做塑料件的都有过这种念头：这玩意儿要是能轻点就好了——实心件死沉，运费贵，客户还嫌重。发泡剂就是来解决这个念想的。往料里加一点点发泡剂，料在模具里自己长出密密麻麻的小气泡，同样大小的件，重量能掉一截，料还省了。今天把AC发泡剂、碳酸氢钠、超临界物理发泡这几条路子讲透：密度怎么降、成本怎么省、化学发泡和物理发泡怎么选。
发泡剂这东西，说白了就是让塑料在加工时“充气”。化学发泡剂是靠自己受热分解、放出气体；物理发泡剂是把超临界的气体直接打进料里。不管哪条路，结果都一样——件的内部变成蜂窝状，用气体替掉一部分塑料。宁波市科隆新材料有限公司长期经营各类塑料助剂，AC发泡剂、碳酸氢钠发泡母粒、物理发泡配套方案都有稳定货源，配方和发气数据随货可查。
| 类型 | 代表品种 | 发气/机理 | 典型制品 | 添加比例 |
|---|
| 化学偶氮类 | AC发泡剂 | 受热分解放氮气等，发气量大 | PVC/PE/PP鞋材、板材 | 0.5%-5% |
| 无机碳酸盐 | 碳酸氢钠 | 受热放CO₂，温和 | PP/PE片材、食品接触 | 1%-3% |
| 磺酰肼类 | OBSH | 分解温度低、气味小 | PVC、浅色/食品件 | 0.5%-3% |
| 物理发泡 | 超临界CO₂/氮气 | 气体注入成核发泡 | 精密件、汽车轻量化 | 按工艺 |
| 发泡母粒 | AC/碳酸氢钠母粒 | 预分散、易加料 | 通用注塑挤出 | 2%-5% |
注：AC发泡剂分解温度约200—215℃，发气量约220毫升每克，常配氧化锌活化剂降分解温度；物理发泡密度降幅以实际工艺为准。以上为行业通用口径，具体以厂家TDS和实测为准。
密度掉下来，钱才真省下来
先把这层窗户纸捅破。发泡降本的账，核心就一条：同样体积的件，发泡后用的塑料少了。实心件一公斤就是一公斤塑料钱；发泡件内部空了一块，同样大小、同样外观，塑料用得少，料钱自然省。做鞋底的都知道，实心TPE条比重零点八五到一点二，发泡后能掉到零点一五到零点三，轻了三到七成；做板材、做汽车件的，密度往下压一截，材料成本跟着往下走。
发泡还附带俩好处：一是隔音隔热，蜂窝结构本身就挡声音、隔温度，做隔音件、保温件正好；二是同样重量下，件的尺寸可以做得更厚实、更挺，省了又好看。所以轻量化降本不只是减料，是用气体换出性能和手感。
这里头有个技术细节得讲明白：发泡成不成，一半看熔体撑不撑得住。你想，气体在料里鼓泡，料得有足够的强度把泡壁撑住，不让泡破了、塌了。所以发泡常要配点成核剂——拿碳酸钙这类当“种子”，让气泡围着种子均匀长出来，泡孔又细又密；没成核剂，气泡到处乱跑，长得又大又歪，件表面就坑坑洼洼。AC分解还常配氧化锌当活化剂，把它两百多度的分解温度往下降，不然加工温度还没到分解点，它不发气；温度过了头，气又放得太快，全跑了。
再补一句：发泡还不是越轻越好。泡发太狠，件一捏就软、一压就瘪，强度扛不住；发到刚刚好，表面还有一层密实结皮，看着跟实心件差不多，里头却是蜂窝。做这块的老师傅，天天就是在“想轻一点”和“别塌”之间找那个平衡点。这个度，靠打样摸，不是看配方表一眼就能定。
图1 微发泡型材断面与挤出
实心件死沉，加一点发泡剂就轻一截
那厂家为啥要买发泡剂？做壁厚件、做板材、做鞋底的，最头疼的就是重。一重，料钱按吨算上去了；二重，运费、客户的手感都下来了。有研究拿超临界二氧化碳做聚氨酯类发泡，密度从约八十公斤每立方米降到四十五，减重四成多；做PP微发泡的配方里，发泡母粒加几个点，配合交联和成核，能在保住性能的前提下把成本降个一成左右。这都是看得见的账。
做壁厚件的厂都有这体会：同样一个件，重几两，一车货下来运费差出一截；客户拿在手里嫌沉，转头就找更轻的竞品。更别提做出口的，海运按体积重计费，件重一分，成本多一分。发泡省下的这百分之几十的重量，摊到一年几十万件上，是真金白银。
