一批深腔洗衣机外壳,脱模时底部被撕裂,缺口从2%的正常水平飙到18%。眼看交期只剩五天,生产经理急得在车间转圈——外脱模剂喷了不少,但深腔底部喷不到,内脱模剂又没加,等于只给模具表面涂了层油,深处还是干磨。
硬拽出来的制品翘成饺子,都是脱模剂没当好那个和事佬。
本文由长期经营塑料原料及助剂的宁波市科隆新材料有限公司整理,牌号与批次信息以实际供货渠道为准。
脱模剂速查总表:内加和外用两条路
脱模剂分两条路线:一条是“内脱模”,直接掺进原料里,随料走、省人工;一条是“外脱模”,喷涂在模面上,救急、灵活。先看这张表,把两条路的适用场景和用量搞清楚。
| 路线 | 代表品种 | 作用方式 | 典型用途 | 添加/用量 |
|---|
| 内脱模 | 脂肪酸酰胺类、EBS母粒 | 掺进料里,迁移到表面 | 批量稳定件、自动化生产 | 0.3%-1% |
| 外脱模(蜡基) | 石蜡/蜡乳液喷涂 | 喷在模面成膜 | 复杂件、试模 | 每若干模喷一次 |
| 外脱模(硅酮) | 硅氧烷喷涂 | 高效脱模、超顺滑 | 难脱模件、高光件 | 少量喷涂 |
| 外脱模(氟素) | 含氟脱模剂 | 长效、不影响后工序 | 需印刷涂装的件 | 少量喷涂 |
注:表中为常见品类参数区间,实际脱模力和表面残留受配方和模具影响,以实测和官方TDS为准。外脱模用量随工况现场试模,内脱模用量为对树脂比例。
图1 脱模剂——制品与模具之间的体面分离
内脱模省人工,外脱模救急场,路线选错天天救火
这位主角,专门管“分手”这件事。宁波市科隆新材料有限公司长期经营各类塑料助剂及改性原料,覆盖国内外多个品牌货源,在润滑剂、内脱模母粒、加工助剂等品类上有稳定供货渠道。而脱模剂这个品类,是模具和制品之间的“第三者”——塑料熔体冷却收缩时会包紧模具型芯,开模瞬间如果没有润滑隔离,制品就被粘住、顶白、翘曲。内脱模剂是预先掺在料里的助剂,成型时迁移到金属表面形成隔离层;外脱模剂则是直接喷在模面上的脱模介质。
脱模剂就是模具和制品之间的“第三者”,撮合一次体面的分手。
内脱模和外脱模的差别,像“自带润唇膏”和“随身带护手霜”。内脱模把润滑做进料里,每一模自动生效,省掉人工喷涂的工序和时间,适合大批量、自动化生产;外脱模是“随用随喷”,灵活、见效快,适合小批量、多品种、试模或突然卡模的救急场。路线选择的本质是:你的产品是天天跑同一种件的流水线,还是经常换型的多品种车间。
好的脱模,是制品和模具体面分手,不是开模时的暴力撕扯。
很多车间习惯了“卡模就喷”,把外脱模当万能药,却没算过账:频繁喷涂会在模面上堆积油膜,越积越厚,制品表面发花、光亮不均;更要命的是,残留的脱模剂会让后续的丝印、喷漆、粘接附着力下降。所以成熟做法是:批量稳定件优先上内脱模,把喷涂量压到低;外脱模只用来救急和试模,而不是日常依赖。
天天停产喷脱模剂还觉得正常?那是配方里压根没想过内脱模这回事。
逐品种速查:内脱模掺进料,外脱模喷在模
脱模剂品种不少,抓住内、外两条线的主力即可。内、外两条线挨个过一遍,定位和雷区都摆到台面上。
批量稳定件走内脱模,小批量复杂件喷外脱模,路线先选对。
