GRAEFF（格拉夫）G系列熔体压力传感器/变送器——应用与重要性

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Part.1

一、产品简介

GRAEFF（格拉夫）G 系列熔体压力传感器 / 变送器是针对高温、高压、高粘度及腐蚀性熔融介质环境研发的全系列监测设备，涵盖多个子系列以适配不同工业场景需求。全系列产品普遍采用不锈钢主体结构，结合特殊工艺材料与先进技术（如钛化合物涂层、高温标定与温度补偿等），具备高精度（±0.25% FSO / ±0.5% FSO）、强稳定性、抗干扰及长寿命等核心优势，可满足从常规工业控制到食品、制药等特殊领域的严苛要求，为熔体压力监测提供可靠解决方案。

（注：文中部分图片来源于网络，侵删）

GINS系列熔体压力传感器/变送器

✔精度优于±0.5%FSO；测量范围0…17.5bar…2000bar

✔不锈钢主体，钛化合物涂层膜片抗高粘度 / 摩擦介质，温度漂移小，寿命长

GMP系列熔体压力传感器/变送器

✔精度优于±0.5%FSO；6点精细化测试工艺

✔高性能核心元件搭配抗干扰模拟电路，350°C 高温标定确保高精度测量

GHP系列熔体压力传感器/变送器

✔精度优于±0.25%FSO；测量范围0…17.5bar…2000bar

✔高性能元件与抗干扰电路设计，350°C 高温标定，实现高测量精度

GCM系列熔体压力传感器/变送器

✔精度优于±0.5%FSO；测量范围0…17.5bar…2000bar

✔不锈钢主体 + 钛涂层膜片抗高粘度介质，适配食品、制药领域，温度稳定性强，寿命长

GM系列熔体压力传感器/变送器

✔精度优于±0.25%FSO，±0.5%FSO；6点精细化测试工艺

✔不锈钢主体 + 钛涂层膜片，适配食品、制药领域，测量精确且温度漂移小

GMX系列熔体压力传感器/变送器

✔输出信号4-20mA（＋HART）；6点精细化测试工艺

✔不锈钢主体 + 钛涂层膜片，食品级传输介质，适配食品、制药领域，性能稳定

GMC系列熔体压力传感器/变送器

✔精度优于±0.25%FSO，±0.5%FSO；多种输出信号可选

✔80%内部校准,良好的稳定性和重复性。多种可选电气连接。采用特殊螺纹安装设计,具有简便、受温度漂移的影响更小更稳定等特点,特殊的裸露设计可满足特殊的应用环境需求

GMR系列熔体压力传感器/变送器

✔特殊电路设计、超强抗干扰

✔采用TI系列高性能数字芯片,特殊电路设计抗干扰性强，符合 SIL2、PL'C' 安全标准。通过继电器控制量程限度，保障挤出设备及产线安全，适用于制冷、化工、环保等领域

GAIM系列AI智能型（零温漂）熔体压力传感器/变送器

✔高温下温度补偿；特殊膜片涂层、抵抗熔体降温粘附膜片损坏

✔采用了温度补偿技术,在350°C下对产品进行零点漂移补偿,压力测量探头受到高温时,实现接近于零温漂，测量更准确、稳定

GAIMX防爆系列AI智能型（零温漂）熔体压力传感器/变送器

✔4…20mA+Hart协议；防爆环境下使用

✔采用了温度补偿技术,在350°C下对产品进行零点漂移补偿,压力测量探头受到高温时,实现接近于零温漂,再集成一块智能4...20mA+Hart协议电路，测量更准确、稳定

GPX系列熔体压力传感器/变送器

✔200℃环境下零点标定；6点精细化测试工艺

✔不锈钢主体 + 钛涂层膜片，食品级介质填充，适配食品、制药领域，温度稳定性强

GMPG系列熔体机械压力表

✔可选4…20mA，2mV/V，0…10V输出型号；IP65防护等级

✔特殊覆膜膜片 + 高耐磨涂层，400°C 高温下稳定工作，标准螺纹安装，适配注塑、化纤领域

GMG系列智能数字熔体表

✔4位LED显示，无示值误差；两路控制点继电器输出220V3A

✔400°C 高温适配，标准螺纹安装，高稳定性、长寿命，适用于高温压力监测

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Part.2

二、应用与重要性

高温熔体压力传感器是工业过程控制中不可或缺的关键元件，尤其在涉及高温、高压、高粘度、腐蚀性熔融材料的领域。它们在确保工艺稳定性、产品质量、设备安全和生产效率方面扮演着至关重要的角色。