账怎么算？发泡的钱从哪省？按改性料的成本拆——料钱之外，后头还背着加工、包装、管销财和供应商利润这几块。你自己拿基料加发泡母粒改，加工费自己厂里摊，利润那层不用让出去。更要紧的是，发泡省的是实实在在的塑料——密度降一成，料就省一成，这比在添加剂上抠几毛钱实在多了。
| 成本项 | 实心件 | 发泡件 | 差异说明 |
|---|
| 材料投入 | 整体积实心料 | 基料+百分之几发泡剂 | 用气量替塑料 |
| 密度/重量 | 密度高、件重 | 密度降、减重一到七成 | 料钱按体积省 |
| 加工 | 常规工艺 | 需控温、配成核剂 | 工艺要调 |
| 外观 | 密实表面 | 有结皮、表面可平整 | 工艺到位不影响 |
| 隔音隔热 | 一般 | 蜂窝结构自带来 | 顺带加分 |
| 综合账 | 料贵件重 | 减重又省料 | 体积越大越划算 |
那直接买发泡改性料，还是自己拿基料加发泡母粒？发泡这事自己做还是买来用，下面的表帮你分个高下。
| 对比项 | 直接买发泡改性料 | 基料+发泡母粒自改 | 提醒 |
|---|
| 料本 | 含加工费+利润加价 | 基料成本更低 | 行业通用口径 |
| 密度控制 | 供应商定好的倍率 | 按工况自调 | 自己测密度 |
| 起订/货期 | 整吨起订、货期长 | 母粒添加量小、随调 | 库存压力小 |
| 工艺适配 | 换牌号试机 | 自己设备微调更准 | 发泡窗口要摸 |
| 合规数据 | 供应商掌握 | 自己掌握、可送检 | 食品件另证 |
| 适合谁 | 用量小/要求死 | 有工艺能力、走量 | 没摸透发泡窗口别硬上 |
边界得讲清楚：发泡不是加点料就完事，温度、剪切、成核剂配合缺一不可，泡孔一大就塌、表面就花；食品接触件得选无味的OBSH或碳酸氢钠体系，别用有气味的AC；做精密外观件，工艺没摸熟前先打样，别直接大货。
顺带提醒一句采购里的门道：别光听人说“发泡能省多少料”就冲，先掂量自己设备行不行。普通单螺杆挤出机、老注塑机，想做均匀微孔，可能得改螺杆、加装气体注入口；做超临界发泡，那是另一套设备，不是加点母粒就能搞定的。多数中小厂起步，还是化学发泡母粒这条路最现实——设备改动小，先把减重跑通，尝到甜头再往上走。别一上来就追超临界，设备和工艺投进去，量没起来，钱先花出去了。
发泡这活，看你在什么基材上做什么件
化学发泡和物理发泡怎么选？简单说，日常挤出、注塑用化学发泡剂便宜省事；要做精密轻量化、泡孔又细又匀的，上超临界物理发泡。基材不同，选型也不同。发泡体系在不同基材上怎么用，下面这张表按基材和用途列清楚。
| 塑料品类 | 典型场景 | 推荐发泡体系 | 添加量 | 注意事项 |
|---|
| PP | 汽车内饰、板材 | 化学发泡母粒/超临界 | 2%-5% | 配成核剂控泡 |
| PE/HDPE | 户外板、包装 | AC/碳酸氢钠 | 0.5%-3% | 控结皮 |
| PVC | 型材、鞋底、卡片 | AC/OBSH | 0.5%-3% | 配氧化锌活化 |
| TPE/TPU | 鞋底、软触感件 | 化学/超临界 | 按倍率 | 减重30%-70% |
| ABS | 外壳、轻质件 | 化学发泡母粒 | 2%-4% | 注意表面 |
| PS/EPS | 包装、保温 | 物理/可发性 | 按工艺 | 经典发泡 |
| PET | 结构发泡、包装 | 化学/超临界 | 按配方 | 注意结晶 |
| 薄壁注塑 | 薄壁件、减重 | 微孔发泡 | 按工艺 | 尺寸稳定 |
有发泡工况拿不准的？把基材、制品厚度和想减的重量发来，先帮你看该上化学发泡还是超临界，不强制下单。宁波市科隆新材料有限公司的发泡剂按基材分——AC、碳酸氢钠母粒走挤出注塑，OBSH走浅色食品件，物理发泡配套走精密轻量化，每批附发气和分解温度数据，公斤级母粒可以先打样测密度。