内脱模母粒(脂肪酸酰胺类、EBS类):掺进原料0.3%到1%,成型时迁移到表面助脱模,省去人工喷涂,自动化产线友好。选它的信号:大批量同一品种、自动化注塑、想省人工。注意:内脱模有析出风险,做涂装印刷件要控制用量并测附着。
供货提示:内脱模剂科隆新材有稳定货源,每批附酸值和熔点数据,公斤级试样可先做脱模力对比测试。
蜡基外脱模剂(石蜡、蜡乳液):喷在模面成蜡膜,成本低、见效快,适合一般注塑和试模。选它的信号:一般件、小批量、试模调机。注意:蜡膜易堆积,高频喷涂会污染模面。
硅酮外脱模剂(硅氧烷):脱模高效、超顺滑,难脱模的深腔、薄壁件好用。选它的信号:难脱模件、高光件、救急场。注意:含硅脱模剂残留会让丝印喷漆发花掉附,后工序件慎用或选无硅型。
要后工序喷漆丝印的件,慎选含硅外脱模剂,移印会发花。
含氟/无硅外脱模剂:脱模长效、残留少,对后工序友好,做需要印刷涂装的件更稳妥。选它的信号:制品要丝印、喷漆、粘接,又离不开外脱模。注意:价格高于普通蜡基硅酮,按件选用。
含氟内脱模剂(氟系聚合物母粒):定位高端复杂件,耐温性好、脱模长效,迁移到模面后残留极低,对后续涂装、丝印几乎不干扰,缺点是价格偏高。选它的信号:深腔、高温、又要求后涂装的复杂件——普通内脱模扛不住温度,或析出影响涂装附着时再上。注意:添加量0.1%-0.3%即可,过量会削弱超声波焊接强度,需要后焊接的件要从严控制。具体牌号物性以官方TDS为准。
注意,脱模剂和润滑剂是近亲:内脱模母粒常和润滑EBS、PE蜡重合。配方里要统筹,别把脱模剂和润滑剂叠加到超量喷霜。
替代对照:进口脱模体系能不能换?先看这张表
采购常问:进口脱模母粒、脱模喷剂能不能用国产替代?内脱模母粒国产替代空间较大;外脱模喷剂涉及配方和应用习惯,要上机验证。常见替代路线和上机前提,见下表对照。
| 原用方向 | 典型应用 | 可对标方案 | 切换前提 |
|---|
| 进口内脱模母粒 | 批量自动化注塑 | 国产脂肪酸酰胺内脱模 | 小试对比脱模周期、析出、涂装附着 |
| 进口硅酮脱模喷剂 | 难脱模高光件 | 国产硅酮脱模剂 | 对比脱模效果、模面残留、后工序 |
| 进口含氟脱模剂 | 印刷涂装件 | 国产无硅/含氟脱模 | 对比后工序附着力、残留堆积 |
| 进口蜡基脱模 | 试模/一般件 | 国产蜡基脱模 | 对比成膜、堆积周期、成本 |
表中是常见替代路线,真实脱模表现得在自己的模具上验。替代必须上机试脱模周期和后工序附着,别只看样品手感。
深腔件的脱模验证要做实际开模测试,科隆新材提供公斤级内脱模剂试样时附酸值和熔点数据,客户可以先在模具上对比脱模力和表面残留,再决定是否替换外脱模。
脱模剂一喷万事大吉?那层油膜迟早让你丝印时掉眼泪。
行业场景速查:不同制品对脱模的要求差在哪
同样是脱模,做普通周转箱和做要喷漆的汽车件,要求完全不同。不同行业对脱模的要求,下表逐行对照。
| 行业 | 典型制品 | 客户先问的参数 | 推荐路线 | 后工序注意 |
|---|
| 通用注塑 | 周转箱、家电壳 | 脱模周期、废品率 | 内脱模母粒为主 | 一般无后工序 |
| 汽车 | 内饰件、门板 | 低VOC、可喷漆焊接 | 低析出内脱模+无硅外脱 | 涂装焊接测附着 |
