劝你别轻易碰再生EVA，除非你先把VA含量这件事、把边角料从哪来这件事搞明白。今天这篇，就把鞋材和胶膜的边角料都去哪了、怎么分类、怎么变废为宝，一次说个明白。
先花两分钟认识下主角。EVA学名叫乙烯-醋酸乙烯酯共聚物，介于塑料和橡胶之间，软、轻、弹、粘，还透明。你脚下的运动鞋中底、手机的边框泡棉、光伏板封电池片的那层胶膜，背后都有它。它的性能几乎全看一个参数——VA含量，也就是醋酸乙烯酯占多少。VA低一点，偏塑料、偏硬；VA高一点，偏橡胶、偏软偏粘。做鞋发泡常用中等VA，做光伏胶膜常用更高一点的VA，做热熔胶要的是高VA。宁波市科隆新材料有限公司做塑料原料供应，工贸一体，常见再生塑料品类常年备货，EVA是其中按VA含量分档供货的一个。
再生EVA的来源，说出来你可能意外：据行业资料，现在EVA再生料的原料里，光伏胶膜边角料占了约三成，主要来自头部胶膜厂裁下来的余料；发泡鞋材废料也占约三成，集中在泉州、东莞一带鞋厂的成型边角；剩下的是电缆护套、热熔胶和农膜碎片。换句话说，再生EVA很多不是从旧鞋底里捡出来的，而是工厂里干干净净的生产边角料。宁波市科隆新材料有限公司收这类料，讲究按VA含量和来源分开收，不把鞋的和胶膜的搅成一锅，也不把好料和杂料混装。
EVA废料不是垃圾，是没分好类的原料
一提EVA废料，鞋厂老板的反应多半是：堆在那儿占地方，便宜处理给收废品的算了。胶膜厂的反应也差不多：裁下来的余料又厚又整，扔了可惜，卖了不值钱。
这些边角料被当成垃圾，问题不在料本身，在于没分类。干净的光伏胶膜边角料，VA含量高、材质单一、几乎没杂质，重新造粒后是做改性掺混的好料；鞋厂的发泡水口，只要VA对得上、发泡工艺没怎么交联，回收回去掺回新料做中底、鞋垫，性能照样用。真正不值钱的，是那种旧鞋底粉碎、混着橡胶和颜料、说不清VA多少的杂料——发泡后泡孔大小不均，回弹率只有三四成，踩久了塌，还带味。
所以再生EVA的头一条认知是：废料值不值钱，七分看分类，三分看价格。把光伏胶膜余料、鞋材水口、电缆料分开收、分开造粒，每一类都有下家；混在一起打成一锅，就只能当低档填充贱卖。这也是为什么有的厂把边角料当成本，有的厂把边角料当第二利润来源——差的就是一道分拣的功夫。
这里得专门说说光伏胶膜这个来源。光伏板里封电池片的那层透明膜，主要材料就是EVA（现在也有POE路线，但EVA胶膜用量仍然很大）。胶膜厂生产时要按组件尺寸裁切，裁下来的余料又干净、又整、VA含量还高，是再生EVA里的“上等米”。行业资料显示，头部胶膜企业的裁切余料，占了再生EVA原料来源的约三成。这类边角料几乎没沾杂质，回收造粒后常被拿去做改性掺混、透明次料。不过要注意：光伏级对耐候、抗黄变要求极高，普通再生EVA很难直接回做封装膜，但作为改性原料掺在别的制品里，它的干净和高VA就很值钱。
回答标题那个问题：这些边角料回收后去哪了？干净的光伏胶膜余料，造粒后大多做了改性掺混的“调料”，掺进新料或别的聚烯烃里降本；鞋材干净水口，按VA掺回做中底、鞋垫；交联发泡水口和杂料，降级做了地垫、拖鞋、包装衬垫这些对回弹要求不高的件；实在说不清来源的，就只能去低档填充。同一种废料，分选得越细，去的地方越高，身价也越高。
图1 EVA发泡中底与胶膜边角料
VA含量是EVA的脾气表，差五个点性格全变
买再生EVA，别的参数都能凑，唯独VA含量不能含糊。它就像EVA的脾气表——差几个点，材料的软硬、发泡、粘接、透明全变。
行业里大致这么分：VA偏低的，偏硬，做膜和电缆；中等VA的，柔韧，做鞋材发泡；VA更高的，像橡胶，做热熔胶、涂层；光伏胶膜对VA控制很严，主流在百分之二十多到三十几这个区间，还要把熔指卡死，太柔了裹不住电池片，太硬了层压会溢。再生EVA的麻烦在于：回收料的VA含量是“继承”自原来的料，你拿鞋材VA的再生料去做需要高VA的热熔胶，粘不住；拿光伏VA的料去发泡，成本又高、发泡行为也不对。所以买再生EVA，头一个问题永远是“VA多少”，而不是“多少钱一吨”。