前面说的那家踢脚线厂，后来把密度也写进了自己的出厂巡检：每批型材抽几根切比重，达标再装箱。就这么一个动作，客户再没因为“这批怎么比上次重”找过来。做发泡久了都明白，轻量化不是赌一把，是把密度测稳、把窗口摸熟的细活；省下来的料钱，也是这一格一格测出来、一寸一寸磨出来的踏实。
原来买发泡料，自己加母粒密度反而更稳
说个典型情景示例，宁波市科隆新材料有限公司经手的发泡客户里，按行业常见情形还原如下。
华东有家做塑料踢脚线的厂，以前买人家调好的发泡PS型材料，料价高，发泡倍率还是供应商定死的，想要更轻一点、或者更挺一点，都得求着人家调。冬天车间温度低，型材表面还时不时发花。
转机出现在他们联系上科隆新材的时候。科隆新材先问清楚：型材壁厚、客户要的比重、设备螺杆长径比，建议改成基料加发泡母粒自改：用通用PS打底，按目标比重加发泡母粒，配合成核剂把泡孔打细，再把机筒温度窗口摸稳。先寄公斤级母粒试样。
这么试下来，型材比重稳在了客户要的数上，表面花斑少了，料本比买现成发泡料低一截。老板算了笔细账：以前一吨发泡PS里含着别人的加工费和利润，现在自己拿通用PS加母粒，密度一压，每吨省下的塑料钱摊到一年用量上很可观；外观也没打折扣，结皮平整，客户验收照样过。更让他踏实的是，现在要换个比重，自己加减母粒、微调温度就行，不用再排队等供应商改牌号。这也是宁波市科隆新材料有限公司做发泡助剂供货的路子——不只卖母粒，帮客户把密度和工艺窗口一起摸出来。
采购常问：发泡剂加多少、化学物理怎么选、出问题查哪
问：发泡剂一般加多少合适？答：AC类化学发泡剂加树脂总量的百分之零点五到五个点，做母粒再掺时母粒加二到五个点；碳酸氢钠类加一到三个点；超临界物理发泡按工艺参数走。具体看你要的发泡倍率，先打样测密度再定。
问：化学发泡和物理发泡有什么区别？答：化学发泡靠AC、碳酸氢钠自己受热放气，设备改动小、成本低，日常挤出注塑够用；物理发泡用超临界二氧化碳或氮气直接注进料，泡孔更细更匀、减重更精，但要专门设备。日常件用化学，精密轻量化上物理。
问：发泡件表面发花、泡孔一大就塌，先查什么？答：先查三样——温度有没有落在发泡剂分解窗口里，过高过低都不行；成核剂够不够，没成核剂泡孔就粗就塌；熔体强度撑不撑得住，料太稀气泡就破。这三样排查完还不行，找科隆新材对着你的设备调配方。
密度降不降得下来，先问基材再问倍率
把应用场景与推荐体系列成对照，按你的基材和想减的重量找方案，省得来回试错。发泡这活，温度窗口和成核剂是关键，对象对了百分之几的母粒就能把密度压下来、把料钱实实在在省到自己的口袋里，才是真本事、真划算。
| 你的场景 | 推荐体系 | 添加量 | 关键验证 | 别这么干 |
|---|
| PP汽车/板材 | 化学发泡母粒 | 2%-5% | 比重+表面 | 不配成核剂 |
| PVC型材/鞋底 | AC/OBSH | 0.5%-3% | 分解温度窗口 | 不配氧化锌活化 |
| TPE/TPU鞋底 | 化学/超临界 | 按倍率 | 减重30%-70% | 熔体强度不够硬发 |
| 精密外观件 | 超临界物理 | 按工艺 | 泡孔细密+外观 | 工艺没熟就大货 |
| 食品接触件 | 碳酸氢钠/OBSH | 1%-3% | 气味+合规 | 用有气味的AC |
再补一句：发泡件还得看应用，承力件、受力卡扣别盲目减重，减到强度不够、一受力就裂，反而得不偿失，还把客户吓退，这笔减重账就彻底算反了，省了料钱赔了订单。
件重不是天生的，是你还没往里吹气——密度降下来，料钱跟着就轻了。
想给件减重，发个基材和目标比重过来