| 高光/薄壁 | 透明盖、薄壁件 | 不拉伤、高光洁 | 硅酮外脱模慎用无硅 | 控制残留 |
| 多品种车间 | 试模、小批量 | 灵活、随用随喷 | 蜡基/硅酮外脱模 | 勤清洁模面 |
| 3C/包装 | 手机壳、化妆品盒 | 丝印烫金附着 | 无硅/含氟脱模 | 迁移测试 |
举个具体场景:做要丝印的手机壳,脱模一旦用了含硅喷剂,丝印油墨就缩孔发花,返工率居高不下。这种件就得换无硅或含氟脱模,并控制模面残留,先把附着问题压住再谈产量。
再看汽车内饰这条线:门板、仪表台、立柱这类件对VOC和气味等级卡得很严,喷涂外脱模剂容易把溶剂和油雾带进车内,反而拖低气味测试,所以更倾向用低析出的内脱模母粒,从源头免去喷涂污染。搭配上还要留意它与发泡剂、搪胶表皮工艺的兼容性——含氟或硅酮类脱模残留一旦析出,会影响后续水胶复合和表皮粘接。这类件的脱模体系宁可加得稳一点,也要先过小样VOC和气味等级,再谈放量。毕竟车内空间密闭,一点脱模剂的油雾味道都会被放大成整批客诉,容不得侥幸。
添加量与搭配要点:四条思路记住就够了
脱模路线选择有规律,不用每次从零试。下面四条思路覆盖主流场景。
内脱模多是脂肪酸酰胺类,掺进去一点,就够模具张嘴放人。
◆ 大批量自动化件:内脱模母粒0.3%-1%,随料走、省喷涂人工,前提是后工序允许析出。
◆ 难脱模高光/薄壁件:外脱模喷剂救急,硅酮高效,但后工序件改无硅型。
◆ 印刷涂装焊接件:低析出内脱模+无硅/含氟外脱模,守住后工序附着。
◆ 多品种试模车间:蜡基/硅酮喷剂灵活救急,勤清洁模面防堆积。
另有三条搭配经验:一是脱模剂和润滑剂常共用EBS/PE蜡,配方要统筹算量,防叠加超量喷霜;二是外脱模喷涂要控制频率和用量,模面堆积会污染制品、影响光泽;三是做后工序(丝印、喷漆、粘接、焊接)的件,脱模体系要优先“不影响附着”,脱模效率让位于后工序质量。
模具那张脸,要的是轻轻一推,不是死拉硬拽。
脱模:内外有别。
加工与合规红线:这五个坑别踩
脱模用不好,不是废品多就是后工序掉链子。关键环节和翻车后果见下表,照着避坑。
| 环节 | 参考值 | 做错的后果 |
|---|
| 内脱模用量 | 0.3%-1%按树脂 | 超量→析出、后工序附着差 |
| 外脱模喷涂 | 按需少量、定期清洁模面 | 堆积→模面污染、表面发花 |
| 含硅脱模 | 后工序件禁用或改无硅 | 残留→丝印喷漆发花掉附 |
| 顶出与工艺 | 配合顶出、模温 | 只靠脱模剂→顶白翘曲 |
| 模具清洁 | 定期清模去堆积 | 积垢→制品光泽不均 |
合规红线:食品接触制品的脱模体系要符合GB 4806或FDA相关条款;含硅、含氟脱模剂的迁移和残留要关注;汽车内饰注意低VOC。脱模剂残留往往是后工序投诉的源头,小试阶段务必做丝印、喷漆或焊接附着验证。
FAQ:采购和注塑车间常问的六个问题
Q1:国产脱模体系能不能替代进口料?
可以,但要分路线。内脱模母粒国产替代空间大,上机对比脱模周期、析出和附着即可;外脱模喷剂涉及应用习惯和后工序,要现场验证。正确做法是拿样品先试脱模效果,再测后工序附着,合格再小批量放量。做脱模力对比用的试样,科隆新材可按公斤级提供,附酸值、熔点数据随货同行。
Q2:为什么我的件丝印喷漆老是掉?
