Introduction | 简介

The reliability and longevity of medium-voltage mining cables depend fundamentally on the quality of their insulation materials. For (N)TSCGEWÖU cables designed for demanding reeling applications in mining and heavy industry, the cross-linked ethylene propylene rubber (EPR) insulation compound designated as 3GI3 according to DIN VDE 0207 Part 20 provides essential electrical and mechanical properties. The Hot Set Test, standardized in IEC 60811-507, serves as a critical quality verification procedure that confirms complete vulcanization and proper cross-linking of these thermoset insulation materials during the manufacturing process. This technical document explains the Hot Set Test methodology, its significance in validating curing quality, and its application to ensuring the performance integrity of (N)TSCGEWÖU cable insulation systems.

中压采矿电缆的可靠性和使用寿命从根本上取决于其绝缘材料的质量。对于为采矿和重工业中要求严格的卷筒应用而设计的(N)TSCGEWÖU电缆，根据DIN VDE 0207第20部分指定为3GI3的交联乙丙橡胶（EPR）绝缘化合物提供了必需的电气和机械性能。热定型测试在IEC 60811-507中标准化，作为一个关键的质量验证程序，确认这些热固性绝缘材料在制造过程中的完全硫化和适当的交联。本技术文件解释了热定型测试方法、其在验证固化质量方面的重要性以及其在确保(N)TSCGEWÖU电缆绝缘系统性能完整性方面的应用。

Understanding Cross-Linking and Vulcanization | 理解交联和硫化

The Nature of Thermoset Materials | 热固性材料的本质

Ethylene Propylene Rubber (EPR) belongs to the family of thermoset polymers, materials that undergo irreversible chemical transformation during processing. Unlike thermoplastic materials that can be repeatedly melted and reshaped, thermoset compounds form permanent three-dimensional molecular networks through a process called cross-linking or vulcanization. In this chemical transformation, individual polymer chains become chemically bonded to adjacent chains through covalent bonds, creating a rigid molecular structure that cannot be reversed by heating. This cross-linked molecular architecture provides EPR insulation with superior thermal stability, mechanical strength, and resistance to deformation under elevated temperatures compared to non-cross-linked materials.

乙丙橡胶（EPR）属于热固性聚合物家族，这些材料在加工过程中经历不可逆的化学转变。与可以反复熔化和重塑的热塑性材料不同，热固性化合物通过称为交联或硫化的过程形成永久的三维分子网络。在这种化学转变中，单个聚合物链通过共价键与相邻链化学键合，创建一个不能通过加热逆转的刚性分子结构。这种交联分子结构为EPR绝缘提供了优越的热稳定性、机械强度和在高温下抗变形的能力，与非交联材料相比。

Vulcanization Process for EPR Insulation | EPR绝缘的硫化过程

For medium-voltage EPR cables, the vulcanization process typically occurs through exposure to high-temperature steam or gas environments immediately after the extrusion of the insulation layer onto the conductor. The raw EPR compound contains carefully selected vulcanizing agents, including peroxide cross-linking initiators and diene monomers that provide reactive sites for cross-linking reactions. When heated to temperatures typically ranging from 150°C to 220°C for specified durations, these chemical agents initiate free radical reactions that form carbon-carbon bonds between polymer chains, progressively building the three-dimensional cross-linked network. The degree of cross-linking achieved during vulcanization directly affects the final material properties, including tensile strength, elongation capacity, thermal resistance, and long-term dimensional stability.

