Shanghai Daoqin Plastics Co., Ltd.

         in plastics products production process in, can can generate waste material can separation is solid 体, liquid and gas large type. its in gas waste material relatively more, relatively large. main/primary has machine property gas 体(VOC) and machine gas large type.

        当VOC达 to concentrated degree 时, for 人体健康 has large effect/influence. for policy pressure, 消费者 诉求, reduce plastics products VOC content already formed is material enterprise and other large 事. detailed commonly used remove VOC methods.

        何 is VOC gas 体?

        VOC is can property has machine material 简称, in 50-260℃ temperature degree scope/range inner tool has very strong/high property. Common property has machine combined material 包括:

        苯 type (如苯, 甲苯, 二甲苯, 乙苯)

        烷 type (十四 carbon 烷)

         aldehyde type (甲 aldehyde)

         alcohol type (乙 alcohol)

         ether type, ester type (乙 acid ester)

         ketone type (丙 ketone)

         this VOC gas 体我们 generally is 看不见, and to odor has full is this gas 体本身 味道. this has machine material generate main/primary 源包括:

        (1)POM production in separation understanding generate aldehyde 味;

        (2)PVC production in separation understanding generate HCl遇 water rear acid 味;

        (3) ethylene-vinyl acetate copolymer (EVA) processing in mono acid ethylene 残留释放 醋味 and other.

        VOC gas from 何而?

         in plastics products processing process in, remove raw materials resin and modified add additives outer, below/following material generate VOC gas 体:

        01, printing ink

        (1) solvent agent property ink in printing, dry and other process in generate type and ketone type and acid ester and other VOC污染. is printing add good, especially is for/regarding plastics 基材.

        (2) water property ink in has machine solvent agent content relatively low (20% left right), therefore use process in (drying) generate VOC relatively less.

        02, bonding agent

         commonly used acrylic and polyurethane ester type bonding agent, still acid ester has machine solvent agent is 主.

        03, surface coating

         coating can remove plastics products surface various defect, 并赋予 products conductive, anti-static, wear resistant and other function, also can will deep color plastics products formed shallow color products. commonly used is acrylic ester or polyurethane ester type coating material.

        04, demolding agent

         commonly used demolding machine in has CH2Cl2, CH3CHCl and other has machine solvent agent.

        VOC gas how to remove?

        01, selection mono 体残留 amount relatively low resin

        尽 can can selection mono content comparison low resin. medical grade PVC resin VC mono content very low, VC content can to 1ppm(mg/kg)(positive value is 5); automotive inner sheet/plate use PP, need selection small separation 子挥发 material content low resin.

        02, use molecular weight relatively large additives

        尽 can can selection molecular weight large additives, most good is polymer additives, ensure in processing temperature degree lower 不会挥发以 and external 迁移.

        (1)如 coupling agent use compatibilizer, specific grafting polymer or 者枝化 polymer, is maleic anhydride grafted material separation tool has odor.

        (2) lubricant use poly 季戊四 alcohol hard acid ester (PETS) and other; dispersant selection molecular weight large 于5000 polyethylene wax (PE-WAX).

        (3) flame retardant can can selection polymer/macromolecule type type, specific bromine polystyrene (PS), bromine ring oxygen resin and other.

        03, add agent

         is utilizing agent or resin in has machine small separation to control VOC content requirements. method separation is chemical reaction and material 理吸附两 large type. Common material 理吸附材 material is more material, 如: 沸石, active property 炭, separation 子筛, silicon and other.

         chemical reaction is add can and VOC reaction additives formed versus for separation quality relatively large, in positive use ring lower (如 temperature degree low 于100 ℃)不会挥发 一 types combined material or formed more easy gas 体进而消 remove material in has VOC methods.

        04, control processing conditions

        (1) low temperature production: in ensure products separation front lower, relatively low processing temperature degree, from decrease/reduce small separation separation understanding material generate.

        (2) more grade true 空: increase true 空 次数, can to 3 grade 甚至4 grade, will generate small separation 子挥发 material and remove.

        05, decrease/reduce has machine solvent agent type material use

        (1) water property coating material: water is dispersion 介质代替 has machine solvent agent, currently technology also need has 20% left right ether type and alcohol type solvent agent, can low VOC coating material, is 无VOC coating material.

        (2) solid powder coating material: has has machine solvent agent, VOC排放零.

        (3) UV curable coating material: formed film material UV curable reaction molding, can decrease/reduce has machine solvent agent use amount, 但往往 need has 30% left right has machine solvent agent.

        (4) water property bonding agent and water property demolding agent: currently can is has machine solvent agent low content product.

         currently, 消费者 for automotive inner use plastics VOC requirements add 严格, how to reduce modified plastics in processing and use process in VOC 释放, is modified enterprise research focus/key point.

        06, high temperature dry 蒸

         plastics 基体经 di screw extrusion machine, pellet cutting machine rear, to VOC处理 system, 经 80-120℃ high temperature add hot, make plastics pellets VOC material 质(苯, 甲苯, and other type material 质)尽 can can dry dry 净, dry time temperature degree 而定, temperature degree high, time less, generally is 3 small left right. currently large modified enterprise basic use this methods.