为啥发泡水口有的不能直接再发泡？因为鞋用EVA中底很多是交联发泡——发泡剂加交联剂一起上，把泡孔结构“锁”住，中底才有支撑。可一旦交联过，分子连成了网，再加热也熔不回原来的颗粒流动性，硬去造粒再发泡，孔又大又乱。所以交联发泡水口的正确出路不是回炉再发泡，而是降级做改性掺混、地垫、低档制品；没交联的水口、洁净的膜边角料，才适合再生造粒、掺回生产。搞懂这一层，你就不会把值钱的料和该降级的料搞混。
正规再生EVA的路子是：按来源和VA分选，破碎、清洗、去掉杂质和标签，烘干后造粒。EVA多次再生时，醋酸乙烯酯基团容易氧化变色，所以要控温、补抗氧，不然越回越发黄。鞋材发泡的水口因为经过发泡、有些已经交联，直接再发泡不好使，更多是降级做改性掺混、地垫、低档制品。下面这张等级表，就是按来源和VA分的。
| 等级 | 主要来源 | 关键指标 | 典型用途 |
|---|
| 光伏胶膜边角料再生EVA | 头部胶膜厂裁切余料 | VA约28%-33%，洁净，透明度较好 | 改性掺混、透明制品、次料 |
| 鞋材发泡干净再生EVA | 发泡鞋厂同VA水口 | VA约18%-28%，泡孔可控，回弹尚可 | 发泡中底、鞋垫、缓冲件 |
| 高VA回收EVA | 热熔胶、涂层边角料 | VA高，粘接性好 | 热熔胶、涂层、改性 |
| 电缆护套回收EVA | 电缆护套边角料 | 绝缘性好，按VA分级 | 电缆料、改性掺混 |
| 消费后鞋底再生EVA | 旧鞋底粉碎回收 | 杂质多，回弹偏低，泡孔不均 | 低档拖鞋、地摊鞋、填充 |
| 改性再生EVA | 再生料复配助剂/填料 | 按需调硬度与回弹 | 鞋垫、地垫、改性原料 |
说明：EVA再生目前主要参照GB/T 40006.1《塑料 再生塑料 第1部分：通则》及各生产企业的企业标准；VA含量是核心指标，不同VA性能差异大，表中指标为行业公开资料与厂家技术数据归纳，更多等级与物性参数以厂家官方TDS为准。
发泡料省的是边角料钱，塌的是鞋底寿命
再生EVA是便宜，低端料一吨才几千块，看着挺诱人。可做鞋、做地垫的老板心里都有数：EVA这料一塌、一不回弹，整双鞋、整张垫跟着废，亏的可不是一星半点。这笔账得这么算才不亏。
行情上也能看出门道：低端消费后再生EVA，就是旧鞋底、杂料粉碎造的，一吨只要几千块；而干净的、来源清楚的边角料再生，价格高一些但用得稳；新料EVA根据VA和熔指不同，一吨上万甚至更高。价差背后，差的不是“再生”两个字，是VA含量、来源干净度和回弹。有的厂图那个几千块的便宜料，发泡回弹只有三四成，做出来的中底踩三个月就塌；有的厂用干净边角料，性能守住了，成本还下来了。同样叫再生EVA，价格能差出一倍多，选对哪一档，比砍价重要得多。
| 成本项 | 新料EVA | 再生EVA | 差异说明 |
|---|
| 吨料价 | 较高 | 低一截 | 干净边角料便宜，旧鞋底料更便宜 |
| VA含量 | 批次准 | 回收料VA有波动 | VA差几个点，性能全变 |
| 发泡回弹 | 回弹好 | 干净料尚可，旧鞋底料仅三四成 | 低端再生回弹低，易塌陷 |
| 泡孔均匀性 | 均匀 | 干净料好，杂料不均 | 杂料泡孔不均，外观差 |
| 气味杂质 | 低 | 回收料偏高 | 旧鞋底料有异味 |
| 综合成本 | 基准 | 同VA干净边角料划算 | 乱掺VA、乱混来源风险高 |
结合这笔账，下面的边界清单帮你判断手里的件能不能上再生EVA。
适合用再生EVA：同VA、同来源的干净边角料直接回用或掺混；发泡中底、鞋垫、地垫、包装；做改性原料掺新料调性能。
光伏组件封装：对透明度、耐候、抗黄变要求极高，普通再生EVA别上，认准光伏级。
食品接触、婴儿用品：需对应合规，普通再生料别碰。
高端运动鞋中底：别用旧鞋底杂料，回弹和一致性扛不住。
VA含量说不清的低价料：别买，发泡行为和成品性能都没谱。