有板材、鞋底、汽车件想轻量化拿不准的？把基材、壁厚和目标减重比例发来，先帮你看化学发泡还是超临界，不强制下单。发泡比例拿不准？把基材和密度要求发来，宁波市科隆新材料有限公司先帮你算该上哪套发泡体系。
想看电子包装怎么降表面电阻，翻上一篇抗静电剂；前面讲过的增韧剂、抗静电剂也在本系列里，翻回去看看。
声明：本文涉及的品牌、商标及产品名称权归各自原厂所有。本文为第三方选材知识分享，文中提及的牌号、参数、价格、认证及应用案例仅供参考，具体以各生产企业官方最新资料及批次检测报告为准。本文不构成任何采购或投资建议，读者据此操作风险自担。
Anyone making plastic parts has had this thought: it would be great if these things were lighter——solid parts are heavy, shipping is expensive, and customers still complain about the weight. Foaming agents exist to address this very idea. By adding a tiny amount of foaming agent to the material, small bubbles form throughout the material inside the mold, so parts of the same size can be significantly lighter, and material is also saved. Today, we'll explain in detail three approaches: AC foaming agents, baking soda, and supercritical physical foaming—how to reduce density, save costs, and how to choose between chemical foaming and physical foaming.
Foaming agents, to put it simply, are substances that make plastic 'inflate' during processing. Chemical foaming agents decompose upon heating and release gas on their own; physical foaming agents involve directly injecting supercritical gas into the material. No matter which method is used, the result is the same — the interior of the piece becomes honeycomb-like, with gas replacing some of the plastic. Ningbo Kolon New Materials Co., Ltd. has long been engaged in various plastic additives. There is a stable supply of AC foaming agents, sodium bicarbonate foaming masterbatches, and physical foaming support solutions, with formulas and gas generation data available upon delivery.