对于中压EPR电缆，硫化过程通常通过在绝缘层挤出到导体上后立即暴露于高温蒸汽或气体环境中发生。原始EPR化合物包含精心选择的硫化剂，包括过氧化物交联引发剂和提供交联反应活性位点的二烯单体。当加热到通常在150°C到220°C范围内的温度并持续指定的时间时，这些化学剂启动自由基反应，在聚合物链之间形成碳-碳键，逐渐构建三维交联网络。硫化期间实现的交联程度直接影响最终材料性能，包括拉伸强度、伸长能力、热阻和长期尺寸稳定性。

The Hot Set Test Standard: IEC 60811-507 | 热定型测试标准：IEC 60811-507

Purpose and Principle | 目的和原理

The Hot Set Test, formally specified in IEC 60811-507:2012 “Electric and optical fibre cables – Test methods for non-metallic materials – Part 507: Mechanical tests – Hot set test for cross-linked materials,” provides a straightforward and reliable method to verify whether insulation or sheathing materials have been sufficiently cross-linked during the manufacturing process. The test operates on a fundamental principle: properly cross-linked thermoset materials resist permanent deformation when subjected to mechanical stress at elevated temperatures, whereas insufficiently cross-linked materials will exhibit excessive elongation and permanent set under the same conditions. By measuring the dimensional change of test specimens under controlled temperature and tensile loading, the Hot Set Test directly assesses the effectiveness of the vulcanization process and the resulting degree of molecular cross-linking.

热定型测试，在IEC 60811-507:2012″电气和光纤电缆-非金属材料的测试方法-第507部分：机械测试-交联材料的热定型测试”中正式规定，提供了一种简单可靠的方法来验证绝缘或护套材料在制造过程中是否已充分交联。该测试基于一个基本原理：适当交联的热固性材料在高温下受到机械应力时抵抗永久变形，而交联不足的材料在相同条件下将表现出过度伸长和永久变形。通过在受控温度和拉伸负载下测量测试样品的尺寸变化，热定型测试直接评估硫化过程的有效性和由此产生的分子交联程度。

This standard replaced and superseded Clause 9 of the earlier IEC 60811-2-1:1998 specification as part of the restructured IEC 60811 series, which follows the principle of “one test – one part” for improved clarity and usability. The Hot Set Test is universally recognized by national and international certification bodies including VDE (Verband der Elektrotechnik), BASEC (British Approvals Service for Cables), UL (Underwriters Laboratories), and other testing authorities worldwide as an essential verification procedure for cross-linked cable materials.

该标准作为重组的IEC 60811系列的一部分，取代并替代了早期IEC 60811-2-1:1998规范的第9条，该系列遵循”一个测试-一个部分”的原则，以提高清晰度和可用性。热定型测试被包括VDE（德国电气技术协会）、BASEC（英国电缆批准服务）、UL（保险商实验室）和全球其他测试机构在内的国家和国际认证机构普遍认可，作为交联电缆材料的基本验证程序。

Hot Set Test Procedure and Methodology | 热定型测试程序和方法

Sample Preparation | 样品准备

The Hot Set Test requires careful preparation of test specimens from the cable insulation or sheathing material. First, the insulation is separated from the metallic conductor and any semiconductive layers, ridges, or tapes are removed to obtain clean material samples. Depending on the original thickness and diameter of the cable component being tested, specimens are prepared in one of two configurations: dumbbell-shaped pieces for materials where sufficient thickness is available, or tubular sections cut directly from the insulation layer for thinner materials. The test standard specifies that specimen thickness should fall between 0.8mm and 2.0mm for optimal testing accuracy, though thinner specimens are permitted when the original cable design has insulation thickness less than 0.8mm.

热定型测试需要从电缆绝缘或护套材料中仔细准备测试样品。首先，绝缘与金属导体分离，并去除任何半导电层、脊或胶带，以获得清洁的材料样品。根据被测试的电缆组件的原始厚度和直径，样品以两种配置之一准备：对于厚度足够的材料，准备哑铃形片，或对于较薄的材料，直接从绝缘层切割的管状截面。测试标准规定样品厚度应在0.8mm到2.0mm之间，以获得最佳测试精度，尽管当原始电缆设计的绝缘厚度小于0.8mm时，允许使用更薄的样品。

For dumbbell-shaped specimens, the critical measurement zone is the central parallel section, which is marked with two precise lines spaced either 20mm apart for larger dumbbell configurations or 10mm apart for smaller specimens. These marker lines define the measurement zone where elongation will be quantified during the test. Two test pieces are prepared from the sheath material and two from each conductor’s insulation layer to provide statistically valid results and to account for potential material variability within the cable construction.