加工上再提醒一句：EVA料轻、易吸水，造粒和发泡前都要烘干，含水的料发泡容易出气孔、发暗。再生EVA因为已经经历过一次热历史，熔指和VA可能跟新料有出入，发泡剂用量、温度曲线要重新摸，别直接照新料的配方打。还有颜色——不同来源的EVA再生后颜色杂，做浅色、白色件时要提前评估色差，别等成品发黄发白了才发现。
鞋厂的废料堆，其实是下一家的原料库
来看一个常见场景。宁波市科隆新材料有限公司常年收EVA边角料，接触过不少这样的厂，下面按典型情景还原，细节不必对号入座。
泉州有家做发泡鞋材的厂，车间里堆满了发泡水口和裁下来的边角，老板一直按废料低价处理，一年下来废了不少钱，还占地方。他也想过自己造粒回用，可试过几次，混料发泡要么孔不均、要么回弹不够，干脆就不当回事了。
后来他跟科隆新材聊起这事。科隆新材没先问你这料卖多少钱，倒先问起这堆边角：有多少是同VA的干净水口、多少是交联发泡块、有没有混进别的颜色。问清楚后给了个思路：干净的同VA水口，分选出来单独造粒，按比例掺回新料做普通中底和鞋垫，回弹和泡孔都稳；交联过的发泡块，别再拿去发泡，降级做成改性原料、地垫和低档掺混料；不同颜色、不同VA的坚决分开，绝不混打。这样一来，原来当废品卖的边角，一半变成了能回生产的料，剩下一半也卖了个比废品高的价。
科隆新材还提醒他，掺回新料别贪多。再生EVA掺量一般从百分之十几往上试，先小批量打样，看泡孔、回弹和外观稳不稳，再逐步加量；不同颜色的料要分开，混着做会串色。发泡温度、发泡剂配比也要跟着微调，不能拿纯新料的工艺直接套再生料。这些细节听着琐碎，却决定了掺回的边角料是变废为宝，还是变成一炉废品。
这家厂后来把分拣写成了车间规矩：不同来源的边角料分桶放、分开造粒、分开台账。一年下来，废边角料外销量少了，掺回生产线的多了，料成本降了，车间也干净了。老板说，早知道分拣这么值钱，前几年就不该把那些好边角当废料贱卖。
这单没有什么惊天动地的配方，就是把“分拣”这道功夫做扎实。做EVA久了有个共识：废料堆里藏着利润，就看你肯不肯分类、愿不愿意花那道分拣的功夫。这也是宁波市科隆新材料有限公司收EVA边角料时，坚持按VA和来源分选、不混装的原因。
EVA再生料，先问VA再问价
要点都在这儿了，下面这张表拿去直接用，照着勾不踩空。再生EVA省料不假，但VA含量和来源对不上，省下来的钱最后都得赔回去，还搭上客户的口碑。
| 应用场景 | 推荐等级 | 注意事项 | 何时别用 |
|---|
| 发泡中底/鞋垫 | 鞋材干净再生EVA | 看VA与回弹 | 旧鞋底杂料别用 |
| 改性掺混原料 | 光伏胶膜边角料再生 | 测VA含量 | 高透要求别用 |
| 热熔胶/涂层 | 高VA回收EVA | 看粘接性 | 低VA别用 |
| 地垫/包装低档 | 通用掺混再生EVA | 成本低 | 回弹要求高别用 |
| 拖鞋/地摊鞋 | 消费后再生EVA | 接受低端定位 | 高端鞋别用 |
| 光伏封装 | 谨慎评估 | 需高透耐候认证 | 普通再生别碰 |
EVA的边角料从来不是麻烦，是还没分好类的钱。
再生EVA，发泡废料变身改性原料
声明：本文提及的品牌及商标权归各自原厂所有。本文为第三方选材知识分享，文中涉及的具体等级、参数、价格、认证等信息以各厂家官方最新资料为准。本文不构成任何采购或投资建议。
I advise you not to handle recycled EVA lightly, unless you first understand the matter of VA content and where the scraps come from. In today's article, we will clearly explain where the scraps from shoe materials and adhesive films go, how they are classified, and how waste is turned into treasure.