| Type | Representative varieties | Gas Emission/Mechanism | Typical products | Add ratio |
|---|
| Chemical azo compounds | AC foaming agent | Decomposes upon heating to release nitrogen and other gases, producing a large amount of gas | PVC/PE/PP shoe materials, sheets | 0.5%-5% |
| Inorganic carbonate | Sodium bicarbonate | Releases CO₂ when heated, mild | PP/PE sheets, food contact | 1%-3% |
| sulfonylhydrazines | OBSH | Low decomposition temperature, low odor | PVC, light-colored/food-grade parts | 0.5%-3% |
| Physical foaming | Supercritical CO₂/nitrogen | Gas injection nucleation foaming | Precision parts, automotive lightweighting | By process |
| Foaming masterbatch | AC/Sodium Bicarbonate Masterbatch | Pre-dispersed, easy to add | General-purpose injection molding and extrusion | 2%-5% |
Note: The decomposition temperature of AC foaming agent is about 200–215℃, with a gas generation of about 220 milliliters per gram. It is often combined with zinc oxide activator to lower the decomposition temperature; the reduction in physical foaming density should be based on the actual process. The above is the industry general guideline, and specific details should be based on the manufacturer's TDS and actual measurements.
Only when the density drops will money truly be saved.
First, punch a hole in this layer of window film. The core idea behind cost reduction with foaming is simple: for the same volume part, less plastic is used after foaming. A solid part weighs one kilogram, so that’s the cost of one kilogram of plastic; in a foamed part, there’s an empty space inside, so a part of the same size and appearance uses less plastic, naturally saving on material costs. Anyone making shoe soles knows that solid TPE strips have a density of 0.85 to 1.2, but after foaming, it can drop to 0.15 to 0.3, making them 30% to 70% lighter; for panels or automotive parts, if the density is lowered, material costs go down accordingly.
Foaming also comes with two additional benefits: first, sound and heat insulation. The honeycomb structure itself blocks sound and insulates temperature, making it perfect for soundproofing and thermal insulation parts; second, for the same weight, the part can be made thicker and more solid, which saves material and looks good. So lightweight cost reduction is not just about using less material; it's about using gas to achieve performance and feel.
There's a technical detail here that needs to be clarified: whether foaming works or not is half about whether the melt can hold up. Think about it: gas bubbles in the material require the material to have enough strength to hold up the bubble walls, preventing them from bursting or collapsing. That's why foaming often requires adding some nucleating agents—using something like calcium carbonate as a 'seed,' so the bubbles grow evenly around the seed, resulting in fine and dense pores. Without nucleating agents, bubbles scatter randomly, growing large and crooked, leaving the surface pitted. The decomposition of azodicarbonamide (AC) is also often paired with zinc oxide as an activator, which lowers its decomposition temperature from over 200 degrees; otherwise, the processing temperature hasn't reached the decomposition point yet, and it won't release gas; if the temperature goes too high, the gas is released too quickly and escapes entirely.
One more thing: the lighter the foam, the better is not necessarily true. If it foams too much, it becomes soft to the touch and collapses when pressed, unable to hold strength; if foamed just right, the surface still has a dense skin layer that looks almost like a solid piece, while the inside is honeycombed. The experienced artisans working on this are constantly seeking the balance between 'making it lighter' and 'not collapsing.' Achieving this degree comes from trial and error, not just by glancing at the formula.
Figure 1 Cross-section and extrusion of micro-foamed profiles
Solid parts are heavily solid; adding a bit of foaming agent makes them much lighter.
So why would manufacturers buy foaming agents? When making thick-walled parts, boards, or shoe soles, the biggest headache is weight. First, if it's heavy, the material cost calculated per ton goes up; second, if it's heavy, shipping costs increase and the customer's tactile experience decreases. Some studies have used supercritical carbon dioxide to foam polyurethane, reducing the density from about 80 kg per cubic meter to 45, cutting the weight by over 40%; in PP micro-foaming formulations, adding a few points of foaming masterbatch, combined with crosslinking and nucleation, can reduce costs by about 10% while maintaining performance. These are all visible savings.
Factories that make thick-walled parts all have this experience: for the same part, weighing a few ounces, the shipping cost for a truckload can differ significantly; customers complain it's too heavy when they hold it and immediately look for a lighter competitor's product. Not to mention exports, where sea freight is charged by volumetric weight—every ounce of weight increases the cost. Saving a few tens of percent of weight through foaming, spread over hundreds of thousands of parts in a year, is real money.
