綠色活力模具的汽車零件製造商

Successful injection molding depends on a delicate balance of multiple factors, including material selection, mold design, and process control. Any disruption to this balance can lead to defects, with part adhesion to the mold and poor ejection being particularly challenging. These issues, often referred to as “sticking” tabi “dragging,” can cause production delays, damage to the mold, and compromise the quality of the final product.



Improper Process Control

If the injection molding machine is oversized, with a screw speed that is too high, injection pressure that is too great, and injection hold time that is too long, it will result in overpacking. This leads to a lower than expected shrinkage rate, making ejection difficult.

If the barrel and melt temperatures are too high, and the injection pressure is too great, the hot melt easily enters the gaps between the mold inserts, creating flash and leading to poor ejection.


Additionally, a nozzle temperature that is too low, insufficient cooling time, and interrupted material flow can also cause poor ejection.



Therefore, when troubleshooting adhesion and ejection problems, the following actions should be taken:

• Reduce the injection pressure.

• Shorten the injection time.

• Lower the barrel and melt temperatures.

• Extend the cooling time.

• Prevent material flow interruptions.



Inadequate Material Quality

If impurities are introduced into the raw material during packaging and transportation, or if different grades of materials are mixed during pre-drying and pre-heating processes, it can lead to part adhesion to the mold. Additionally, the presence of foreign objects in the barrel and hopper can also cause this issue.

Inconsistent or overly large particle sizes of the raw material can also contribute to adhesion to some extent.

Therefore, it is crucial to properly clean and screen the molding materials before use.



Improper Use of Release Agents

The purpose of using release agents is to reduce the adhesion between the plastic part surface and the mold cavity surface, preventing them from sticking to each other. This facilitates shorter molding cycles and improves the surface quality of the plastic parts. However, the effectiveness of release agents is influenced by both chemical interactions and physical conditions. Furthermore, since molding materials and processing conditions vary, the optimal type and amount of release agent must be determined based on the specific situation. Improper use often fails to produce the desired release effect.



Regarding the molding temperature, the effective working temperature of fatty oil-based release agents generally should not exceed 150°C and are not suitable for high-temperature molding. Silicone oil and metal soap-based release agents typically work within a temperature range of 150°C si 250°C. Polytetrafluoroethylene (PTFE)-based release agents can withstand temperatures above 260°C, making them the most effective for high-temperature molding.

In terms of material type, soft polymer parts are generally more difficult to release than hard polymer parts.

Regarding the application method, paste-like release agents should be applied with a brush, while sprayable release agents are applied using a spray device. Since it is difficult to form a regular and uniform layer when applying paste-like release agents with a brush, the surface of the molded part may exhibit wave marks or streaks after ejection. Therefore, it is preferable to use sprayable release agents whenever possible.



Overfilling

When molding with excessively high injection pressure, the shrinkage rate is smaller than expected, making ejection difficult. In such cases, reducing the injection pressure, shortening the injection time, and lowering the temperature of the melt and mold can facilitate ejection. In these situations, using release agents that reduce the friction between the plastic and the mold is more effective. For the mold, increasing the surface finish, eliminating side wall irregularities, polishing, and adding ejector pins are also effective measures. When molding deep parts, blowing compressed air between the mold and the part can further assist in ejection.



Addressing poor demolding in injection molding requires a comprehensive approach, considering process parameters, material quality, release agent selection, and mold design. By carefully optimizing these factors and implementing the suggested solutions, manufacturers can achieve consistent, efficient ejection and produce high-quality molded parts.