Let's spend two minutes getting to know the main character. EVA, scientifically named ethylene-vinyl acetate copolymer, lies between plastic and rubber; it is soft, light, elastic, sticky, and even transparent. The midsole of your sneakers, the foam around your phone's frame, the adhesive film that encapsulates the battery cells in solar panels—all of these use it. Its properties almost entirely depend on one parameter—the VA content, which is the proportion of vinyl acetate. A lower VA content makes it more plastic-like and harder; a higher VA content makes it more rubber-like, softer, and stickier. Medium VA is commonly used for foamed shoe soles, a slightly higher VA for solar adhesive films, and high VA for hot melt adhesives. Ningbo Kolon New Materials Co., Ltd. supplies plastic raw materials, integrating industry and trade, and stocks common types of recycled plastics year-round. EVA is one of these, supplied in grades according to VA content.
The source of recycled EVA might surprise you: According to industry data, among the raw materials for recycled EVA, about 30% comes from photovoltaic film scraps, mainly leftover material cut off by leading film manufacturers; foam shoe material waste also accounts for about 30%, concentrated in the shoe factories around Quanzhou and Dongguan, originating from molded scraps; the rest comes from cable sheathing, hot melt adhesives, and agricultural film fragments. In other words, a lot of recycled EVA is not picked from old shoe soles, but is clean leftover material from factories. Ningbo Cologne New Materials Co., Ltd. collects this type of material with attention to separating it according to VA content and source, not mixing shoe material with film material in one batch, nor mixing good material with miscellaneous material.
EVA waste is not garbage; it is raw material that hasn't been properly sorted.
Whenever EVA waste is mentioned, the reaction of shoe factory owners is mostly: it just takes up space, so it's better to cheaply give it to scrap collectors. The reaction of adhesive film factories is similar: the leftover materials are thick and intact, it's a pity to throw them away, but selling them isn't worth much.
These scrap materials are treated as garbage, but the problem isn’t the material itself, it’s that they aren’t sorted. Clean photovoltaic film scraps have high VA content, a single material type, and almost no impurities; after being re-pelletized, they make good material for modified blends. Foam sprues from shoe factories, as long as the VA matches and the foaming process hasn’t caused much cross-linking, can be recycled and mixed back into new material for midsoles and insoles, and their performance remains usable. The truly worthless ones are the scraps from old shoe soles, mixed with rubber and pigments, with unclear VA content—after foaming, the cell size is uneven, the rebound rate is only thirty to forty percent, and they compress after prolonged use, plus they have an odor.
So the first understanding of recycling EVA is: whether scrap is valuable depends 70% on classification and 30% on price. Collect and granulate leftover photovoltaic films, shoe material sprues, and cable materials separately; each type has its own buyer. If mixed together and granulated in one batch, it can only be sold cheaply as low-grade filler. This is also why some factories treat scraps as a cost, while others treat scraps as a secondary source of profit—the difference is just a step of sorting.
