wiper blades

This standard specifies the terminology and definitions, model specifications, requirements, test methods, inspection rules, marking, packaging, transportation, storage and operating instructions for a soft windshield wiper blade (hereinafter referred to as a wiper blade).

This standard applies to windshield wiper blades for vehicles.

The following documents are indispensable for the application of this document. Where dated references are given, only the dated version of those documents applies to this document. Where referenced documents are undated, only the latest version of the referenced documents (including any amendments) applies.

GB/T 528-2009 Rubber, vulcanized or thermoplastic – Determination of tensile and deformation properties
GB/T 531.1 Rubber, vulcanized or thermoplastic – Determination of indentation hardness – Part I: Shore hardness
GB/T 1040.1-2006 Plastics – Determination of tensile properties – Part 1: General principles
GB/T 1720 Test method for adhesion of paint films
GB/T 1732 Determination of impact resistance of films
GB/T 1771 Paints and varnishes – Determination of resistance to neutral salt spray
GB/T 2411 Plastics and ebonite — Determination of hardness by the indentation durometer method (Shore hardness)
GB/T 2828.1-2003 Sampling inspection procedures by attributes — Part 1: Sampling schemes indexed by acceptable quality level (AQL) for random inspection of lots
GB/T 3512 Rubber, vulcanized or thermoplastic — Accelerated ageing and heat resistance tests — Air oven method
GB/T 6461 Test methods for corrosion of metallic and other inorganic coatings on metallic substrates — Evaluation of test pieces and articles subjected to corrosion tests
GB/T 6739 Paints and varnishes — Determination of film hardness by the pencil test
GB/T 7762 Rubber, vulcanized or thermoplastic — Resistance to ozone cracking — Test for static tensile
GB/T 7141 Plastics – Heat ageing methods
GB/T 9969 General rules for instruction manuals for industrial products
GB/T 12584 Rubber or plastic coated fabrics – Low temperature impact test
GB/T 13452.2-2008 Paints and varnishes – Determination of paint film thickness
GB/T 14436 General rules for warranty documents for industrial products
QC/T 44-2009 Electric windshield wiper
QC/T 46 Wiper blade model and size

The following terms and definitions, together with those specified in QC/T 44, apply to this standard.

3.1 Soft wiper blade
Unlike a conventional wiper blade, which has a rubber strip supported by a metal frame, a soft wiper blade consists entirely of rubber strips that are supported by a flat spring steel sheet, enabling it to effectively clean the outer surface of the windshield.

3.2 Rubber wiper strip (hereinafter referred to as rubber strip)
The rubber strip is the main part mounted on the soft wiper blade. It is made of rubber or other elastomers, allowing it to adhere closely to the glass surface and remove any dirt or residue.

1—Rubber strip;
2—Adapter;
3—Flat spring steel sheet;
4—Shell.

3.3 Flat spring steel sheet
It is the main support part of the soft wiper blade, having a curved surface. The spring steel strip (or spring wire) supports the rubber strip. The spring pressure exerted by the wiper arm allows the rubber strip to adapt to the curvature of the windshield.

3.4 Sheath
It is installed outside the flat spring steel sheet, made of flexible plastic, rubber or other elastomers. It is used for the external decoration of the soft wiper blade and wind resistance.

3.5 Connecting adapter
Connecting part between the soft wiper blade and the wiper arm.

4.1 Model specification is as follows:

MT – Product specification (rubber strip length, measured in mm or inch)
WB – Product number
* – Soft wiper blade code

4.2 Example of model specification
MT-WB-510-500 refers to 510 type soft wiper blade with 500mm rubber strip length, produced by Xiamen Meto Auto Parts Industry Co.,Ltd.

5.1 General requirements
5.1.1 The soft wiper blade shall comply with this standard and shall be manufactured in accordance with a sample approved in accordance with the specified procedures and technical documentation.
5.1.2 The length of the rubber strip mounted on the soft wiper blade shall comply with QC/T 4 and the adapter shall be connected to the wiper arm in the manner specified in QC/T 46.

5.2 Appearance quality
5.2.1 The metal parts of the soft wiper blade shall be subjected to anti-corrosion treatment or made of anti-corrosion
materials.
5.2.2 The metal parts of the soft wiper blade shall be painted and uniformly covered with a plastic coating without
air bubbles, sag or runs.
5.2.3 Galvanization shall be uniform, without exposure base, as well as pronounced cracks and
other harmful defects.
5.2.4 The surface of the rubber strip and casing must be smooth and even without scratches and cracks, and the wiper blade must not have nicks.