先怀疑脱模剂残留。含硅或蜡基脱模喷多了,膜面有油,油墨油漆附不住。改用无硅/含氟脱模、清洁模面,再做百格附着测试。
Q3:内脱模和外脱模到底选哪个?
大批量自动化、品种单一的件选内脱模,省人工;小批量、多品种、试模救急选外脱模。批量稳定件别长期依赖外喷。
Q4:脱模剂喷得越勤越省事吗?
恰恰相反。喷得勤,模面堆积越快,制品越花,后工序越麻烦。控制频率、定期清模才是正道。
Q5:脱模剂能解决顶白翘曲吗?
能缓解粘模,但顶白、翘曲往往还和顶出设计、模温、冷却有关。脱模剂是助攻,不是万能,工艺该调还得调。
Q6:脱模剂和润滑剂是不是一回事?
近亲,但不同。内脱模母粒常和润滑EBS/PE蜡重合,配方要统筹;外脱模是喷剂,独立于配方。别把两者叠加到超量。
选型三步清单:照着做不踩坑
◆ 第1步·看批量后工序:品种单一自动化件优先内脱模;要丝印喷漆焊接的件,先把“不影响附着”摆在前面。
◆ 第2步·选路线:批量稳定件上内脱模母粒0.3%-1%;救急试模用外脱模,后工序件选无硅/含氟型。
◆ 第3步·上机验证:小试看脱模周期、表面光泽,再测丝印/喷漆/焊接附着,合格再放量并归档批次报告。
脱模这件事,内脱模比喷罐靠谱
复杂深腔件和批量稳定生产,内脱模比外脱模更可控——不用每模喷、不影响后工序喷漆丝印。科隆新材供应脂肪酸酰胺类内脱模剂,可提供脱模力测试参考数据;对需要后涂装的制品,可推荐低迁移、不影响附着力的品类,公斤级试样支持先做脱模和涂装附着力双重验证。
那是去年秋天,一家家电厂做深腔滚筒洗衣机外壳,脱模撕裂率居高不下,外脱模剂喷了不少但深腔底部够不着。科隆新材给他们推荐了内脱模剂,寄了公斤级样品。客户试了两批,撕裂率从约18%降到约3%,而且因为不用每模喷外脱模剂,后工序喷漆的良率也从82%升到了约96%。生产经理说,原来以为脱模就是多喷点油的事,没想到内脱模才是治本。
你的件,还在靠喷罐脱模吗?
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。
A batch of deep-cavity washing machine shells were torn at the bottom during demolding, with defects jumping from the normal 2% to 18%. With only five days left until the delivery deadline, the production manager was nervously pacing around the workshop — quite a bit of external release agent had been sprayed, but the deep cavity bottoms couldn't be reached, and no internal release agent was added, which meant only a layer of oil was applied to the mold surface, while the deep parts were still dry and grinding.
The products forcibly pulled out warp like dumplings; it's all because the release agent wasn't applied properly, that mediator.
This article is compiled by Ningbo Kolong New Materials Co., Ltd., which has long been engaged in the business of plastic raw materials and additives. The grade and batch information are subject to the actual supply channels.
Quick Reference Table of Release Agents: Two Approaches – Internal Addition and External Application
Release agents are divided into two routes: one is 'internal release,' which is directly mixed into the raw materials, moves with the material, and saves labor; the other is 'external release,' sprayed onto the mold surface, useful for emergencies and flexible. First, look at this table to understand the applicable scenarios and dosages for the two routes.
| Route | Representative varieties | Mode of action | Typical uses | Add/Dosage |
|---|
| Internal demolding | Fatty acid amides, EBS masterbatch | Mixed into the material, migrated to the surface | Mass production of stable components, automated production | 0.3%-1% |
| External Demolding (Wax-Based) | Paraffin/Wax Emulsion Spraying | Spray on the mold surface to form a film | Complex parts, trial mold | Spray once every several molds |
| External demolding (silicone) | Siloxane spraying | Efficient demolding, ultra-smooth | Difficult-to-demold parts, high-gloss parts | Light spraying |
| External release (fluorine) | Fluorine-containing release agent | Long-lasting, does not affect subsequent processes | Parts that need to be printed and coated | Light spraying |
Note: The table shows the typical parameter ranges for common categories. The actual demolding force and surface residue are affected by the formulation and mold, and should be based on actual measurements and the official TDS. The external demolding amount should be tested on-site according to working conditions, and the internal demolding amount is based on the resin ratio.