Here we need to specifically talk about the source of photovoltaic (PV) films. The transparent film that encapsulates the solar cells in PV panels is mainly made of EVA (there is also a POE route now, but EVA films are still used in large quantities). When film manufacturers produce the films, they cut them according to the size of the modules, and the leftover scraps are clean, intact, and have a high VA content, making them the 'premium rice' among recycled EVA. Industry data shows that the cutting scraps from top film companies account for about 30% of the raw materials for recycled EVA. These edge scraps are almost free of impurities, and after being recycled and pelletized, they are often used for modified blends or as transparent secondary material. However, it should be noted that PV grade materials have extremely high requirements for weather resistance and anti-yellowing properties, making it difficult for ordinary recycled EVA to be directly used again for encapsulation films. But as a modified raw material blended into other products, its cleanliness and high VA content are very valuable.
Answering the question in the title: Where do these scraps go after recycling? Clean leftover photovoltaic films, after being pelletized, are mostly used as modified additive 'seasoning,' mixed into new materials or other polyolefins to reduce costs; clean shoe materials scraps are mixed back according to VA to make midsoles and insoles; cross-linked foam scraps and miscellaneous materials are downgraded to make items like floor mats, slippers, and packaging pads, which do not require high resilience; scraps whose origins are unclear can only be used as low-grade fillers. The more precisely the same type of waste is sorted, the higher the quality of the products it goes into, and the higher its value.
Figure 1 EVA foam midsole and adhesive film scrap
The VA content is the temperament chart of EVA; a difference of five points can completely change its character.
When buying recycled EVA, all other parameters can be adjusted, but the VA content cannot be vague. It is like a temperament meter for EVA—if it differs by a few points, the material's hardness, foaming, adhesion, and transparency all change.
The industry is roughly divided like this: low VA, harder, used for films and cables; medium VA, more flexible, used for shoe material foams; higher VA, rubber-like, used for hot melt adhesives and coatings. PV (photovoltaic) adhesive films have very strict VA control, with the mainstream in the 20+ to 30+ percent range. The melt index also needs to be tightly controlled: if it's too soft, it won’t encapsulate the solar cells, and if it's too hard, it will overflow during lamination. The trouble with recycled EVA is that the VA content in the recycled material is 'inherited' from the original material. If you use recycled shoe material EVA to make high-VA hot melt adhesive, it won’t stick; if you use PV EVA material to make foam, the cost is high and the foaming behavior is off. So when buying recycled EVA, the first question is always 'How much VA?' and not 'How much per ton?'
Why can't some foam sprues be directly re-foamed? Because many EVA midsoles for shoes are cross-linked foams—the foaming agent is added together with a cross-linking agent, which 'locks' the foam cell structure so that the midsole has support. Once cross-linked, the molecules form a network and cannot melt back into the original granular flow when heated. If you forcibly granulate and re-foam it, the pores will be large and irregular. Therefore, the proper route for cross-linked foam sprues is not to refoam them but to downgrade them for modified blending, floor mats, or low-end products. Only sprues that are not cross-linked and clean film edge scraps are suitable for recycling into granules and reintegrating into production. Understanding this will prevent you from mixing valuable material with material that should be downgraded.
The proper process for recycling EVA is: sort according to source and VA content, crush, wash, remove impurities and labels, and then dry and pelletize. When EVA is recycled multiple times, the vinyl acetate groups are prone to oxidation and discoloration, so temperature control and antioxidant replenishment are necessary; otherwise, it will turn increasingly yellow. The sprues from shoe material foaming, because they have undergone foaming and some are cross-linked, do not work well for re-foaming. They are more often downgraded for modification, blending, floor mats, and low-end products. The grade table below is based on source and VA content.
