聚氨酯筛板与橡胶筛板性能、成型工艺及设备的比较

新材料、新技术的产生导致了各种新产品的应用与开发。矿用聚氨酯筛板就是其中之一。由于聚氨酯材料优良的特性使得聚氨酯筛板在应用与加工方面明显优于橡胶筛板。笔者主要将新开发的聚氨酯筛板与橡胶筛板在性能、成型工艺及设备方面进行比较，指出开发应用聚氨酯成型技术的重要性。     

聚氨酯橡胶性能及应用简介

聚氨酯橡胶性能及应用简介聚氨酯橡胶具有一系列优异性能。如：①卓越的耐磨性能。实验室测定的耐磨性是天然橡胶的３－５倍，而在实际应用中往往高达１０倍，特别是当磨擦表面存在水、油等润滑介质时，在目前所知的所有有机无机材料中表现出最高的耐磨耗性，可制作筛板、...     

国内简讯

聚氨酯橡胶筛板 由山西省化工研究所合成材料厂研制的不堵塞型聚氨酯橡胶筛板于1991年12月通过新产品技术鉴定。该产品质量与进口产品相当,价格降低了1/3。其生产工艺合理,设备和检测手段齐全,具备批量生产条件。这种筛板采用浇注预聚法工艺路线,由聚酯或聚醚类低聚物二元醇、甲     

聚氨酯橡胶筛板研制成功

选煤、选矿、采石、钻井泥浆回收及城市垃圾处理等部门都离不开各种规格型号的筛机。筛板是筛机上确保筛分质量的核心部件它常年在震动、冲击、摩擦的恶劣条件下工作，极易破损。清洗使用的筛板是不耐磨、噪音大、寿命短、更换频繁的钻孔、冲孔或拼焊的碳钢和不锈钢筛板，为克服金属筛板的上述缺点，山西省化工研究所参照进口同类筛板的结构，采用本所技术，研制成功不阻塞型聚氨酯橡胶筛板。其主要特点为：①耐磨性好，使用寿命长，一般为钢制筛板的3—5倍②耐温性好，可以在水或油介质的条件下长期工作；③耐腐蚀性好，可在PH6—12的酸碱…     

浇注型聚氨酯筛板的成型工艺及设备

介绍了一种新型工业用筛板－浇注型聚氨酯筛板的成型工艺和成型设备。并将其与橡胶筛板的成型工艺和成型设备进行了对比。指出开发应用浇注型聚氨酯成型技术的重要性。     

不阻塞型聚氨酯橡胶筛板通过技术鉴定

山西省化工研究所试制成功的不阻塞型聚氨酯橡胶筛板于1991年12月在太原通过省级技术鉴定。外形尺寸为2400×1200×25的大型方孔筛板在山西安太堡露天煤矿(年造煤能力1500万吨)的直线振动筛上使用,筛分效果和使用寿命与同类进口筛板相当,为     

不阻塞型聚氨酯橡胶筛板的开发与研制

1 前言 随着选矿和冶金工业的发展,筛机的设计和制造日新月异,而筛板的选材和设计又是筛机发展的一个重要标志。由于聚氨酯弹性体机械强度高、弹性好,消声能力强,耐磨性能极佳,已越来越普遍地用作筛板材料,替代原来的金属筛板和普通橡胶筛板,     

聚氨酯橡胶筛板在选煤工业中的应用及发展前景

本文简单介绍了我国选煤工业概况，聚氨酯筛板的生产工艺、性能、特点。详细介绍了山西省化工研究所生产的聚氨酯筛板在洗煤厂的应用     

一种新型的喷射鼓泡传质设备:泡罩立体筛板

介绍了泡罩立体筛板的结构特点和实验情况,采用空气-水物系在1 000 mm×400 mm的有机玻璃塔中进行了塔板压降、雾沫夹带和漏液量的流体力学性能研究,并与垂直筛板的流体力学性能进行对比,结果表明,泡罩立体筛板的流体力学性能优于垂直筛板。     

聚四氟乙烯筛板的研制

通过对影响晒图质量和使用寿命的主要因素--聚四氟乙烯筛板的孔径及厚度的分析研究，并利用不同型号的高速晒图机对所研制的聚四氟乙烯筛板进行对比试验，确定了聚四氟乙烯筛板的主要工艺参数。所制得的聚四氟乙烯筛板具有优异的透气性、自润滑性及耐高低温性能，晒图质量好且使用寿命长达1800h，完全可以满足高速晒图机的使用要求。     

可循环再利用橡胶制品的制备研究

介绍以废旧轮胎或废旧橡胶制品的脱硫橡胶为主要原料、采用注射成型工艺制备可循环再利用橡胶制品的方法。废旧轮胎先经过去除钢丝、锦纶丝,粉碎、筛分预处理,再经过无污染的真空脱硫,混炼制成原料胶粒;无骨架材料的废旧橡胶制品直接经过真空脱硫处理也可以制成混炼胶颗粒;真空脱硫胶粒通过注射成型机和专门设计的模具,直接制成可以循环再利用的橡胶制品。     

卫浴产品的发展趋势

叙述了卫浴产品的市场现状．介绍了几种不同的卫浴产品的成分和性能，指出卫浴产品将会朝着多功能的趋势发展；     

我国锡焊料松香产品的研发应用与生产概况

介绍了松香相关产品在锡焊料中的开发应用；对锡焊料松香产品的品种及性能进行了分析探讨；提出了锡焊料松香产品基本实现国产化后，其质量与国际同类产品的差异和应努力改进的方向。     