Figure 1 Release Agent — Proper Separation Between Product and Mold
Internal demolding saves labor, external demolding helps in emergency situations, choosing the wrong route leads to daily firefighting.
This protagonist specializes in handling 'breakups.' Ningbo Cologne New Materials Co., Ltd. has long been engaged in various plastic additives and modified raw materials, covering multiple domestic and international brands, and has stable supply channels for categories such as lubricants, internal release masterbatches, and processing aids. As for release agents, this category acts as a 'third party' between the mold and the product—when the plastic melt cools and shrinks, it tightly wraps around the mold core, and at the instant of demolding, without lubrication or separation, the product can stick, show flash, or warp. Internal release agents are additives pre-mixed into the material, migrating to the metal surface during molding to form a release layer; external release agents are media sprayed directly onto the mold surface.
A release agent is the 'third party' between the mold and the product, facilitating a decent breakup.
The difference between internal release and external release is like 'built-in lip balm' and 'carrying hand cream.' Internal release incorporates the lubricant into the material, making each mold effective automatically, saving the labor and time of spraying, suitable for large-scale, automated production. External release is 'spray as needed,' flexible and quick-acting, suitable for small batches, multiple varieties, trial molds, or emergency situations like sudden mold sticking. The essence of choosing the approach is: is your production a line that runs the same part every day, or a workshop that frequently switches between multiple varieties?
A good demolding means the product separates from the mold surface, not being violently torn off when opening the mold.
Many workshops are used to the practice of 'spray whenever the mold sticks,' treating external mold release as a cure-all, but they haven't done the math: frequent spraying causes an accumulation of oil film on the mold surface, which keeps getting thicker, leading to blotchy surfaces and uneven gloss on the products; even worse, the residual release agent reduces the adhesion of subsequent screen printing, painting, and bonding. Therefore, the mature approach is: prioritize internal mold release for stable batch parts and keep the spraying amount low; external mold release should only be used for emergencies and trial molds, not relied on daily.
Do you think it's normal to stop production every day to spray release agent? That’s because the formula never even considered internal release.
Quick reference by variety: internal demolding mixed into the material, external demolding sprayed on the mold
There are quite a few types of mold release agents, so just focus on the main ones of the internal and external lines. Go through the internal and external lines one by one, and lay out both the positioning and the pitfalls on the table.
For mass-produced standard parts, use internal demolding; for small-batch complex parts, use external demolding. Choose the route correctly first.
Internal release agent masterbatch (fatty acid amide type, EBS type): mix 0.3% to 1% into the raw material, it migrates to the surface during molding to aid demolding, eliminating the need for manual spraying and is friendly for automated production lines. Signs to choose it: large quantities of the same variety, automated injection molding, and wanting to save labor. Note: internal release agents have a risk of migration, for coated or printed parts, the usage should be controlled and adhesion tested.
Supply Tip: Kolon New Materials has a stable supply of internal mold release agents, with each batch accompanied by acid value and melting point data. Kilogram-scale samples can first be used for mold release force comparison tests.
Wax-based external release agents (paraffin, wax emulsion): sprayed on the mold surface to form a wax film, low cost, quick effect, suitable for general injection molding and mold testing. Signals to choose it: general parts, small batches, mold testing and machine adjustment. Note: wax film is prone to accumulation, and high-frequency spraying can contaminate the mold surface.
Silicone Release Agent (Siloxane): High-efficiency demolding, ultra-smooth; effective for deep cavities and thin-walled parts that are difficult to demold. Signals to choose it: difficult-to-demold parts, high-gloss parts, emergency situations. Note: Residual silicone release agent can cause silkscreen and spray paint to have uneven adhesion, so use with caution on subsequent processing parts or choose a silicone-free type.