（一）主要应用领域

1、塑料工业

挤出成型： 监测挤出机机筒内、换网器前后、模具入口处的熔体压力。这是其最核心的应用领域之一。用于控制塑化质量、保护设备（如防止过压损坏滤网或螺杆/机筒）、稳定挤出量、优化产量和保证产品尺寸精度（如管材、板材、薄膜、型材、电线电缆包覆）。

注塑成型： 测量注射过程中模具型腔内的熔体压力（型腔压力传感器）或喷嘴处的压力。对控制保压切换点、优化保压曲线、监控填充状态、减少飞边和缩痕、提高产品一致性和降低废品率至关重要。

吹塑成型： 监测挤出机头或储料缸的熔体压力，确保型坯壁厚均匀和成型稳定。

流延/压延： 控制模唇间隙处的熔体压力，以获得厚度均匀的薄膜或片材。

2、化纤工业

熔融纺丝： 在纺丝箱体和计量泵前后测量高温聚合物熔体（如聚酯、尼龙、聚丙烯）的压力，精确控制纺丝泵的输送量，保证纤维的纤度均匀性和产品质量。这是另一个极其重要的应用领域。

3、化工行业

高温/高压反应釜： 监测合成反应过程中反应器内的压力，确保反应在设定的安全压力范围内进行，对工艺控制和安全生产至关重要。

熔融物料输送： 在输送高温熔融态化学品（如硫磺、碱、熔盐、热媒）的管道上测量压力，监控管道状态和泵送性能。

4、橡胶工业

挤出和压延： 类似于塑料挤出，用于监测橡胶混炼胶在挤出机、压延辊筒处的熔体压力，控制挤出尺寸稳定性和压延厚度。

5、食品工业

高温加工： 在巧克力、糖果、油脂等需要熔融加工的食品生产线中，监测熔融物料的压力，保证工艺连续性和产品一致性（需符合食品级卫生要求）。

6、冶金工业

金属熔炼与铸造： 在熔炉、保温炉或压铸机的压射系统中测量熔融金属（如铝、锌、铜合金）的压力。虽然面临更高温度和更严苛环境，但特殊设计的传感器在此领域也有应用。

7、制药工业

热熔挤出： 在制备药物缓释制剂等工艺中，监测药物-聚合物共混熔体在挤出机内的压力，控制混合均匀度和工艺稳定性。

（二）重要性

Part.1

1.  工艺过程控制的核心参数：

熔体压力是反映物料流动状态、塑化均匀度、设备负载最直接的信号之一。实时、准确的压力数据是实现闭环自动控制（如调节螺杆转速、背压阀开度）的基础，确保工艺稳定运行在最优状态。

Part.2

2.  产品质量保证的关键：

熔体压力的波动直接影响产品的尺寸精度、机械性能、外观质量（如表面缺陷、熔接线强度）和批次间一致性。精确控制压力是生产高质量产品的前提。例如，注塑中的保压压力决定了制品的密度和内应力。

Part.3

3.  设备安全运行的守护者：

过高的熔体压力会损坏昂贵的核心设备部件，如挤出机螺杆和机筒、换网器的滤网、模具流道，甚至引发安全事故（如管路爆裂）。压力传感器是超压报警和停机保护系统的关键输入。