5.3 Design requirements
5.3.1 The soft wiper blade connecting adapter must be tightly and securely connected to the wiper arm, and also easy to mount and dismount. No play or pronounced deformation is allowed during use.
5.3.2 The soft wiper blade must be easy to mount and dismount, as well as components of the same model

5.4 Component requirements must be interchangeable. Interchangeable parts shall not vibrate under normal operating conditions.
5.4.1 Flat spring steel sheet
5.4.1.1 Flat spring steel sheet (or spring steel wire) has a curved structure. When flattened by applying pressure to the middle of the bend, its distance from the ground shall be less than 0.3 mm.
5.4.1.2 When assembled into a finished product, the flat spring steel sheet shall meet the following
elastic pressure requirements:
a ） For new vehicle installation at the vehicle manufacturer, the elastic pressure is
0.15 N/cm±0.03 N/cm;
b ） For replacement installation in the aftermarket, the elastic pressure is
0.13 N/cm±0.03 N/cm.
5.4.1.3 The coating thickness on the surface of the flat spring steel sheet shall meet the requirements
specified in Table 1.

5.4.1.4 The coating performance on the surface of the flat spring steel sheet shall not be lower than the requirements specified in Table 2.

5.4.2 Rubber tape
The physicochemical properties of the materials from which the rubber tape is made shall correspond to the
characteristics specified in Table 3

5.4.3 Sheath
The physicochemical properties of the materials from which the sheath is made shall correspond to the
characteristics specified in Table 4.

5.4.4 Connecting adapter
5.4.4.1 After a 72-hour high-temperature resistance test, no fading or visible cracks.
5.4.4.2 After the 24-hour low-temperature resistance test, neither color fading nor visible brittle fractures are observed on the surface of the connection adapter.
5.4.4.3 After the 72-hour ozone resistance test, neither color fading nor visible brittle fractures are observed on the surface of the connection adapter.

5.5 Performance characteristics
5.5.1 Surface gloss
The exposed part of the soft wiper blade shall not create a dazzling surface.
5.5.2 Wiping effect
5.5.2.1 The extent of the wiping effect is classified by one wiping cycle and is shown in Table 5.

5.5.2.2 The wiping effect is shown in Table 6.

5.5.3 Weather Resistance Requirements
Under temperature conditions of -21℃ to -16℃ and 45℃ to 50℃, the soft wiper blade
should be able to continue working for 5 minutes with a cleaning effect above the 8th scale.
5.5.4 Durability Requirements
5.5.4.1 After 50×104 cleaning cycles, the surface of the soft wiper blade shell should be smooth
and even without scratches and cracks; the blade on the rubber strip has no burrs, and there are no cracks on
the surface.

5.5.4.2 After 100×104 cleaning cycles, the blade on the rubber strip has no burrs, and there are no cracks on
the surface; the change in pressure on the flat spring steel sheet should be less than 10%.
5.5.4.3 After 150×104 wiping cycles, the blade on the rubber strip has no burrs and there is no crack on the surface; there is no noticeable weakening or other abnormal phenomena in all parts and components; and there is no shrinkage, delamination or peeling of the anti-corrosion layer on the surface of the metal parts.

6.1 Quality of Appearance
Under natural light or equivalent artificial light, visually inspect the appearance of the product (the distance between the eye and the part to be inspected shall be 0.3 m).

6.2 Inspection of Design Requirements

The inspection shall be carried out based on visual measurement and operation.