For parts that will undergo spraying and screen printing in later processes, be cautious about using silicone-containing external release agents, as pad printing may cause blooming.
Fluorine-containing/Silicone-free external release agent: Long-lasting release, minimal residue, friendly to subsequent processes, more reliable for parts requiring printing and coating. Signals for choosing it: the product needs screen printing, painting, or bonding, and still requires external release. Note: Priced higher than ordinary wax-based silicone, select per piece.
Fluorine-containing internal mold release agent (fluoropolymer masterbatch): Positioned for high-end complex parts, it has good heat resistance and long-lasting release performance. After migrating to the mold surface, the residue is extremely low, causing almost no interference with subsequent painting or screen printing. The drawback is that it is relatively expensive. Signals to choose it: deep cavities, high temperature, and complex parts requiring subsequent coating—ordinary internal mold releases cannot withstand the temperature, or exudation affects coating adhesion, so use this one. Note: The addition amount should be 0.1%-0.3%; excessive amounts may weaken ultrasonic welding strength, so parts requiring post-welding must be strictly controlled. For specific grades and properties, refer to the official TDS.
Note, release agents and lubricants are closely related: internal release masterbatches often overlap with lubricants like EBS and PE wax. In the formulation, plan comprehensively, and do not stack release agents and lubricants into excessive frosting.
Alternative comparison: Can imported demolding systems be replaced? Take a look at this chart first
Common Purchasing Questions: Can imported mold release masterbatches and mold release sprays be replaced by domestic products? There is more room for domestic substitution for internal mold release masterbatches; external mold release sprays involve formulation and usage habits, and need to be tested on the machine. The common substitution routes and prerequisites for machine testing are listed in the table below for reference.
| Original direction | Typical applications | Benchmark solution | Switch premise |
|---|
| Imported internal release agent masterbatch | Batch Automated Injection Molding | Demolding of domestic fatty acid amides | Small-scale test comparing demolding cycle, precipitation, and coating adhesion |
| Imported Silicone Release Spray | High-gloss parts that are difficult to demold | Domestic silicone release agent | Compare demolding effect, mold surface residue, and subsequent processes |
| Imported Fluorine-Containing Release Agent | Printed coated parts | Domestic silicone-free/fluorine-containing release | Adhesion and residual accumulation of subsequent processes after comparison |
| Imported wax-based release agent | Trial Mold / Standard Parts | Domestic wax-based release | Comparison of film formation, accumulation cycles, and cost |
The table shows common alternative routes, but the actual demolding performance should be tested on your own mold. Alternatives must undergo machine demolding cycle tests and subsequent process adhesion checks; do not just judge by the feel of the sample.
The demolding verification of deep cavity parts requires actual mold testing. When Kolon New Materials provides kilogram-level internal release agent samples, they include acid value and melting point data. Customers can first compare the demolding force and surface residue on the mold before deciding whether to replace with external release agents.
Is everything fine just by spraying the release agent? That layer of oil film will sooner or later make you cry when screen printing.
Quick Industry Reference: How the Demolding Requirements Differ for Various Products
Demolding is the same, but the requirements are completely different for ordinary turnover boxes and car parts that need painting. The requirements for demolding in different industries are listed row by row in the table below.
| Industry | Typical products | The parameters the client asked about first | Recommended Route | Attention to subsequent processes |
|---|
| General injection molding | Turnover box, appliance casing | Demolding cycle, defect rate | Primarily inner demolding masterbatch | Generally no subsequent process |
| Car | Interior parts, door panels | Low VOC, paintable and weldable | Low-exudation internal demolding, silicone-free external demolding | Coating Welding Adhesion Test |
| Highlight/Thin Wall | Transparent cover, thin-walled part | No strain, high gloss | Be cautious using silicone-free products for silicone external demolding | Control Residue |
| Multi-product workshop | Trial mold, small batch | Flexible, spray as needed | Wax-based/Silicone external demolding | Keep the mold surface clean |
| 3C/Packaging | Phone cases, cosmetic boxes | Silk screen gold stamping adhesion | Silicone-free/fluorine-containing release | Migration Test |
A specific scenario: when making phone cases that need screen printing, if a silicone-containing release agent is used during demolding, the screen printing ink will develop pinholes and blooming, resulting in a high rework rate. For these parts, you have to use silicone-free or fluorine-containing release agents, and control residue on the mold surface. You need to address adhesion issues first before talking about production volume.