Part.4

4.  提高生产效率和降低成本：

减少废品与停机： 通过稳定工艺和预防过压损坏，显著降低废品率和非计划停机时间。

优化产能： 在保证质量和安全的前提下，允许设备在更接近极限的工艺参数下运行，提高产出速度。

降低能耗： 优化工艺（如减少不必要的背压）可以降低驱动电机能耗。

延长设备寿命： 避免设备在超负荷或异常压力下运行，减少磨损。

Part.5

5.  故障诊断与工艺优化的依据：

压力曲线的变化（如压力峰值、波动、达不到设定值）是诊断设备故障（如滤网堵塞、螺杆磨损、物料塑化不良、泄漏）和优化工艺参数（如温度曲线、螺杆转速）的重要线索。

Part.6

6.  实现自动化与智能制造的基础：

作为关键的在线过程参数，熔体压力数据是实现生产自动化、数字化监控（SCADA/MES）和智能制造（如预测性维护、工艺参数自优化）不可或缺的输入。

Part.7

7.  应对极端工况的挑战：

在高温（常达350-400°C以上，特殊应用如冶金更高）、高压（几十到几百兆帕）、高粘度、可能具有化学腐蚀性或磨蚀性的熔体环境中进行精确测量，本身就是一项技术挑战。高性能高温熔体压力传感器是克服这些挑战、实现上述应用价值的工程解决方案。

总结

高温熔体压力传感器是现代工业，特别是高分子材料加工（塑料、化纤、橡胶）和高温化工领域的“工艺之眼”和“安全之盾”。它们通过提供关键的熔体压力信息，直接关系到生产过程的安全性、稳定性、效率、产品质量以及成本控制，是实现高效、优质、安全生产不可或缺的核心传感器。其技术发展和性能提升对这些行业的进步有着深远影响。

Part.1

I. Product Introduction

GRAEFF's G series melt pressure sensors/transmitters are a full range of monitoring equipment developed for high-temperature, high-pressure, high-viscosity and corrosive molten medium environments, covering multiple sub-series to meet the needs of different industrial scenarios. The entire series of products generally adopt a stainless steel main structure, combined with special process materials and advanced technologies (such as titanium compound coating, high-temperature calibration and temperature compensation, etc.), featuring core advantages such as high precision (±0.25% FSO to ±0.5% FSO), strong stability, anti-interference and long service life It can meet the strict requirements ranging from conventional industrial control to special fields such as food and pharmaceuticals, providing reliable solutions for melt pressure monitoring.

(Note: Some of the pictures in this article are from the Internet. If there is any infringement, please delete them.)

GINS series Melt pressure sensors/transmitters

✔Accuracy is better than ±0.5%FSO; Measurement range 0... 17.5 the bar... 2000bar

✔Stainless steel body, titanium compound coated diaphragm, resistant to high-viscosity/friction media, small temperature drift, long service life

GMP series Melt pressure sensors/transmitters

✔Accuracy is better than ±0.5%FSO; Six refined testing processes

✔High-performance core components combined with anti-interference analog circuits and high-temperature calibration at 350°C ensure high-precision measurement

GHP series Melt pressure sensors/transmitters

✔Accuracy is better than ±0.25%FSO; Measurement range 0... 17.5 the bar... 2000bar

✔High-performance components and anti-interference circuit design, with high-temperature calibration at 350°C, achieve high measurement accuracy

GCM series Melt pressure sensors/transmitters

✔Accuracy is better than ±0.5%FSO; Measurement range 0... 17.5 the bar... 2000bar

✔Stainless steel body + titanium-coated diaphragm, resistant to high-viscosity media, suitable for food and pharmaceutical fields, with strong temperature stability and long service life

GM series Melt pressure sensors/transmitters

✔The accuracy is better than ±0.25%FSO and ±0.5%FSO. Six refined testing processes

✔Stainless steel body + titanium-coated diaphragm, suitable for food and pharmaceutical fields, with precise measurement and small temperature drift

GMX series Melt pressure sensors/transmitters

✔Output signal: 4-20mA (+HART); Six refined testing processes

✔Stainless steel body + titanium-coated diaphragm, food-grade transmission medium, suitable for food and pharmaceutical fields, stable performance

GMC series Melt pressure sensors/transmitters

✔The accuracy is better than ±0.25%FSO and ±0.5%FSO. Multiple output signals are available for selection