How do you calculate the costs? Where do you save the money on foaming? Break it down according to the cost of modified material—besides the material cost, you still have to bear processing, packaging, sales and administrative expenses, and supplier profit. If you take the base material and add the foaming masterbatch yourself, with processing costs spread within your own factory, you don’t need to let go of the profit. More importantly, foaming saves actual plastic—if the density drops by 10%, the material is reduced by 10%, which is much more tangible than saving a few cents on additives.
| Cost item | Solid piece | Foam part | Difference Explanation |
|---|
| Material Input | Solid material throughout | Base material with a few percent of foaming agent | Replace plastic with gas consumption |
| Density/Weight | High density, heavy parts | Density decreases, weight reduction of 10% to 70% | Material cost is saved according to volume |
| Processing | Conventional process | Temperature control required, preparation into nucleating agent | The process needs to be adjusted |
| Appearance | Dense surface | Has crusting, surface can be smooth | The craftsmanship is in place and it does not affect it |
| Soundproof and heat-insulating | general | The honeycomb structure comes naturally | Bonus points on the side |
| General account | Expensive material, heavy item | Weight reduction and material saving | The bigger the volume, the more cost-effective it is. |
Should we directly buy the foam-modified material, or mix the base material with a foaming masterbatch ourselves? Whether to do the foaming yourself or buy it ready-made, the table below will help you compare.
| Comparison item | Directly buy foamed modified material | Base material foam masterbatch self-modified | Reminder |
|---|
| material cost | Including processing fee and profit markup | The base material cost is lower | Industry standard caliber |
| Density control | Multiplier set by the supplier | Automatically adjust according to operating conditions | Measure the density yourself |
| Minimum order / Delivery time | Minimum order: whole tons, long delivery time | Small amount of masterbatch added, adjustable | Low inventory pressure |
| Process Adaptation | Try the machine with a different model number | Fine-tuning your own device is more accurate | The foam window needs to be touched |
| Compliance data | Supplier Mastery | Keep it yourself, can be sent for inspection | Food item and other certificates |
| Suitable for whom | Small dosage / strict requirements | Has manufacturing capability and high volume | Don't force it if you haven't figured out the foaming window |
Boundaries need to be made clear: foaming is not just a matter of adding some material; temperature, shear, and nucleating agent all need to be coordinated. If the bubbles get too big, they collapse and the surface becomes uneven. Food-contact parts should use odorless OBSH or bicarbonate systems, and avoid using odorous AC. When making precision appearance parts, create a sample before the process is fully mastered, and don't go straight to mass production.
A quick tip about purchasing: don’t just rush in because someone says, 'foaming can save so much material.' First, evaluate whether your equipment can handle it. Ordinary single-screw extruders or old injection molding machines may require screw modifications or gas injection ports to achieve uniform microcellular foam; making supercritical foam is a completely different set of equipment—it’s not something you can accomplish just by adding some masterbatch. For most small to medium factories starting out, chemical foaming masterbatch is the most realistic path—minimal equipment changes, you can first get the weight reduction process running, enjoy the benefits, and then scale up. Don’t jump straight to supercritical foam; if the equipment and process investment goes in first and production volume doesn’t pick up, you’ll spend money without getting results.
Foaming work depends on what substrate you are working on and what part you are making.