Looking at the automotive interior line: parts like door panels, instrument panels, and pillars are very strict about VOC and odor levels. Spray-on external release agents easily carry solvents and oil mist into the car interior, actually lowering the odor test results. Therefore, it's more preferable to use low-exudation internal release masterbatches, eliminating spray contamination from the source. At the same time, attention must be paid to their compatibility with foaming agents and TPE skin processes—if fluorine-containing or silicone release residues are released, they can affect subsequent water-based adhesive lamination and skin bonding. For these parts, the release system should be made more stable, and small sample VOC and odor levels must pass before considering full-scale production. After all, the car interior is a confined space, and even a bit of odor from a release agent can be amplified into a batch-wide customer complaint, leaving no room for chance.
Dosage and Key Points of Matching: Remembering four ideas is enough
The choice of demolding route follows a pattern, so you don't have to start from scratch every time. The following four approaches cover mainstream scenarios.
Internal demolding agents are mostly fatty acid amides, just a little added is enough to make the mold open its mouth for the person.
◆ High-volume automated parts: Internal release masterbatch 0.3%-1%, goes along with the material, saving spraying labor, provided that subsequent processes allow for exudation.
◆ Hard-to-demold highlights/thin-walled parts: Use external mold-release spray as an emergency measure; silicone is highly effective, but for subsequent processing parts, switch to a silicone-free type.
◆ Printed, coated, and welded parts: low-exudation internal release, silicone-free/fluorine-containing external release, ensuring adhesion in subsequent processes.
◆ Multi-variety trial molding workshop: Wax-based/silicone sprays are used flexibly for urgent needs, and mold surfaces are cleaned frequently to prevent accumulation.
There are three additional blending experiences: First, release agents and lubricants often share EBS/PE wax, so the formulation should be planned to calculate the amounts and avoid excessive overlapping spraying; second, the frequency and amount of external release spraying should be controlled, as accumulation on the mold surface can contaminate the product and affect gloss; third, for parts undergoing subsequent processes (such as silk screening, painting, bonding, or welding), the release system should prioritize 'not affecting adhesion,' and release efficiency should yield to the quality of the subsequent process.
That mold face requires a gentle push, not a forceful pull.
Demolding: There is a difference between the inside and the outside.
Processing and Compliance Red Lines: Avoid These Five Pitfalls
If demolding is done poorly, it will either result in a lot of defective products or cause failures in subsequent processes. Key steps and the consequences of mistakes are shown in the table below; follow it to avoid pitfalls.
| link; segment; part | Reference value | The consequences of doing wrong |
|---|
| Internal demolding dosage | 0.3%-1% by resin | Excess → precipitation, poor adhesion in subsequent processes |
| External demolding spraying | Clean the mold surface in small amounts as needed and on a regular basis | Accumulation → Mold surface contamination, surface marbling |
| Silicone release | Post-process parts are prohibited or changed to silicone-free | Residual → Screen printing paint spraying blotch falling off |
| Ejection and Process | Coordinate ejection and mold temperature | Relying only on mold release agent → white spotting and warping |
| Mold Cleaning | Regularly clean the mold to remove accumulation | Build-up → Uneven product gloss |
Compliance Red Lines: The release system of food contact products must comply with GB 4806 or relevant FDA regulations; attention should be paid to the migration and residue of silicone- or fluorine-containing release agents; for automotive interiors, low VOC should be considered. Residues of release agents are often the source of complaints in subsequent processes, so it is essential to conduct screen printing, painting, or welding adhesion verification during the small-scale trial stage.
