameter of a tube that can accommodate a coil spring.

3.3 Sectional size of wire

The cross-sectional size of the wire used to make the spring.

3.5 Unloaded spring length

< tension spring> The maximum size including hooks, holes or connectors in the unloaded state.

3.6 Spring length

For springs with attachments, in the unloaded state, the maximum size including hooks, holes or connectors.

3.7 Maximum compression rate

The percentage of the length of the spring when fully compressed to the length of the unloaded spring.

3.8 Maximum elongation

When 1% permanent deformation occurs, the percentage of the extension of the spring to the length of the unloaded spring.

3.9 Spring force

After the spring is loaded to the specified maximum tension or compression deformation, it reaches the maximum extension or compression during the return process (during unloading)

The force generated by the spring at 80%, 60%, 40% and 20% of the rate.

4.1 General requirements

The manufacturer shall declare the following properties, when tested in accordance with the test methods in Chapter 5, the measured results shall be within the range claimed by the manufacturer.

4.2 Dimensions

4.2.1 The following dimensions should be declared and accurate to 0.01mm. According to the test in Chapter 5, the following dimensions of the product should meet the manufacturer's claim range.

a) Inner diameter di;

b) outer diameter do;

c) Unloaded spring length luc or lue;

d) The total length of the spring is lt.

4.3 Mechanical properties

Measuring the elastic performance during unloading.

a) Maximum elongation epsilonmax;

b) The maximum compression rate cmax;

4.4 Harmful elements

In this standard, cadmium, beryllium, lead and nickel are considered hazardous elements, and manufacturers must declare their content, expressed in mass fraction.

5.1 Sampling

Each test shall take 6 samples from the same batch of the same product.

5.2 Dimensions

Measure each size of each sample.

5.2.1 Appliances

Use calipers, micrometers, optical measuring instruments or other instruments with an accuracy of 0.005mm.

5.2.2 Measurement procedure

According to their respective definitions, measure the following items and should be accurate to 0.01mm. inner diameter di, outer diameter do, full length lt and unloaded spring Length luc or lue.

5.3 Mechanical properties

5.3.1 Appliances

A testing machine with a crosshead speed of 0.5mm/min~10.0mm/min and calibrated for force and displacement should be used for measurement.

5.3.2 Test procedure

5.3.2.1 The test shall be carried out at (23±2)°C, and the temperature-sensitive spring shall be tested at (36±1)°C.

5.3.2.2 The crosshead speed should be 0.5mm/min~10.0mm/min.

5.3.2.3 (20 ± 0.2) mm should be taken as the sample length, or the length of the unloaded spring should be taken when the length is less than 20 mm.

5.3.2.4 Measure the following mechanical properties of the spring.

a) Maximum elongation, epsilonmax;

b) Maximum compression rate, cmax;

5.4 Results processing

The test results of each sample are within the range specified by the manufacturer, and the material meets the requirements.

6.1 General requirements

The following information should be clearly indicated by the manufacturer in the catalog, package insert, label, or in other easily accessible ways.

a) Chemical composition. The composition range of the alloy should include all elements with a content greater than or equal to 0.1% (mass fraction), and 4.4 The quality score of any harmful elements

b) The range of each size should meet the requirements of 5.2;

c) The design of the spring, that is, compression rate (push spring) or elongation (tension spring);

d) The range of various mechanical properties should meet the requirements of 5.3.2.4.

6.2 Packaging

During transportation and storage, appropriate packaging and pollution protection should be provided in accordance with acceptable business practices.

6.3 Identification

At least the following information should be marked on each package.

a) The name and address of the manufacturer, if applicable, the name and address of the distributor;

b) The name of the spring;

c) The design of the spring;

d) Lot number;

e) The number of springs in the package;

f) Warning of harmful elements contained in the product (if applicable, the information should be expressed in symbolic form). references [1] GB/T 16886.1 Biological Evaluation of Medical Devices Part 1: Evaluation and Testing in the Process of Risk Management (GB/T 16886.1- 2011, ISO 10993-1:2009, IDT)

[2] YY/T 0268-2008 Biological Evaluation of Dental Oral Medical Devices Unit 1.Evaluation and Testing (YY/T 0268- 2008, ISO /FDIS7405.2008, NEQ)