| Level | Main source | Key indicators | Typical uses |
|---|
| Recycled EVA from photovoltaic film scraps | Head film factory cutting scraps | VA about 28%-33%, clean, with good transparency | Modified blends, transparent products, secondary materials |
| Shoe material foamed clean recycled EVA | Foam shoe factory same VA sprue | VA approximately 18%-28%, pore size controllable, rebound acceptable | Foaming midsole, insole, cushioning components |
| High VA Recycled EVA | Hot melt adhesive, coating scraps | High VA, good adhesion | Hot melt adhesive, coating, modification |
| Cable Sheath Recycling EVA | Cable sheath scraps | Good insulation, classified by VA | Cable materials, modified blending |
| Recycled EVA from shoe soles after use | Old shoe sole crushing and recycling | Many impurities, low rebound, uneven foam pores | Low-end slippers, street stall shoes, padding |
| Modified Recycled EVA | Recycled material compounding additives/fillers | Adjust hardness and rebound as needed | Insoles, floor mats, modified raw materials |
Explanation: Currently, EVA recycling mainly refers to GB/T 40006.1 "Plastics – Recycled Plastics – Part 1: General Principles" and the corporate standards of various manufacturers; VA content is the core indicator, with significant differences in performance between different VA levels. The indicators in the table are summarized from publicly available industry information and manufacturers' technical data. For more grades and physical parameters, please refer to the manufacturers' official TDS.
Saving on foam material cuts costs on scrap, but shortens the lifespan of the shoe sole.
Recycled EVA is cheap; low-end material costs only a few thousand yuan per ton, which looks quite tempting. But bosses making shoes or floor mats know the truth: if EVA collapses and doesn't rebound, the whole pair of shoes or the entire mat becomes useless, and the loss is far from trivial. To avoid losing money, you have to calculate the costs this way.
The market situation also reveals some insider knowledge: recycled EVA from low-end consumer products is made from old shoe soles and miscellaneous ground materials, costing only a few thousand yuan per ton; cleaner recycled scraps with a clear source are more expensive but reliable in use; new EVA, depending on VA content and melt index, can cost over ten thousand yuan per ton or even more. Behind these price differences, what varies isn’t the word 'recycled,' but the VA content, source cleanliness, and resilience. Some manufacturers go for that cheap material costing a few thousand yuan, but the foam's rebound is only 30-40%, and the midsoles will collapse after three months; other manufacturers use clean scraps, maintain performance, and even reduce costs. Even with the same label of recycled EVA, prices can differ by more than double, so choosing the right grade is far more important than haggling over the price.
| Cost item | New EVA material | Recycled EVA | Difference Explanation |
|---|
| Price per ton of material | Higher | a bit lower | Clean scraps are cheap, old shoe sole materials are even cheaper |
| VA content | Batch approved | Recycled VA has fluctuations | A few points difference in VA, and the performance changes completely. |
| Foam rebound | Good rebound | The clean material is acceptable, but the old shoe sole material is only thirty to forty percent. | Low-end regeneration has poor rebound and is prone to collapse |
| Pore uniformity | Even | Clean material is good, mixed material is uneven | Impurities cause uneven pores and poor appearance |
| Odor impurities | Low | Recycled material is relatively high | The old shoe sole material has an unusual odor |
| Comprehensive cost | Benchmark | It's more cost-effective than VA with clean scraps | Randomly mixing VA and sources carries high risk |
Based on this calculation, the following boundary list helps you determine whether the pieces in your hands can be put on recycled EVA.
Suitable for using recycled EVA: clean scraps of the same VA and from the same source can be reused directly or mixed; for foamed midsoles, insoles, floor mats, packaging; used as modified material blended with new material to adjust performance.
Photovoltaic module encapsulation: has very high requirements for transparency, weather resistance, and anti-yellowing. Ordinary recycled EVA won’t do; be sure to choose photovoltaic-grade.
Food contact and baby products: must comply with regulations; ordinary recycled materials should not be used.
Midsole of high-end sports shoes: Don't use old sole scraps, the rebound and consistency can't hold up.
Low-priced material with uncertain VA content: don't buy it, the foaming behavior and finished product performance are unpredictable.
One more reminder regarding processing: EVA material is light and absorbs water easily, so it must be dried before granulating and foaming. Material containing moisture is prone to developing pores and darkening during foaming. Recycled EVA, having already gone through a thermal history, may have differences in melt index and VA content compared to virgin material, so the amount of foaming agent and the temperature profile need to be recalibrated, rather than simply following the recipe for new material. Also, regarding color—recycled EVA from different sources can be inconsistent in color, so when making light or white parts, color differences should be evaluated in advance, rather than realizing the product has turned yellow or white after molding.