How to choose between chemical foaming and physical foaming? Simply put, for everyday extrusion and injection molding, chemical foaming agents are cheap and convenient; if you want to achieve precise lightweighting with fine and uniform pores, use supercritical physical foaming. Different base materials require different selections. The table below clearly lists how foaming systems are used on different base materials according to material and application.
| Plastic products | Typical scenario | Recommended foaming system | Addition amount | Precautions |
|---|
| PP | Car interiors, panels | Chemical Foaming Masterbatch / Supercritical | 2%-5% | Prepared as a nucleating agent to control foaming |
| PE/HDPE | Outdoor boards, packaging | AC/Sodium Bicarbonate | 0.5%-3% | Control crust |
| PVC | Profiles, shoe soles, cards | AC/OBSH | 0.5%-3% | Activated with zinc oxide |
| TPE/TPU | Shoe sole, soft touch parts | Chemistry/Supercritical | By ratio | Weight loss 30%-70% |
| ABS | Shell, lightweight parts | Chemical foaming masterbatch | 2%-4% | Pay attention to the surface |
| PS/EPS | Packaging, insulation | Physical / Eruptibility | By process | Classic Foaming |
| PET | Structural foaming, packaging | Chemistry/Supercritical | According to the recipe | Caution: Crystallization |
| thin-wall injection molding | Thin-walled parts, weight reduction | Microcellular foaming | By process | Dimensional stability |
Are you unsure about the foaming conditions? Send over the substrate, the product thickness, and the weight you want to reduce, and we’ll first help you see whether to use chemical foaming or supercritical, without forcing you to place an order. The foaming agents from Ningbo Kelong New Materials Co., Ltd. are categorized by substrate—AC and sodium bicarbonate masterbatches are used for extrusion and injection molding, OBSH is used for light-colored food parts, and physical foaming support is used for precision lightweighting. Each batch comes with gas release and decomposition temperature data, and kilogram-level masterbatches can be used for sample density testing first.
The skirting board factory mentioned earlier later included density checks in their own outbound inspection: for each batch of profiles, they would randomly cut a few to check the specific gravity, and only pack them if they met the standard. With just this one practice, customers never came back asking, 'Why is this batch heavier than the last one?' Anyone who's been in foaming for a long time understands that lightweighting isn't about taking a gamble; it's about consistently measuring density and becoming familiar with the parameters. The material money saved also comes from this meticulous process of measuring every section and fine-tuning every inch.
It turns out that buying foam material and adding masterbatch yourself actually makes the density more stable.
Here's a typical scenario example: among the foam clients handled by Ningbo Kolon New Materials Co., Ltd., the following restores the common situations in the industry.
In East China, there is a factory that makes plastic baseboards. They used to buy pre-adjusted foamed PS materials from others. The material price was high, and the foaming ratio was fixed by the supplier. If they wanted it to be a bit lighter or a bit firmer, they had to beg the supplier to adjust it. In winter, the workshop temperature is low, and the surface of the profiles would occasionally develop spots.
The turning point came when they got in touch with Koln New Materials. Koln New Materials first asked for details: the wall thickness of the profile, the specific gravity the customer wanted, and the screw L/D ratio of the equipment. They suggested changing to self-modification with base material plus foaming masterbatch: use general PS as a base, add foaming masterbatch according to the target specific gravity, use a nucleating agent to refine the cell structure, and then stabilize the temperature window of the barrel. First, send kilogram-level masterbatch samples for testing.
After trying this out, the profile's specific gravity stabilized at the number the customer wanted, the surface spots decreased, and the raw material cost was lower than buying ready-made foaming material. The boss did the math carefully: previously, a ton of foamed PS included other people's processing fees and profits; now, he used general-purpose PS plus masterbatch, pressed it to the desired density, and the plastic cost saved per ton spread over a year's usage was quite significant. The appearance was not compromised either—the skin was smooth, and customers still passed inspection. What reassured him even more was that now, if he wanted to change the specific gravity, he could just add or reduce masterbatch and slightly adjust the temperature, without waiting in line for the supplier to change the grade. This is also the approach of Ningbo Cologne New Materials Co., Ltd. in supplying foaming additives—not just selling masterbatch, but helping customers figure out both the density and the process window together.