6.3 Inspection of Component Requirements

6.3.1 Flat Spring Steel Sheet

6.3.1.1 After the flat spring steel sheet is flattened on the plate glass, the gap between the steel sheet and the flat surface shall be measured using a gauge.
6.3.1.2 The elastic pressure of the flat spring steel sheet assembled into a finished product
shall be inspected in accordance with 5.2.4 in QC/T 44-2009.
6.3.1.3 Thickness surface coating is tested according to GB/T 13452.2-2008.
6.3.1.4 Surface coating quality
6.3.1.4.1 Paint film adhesion is tested according to GB/T 1720.
6.3.1.4.2 Pencil hardness of paint film is tested according to GB/T 6739.
6.3.1.4.3 Impact strength of paint film is tested according to GB/T 1732.
6.3.1.4.4 The 48-hour neutral salt spray test of paint film is subject to GB/T 1771 and evaluated according to GB/T 6461.
6.3.2 Rubber strip
6.3.2.1 The rubber strip is selected and its hardness is tested according to GB/T 531.1, and the instantaneous reading (within one second) is obtained at a temperature of 23℃士2℃
6.3.2.2 The tensile strength, elongation at break and 300% stress at a certain elongation of the rubber strip are tested based on the I-type dumbbell-shaped specimen and the testing speed of 500mm/min士50mm/min
in accordance with GB/T 528-2009.
6.3.2.3 Hot air aging
The change in hardness, change in tensile strength and elongation at break of the rubber strip are tested in accordance with GB/T 3512, where the following test conditions shall be met:
a) Test temperature: 70℃±3℃;
b) Test duration: 72h;
c) The hardness specimen shall conform to GB/T 531.1;
d) The I-type dumbbell specimen is used for tensile test with an elongation of 10±1%.
6.3.2.4 Low temperature brittleness
Low temperature brittleness is tested in accordance with GB/T 12584, where the following test conditions shall be met:
a) Test temperature: -40℃±3℃;
b) Test duration: 24h;
c) Hardness specimen shall comply with GB/T 531.1.
6.3.2.5 Ozone resistance
The ozone resistance of the rubber strip is tested in accordance with GB/T 7762, where a 5× magnifying device is used to observe the specimen, and the following test conditions shall be met:
a) Ozone concentration: 50 pphm士3 pphm;
b) Test temperature: 38℃±3℃;
c) Test duration: 72h;
d) Length of rubber strip specimen: 100mm士1mm; elongation: 10士1%。
6.3.3 Shell
6.3.3.1 The shell is selected and its hardness is tested according to GB/T 2411, and instantaneous readings (within one second) are obtained at a temperature of 23℃士2℃.
6.3.3.2 The tensile strength and elongation at break of the shell are tested based on the type II dumbbell-shaped specimen and the testing speed of 100mm/min士10mm/min according to GB/T 1040.1-2006.
6.3.3.3 Hot air aging
The change in hardness, change in tensile strength and elongation at break of the shell are tested according to GB/T 7141, where the following test conditions shall be met:
a） Test temperature: 70℃±3℃;
b) Test duration: 72h;
c) The hardness specimen shall comply with GB/T 2411;
d) Type II dumbbell specimen shall be used for tensile test.
6.3.3.4 Low Temperature Brittleness
Low temperature brittleness shall be tested in accordance with GB/T 12584, where the following test conditions shall be met:
a) Test temperature: -21℃±3℃;
b) Test duration: 24h;
c) The hardness specimen shall comply with GB/T 2411.
6.3.3.5 Ozone Resistance
The ozone resistance of the shell shall be tested in accordance with GB/T 7762, where a 5X magnifying glass is used to observe the specimen, and there shall be the following test conditions are met:
a) Ozone concentration: 50 pphm士3 pphm;
b) Test temperature: 38℃±3℃;
c) Test duration: 72 h.
Note: The length and elongation of the flexible material sheath specimen are 100 mm±1 mm and 10 ±1%
respectively; the length of the specimen mixed with flexible and hard materials, which is rolled into a circular arc, with the hard materials rolled as the inner arc and the flexible materials as the outer arc, is 10 mm ± 1 mm.
6.3.4 Connecting adapter
6.3.4.1 Visual observation of the specimen placed in the high-temperature test chamber for 72 hours
at a temperature of 70℃ ± 3℃.
6.3.4.2 Visual observation of the specimen placed in a low temperature test chamber for 24 hours
at a temperature of -21℃±3℃.
6.3.4.3 Ozone resistance
The ozone resistance of the connection adapter is tested in accordance with GB/T 7762, and visual observation is carried out on the specimen, where the following test conditions shall be met:

a) Ozone concentration: 50 pphm士3 pphm;
b) Test temperature: 38℃±3℃;
c) Test duration: 72 h.

6.4 Performance test
6.4.1 Visual measurement of the surface gloss of the soft wiper blade is carried out based on the backup sample comparison method (compare the backup sample with the sample).
6.4.2 Wiping performance test
6.4.2.1 Test devices
a) Test bench —— During the whole test process, the test bench shall meet the installation requirements of the windshield, motor, swing arm and wiper blade;
b) Water spray device —— The nozzle shall spray water uniformly on the outer surface of the glass at a flow rate of not less than 800 ml/min;
c) Counter —— Record the time of cleaning cycles;
d) FM device —— The frequency is in the range of 20 times/min to 80 times/min.
6.4.2.2 Test procedure
a ） The soft wiper blade is installed on the test bench, the residue or dirt on the windshield

