PE, or Polyethylene, is one of the most versatile and widely used thermoplastic polymers globally. At Kaxite Sealing, we specialize in engineering high-performance PE materials and sealing solutions that meet the most demanding industrial specifications. This guide provides a detailed technical overview of our PE products, their key parameters, and answers to common questions, crafted to serve procurement managers, engineers, and industry professionals.
**Understanding Polyethylene: Types and Grades**
PE is categorized primarily by its density and branching, which dictate its mechanical properties and applications. Kaxite Sealing offers a comprehensive range.
* **HDPE (High-Density Polyethylene):** Known for its high strength-to-density ratio, rigidity, and excellent chemical resistance. Ideal for high-pressure piping, chemical tanks, and geomembranes.
* **MDPE (Medium-Density Polyethylene):** Offers a balance of good stress-cracking resistance and stiffness. Commonly used for gas pipes, fittings, and packaging films.
* **LDPE (Low-Density Polyethylene):** Characterized by its high ductility, flexibility, and transparency. Perfect for squeeze bottles, plastic bags, and various coatings.
* **LLDPE (Linear Low-Density Polyethylene):** Similar to LDPE but with superior tensile strength, impact, and puncture resistance. Widely used in stretch films, covers, and flexible tubing.
**Technical Parameters of Kaxite Sealing PE Products**
Our materials are manufactured to precise standards, ensuring consistency and reliability. Below are the critical parameters we control.
**Key Physical & Mechanical Properties:**
* **Density:** Ranges from 0.915-0.941 g/cm³ (for LDPE/LLDPE) to 0.941-0.965 g/cm³ (for HDPE). Directly influences stiffness and barrier properties.
* **Melt Flow Index (MFI):** Measures the ease of flow of the polymer melt. A lower MFI indicates higher molecular weight and better mechanical strength. Our grades range from 0.1 g/10min (for high-strength applications) to 50+ g/10min (for high-speed injection molding).
* **Tensile Strength at Yield:** HDPE can exhibit values from 20-30 MPa, demonstrating its robustness for structural parts.
* **Elongation at Break:** Often exceeds 600% for LDPE/LLDPE, highlighting exceptional flexibility and durability.
* **Hardness (Shore D):** Typically between D50-D65 for HDPE, indicating good resistance to indentation.
* **Melting Point:** Approximately 105-135°C, varying with the grade and crystallinity.
**Chemical & Environmental Resistance:**
* **Excellent resistance to:** Most acids, alkalis, salts, alcohols, and polar solvents.
* **Poor resistance to:** Strong oxidizing acids, certain hydrocarbons, and halogenated solvents.
* **UV Stabilization:** We offer additive packages with UV inhibitors for outdoor applications to prevent degradation and extend service life.
* **Temperature Range:** Suitable for continuous use from -50°C to +80°C, with specific high-temperature grades exceeding +100°C for short periods.
**Detailed Product Specification Table**
The following table outlines the standard specifications for several flagship PE grades from Kaxite Sealing.
| Grade Code |
Type |
Density (g/cm³) |
MFI (g/10min) |
Tensile Strength at Yield (MPa) |
Primary Applications |
| KS-HDPE 100 |
High-Density |
0.955 - 0.962 |
0.25 |
28 |
Pressure pipes, large blow-molded containers |
| KS-HDPE 200 |
High-Density |
0.948 - 0.955 |
8.0 |
24 |
Injection molded fittings, crates, pallets |
| KS-LLDPE 500 |
Linear Low-Density |
0.918 - 0.922 |
2.0 |
22 |
Stretch film, heavy-duty sacks, flexible hoses |
| KS-LDPE 700 |
Low-Density |
0.921 - 0.925 |
4.0 |
14 |
Extrusion coatings, flexible lids, cable sheathing |
| KS-MDPE 300 |
Medium-Density |
0.930 - 0.938 |
0.8 |
20 |
Gas distribution pipes, carrier bags |
**Processing Guidelines for PE**
Proper processing is vital to achieving the optimal performance of the final product.
* **Drying:** Typically not required due to low moisture absorption. However, for critical applications or after prolonged storage, drying at 70-80°C for 1-2 hours is recommended.