对于哑铃形样品，关键测量区域是中央平行部分，标有两条精确的线，对于较大的哑铃配置间隔20mm，对于较小的样品间隔10mm。这些标记线定义了测量区域，在测试期间将量化伸长。从护套材料准备两个测试片，从每个导体的绝缘层准备两个，以提供统计上有效的结果并考虑电缆结构内的潜在材料变异性。

Test Equipment and Setup | 测试设备和设置

The Hot Set Test apparatus consists of a precision temperature-controlled oven capable of maintaining the specified test temperature within tight tolerances, specialized grips to hold the test specimens vertically, and calibrated weights that apply defined tensile forces to the specimens. The test specimens are suspended vertically inside the oven with the upper end secured in a fixed grip and calibrated weights attached to the lower end via a second grip. The magnitude of the applied weight is determined by the cross-sectional area of the test specimen and is specified in the relevant cable standard for each material type, ensuring consistent testing conditions across different laboratories and manufacturers.

热定型测试装置由能够在严格公差范围内保持指定测试温度的精密温度控制炉、用于垂直保持测试样品的专用夹具以及对样品施加确定拉伸力的校准重量组成。测试样品垂直悬挂在炉内，上端固定在固定夹具中，校准重量通过第二个夹具附在下端。施加重量的大小由测试样品的横截面积确定，并在每种材料类型的相关电缆标准中规定，确保不同实验室和制造商之间的一致测试条件。

Test Execution Sequence | 测试执行序列

The test begins with precise measurement of the initial distance between the marker lines on each specimen at ambient temperature. The oven is pre-heated to the specified test temperature, which for 3GI3 EPR materials is typically 180°C, though specific values are defined in the applicable cable standard. Once thermal equilibrium is achieved, the weighted test specimens are suspended vertically inside the oven and the timer is started. During the 10-minute heating period, the elevated temperature reduces the material’s resistance to deformation, and the applied tensile weight causes the specimen to elongate. For properly cross-linked EPR, the three-dimensional molecular network restricts this elongation to acceptable limits defined by the standard.

测试开始时，在环境温度下精确测量每个样品上标记线之间的初始距离。炉子预热到指定的测试温度，对于3GI3 EPR材料通常为180°C，尽管具体值在适用的电缆标准中定义。一旦达到热平衡，加重的测试样品垂直悬挂在炉内，计时器启动。在10分钟的加热期间，升高的温度降低材料对变形的抵抗力，施加的拉伸重量导致样品伸长。对于适当交联的EPR，三维分子网络将这种伸长限制在标准定义的可接受限度内。

After precisely 10 minutes at test temperature, the distance between marker lines is measured again to determine the hot elongation percentage. Immediately following this measurement, the weight is released by cutting the specimen flush with the lower grip, removing the tensile stress while the specimen remains at elevated temperature for an additional 5 minutes. The specimen is then removed from the oven and allowed to cool slowly to ambient temperature over 5 to 10 minutes. Once fully cooled, a final measurement is taken between the marker lines to quantify the permanent set, which represents the degree of irreversible deformation that occurred during the test.

在测试温度下精确10分钟后，再次测量标记线之间的距离以确定热伸长百分比。在此测量后立即通过与下夹具齐平地切割样品来释放重量，在样品保持高温的同时去除拉伸应力额外5分钟。然后将样品从炉中取出，并在5到10分钟内缓慢冷却至环境温度。完全冷却后，在标记线之间进行最终测量，以量化永久变形，这代表了测试期间发生的不可逆变形程度。

Interpreting Hot Set Test Results | 解释热定型测试结果

What the Test Indicates About Cross-Linking Quality | 测试对交联质量的指示

The Hot Set Test provides two critical measurements that directly correlate with the degree of molecular cross-linking achieved during vulcanization. The hot elongation value reveals how much the material stretches under combined thermal and mechanical stress. Insufficiently cross-linked EPR will exhibit excessive elongation because the polymer chains remain relatively mobile and can slide past each other under stress, lacking the rigid three-dimensional network structure that characterizes properly cured thermoset materials. Conversely, well-cross-linked EPR demonstrates restricted elongation because the extensive carbon-carbon bonds between polymer chains create a stable molecular framework that resists deformation even at elevated temperatures.