✔80% internal calibration, excellent stability and repeatability. A variety of optional electrical connections. It adopts a special threaded installation design, featuring simplicity, less and more stable influence by temperature drift, etc. The special exposed design can meet the requirements of special application environments

GMR series Melt pressure sensors/transmitters

✔Special circuit design, super strong anti-interference

✔It adopts TI series high-performance digital chips, with a special circuit design that has strong anti-interference ability and complies with SIL2 and PL'C' safety standards. The range limit is controlled by relays to ensure the safety of extrusion equipment and production lines, and is suitable for fields such as refrigeration, chemical engineering, and environmental protection

GAIM series AI intelligent (zero temperature drift) melt pressure sensor/transmitter

✔Temperature compensation at high temperatures Special diaphragm coating, resisting the adhesion and damage of the diaphragm due to the cooling of the melt

✔The temperature compensation technology is adopted to perform zero drift compensation on the product at 350° C. When the pressure measurement probe is exposed to high temperatures, it achieves nearly zero temperature drift, making the measurement more accurate and stable

GAIMX explosion-proof series AI intelligent (zero temperature drift) melt pressure sensor/transmitter

✔4... 20mA+Hart protocol Used in explosion-proof environments

✔It adopts temperature compensation technology to perform zero drift compensation on the product at 350° C. When the pressure measurement probe is exposed to high temperatures, it achieves nearly zero temperature drift. Additionally, it integrates an intelligent 4... The 20mA+Hart protocol circuit ensures more accurate and stable measurement

GPX series Melt pressure sensors/transmitters

✔Zero point calibration in a 200℃ environment; Six refined testing processes

✔Stainless steel main body + titanium-coated diaphragm, food-grade medium filling, suitable for food and pharmaceutical fields, with strong temperature stability

GMPG series melt mechanical pressure gauge

✔Optional 4... 20mA, 2mV/V, 0... 10V output model IP65 protection rating

✔Special coated film sheet + high wear-resistant coating, stable operation at 400°C high temperature, standard thread installation, suitable for injection molding and chemical fiber fields

GMG series Intelligent digital melt meter

✔4-digit LED display, no indication error; Two control point relay outputs 220V3A

✔High-temperature compatibility with 400°C, standard threaded installation, high stability and long service life, suitable for high-temperature pressure monitoring.

Part.2

Ii. Application and Significance

High-temperature melt pressure sensors are indispensable key components in industrial process control, especially in fields involving high-temperature, high-pressure, high-viscosity, and corrosive molten materials. They play a crucial role in ensuring process stability, product quality, equipment safety and production efficiency.

(1) Main application fields

1. Plastic industry

Extrusion molding: Monitor the melt pressure inside the extruder barrel, before and after the screen changer, and at the mold inlet. This is one of its most core application fields. It is used to control plasticizing quality, protect equipment (such as preventing overpressure from damaging the filter screen or screw/barrel), stabilize extrusion volume, optimize output and ensure product dimensional accuracy (such as pipes, plates, films, profiles, wire and cable coating).

Injection molding: Measure the melt pressure in the mold cavity (cavity pressure sensor) or the pressure at the nozzle during the injection process. It is crucial for controlling the pressure-holding switching point, optimizing the pressure-holding curve, monitoring the filling status, reducing flash and shrinkage, improving product consistency and lowering the scrap rate.

Blow molding: Monitor the melt pressure of the extruder head or storage cylinder to ensure uniform wall thickness of the parison and stable molding.

Casting/calendering: Control the melt pressure at the lip gap of the die to obtain a film or sheet of uniform thickness.

2. Chemical fiber industry

Melt spinning: The pressure of high-temperature polymer melts (such as polyester, nylon, and polypropylene) is measured before and after the spinning box and the metering pump to precisely control the conveying volume of the spinning pump, ensuring the uniformity of fiber fineness and product quality. This is another extremely important application field.

3. Chemical Industry

High-temperature/high-pressure reactor: Monitoring the pressure inside the reactor during the synthesis reaction process to ensure that the reaction takes place within the set safe pressure range is crucial for process control and safe production.

