Texin — PE material injection molding products built to tighter real-world tolerances

At Texin we run hundreds of PE jobs every year, so we speak from experience: PE parts look simple, but getting them right takes attention to details most vendors under‑estimate. If you’re shopping for PE material injection molding products, you’re likely worried about warpage, shrinkage, surface quality and repeatable cycles. Those are exactly the problems we design for.

What makes PE tricky (and why it matters)

• PE is crystalline with a melting range roughly 100–130°C. Because crystallinity controls final strength and shrinkage, mold temperature matters a lot.
• Shrinkage is large and directional: LDPE about 1.22%, HDPE about 1.5%. That kind of anisotropic shrinkage causes warpage unless cooling and gate strategy are right.
• PE absorbs almost no moisture (<0.01%), so drying is not normally required — but the melt oxidizes easily, causing discoloration or surface streaks if not handled.
• PE has a fairly high specific heat, so plasticizing needs real heating power; we commonly run LDPE barrels in the 140–200°C band (rear zone lower, front zone higher) and HDPE around 220°C. For high‑molecular‑weight grades we use 200–250°C melt zones.
• The melt flows well and is not strongly shear‑sensitive (non‑Newtonian effects are mild), but it cools slowly — good, uniform cooling is essential. We recommend cooling channels ≥ 8 mm diameter with spacing so the channel center is within 1.3×d of the cavity surface.

Questions our customers actually ask (and short, data‑backed answers)

Q — Will my PE part warp? How much shrinkage should I expect?
A — Yes, warp is a top risk. Expect LDPE ≈ 1.22% shrink and HDPE ≈ 1.5%, and note the shrinkage is directional. Uneven mold cooling or a poor gate location will amplify warpage.

Q — Do I need to dry PE pellets before molding?
A — No. PE absorbs <0.01% moisture, so with normal storage you can skip drying. That said, contamination or long open exposure still causes quality issues, so keep material handling disciplined.

Q — What barrel and mold temperatures should I ask for on the quote?
A — Typical practice: LDPE barrel/melt zones 140–200°C (rear lower, front higher); HDPE ~220°C; general melt ranges for many PE grades sit between 220–260°C, with very high‑MW grades processed around 200–250°C. Mold temps: LDPE ~30–45°C, HDPE ~10–20°C higher. Thin walls (≤6 mm) usually benefit from the higher end of mold temperature.

Q — What injection pressure do you recommend?
A — PE flows very well; we run moderate pressures: 50–100 MPa in most cases. Thin‑wall or very long flow parts may need higher pressures; thick simple parts can use lower pressure to reduce clamp strain.

Q — How do you avoid surface discoloration and melt oxidation?
A — Minimize melt residence time, use short hot‑runner/nozzle designs, or positive shut‑off nozzles. For visual parts we specify antioxidants and tighter melt handling. Remember: PE oxidizes easily in the melt, so design to limit air contact.

Q — Can I use recycled PE in production parts?
A — You can — PE is highly recyclable — but recycled material changes crystallinity and shrinkage. Expect dimensional and mechanical shifts; we recommend trials and controlled blends rather than 100% unknown regrind for critical parts.

Q — What mold design features are most effective for PE material injection molding products?
A — Balanced, robust cooling (channels ≥ 8 mm and within 1.3×d of the cavity), gates that avoid direct filling into thin ribs, and ejection strategies for soft parts (PE parts demold easily, but shallow side features may need stronger, controlled ejection). Also avoid direct sprue injection into sensitive thin sections to reduce internal stress.

Q — Is PE thermally stable during processing?
A — Generally yes — PE shows no significant decomposition below ~300°C. Normal processing windows are safe from thermal degradation, but oxidation at melt temperatures can still affect surface finish and color.

Why Texin is the right partner for PE material injection molding products

• We tune barrel and mold temperature profiles to the resin and geometry (LDPE, HDPE, high‑MW grades).
• Our molds are built for balanced cooling and controlled crystallization (cooling channel specs we use: Ø ≥ 8 mm, spacing per 1.3×d rule).
• We configure machines with the heating capacity to handle PE’s higher heat‑absorption during plasticizing, keeping cycles competitive.
• We design gates and runner systems to reduce internal stress, and we offer material handling practices to minimize melt oxidation.
• We validate parts with dimensional checks against expected LDPE/HDPE shrink rates (1.22% / 1.5%) and run warpage trials before production.

Summary：

PE material injection molding products are deceptively demanding: the resin flows easily but final part quality hinges on crystallization control, uniform cooling and smart gate/ejector design. At Texin we combine hands‑on tooling, tuned processing parameters and real shop‑floor experience to reduce warpage, control shrinkage (LDPE ≈1.22%, HDPE ≈1.5%), and protect part appearance from oxidation. If you need consistent PE parts at scale, contact Texin for a chat — we’ll review your part geometry, recommend barrel/mold temperatures, and outline the cooling and gate strategy that will give you repeatable parts.

● Many years of mold design, development and manufacturing experience

● Pursue excellence and cast high quality

● High quality, high efficiency and high precision

● Take the initiative to provide timely, fast and dynamic customer service