塑料沖擊脆化溫度試驗儀  結構原理

A、本設備由制冷壓縮機主機體、加熱裝置、電子控制箱、冷卻槽、冷卻介質循環系統、自動報警裝置等部分組成。啟動制冷開關后，壓縮機開始工作，制冷系統進入正式工作狀態。制冷壓縮機連續不斷的工作，當接近設定溫度時，冷卻槽中的加熱裝置開始按比例提供熱量，用以平衡制冷系統產生的多余冷量，以達到恒溫的目的。攪拌可使冷卻槽內的冷卻介質不斷循環，使溫度均勻一致。

B、試樣夾持器

試樣一邊夾持4個試樣（橡膠類），另一邊夾持15個試樣（塑料類）。

C、沖擊裝置

沖擊裝置由沖擊錘和自鎖機構組成。

D、沖擊器

沖擊頭半徑為1.6?0.1mm；

沖擊時，沖擊頭和試樣夾持器之間間隙為6.4?0.3mm；

沖擊頭的中心線與試樣夾持器之間的距離為8?0.3mm。

塑料沖擊脆化溫度試驗儀  儀器標準：

本儀器是根據GB1682國家標準設計的，各項技術指標符合HG 2-162-1965塑料低溫沖擊壓縮試驗方法和GB5470-2008 塑料沖擊脆化溫度試驗方法等國家標準的要求。

適用行業：

可以用來考核和確定電工、電子、汽車電器、材料等產品，在低溫環境條件下貯存和使用的適應性，適用于學校，工廠，軍工，研位，等單位。

技術參數:

1.控溫范圍：室溫-70℃（室溫≤25℃）

2.恒溫精度：?0.3℃       

3.降溫速度：0℃～﹣30℃    約2.5℃/min

﹣30℃～﹣40℃   約2.5℃/min

﹣40℃～﹣70℃   約2.0℃/min

4.最大外形尺寸：900?500?800mm（長?寬?高）

5.工作室有效工作空間：280?170?120mm（長?寬?高）    

6.可裝試樣數量：1

7.數字計時器數字計時器：0秒-99分鐘，分辨率1秒

8.冷卻介質：乙醇或其他不凍液

9.攪拌電機：8W

10.工作電源：220V--240V，50Hz，1.5kW

11.工作溫度:≤25℃

組成

設備由工作臺、升降夾持器、沖擊裝置、低溫測溫計、盛裝冷凍介質的低溫容器、攪拌器等部分組成。

升降夾持器

升降夾持器由夾持器和升降裝置組成

從試樣受沖擊部位，到夾持器下端的距離為（11.0加或等于0.5）mm。

沖擊裝置

沖擊裝置由沖擊器和沖擊彈簧等組成。

沖擊器

沖擊器頭部形狀和尺寸，沖擊器的質量為（200?20）g,其工作行程為（40?1）mm。沖擊裝置的彈簧在壓縮狀態下，沖擊器端部到試樣的距離為（25?1）mm。

低溫測溫計

采用最小分度不大于1度的低溫測溫計測量冷凍介質的溫度，可使用低溫溫度計、熱電偶、電阻溫度計等。低溫溫度計為內標式半浸的，以尾長150MM，浸入液體深度75MM為宜。

冷凍介質

冷凍介質由適宜的傳熱介質加致冷劑調配而成。

傳熱介質

在試驗溫度下，能保持流動，對試樣無附加影響的液體均可作傳熱介質。這類傳熱介質通常使用乙醇，此外還有丙酮、硅氧烷等。

致冷劑

可根據需要選用干冰或液氮。

注：也可采用其他降溫方式。

試樣規格：

試樣的長度為（20.5?0.5）MM，寬度為（6.0?0.5）MM，厚度為（2.0?0.2）MM.

試樣要求：

試驗前，試樣應放置在標準實驗室溫度下調節至少3H，并在明亮的光線下彎曲試樣并檢查試樣表面，試樣表面應光滑，無雜質、損傷及微孔。成品應經打磨后裁制成相應尺寸。

試驗報告

A本標準名稱或編號

B樣品的詳細說明及其來源

C使用的傳熱介質、致冷劑或其他降溫方式

D程序A:脆性溫度和試樣破壞現象

E程序B：規定的試驗溫度和試驗結果

試驗結果與處理

程序A

1、試樣出現破壞的最高溫度，就是該試樣的脆性溫度。

2、溫度值應精確到1度。

程序B

如果一組試樣中沒有任何1個試樣破壞，則試驗結果為無破壞。如果一組試樣中有2個或2個以上試樣發生破壞，則試驗結果為破壞。如果一組試樣中只有一個試樣發生破壞，則再次取3個新的完好試樣測試，3個試樣均未發生破壞則試驗結果為無破壞；否則試驗結果為破壞。