* **Injection Molding:**
* Melt Temperature: 200-280°C
* Mold Temperature: 20-60°C
* High injection speeds are suitable for thin-walled parts.
* **Extrusion:**
* Melt Temperature: 180-240°C
* Screw Design: Use a screw with a long feed section and a compression ratio of 3:1 to 4:1.
* **Blow Molding:**
* Parison control is crucial. Our grades offer excellent parison strength and melt strength for consistent wall thickness.
**PE FAQ: Common Questions Answered**
What are the main advantages of using PE from Kaxite Sealing?
Kaxite Sealing PE grades are formulated for consistency, reliability, and specific performance characteristics. Our advantages include superior lot-to-lot uniformity, enhanced additive packages for UV and environmental stress crack resistance (ESCR), and tailored MFI ranges for optimized processing. We provide full technical data sheets and material traceability.
How do I choose between HDPE and LDPE for my application?
The choice depends on required properties. HDPE offers higher rigidity, tensile strength, chemical resistance, and is preferable for rigid containers, pipes, and structural parts. LDPE provides superior flexibility, clarity, and impact resistance at low temperatures, making it ideal for films, squeezable bottles, and applications requiring sealing. Kaxite Sealing technical support can help you select the correct grade.
What is Environmental Stress Cracking Resistance (ESCR) and why is it important?
ESCR is the susceptibility of a plastic part to crack or fail under the combined influence of a stress (internal or external) and a chemical agent (like a detergent or surfactant). It is a critical long-term failure mode for containers, caps, and pipes. Kaxite Sealing offers specific high-ESCR grades of HDPE, especially for bleach bottles, detergent containers, and chemical storage applications.
Can PE be used for outdoor applications?
Yes, but standard PE degrades under prolonged exposure to ultraviolet (UV) radiation from sunlight, becoming brittle. Kaxite Sealing produces UV-stabilized PE grades containing carbon black or specialized HALS (Hindered Amine Light Stabilizer) additives. These grades are essential for geomembranes, outdoor furniture, playground equipment, and exterior piping to ensure a long service life.
Is PE recyclable?
Absolutely. PE is identified by resin identification code #2 (HDPE) and #4 (LDPE/LLDPE). It is one of the most commonly recycled plastics. Kaxite Sealing is committed to sustainability and offers selected grades containing post-industrial recycled (PIR) content upon request, supporting circular economy initiatives without compromising key performance parameters.
What is the typical lead time for ordering specialty PE grades from Kaxite Sealing?
For our standard stocked grades, lead times are typically 1-2 weeks. For custom-compounded materials with specific color or additive requirements, the lead time can range from 4-6 weeks to allow for formulation, testing, and production. Our sales team provides accurate timelines based on current production schedules and order volume.
How does the Melt Flow Index (MFI) affect processing and final part properties?
MFI is inversely related to molecular weight. A low MFI material has high viscosity and is tougher, making it suitable for processes like blow molding or sheet extrusion where melt strength is needed. A high MFI material flows easily, filling intricate molds quickly, which is perfect for thin-walled injection molding. Choosing the wrong MFI can lead to processing difficulties or parts with inadequate strength.
Does Kaxite Sealing provide material certifications?
Yes. We provide full compliance certificates with each shipment, including Certificate of Analysis (CoA) detailing key parameters like density and MFI. We can also supply material certifications such as FDA compliance for food contact, NSF/ANSI 61 for drinking water system components, and other region-specific regulatory documents upon request and for qualifying grades.
What are the key considerations for designing a part in PE?
Consider wall thickness uniformity to avoid sinks and warpage. Incorporate generous radii on all corners to reduce stress concentration. Account for PE's relatively high coefficient of thermal expansion in designs with tight tolerances. For snap-fits and living hinges, utilize PE's flexibility by designing appropriate geometries. Our engineering team can assist with design for manufacturability reviews.
What is the difference between homopolymer and copolymer PE?
Homopolymer PE is made from ethylene monomers only. Copolymer PE, such as our MDPE and some HDPE grades, incorporates a small percentage of other alpha-olefins (like butene, hexene, or octene) as co-monomers. This creates short-chain branching, which improves properties like ESCR, toughness, and low-temperature impact strength compared to homopolymers of similar density.