塑料注塑成型已成為現代製造的基石，從汽車到消費電子產品提供了無與倫比的多功能性。 該綜合指南將OEM和初創企業與利用注入成型的基本見解相對，以實現有效，具有成本效益的生產。



注射成型簡介


注射成型通過具有高精度和可重複性的複雜零件的生產來徹底改變了製造。 它的優勢包括快速的生產率，最小的材料廢物以及塑造複雜的幾何形狀的能力，而其他方法將具有挑戰性或不可能。 在需要大規模生產相同零件的行業中，該過程特別受到青睞，例如汽車，電子，醫療設備和消費品。



過程概述


了解注射成型過程對於最大程度地提高其益處至關重要。 它始於設計和原型製作階段，其中使用CAD模型和快速原型製作技術（例如3D打印）來完善零件設計並確保生產性。 注射成型週期包括幾個階段：材料製備，注入黴菌腔，冷卻以固化零件和彈出。 每個階段都經過精心控制，以達到最佳的零件質量，最大程度地減少週期時間，並確保跨生產運行的一致性。



材料選擇


注射成型中的材料的選擇是廣泛的，從ABS和聚丙烯等商品熱塑性塑料到工程聚合物，例如聚碳酸酯和尼龍，甚至是高性能的材料，例如PEEK和ULTEM。 材料選擇以應用的特定要求為指導，包括機械性能（例如強度，剛度和抗衝擊力），耐化學性，環境條件和調節性。 添加劑（例如填充劑，增援部隊和著色劑）可以合併以增強材料性能並達到所需的美學品質。



設計指南


進行注塑成型的設計需要仔細考慮幾個因素，以優化零件的生產性和性能，同時最大程度地降低生產成本。 主要考慮因素包括:


草稿角度：確保足夠的草稿角（通常每側1-2度），以促進零件從模具中彈出。


均勻的壁厚：在整個零件中保持均勻的壁厚，以促進冷卻並最小化翹曲和下沉痕跡。


肋骨和老闆：使用肋骨以增加強度和boss，以輔助安裝點等功能，確保足夠的厚度和圓角半徑


防止應力濃度。



門控和跑步者的設計：優化門位置和跑步者設計，以最大程度地減少材料浪費並減少週期時間，同時確保甚至填充黴菌腔。


有效的設計實踐不僅提高了零件質量和一致性，而且通過減少廢料率和周期時間來促進成本節省。



工具和黴菌設計


模具的設計和製造是注入成型過程的關鍵方面。 根據生產量，零件複雜性和成本注意事項選擇不同類型的模具，包括單腔，多腔和家庭模具。 高級模具技術，例如熱跑者，保形冷卻系統和快速工具技術，可以提高生產力和零件質量。 設計工程師和模具製造商之間的合作努力確保黴菌對性能，耐用性和易於維護的優化進行了優化。



質量控制


保持嚴格的質量控制措施對於確保零件始終符合規格和監管標準至關重要。 質量控製過程包括:



維度分析：使用精確測量工具來驗證關鍵維度和公差。


視覺檢查：檢查零件是否表面缺陷，化妝品缺陷和模具閃光燈。


功能測試：執行功能測試以在模擬操作條件下驗證零件性能。


統計過程控制（SPC）：實施SPC技術來監視過程變異性並確保過程穩定。


通過在整個生產過程中整合強大的質量控製程序，製造商可以實現具有最小缺陷和返工的高質量零件，從而提高客戶滿意度並降低整體成本。



費用考慮


有效管理成本對於確保市場競爭力至關重要。 注塑成型的成本結構包括:


工具成本：對模具設計和製造的預投資，受黴菌複雜性，材料選擇和生產量的影響。


材料成本：基於數量要求和材料規格的原材料採購。


人工成本：與機器操作，零件檢查和組裝有關的直接勞動力。


間接費用：間接費用，例如設施維護，公用事業和行政費用。



優化成本效率的策略包括:


製造性設計（DFM）：設計易於且成本成本的零件 - 在不損害性能的情況下製造有效。

精益製造實踐：通過持續改進的計劃來最大程度地減少廢物，提高過程效率並減少週期時間。

供應商合作：與可靠的供應商合作，以獲取原材料，工具組件和輔助設備，以協商有利的定價和條款。



了解產品生命週期的總擁有成本（TCO）有助於製造商做出明智的決定，使成本考慮與質量和績效要求保持平衡。