Common procurement questions: How much foaming agent to add, how to choose between chemical and physical, where to check if problems arise
Q: How much foaming agent is generally appropriate? A: For AC-type chemical foaming agents, add 0.5% to 5% of the total resin; when making masterbatch and then mixing, add 2% to 5% to the masterbatch; for sodium bicarbonate type, add 1% to 3%; for supercritical physical foaming, follow the process parameters. Specifically, it depends on the foaming ratio you want. Make a sample and measure the density first before deciding.
Q: What is the difference between chemical foaming and physical foaming? A: Chemical foaming relies on AC and sodium bicarbonate to release gas when heated, requiring minimal equipment modification and low cost, which is sufficient for everyday extrusion and injection molding. Physical foaming uses supercritical carbon dioxide or nitrogen directly injected into the material, resulting in finer and more uniform pores and more precise weight reduction, but it requires specialized equipment. For everyday parts, chemical foaming is used, while for precise lightweight parts, physical foaming is preferred.
Q: When the surface of a foam part has uneven patterns or the bubbles collapse when they are large, what should be checked first? A: Check three things first — whether the temperature falls within the decomposition window of the blowing agent, as too high or too low is not suitable; whether there is enough nucleating agent, because without it, the bubbles will be coarse and collapse; and whether the melt strength is sufficient, since if the material is too thin, the bubbles will break. If checking these three still doesn't work, contact Kolon New Material to adjust the formulation according to your equipment.
Whether the density can be reduced, first ask about the substrate and then about the magnification.
Compare the application scenarios with the recommended series, and find a solution based on your substrate and the weight you want to reduce, so you won’t have to go through trial and error. In foaming, the temperature window and nucleating agents are crucial. When you target the right material, even a few percent of masterbatch can reduce density and save the material cost directly into your own pocket – that’s real skill and truly cost-effective.
| Your scene | Recommendation system | Addition amount | Key Verification | Don't do that |
|---|
| PP Car / Sheet Material | Chemical Foaming Masterbatch | 2%-5% | Specific Gravity Surface | Not qualified to become a nuclear agent |
| PVC profiles / shoe soles | AC/OBSH | 0.5%-3% | Decomposition temperature window | Not suitable for zinc oxide activation |
| TPE/TPU shoe sole | Chemistry/Supercritical | By ratio | Weight loss 30%-70% | The melt strength is not hard enough |
| Precision exterior components | Supercritical Physics | By process | Fine pore texture appearance | Mass production started before the process was perfected |
| Food contact parts | Sodium Bicarbonate/OBSH | 1%-3% | Odor Compliance | Use AC with odor |
One more thing: foam parts still need to be considered based on their application. For load-bearing parts and stress-bearing clips, don’t blindly reduce weight. If you cut down so much that the strength is insufficient and they crack under stress, it will be counterproductive and might even scare off customers. In that case, the weight-saving calculation is completely reversed—you save on material costs but end up losing the order.
The weight of the piece isn't innate; it's just that you haven't blown air into it yet—once the density goes down, the material cost will naturally become lighter.
I want to give a weight reduction, send over the base material and target specific gravity
Not sure how to achieve lightweighting for boards, shoe soles, or car parts? Send over the base material, wall thickness, and target weight reduction ratio, and we can first help you determine whether chemical foaming or supercritical is suitable, without any obligation to order. Unsure about the foaming ratio? Send the base material and density requirements, and Ningbo Kelon New Materials Co., Ltd. can first help you calculate which foaming system to use.
If you want to see how electronic packaging reduces surface resistance, check the previous article on antistatic agents; the toughening agents and antistatic agents mentioned earlier are also in this series, go back and take a look.
Statement: The brands, trademarks, and product names mentioned in this article are owned by their respective original manufacturers. This article is a third-party knowledge sharing on material selection. The grades, parameters, prices, certifications, and application cases mentioned are for reference only; the specific information should be based on the latest official data and batch inspection reports from each manufacturer. This article does not constitute any procurement or investment advice, and readers bear the risks of any actions taken based on it.