热定型测试提供两个关键测量值，直接与硫化期间实现的分子交联程度相关。热伸长值揭示了材料在热和机械应力联合作用下的拉伸程度。交联不足的EPR将表现出过度伸长，因为聚合物链保持相对可移动，并可以在应力下相互滑动，缺乏表征适当固化的热固性材料的刚性三维网络结构。相反，交联良好的EPR表现出受限的伸长，因为聚合物链之间的广泛碳-碳键创建了一个稳定的分子框架，即使在高温下也能抵抗变形。

The permanent set measurement after cooling provides equally important information about material recovery and elastic properties. When the tensile stress is removed and the specimen cools to ambient temperature, a properly cross-linked material should recover most of its original dimensions due to the elastic nature of the cross-linked molecular network. High permanent set values indicate insufficient cross-linking, where the material has undergone plastic deformation rather than elastic stretching. This permanent deformation occurs because polymer chains that are not adequately bonded to neighboring chains can relocate to new positions under stress and remain in those positions after stress removal, lacking the molecular memory that cross-linking provides.

冷却后的永久变形测量提供了关于材料恢复和弹性性能的同样重要的信息。当去除拉伸应力并且样品冷却到环境温度时，适当交联的材料应该由于交联分子网络的弹性性质而恢复其大部分原始尺寸。高永久变形值表明交联不足，其中材料经历了塑性变形而不是弹性拉伸。这种永久变形发生是因为没有充分键合到相邻链的聚合物链可以在应力下重新定位到新位置，并在去除应力后保持在这些位置，缺乏交联提供的分子记忆。

Pass/Fail Criteria and Acceptance Standards | 合格/不合格标准和验收标准

For 3GI3 EPR insulation materials conforming to DIN VDE 0207 Part 20 specifications, the hot elongation measured after 10 minutes at test temperature must not exceed 175% of the original marked length. This means that if the initial distance between marker lines was 20mm, the maximum permissible hot elongation would be 35mm (175% × 20mm), corresponding to an absolute elongation of 15mm beyond the original length. The permanent set after cooling and stress removal must not exceed 15% of the original marked length. Using the same 20mm initial spacing as an example, the maximum acceptable permanent elongation would be 3mm, meaning the cooled specimen’s marker line spacing should not exceed 23mm.

对于符合DIN VDE 0207第20部分规范的3GI3 EPR绝缘材料，在测试温度下10分钟后测量的热伸长不得超过原始标记长度的175%。这意味着如果标记线之间的初始距离为20mm，则最大允许热伸长为35mm（175%×20mm），对应于超出原始长度的15mm的绝对伸长。冷却和去除应力后的永久变形不得超过原始标记长度的15%。使用相同的20mm初始间距作为示例，最大可接受的永久伸长为3mm，意味着冷却样品的标记线间距不应超过23mm。

If both test specimens from a given sample meet these criteria, the material passes the Hot Set Test, confirming adequate cross-linking. If one specimen fails while the other passes, the standard requires testing two additional specimens. Both of these supplementary specimens must pass for overall test acceptance. This statistical approach accounts for potential localized variations in material processing while maintaining rigorous quality standards. Materials that consistently fail the Hot Set Test indicate inadequate vulcanization, which may result from insufficient curing time, incorrect curing temperature, depleted or improperly formulated cross-linking agents, or other manufacturing process deficiencies that must be corrected before cable production can continue.