is cleaned with detergent, then the windshield is sprayed with water and wiped for 3 minutes, and
then The windshield is sprayed with water again, and the wiper performs one cleaning cycle,
and then the cleaning performance is visually observed at both the maximum frequency and the minimum frequency, respectively. The observation result is evaluated according to 5.5.2.
b) The soft wiper blade is installed on the test bench, the wiper is operated at the maximum frequency for 3 minutes, while the water spray device continuously sprays water, and then the cleaning performance is visually observed. The observation result is judged according to 5.5.2.
6.4.3 Weatherproofing Compliance Test
6.4.3.1 Test Devices
a) Test bench, same as 6.4.2.1a)）;
b) Water spray device, same as 6.4.2.1b)）;
c) Meter, same as 6.4.2.1c)）;
d) FM device, same as 6.4.2.1d).
6.4.3.2 Test Conditions
a) Ambient temperature: -21℃～-16℃;
b) Ambient temperature: 45℃～50℃.
6.4.3.3 Procedure tests
A soft wiper blade is mounted on a test bench. Under normal operating conditions, 50×10 4 wiping cycles are performed with a wiping frequency of 60 times/min. The test is performed based on 6.4.3.2, and the test result is evaluated according to 5.5.3.
6.4.4 Durability test
6.4.4.1 Test devices
a) Test rig, same as 6.4.2.1a)）;
b) Water spray device, same as 6.4.2.1b)）;
c) Counter, same as 6.4.2.1c)）;
d) FM device, same as 6.4.2.1d)）;
6.4.4.2 Test conditions

The soft wiper blade performs 25×10 4 cleaning cycles at each specified cleaning frequency.
6.4.4.3 Test procedure
Soft wiper blade The windscreen wiper is mounted on a test bench. Under normal operating conditions, 50×10 4 wiping cycles are performed in accordance with 6.4.4.2. The test is carried out and assessed in accordance with 5.5.2
and 5.5.4.1, then an additional 50×104 wiping cycles are performed and the test is carried out and assessed
in accordance with 5.5.2 and 5.5.4.2; then an additional 50×104 wiping cycles are performed and the test is carried out and assessed
in accordance with 5.5.2 and 5.5.4.3. The windscreen must be clean during the test.

7.1 Inspection Classification
Inspection is divided into delivery inspection and type inspection.
After inspection, the qualified product shall be issued a qualification certificate, which shall comply with GB/T 14436.

7.2 Delivery Inspection
Delivery inspection shall be carried out in accordance with 5.2.1–5.2.4, 5.3.1–5.3.4, 5.4.1.1 and 5.4.1.2 of this document, in which 5.2.3, 5.3.3 and 5.4.1.2 apply to random inspection when sampling is carried out in accordance with 7.3.3.
7.2.3 Qualification Determination Rules
In case of non-conformity of measurement with the standard, it is necessary to conduct a duplicate inspection of the product from the original lot. In case of repeated non-conformity of measurement to the standard, the product is determined to be non-conforming to the standard.

7.3 Type inspection

7.3.1 Type inspection is carried out when one of the following cases occurs:
a) Significant change in structure, process or material;
b) Production is resumed after a long downtime;
c) When quality is unstable;
d) Conducted every two years when production is under normal conditions;
e) Proposed by the state quality supervision body, administrative competent authority or customers.
7.3.2 Products for type inspection shall be selected from a batch that is qualified for delivery inspection. The type inspection is subject to this standard.
7.3.3 Sampling method
According to GB/T 2828.1-2003, one sample is taken for the normal inspection based on the inspection level II and AQL = 4.
7.3.4 Qualification determination rules
The result of the type inspection shall comply with this standard. In addition to durability, if one item fails to meet the standard, double sampling of the product is allowed for re-examination. In case of repeated failure to meet the standard, the lot of the product is determined to be non-conforming. In case of two items failing to meet the standard, re-examination is not allowed.

8.1 Product Marking
The following items shall be marked in a visible place on the product in a permanent manner:

a) Name of the manufacturer;
b) Product name and model specification;
d) Manufacturing number;
e) Year and month of delivery.

8.2 Packaging
8.2.1 The product shall be securely packed to ensure that it will not be damaged under normal transportation conditions.
8.2.2 The packing case shall be complete with the following documents:
a) Packing list: indicate the quantity of products and the date of shipment;
b) Inspector qualification certificate;
C) Operation manual and warranty.
8.2.3 The packing case shall be marked on the outside as follows:
a) Name of the manufacturer;
b) Name, model, quantity and date of manufacture product;
c) Transport marking;
d) Name and address of the consignee.

8.3 Storage
Products should be stored in a dry and well-ventilated warehouse, away from harmful gases, chemicals, acids, alkalis and batteries.

8.4 Operation Manual
The operation manual should comply with GB/T 9969.