FAQ: Six Common Questions in Purchasing and Injection Molding Workshops
Q1: Can domestic release agent systems replace imported materials?
Yes, but it needs to be divided by route. There is a large potential for domestic substitution of internal release agent masterbatches; on machines, just compare demolding cycles, precipitation, and adhesion. External release sprays involve application habits and subsequent processes, so on-site verification is required. The correct approach is to first test the demolding effect on samples, then measure adhesion in subsequent processes, and only after passing should small-scale production be increased. For samples used to compare demolding force, Cologne New Materials can provide them at the kilogram level, with acid value and melting point data sent with the shipment.
Q2: Why does the screen printing paint on my parts always peel off?
First, suspect mold release agent residue. If silicone or wax-based mold release is sprayed too much, there will be oil on the surface of the film, and ink or paint will not adhere. Switch to silicone-free/fluorine-containing mold release, clean the mold surface, and then perform the cross-cut adhesion test.
Q3: Which should be chosen, internal demolding or external demolding?
For large-scale automation with a single variety, choose internal demolding to save labor; for small batches, multiple varieties, or urgent mold testing, choose external demolding. For batches with stable parts over a long term, rely on external coating.
Q4: Does spraying mold release agent more frequently make things easier?
On the contrary. The more frequently you spray, the faster the mold surface accumulates, the more flawed the products become, and the more troublesome the subsequent processes are. Controlling the frequency and cleaning the mold regularly is the right approach.
Q5: Can release agents solve whitening and warping?
can reduce mold sticking, but white ejection and warping are often related to ejection design, mold temperature, and cooling. Release agent is a help, not a cure-all; the process must be adjusted when necessary.
Q6: Are release agents and lubricants the same thing?
Close relatives, but different. Internal release masterbatch often overlaps with lubricating EBS/PE wax, so formulations need to be coordinated; External release masterbatch is spray, independent of formulation. Don't combine the two into excess.
Three-step selection checklist: Follow this to avoid pitfalls
◆ Step 1: Check post-batch processes: prioritize internal demolding for single-type automated parts; For parts requiring silkscreen printing, spray painting, and welding, first put "does not affect adhesion" first.
◆ Step 2: Select route: 0.3%-1% of internal release masterbatch on batch stable parts; Use external demolding for emergency mold trials; for subsequent processes, choose silicone-free or fluoride-containing types.
◆ Step 3 · Machine Verification: Briefly check the demolding cycle and surface gloss, then measure screen screening/painting/welding adhesion. If qualified, scale up and file batch reports.
For demolding, internal demolding is more reliable than spray cans
For complex deep cavity parts and batch stable production, internal demolding is more controllable than external demolding—no need for each mold spraying and does not affect subsequent painting and silkscreen printing. Kolon New Materials supplies fatty acid amide internal release agents, which can provide reference data for release force testing; For products requiring post-coating, they can recommend low-migration products that do not affect adhesion, with kilogram-level samples supporting dual verification of release and coating adhesion.
Last autumn, a home appliance factory was making deep-cavity drum washing machine housings, but the release tear rate remained high. Although a lot of external release agent was sprayed, the bottom of the deep cavity was inaccessible. Kolon New Materials recommended internal release agent and sent kilogram-level samples. The customer tested two batches, reducing tear rate from about 18% to about 3%. Moreover, since no external release agent was sprayed per mold, the post-process painting yield rose from 82% to about 96%. The production manager said he used to think demolding was just about spraying more oil, but it turns out the inner demolding is the real solution.
Are you still relying on spray can demolding for your piece?
Statement: The brands, trademarks, and product names mentioned in this article belong to their respective original manufacturers. This article is a third-party material selection knowledge sharing. The grades, parameters, prices, certifications, and application cases mentioned in the article are for reference only. Please refer to the latest official information and batch test reports from each manufacturer. This article does not constitute any procurement or investment advice. Readers are at their own risk when acting accordingly