如果给定样品的两个测试样品都符合这些标准，则材料通过热定型测试，确认足够的交联。如果一个样品失败而另一个通过，则标准要求测试另外两个样品。这两个补充样品都必须通过才能获得整体测试验收。这种统计方法考虑了材料加工中的潜在局部变化，同时保持严格的质量标准。持续未通过热定型测试的材料表明硫化不足，这可能是由于固化时间不足、固化温度不正确、耗尽或配方不当的交联剂或其他制造过程缺陷造成的，必须在继续电缆生产之前纠正。

Application to (N)TSCGEWÖU Mining Cables | 应用于(N)TSCGEWÖU采矿电缆

Critical Importance for Demanding Applications | 对要求严格的应用的关键重要性

(N)TSCGEWÖU cables are medium-voltage flexible power cables specifically engineered for extreme mechanical and environmental stresses encountered in mining operations, tunneling projects, and heavy industrial reeling applications. These cables must operate reliably under conditions including continuous flexing on monospiral drums, exposure to abrasive materials, mechanical impact, temperature extremes, and chemical exposure from oils and industrial fluids. The quality of the 3GI3 EPR insulation’s cross-linking directly determines the cable’s ability to maintain electrical integrity and mechanical performance throughout its service life in these challenging environments.

(N)TSCGEWÖU电缆是中压柔性电力电缆，专为采矿作业、隧道项目和重工业卷筒应用中遇到的极端机械和环境应力而设计。这些电缆必须在包括单螺旋卷筒上的连续挠曲、暴露于磨料、机械冲击、温度极端和来自油和工业流体的化学暴露等条件下可靠地运行。3GI3 EPR绝缘交联的质量直接决定了电缆在这些具有挑战性的环境中在其使用寿命期间保持电气完整性和机械性能的能力。

Properly cross-linked 3GI3 EPR insulation provides several performance advantages essential for mining cable applications. The three-dimensional molecular network resists creep and cold flow under continuous mechanical stress, preventing conductor-to-insulation contact and maintaining consistent dielectric thickness even during years of flexing operation. The cross-linked structure provides superior resistance to thermal aging, allowing the cable to operate at rated temperatures up to 90°C continuous duty without progressive deterioration of insulation properties. Enhanced chemical resistance protects against degradation from exposure to mineral oils, lubricants, and industrial chemicals commonly encountered in mining environments. Most importantly, the elastic memory of well-cross-linked EPR enables the insulation to recover from repeated bending and compression cycles without developing permanent deformation or cracking that would compromise electrical safety.

适当交联的3GI3 EPR绝缘为采矿电缆应用提供了几个必需的性能优势。三维分子网络在连续机械应力下抵抗蠕变和冷流，防止导体与绝缘接触，并在多年的挠曲操作期间保持一致的介电厚度。交联结构提供了优越的热老化抵抗力，允许电缆在额定温度高达90°C的连续工作下运行，而不会使绝缘性能逐渐恶化。增强的化学抵抗力保护免受暴露于采矿环境中常见的矿物油、润滑剂和工业化学品的降解。最重要的是，交联良好的EPR的弹性记忆使绝缘能够从重复的弯曲和压缩循环中恢复，而不会产生永久变形或开裂，从而损害电气安全。

Quality Control Integration | 质量控制集成

At Anhui Feichun Special Cable Co., Ltd., the Hot Set Test forms an integral component of our comprehensive quality assurance program for (N)TSCGEWÖU cable production. Testing is performed at multiple points in the manufacturing process to ensure consistent cross-linking quality. Initial qualification testing validates that our vulcanization equipment operates within specified temperature and time parameters for the 3GI3 EPR compound formulation. In-process testing occurs during continuous production runs, with Hot Set specimens taken at regular intervals to detect any drift in vulcanization conditions before significant quantities of non-conforming product are manufactured. Final acceptance testing on completed cable validates that all production lots meet specified performance criteria before shipment to customers.