Molten material transportation: Measure pressure on pipelines transporting high-temperature molten chemicals (such as sulfur, alkali, molten salt, heat medium), monitor pipeline conditions and pumping performance.

4. Rubber Industry

Extrusion and calendering: Similar to plastic extrusion, it is used to monitor the melt pressure of rubber compound at the extruder and calendering roller, control the dimensional stability of extrusion and the thickness of calendering.

5. Food Industry

High-temperature processing: In food production lines such as chocolate, candies, and oils that require molten processing, monitor the pressure of the molten material to ensure process continuity and product consistency (which must meet food-grade hygiene requirements).

6. Metallurgical Industry

Metal smelting and casting: Measuring the pressure of molten metals (such as aluminum, zinc, and copper alloys) in the injection system of furnaces, holding furnaces, or die-casting machines. Although facing higher temperatures and harsher environments, specially designed sensors also have applications in this field.

7. Pharmaceutical Industry

Hot melt extrusion: In the process of preparing sustained-release drug preparations, etc., the pressure of the drug-polymer blend melt in the extruder is monitored to control the uniformity of mixing and process stability.

(2) Importance

Part.1

1. Core parameters of process control

Melt pressure is one of the most direct signals reflecting the flow state of mataerials, the uniformity of plasticization, and the load of equipment. Real-time and accurate pressure data is the foundation for achieving closed-loop automatic control (such as adjusting the screw speed and the opening degree of the back pressure valve), ensuring that the process operates stably in the optimal state.

Part.2

2. The key to product quality assurance

The fluctuation of melt pressure directly affects the dimensional accuracy, mechanical properties, appearance quality (such as surface defects, weld line strength) and batch-to-batch consistency of the product. Precise control of pressure is a prerequisite for producing high-quality products. For instance, the holding pressure in injection molding determines the density and internal stress of the product.

Part.3

3. Guardian of Equipment Safe Operation

Excessively high melt pressure can damage expensive core equipment components, such as the extruder screw and barrel, the filter screen of the screen changer, the mold runner, and even cause safety accidents (such as pipe burst). The pressure sensor is a key input in the overpressure alarm and shutdown protection system.

Part.4

4. Enhance production efficiency and reduce costs

Reduce scrap and downtime: By stabilizing the process and preventing overvoltage damage, significantly lower the scrap rate and unplanned downtime.

Optimize production capacity: Under the premise of ensuring quality and safety, allow the equipment to operate at process parameters closer to the limit to increase the output speed.

Reducing energy consumption: Optimizing the process (such as reducing unnecessary back pressure) can lower the energy consumption of the drive motor.

Extend equipment lifespan: Avoid operating the equipment under overload or abnormal pressure to reduce wear and tear.

Part.5

5. Basis for fault Diagnosis and process optimization:

The changes in pressure curves (such as pressure peaks, fluctuations, and failure to reach the set value) are important clues for diagnosing equipment faults (such as filter screen blockage, screw wear, poor plasticization of materials, and leakage) and optimizing process parameters (such as temperature curves and screw speed).

Part.6

6. The Foundation for achieving Automation and intelligent Manufacturing

As a key online process parameter, melt pressure data is an indispensable input for achieving production automation, digital monitoring (SCADA/MES), and intelligent manufacturing (such as predictive maintenance and self-optimization of process parameters).

Part.7

7. Addressing the challenges of extreme working conditions:

Conducting precise measurements in high-temperature (often above 350-400°C, and even higher for special applications such as metallurgy), high-pressure (tens to hundreds of megapascals), high-viscosity, and potentially chemically corrosive or abrasive melt environments is itself a technical challenge. High-performance high-temperature melt pressure sensors are engineering solutions that overcome these challenges and achieve the above-mentioned application values.

Summary

High-temperature melt pressure sensors are the "eye of process" and "shield of safety" in modern industry, especially in the processing of polymer materials (plastics, chemical fibers, rubber) and high-temperature chemical fields. They provide crucial melt pressure information and are directly related to the safety, stability, efficiency, product quality and cost control of the production process. They are indispensable core sensors for achieving efficient, high-quality and safe production. Its technological development and performance improvement have a profound impact on the progress of these industries.