基于双部分丢弃的模拟移动床产率提高策略

在保证产品纯度的情况下,提出一种带额外色谱柱的双部分丢弃策略以提高模拟移动床的产率。通过将工艺点选取在纯提取产品和非纯提余产品区域以增大进料流量,并将由此导致的含较多杂质的提余产品暂时丢弃。丢弃的提余产品作为循环进料通入到一个额外色谱柱中以进一步分离,部分不能达到指定纯度的额外产品被永久丢弃。在模拟移动床和额外色谱柱处分别收集到的产品组成总产品。分析了工艺点的选取、提余产品的积分纯度阈值和额外产品的积分纯度阈值对总产品性能参数的影响。研究结果表明,所提策略能够以较高的回收率利用原料,且能够显著提高分离过程的产率,其分离效果优于传统的模拟移动床工艺和部分丢弃策略。     

基于双部分丢弃的模拟移动床产率提高策略

在保证产品纯度的情况下,提出一种带额外色谱柱的双部分丢弃策略以提高模拟移动床的产率。通过将工艺点选取在纯提取产品和非纯提余产品区域以增大进料流量,并将由此导致的含较多杂质的提余产品暂时丢弃。丢弃的提余产品作为循环进料通入到一个额外色谱柱中以进一步分离,部分不能达到指定纯度的额外产品被永久丢弃。在模拟移动床和额外色谱柱处分别收集到的产品组成总产品。分析了工艺点的选取、提余产品的积分纯度阈值和额外产品的积分纯度阈值对总产品性能参数的影响。研究结果表明,所提策略能够以较高的回收率利用原料,且能够显著提高分离过程的产率,其分离效果优于传统的模拟移动床工艺和部分丢弃策略。     

Thermal oxidation of polypropylene close to industrial processing conditions

Thermal oxidation of isotactic polypropylene (PP) at 220 and 280°C in air was studied. Gas chromatography–mass spectrometric analysis was used to separate and identify the volatile products of PP oxidation. Twenty-three products were identified and 15 substances were quantified. The aldehydes are the principal products formed, followed by ketones, acids, and alcohols. The main organic product quantified was acetaldehyde. The volatile organic products formed constitute about 3% of the amount of water formed. The relative amounts of the most volatile products formed in the range 220–280°C are practically independent on the temperature of oxidation. The mechanism of formation on the oxidation products is discussed.     

Synthesis and Characterization of Poly (Acrylic Acid-co-Divinylbenzene) Microgels by Ultrasonic Degradation

The preparation of pure microgels in high yield was investigated by a new method which restricts the intermolecular crosslinking reaction between second-stage crosslinked products by steric hindrance of the first-stage crosslinked products. This is followed by ultrasonic degradation of the first-stage crosslinked products. The first-stage crosslinked products were prepared by copolymerization of styrene and divinylbenzene monomer in dioxane. with α,α′-azobisisobutyronitrile as initiator. The second-stage crosslinked products were prepared by copolymerization of acrylic acid and divinylbenzene monomer in first-stage crosslinked products highly swollen in dioxane, using α,α′-azobisisobutyronitrile as initiator. Degradation of first- and second-stage crosslinked products was carried out using an ultrasonic vibrator. The characteristics of the crosslinked products synthesized were investigated by gel permeation chromatography, dynamic laser light scattering and electron microscopy. It was found that the styrene-divinylbenzene gel of high molecular weight was scissioned preferentially with increasing ultrasonic degradation time and that ultrasonic degradation of compact and small size crosslinked products was very difficult. The crosslinked poly(acrylic acid)s are small compact microgels having a very narrow size distribution of 20-30 nm diameter. A pure microgel at nearly 100% conversion was obtained by the new preparation method suggested in this study.     

异噻唑啉酮衍生物凯松CG系列产品应用及前景

介绍异噻唑啉酮衍生物凯松系列及下游水处理剂产品在日化、药业、涂胶、水处理及其他工业领域应用的情况,并对高新生化助剂对我国绿色环保产业用途及推动意义进行了展望。     

Co-pyrolysis as a method of upgrading some products of coal processing

Co-pyrolysis was investigated as a method of upgrading various products resulting from coal processing. Co-pyrolysis of vacuum residue (VR) with coal extraction products as well as with primary tars from flash pyrolysis leads to a considerably enhanced yield of liquid products. It has been established that superheated steam and increased outgassing rate, favour the yield of liquid products. The proportion of the ingredients in the mixture as well as the quality of the VR also have a definite effect. The excess yield of liquid products in co-pyrolysis of coal extraction products was 8–23 wt%, depending on operating conditions and the composition of the mixture. The flash co-pyrolysis of primary tars yielded a 1.5–15.9 wt% surplus of liquid products depending on the mixture composition. Products originating from co-pyrolysis of these raw materials with VR are characterized by relatively high atomic hydrogen to carbon ratio, usually not less than 1.5 and the total abscence of asphaltenes. Generally, co-pyrolysis of VR with various products of coal processing is comparable with hydrogenation in the light of good yields of liquid products.     

Literature review of toxicological properties of petroleum and coal-derived oil products

The recent development of synthetic liquid fuel products from coal has raised the question of their relative health hazard compared with natural petroleum products.A review of the literature of natural petroleum products and coal-derived synthetic liquid fuels shows some level of mutagenic activity for each. In general, the coal-derived petroleum substitutes tend to be more mutagenic and carcinogenic than the natural petroleum products. Increased hydrotreatment of the coal-derived oil reduces the mutagenicity to levels comparable to the natural petroleum products. The COED syncrude product consistently shows a lower level of mutagenicity and carcinogenicity than all of the other coal-derived products that appear in the literature.