在安徽飞纯特种电缆有限公司，热定型测试构成了我们(N)TSCGEWÖU电缆生产综合质量保证计划的一个组成部分。在制造过程的多个点进行测试，以确保一致的交联质量。初始资格测试验证我们的硫化设备在3GI3 EPR化合物配方的指定温度和时间参数内运行。在连续生产运行期间进行过程中测试，定期间隔取热定型样品，以在制造大量不合格产品之前检测硫化条件的任何漂移。对完成的电缆进行最终验收测试，验证所有生产批次在发货给客户之前满足指定的性能标准。

Comparison with Other Material Tests | 与其他材料测试的比较

Hot Set Test vs. Aging Oven Test | 热定型测试与老化炉测试

While the Hot Set Test evaluates cross-linking quality through short-term mechanical performance at elevated temperature, the aging oven test assesses long-term thermal stability through extended exposure to elevated temperatures without mechanical loading. Aging oven tests typically subject material specimens to temperatures of 100°C to 150°C for periods ranging from 7 days to several weeks, after which tensile strength and elongation at break are measured and compared to unaged specimens. Both tests provide complementary information about material quality: Hot Set confirms adequate initial cross-linking, while aging oven testing validates resistance to oxidative degradation and thermal decomposition over extended service life.

虽然热定型测试通过在高温下的短期机械性能评估交联质量，但老化炉测试通过在没有机械负载的情况下长时间暴露于高温来评估长期热稳定性。老化炉测试通常使材料样品暴露于100°C到150°C的温度，持续7天到几周不等，之后测量拉伸强度和断裂伸长率，并与未老化的样品进行比较。两种测试提供有关材料质量的互补信息：热定型确认足够的初始交联，而老化炉测试验证在延长使用寿命期间抵抗氧化降解和热分解的能力。

Hot Set Test vs. Pressure Test at High Temperature | 热定型测试与高温压力测试

The pressure test at high temperature, specified in IEC 60811-508, applies to thermoplastic insulation and sheathing materials rather than cross-linked thermoset compounds. In this test, a sharp steel needle is pressed against the material surface at elevated temperature with defined force. Thermoplastic materials that have not been cross-linked will deform permanently under the needle pressure, while cross-linked materials resist indentation. For EPR cables, the Hot Set Test is the appropriate verification method since EPR is specifically formulated as a cross-linkable thermoset material, whereas the pressure test would be applied to verify PVC or polyethylene compounds intended to remain thermoplastic.

高温压力测试在IEC 60811-508中规定，适用于热塑性绝缘和护套材料而不是交联热固性化合物。在这个测试中，用确定的力在高温下将尖锐的钢针压在材料表面上。未交联的热塑性材料将在针压力下永久变形，而交联材料抵抗压痕。对于EPR电缆，热定型测试是适当的验证方法，因为EPR专门配制为可交联的热固性材料，而压力测试将应用于验证旨在保持热塑性的PVC或聚乙烯化合物。

Hot Set Test vs. Gel Content Measurement | 热定型测试与凝胶含量测量

Gel content measurement provides an alternative method to quantify the degree of cross-linking in thermoset materials through chemical extraction techniques. In this test, a weighed sample of cross-linked material is immersed in a solvent (typically xylene or toluene) at elevated temperature for an extended period. The uncross-linked polymer chains dissolve in the solvent and are removed, while the cross-linked molecular network (the “gel”) remains insoluble. After drying, the remaining gel is weighed, and the gel content percentage indicates the proportion of material that successfully cross-linked. While gel content provides precise quantification of cross-linking degree, the Hot Set Test offers the practical advantage of being faster, requiring less specialized equipment, and directly assessing the mechanical performance consequences of cross-linking rather than just its chemical extent.