使用方法 

1接通電源，溫控儀和計時器顯示燈亮。 

2向冷井中注入冷凍介質（一般為工業乙醇），其注入量應保證夾持器的下端到液面的距離為75?10mm。 

3將試樣垂直夾在夾持器上。夾的不宜過緊或過松，以防止試樣變形或脫落。 

4按下夾持器，開始冷凍試樣，同時啟動時序控制開關（或按動秒表）計時。試樣冷凍時間規定為3.0?0.5min。試樣冷凍期間，冷凍介質溫度波動不得超過?1℃。 

5提起升降夾持器，使沖擊器在半秒鐘內沖擊試樣。 

6取下試樣，將試樣按沖擊方向彎曲成180?，仔細觀察有無破壞。 

7試樣經沖擊后（每個試樣只準沖擊一次），如出現破壞時，應提高冷凍介質的溫度，否則降低其溫度，繼續進行試驗。 溫度，如這兩個結果相差不大于1℃時，即試驗結束。 

Structural Principles

A、 This equipment consists of a refrigeration compressor main body, a heating device, an electronic control box, a cooling tank, a cooling medium circulation system, an automatic alarm device, and other parts. After starting the refrigeration switch, the compressor starts working and the refrigeration system enters the official working state. The refrigeration compressor operates continuously, and as it approaches the set temperature, the heating device in the cooling tank begins to provide heat proportionally to balance the excess cooling generated by the refrigeration system and achieve constant temperature. Stirring can continuously circulate the cooling medium in the cooling tank, ensuring a uniform and consistent temperature.

B、 Sample holder

One side of the sample holds 4 samples (rubber type), and the other side holds 15 samples (plastic type).

C、 Impact device

The impact device consists of an impact hammer and a self-locking mechanism.

D、 Impactor

The radius of the impact head is 1.6 ? 0.1mm;

During impact, the gap between the impact head and the sample holder is 6.4 ? 0.3mm;

The distance between the centerline of the impact head and the specimen holder is 8 ? 0.3mm.

Instrument standards:

This instrument is designed according to the national standard GB1682, and all technical indicators comply with the requirements of national standards such as HG 2-162-1965 Low Temperature Impact Compression Test Method for Plastics and GB5470-2008 Plastic Impact Embrittlement Temperature Test Method.

Applicable industries:

It can be used to assess and determine the adaptability of products such as electricians, electronics, automotive appliances, materials, etc. to storage and use in low-temperature environmental conditions, suitable for schools, factories, military industries, research institutes, and other units.

Technical parameters:

1. Temperature control range: Room temperature -70 ℃ (Room temperature ≤ 25 ℃)

2. Constant temperature accuracy: ? 0.3 ℃

3. Cooling rate: 0 ℃~-30 ℃, about 2.5 ℃/min

-30 ℃~-40 ℃, about 2.5 ℃/min

-40 ℃~-70 ℃, about 2.0 ℃/min

4. Maximum external dimensions: 900 x 500 x 800mm (length x width x height)

5. Effective workspace of the studio: 280 x 170 x 120mm (length x width x height)

6. Number of samples that can be loaded: 1

7. Digital timer: 0-99 minutes, resolution of 1 second

8. Cooling medium: ethanol or other non freezing liquids

9. Mixing motor: 8W

10. Working power supply: 220V-240V, 50Hz, 1.5kW

11. Working temperature: ≤ 25 ℃

form

The equipment consists of a workbench, a lifting clamp, an impact device, a low-temperature thermometer, a low-temperature container for storing frozen media, a stirrer, and other parts.

Lifting gripper

The lifting gripper consists of a gripper and a lifting device

The distance from the impact area of the specimen to the lower end of the gripper is (11.0 plus or equal to 0.5) mm.

Impact device

The impact device consists of an impactor and an impact spring.

Impactor

The shape and size of the impactor head, the mass of the impactor is (200 ? 20) g, and its working stroke is (40 ? 1) mm. The spring of the impact device is in a compressed state, and the distance from the end of the impactor to the specimen is (25 ? 1) mm.

Low temperature thermometer

Using a low-temperature thermometer with a minimum division of no more than 1 degree to measure the temperature of the freezing medium, low-temperature thermometers, thermocouples, resistance thermometers, etc. can be used. The low-temperature thermometer is an internal standard semi immersed type, with a tail length of 150mm and a immersion depth of 75mm in the liquid.

Cryogenic medium

The freezing medium is composed of a suitable heat transfer medium and a refrigerant.

Heat transfer medium

At the test temperature, liquids that can maintain flow and have no additional impact on the sample can be used as heat transfer media. This type of heat transfer medium usually uses ethanol, in addition to acetone, siloxane, etc.

Refrigerant

Dry ice or liquid nitrogen can be selected as needed.

Note: Other cooling methods can also be used.

Usage

1. Connect the power, and the temperature controller and timer display lights will light up.  

Inject refrigerant (usually industrial ethanol) into the cold well in two directions, and the injection amount should ensure that the distance from the lower end of the gripper to the liquid level is 75 ? 10mm.  

3. Clamp the sample vertically onto the gripper. The clamping should not be too tight or too loose to prevent deformation or detachment of the sample.  

4. Press the gripper to start freezing the sample, and at the same time, activate the timing control switch (or press the stopwatch) for timing. The freezing time of the sample is specified as 3.0 ? 0.5min. During the freezing period of the sample, the temperature fluctuation of the freezing medium shall not exceed ? 1 ℃.  

Lift the lifting gripper and allow the impactor to impact the specimen within half a second.  

6. Remove the sample, bend it 180 ? in the direction of impact, and carefully observe for any damage.  

After 7 samples have been impacted (each sample is only allowed to be impacted once), if damage occurs, the temperature of the freezing medium should be raised; otherwise, the temperature should be lowered and the test should continue. When the temperature difference between these two results is no more than 1 ℃, the test is completed.