PE-Dow LDPE 722
PE-Dow LDPE 722は、Dow社が製造する高柔軟性低密度ポリエチレンホモポリマーで、密な結晶パッキングを防ぐ高度に分岐した分子構造が特徴です[1]。密度0.920 g/cm³、メルトインデックス8.0 g/10分を備え、高柔軟性キャップ、スナップオン蓋、医療用スクイズ包装の世界的ベンチマークです[2]。Jucheng Precisionは、ISO 9001およびIATF 16949認証システムを活用し、Dow 722の成形に優れ、優れたシール完全性を実現します。35台以上の最新鋭射出成形機と自社製金型により均一な肉厚を確保し、LDPEの高い収縮率（1.5%〜2.5%）をヒケなしで管理します。.
Dow LDPE 722 Mechanical and Flexibility Profile
DOW™ LDPE 722 is a broad molecular weight distribution homopolymer designed to offer maximum structural flexibility and impact resistance under low-load applications:
| Physical & Elastic Attribute | Dow 722 Nominal Value | 成形および最終用途の利点 |
|---|---|---|
| Structural Flexibility | Durometer Hardness 43 Shore D | Ensures a highly bendable, soft-touch material behavior, perfectly suited for snap-on lids, flexible containers, and squeezable caps. |
| Low-Temp Toughness | 脆化温度 -60°C | Maintains exceptional mechanical toughness and ductility in deep-freeze environments, avoiding brittle failure in frozen food packaging. |
| Melt Processability | Melt Flow Rate (MFR) 8.0 g/10 min | Features high flowability under low shear, allowing molten plastic to fill complex closure channels easily under reduced pressure. |
Elastomeric and Closure Process Adaptability for LDPE 722
With a low melting point (107°C), Dow LDPE 722 cools rapidly, supporting high-speed production cycles for seal-critical products:
| Process Application | 成形適合性と実施詳細 |
|---|---|
| Flexible Caps & Snap-Lids | Excellent. Fully optimized for high-volume flexible cosmetic jar lids, secure snap-fit closures, and squeezable food caps. |
| Overmolding Substrates | Good. Can be molded over high-density structural polymers to provide localized flexible seals or dynamic sealing lips. |
| Co-Injection & Multi-Cavity | Excellent. Stable flow behaviors at low melt temperatures reduce energy consumption and shorten cycle times on multi-cavity runs. |
PE-Dow LDPE 722 Tooling & Shrinkage Management Guide
Dow LDPE 722 features highly branched polymer chains, resulting in unique shrinkage behaviors that demand specialized mold design:
- Managing High Volumetric Shrinkage: Due to its low crystallinity, LDPE exhibits a high mold shrinkage rate of 1.5% to 2.5%. Jucheng’s tooling engineers conduct rigorous DFM flow simulations to balance gate pressure, ensuring uniform packing to prevent dimensional sink marks.
- Low Melting Point Thermal Profiling: Because the melting temperature is low (107°C), processing melt temperatures are kept at 170°C–210°C (338°F–410°F). Cold mold temperatures (15°C–40°C / 59°F–104°F) are strictly maintained using water chillers to ensure quick solidifying.
- Ejection & Mold Release: Because molded LDPE 722 is highly flexible and slightly sticky when warm, deep ribs require polished draft angles (minimum 1.5°) and wide ejector pads. We use S136 stainless steel mold cavity inserts to prevent part scuffing.
- Living Hinge & Seal Design: The high elongation at break (500%) allows for molded-in flexible hinges. Our 5-axis CNC machining center cuts precise gates perpendicular to the flex axis to maximize mechanical tear resistance.
Key Application Fields for PE-Dow LDPE 722
- Consumer Goods & Closures: Flexible squeeze-bottle caps, soft snap-on container lids, dynamic dust plugs, and protective caps.
- Medical Device Packaging (ISO 13485 Compliant): Flexible syringe tip caps, squeezable vial dropper tips, medicine container covers, and sterile packaging barriers.
- Industrial Seals: Low-pressure dynamic sealing gaskets, chemical-resistant soft washers, expansion plugs, and wire terminal boots.
プロパティ
| 密度 | 0.918 - 0.920 g/cm³ |
| メルトマスフローレート（MFR）（190°C/2.16kg） | 8.0 g/10分 |
| 降伏点引張強度 | 8.3 MPa |
| 引張破断伸び | 500 % |
| 曲げ弾性率 | 220 MPa |
| Durometer Hardness (Shore D) | 43 - |
| 融点（DSC） | 107 °C |
| Peak Crystallization Temperature | 95.6 °C |
| ビカット軟化温度 | 87.8 °C |
| Deflection Temperature Under Load (66 psi) | 37.2 °C |
| Brittleness Temperature | -60.0 °C |
| 線形成形収縮率 | 1.5 - 2.5 % |
| 最大部品サイズ | 800 x 600 mm |
| 最小部品サイズ | 1 x 1 mm |