凝胶含量测量通过化学萃取技术提供了量化热固性材料中交联程度的替代方法。在这个测试中，将称重的交联材料样品浸入溶剂（通常为二甲苯或甲苯）中，在高温下放置延长时间。未交联的聚合物链溶解在溶剂中并被去除，而交联的分子网络（”凝胶”）保持不溶。干燥后，称重剩余的凝胶，凝胶含量百分比表示成功交联的材料比例。虽然凝胶含量提供了交联程度的精确量化，但热定型测试提供了更快、需要较少专用设备以及直接评估交联的机械性能后果而不仅仅是其化学程度的实际优势。

Troubleshooting and Process Optimization | 故障排除和过程优化

Common Failure Modes and Root Causes | 常见失效模式和根本原因

When EPR insulation specimens fail the Hot Set Test by exhibiting excessive hot elongation or permanent set, systematic investigation can identify the underlying manufacturing process issues. Insufficient vulcanization time is a frequent cause, where the cable passes through the curing tube too quickly for complete cross-linking reactions to occur throughout the insulation thickness. This is particularly problematic for cables with thick insulation walls where heat penetration from the surface to the inner regions requires adequate time. Inadequate curing temperature represents another common failure mode, often caused by steam pressure variations, heat exchanger fouling, or temperature control system malfunctions that prevent the EPR compound from reaching the activation temperature for cross-linking initiators.

当EPR绝缘样品因表现出过度的热伸长或永久变形而未通过热定型测试时，系统调查可以识别潜在的制造过程问题。硫化时间不足是一个常见原因，其中电缆通过固化管的速度太快，无法在整个绝缘厚度上发生完全的交联反应。这对于具有厚绝缘壁的电缆特别有问题，其中从表面到内部区域的热渗透需要足够的时间。固化温度不足代表另一个常见的失效模式，通常由蒸汽压力变化、热交换器结垢或温度控制系统故障引起，这些故障防止EPR化合物达到交联引发剂的活化温度。

Material-related issues can also cause Hot Set failures. Degraded or improperly stored peroxide cross-linking agents lose potency over time, reducing their effectiveness in initiating cross-linking reactions even when processing conditions are correct. Incorrect compound formulation, including improper ratios of base polymer to cross-linking agents or contamination with incompatible materials during mixing, produces material that cannot achieve adequate cross-linking regardless of processing parameters. Moisture contamination in the raw compound or inadequate drying before processing can interfere with peroxide cross-linking chemistry, resulting in reduced cross-link density and corresponding Hot Set Test failures.

材料相关问题也可能导致热定型失败。降解或不当存储的过氧化物交联剂随着时间的推移失去效力，即使处理条件正确，也会降低其在启动交联反应方面的有效性。不正确的化合物配方，包括基础聚合物与交联剂的不当比例或在混合过程中与不相容材料的污染，产生的材料无论处理参数如何都无法实现足够的交联。原始化合物中的水分污染或加工前干燥不足可能干扰过氧化物交联化学，导致交联密度降低和相应的热定型测试失败。

Process Optimization Strategies | 过程优化策略

Manufacturers optimize vulcanization processes through careful attention to multiple interrelated parameters. Establishing the correct relationship between line speed, curing tube length, and steam temperature ensures that every section of insulation receives adequate thermal energy for complete cross-linking. Advanced continuous vulcanization (CV) systems incorporate multi-zone temperature control, allowing gradual heating of the cable to prevent thermal shock to the insulation while ensuring thorough curing throughout the thickness. Regular calibration of temperature sensors and pressure transducers maintains process control accuracy, while statistical process control (SPC) methods using Hot Set Test data identify trends before they result in out-of-specification product.

制造商通过仔细关注多个相互关联的参数来优化硫化过程。建立线速度、固化管长度和蒸汽温度之间的正确关系，确保绝缘的每个部分都接受足够的热能以实现完全交联。先进的连续硫化（CV）系统包含多区温度控制，允许逐渐加热电缆以防止绝缘的热冲击，同时确保整个厚度的彻底固化。温度传感器和压力传感器的定期校准保持过程控制精度，而使用热定型测试数据的统计过程控制（SPC）方法在导致不符合规格的产品之前识别趋势。