The waste pile of the shoe factory is actually the raw material storage for the next company.
Let's look at a common scenario. Ningbo Cologne New Materials Co., Ltd. has been collecting EVA scraps for many years and has come into contact with quite a few such factories. Below is a reconstruction based on a typical situation; the details do not need to correspond exactly.
In Quanzhou, there is a factory that makes foamed shoe materials. The workshop is filled with foamed sprues and trimmed scraps. The boss has always treated them as low-priced waste, which has wasted a lot of money over the year and also takes up space. He has thought about making pellets for reuse himself, but after trying several times, the mixed foaming either had uneven holes or insufficient rebound, so he simply gave up on it.
Later he talked about this with Cologne New Materials. Cologne New Materials didn't first ask how much you were selling this material for; instead, they first asked about this pile of scraps: how much were clean gates of the same VA, how much were cross-linked foam blocks, and whether other colors were mixed in. After clarifying, they gave an idea: clean gates of the same VA should be sorted out and granulated separately, then mixed back into new material in proportion to make ordinary midsoles and insoles, ensuring stable rebound and foam cells; cross-linked foam blocks should no longer be used for foaming, but downgraded into modified raw materials, floor mats, and low-grade mixed materials; different colors and different VAs must be kept separate and never mixed. In this way, half of the scraps that were originally sold as waste became usable material for production, and the remaining half was sold at a higher price than waste.
Kolon New Materials also reminded him not to be greedy when mixing in new material. The proportion of recycled EVA generally starts from a little over ten percent and is tested upwards. Begin with small batch samples to check if the bubbles, rebound, and appearance are stable, then gradually increase the amount; materials of different colors should be kept separate, mixing them will cause color contamination. The foaming temperature and foaming agent ratio also need to be fine-tuned accordingly, and the process for pure new material cannot be directly applied to recycled material. These details may seem trivial, but they determine whether the mixed scrap turns into treasure or becomes a batch of waste.
Later, the factory turned sorting into a workshop rule: scrap materials from different sources were placed in separate bins, granulated separately, and recorded separately. After a year, the amount of scrap material sold externally decreased, more was fed back into the production line, material costs went down, and the workshop became cleaner. The boss said that if he had known sorting was so valuable, he shouldn't have sold those good scraps as waste at low prices in the past few years.
This order doesn't involve any earth-shattering formula; it's just about solidly executing the skill of 'sorting.' After working with EVA for a long time, there's a common understanding: profits are hidden in the scrap pile, and it depends on whether you're willing to sort and willing to put in the effort to sort. This is also the reason why Ningbo Kolon New Material Co., Ltd. insists on sorting EVA scraps by VA and source, without mixing them, when collecting EVA offcuts.
EVA recycled material, first ask about VA then ask about the price
All the key points are here. Take this table below and use it directly, following it so you don't miss anything. It's true that using recycled EVA saves material, but the VA content and source don't match, and the money saved will eventually have to be paid back, not to mention it will affect the client's reputation.
| Application scenario | Recommendation Level | Precautions | When not to use |
|---|
| Foamed midsole/insole | Clean recycled EVA for shoe materials | Check VA and rebound | Do not use old shoe sole scraps |
| Modified blended raw materials | Recycling of photovoltaic film scraps | Test VA content | Do not use high transparency requirements |
| Hot melt adhesive/coating | High VA Recycled EVA | Check the adhesiveness | Do not use low VA |
| Floor mat/Low-end packaging | General Blended Recycled EVA | Low cost | Don't use if high rebound is required |
| Slippers/Street stall shoes | Post-consumer recycled EVA | Accept a low-end positioning | Do not use high-end shoes |
| Photovoltaic Encapsulation | Assess carefully | High transparency and weather resistance certification required | Ordinary recycled materials should not be touched |
EVA scraps have never been a problem; they are just money that hasn't been classified properly yet.
Recycled EVA: Turning foam waste into modified raw materials
Disclaimer: Brands and trademarks mentioned in this article belong to their respective original manufacturers. This article is a third-party material selection knowledge sharing; specific grades, parameters, prices, certifications, and other information mentioned are based on the latest official data from each manufacturer. This article does not constitute any procurement or investment advice.
