Pelletizing Components Since 1993
Pelletizing Die Plates for Underwater Pelletizing Systems
JINFENG manufactures customized die plates for underwater pelletizing systems in polymer production, including large PP and PE lines rated from 200,000 to 600,000 t/a. Each die plate is engineered against the customer drawing or sample, the extruder and pelletizer interfaces, the polymer, and the operating conditions.
How Die Plates Work in Underwater Pelletizing
The die plate forms the working interface between the polymer melt path and the cutting area of an underwater pelletizing system. Polymer melt passes through the die holes to the cutting side, where the pelletizing knives operate against the die face.
The die-hole arrangement, melt passages, heating channels, cutting-side features, and mounting interfaces must work together within the customer's equipment. For replacement projects, the existing component and its interfaces provide important reference information. For new requirements, the drawing and operating data establish the basis for technical discussion.
JINFENG focuses on die plates for plastics extrusion and pelletizing. The product information on this site is written for polymer producers, pelletizing-system manufacturers, maintenance teams, and industrial buyers working with underwater pelletizing equipment.
Die Plates for Large-Scale PP and PE Lines
Most of JINFENG's current die plate work is for world-scale polyolefin plants. In 2012 JINFENG designed and built a die plate for a 450,000 t/a polypropylene line at Tianjin Sinopec SABIC, at that time the largest die plate of its type. Since then the company has supplied die plates for PP and PE lines from 200,000 to 600,000 t/a, with diameters up to 1,570 mm and more than 7,500 die holes.
Large die plates have to hold uniform temperature across thousands of die holes. JINFENG uses thermal and melt-flow simulation to check heating-channel layout and reduce the risk of frozen holes before the plate is machined.
| Line capacity | Polymer | Extruder platform | Die plate (mm) | Die holes | First run |
|---|---|---|---|---|---|
| 600,000 t/a | PP | Coperion ZSK 380 | Φ1223 × 112.5 | 3,375 | 2023 |
| 500,000 t/a | PE | JSW CIM 510 | Φ1570 × 135 | 7,584 | 2025 |
| 450,000 t/a | PP | JSW CMP 387 | Φ1300 × 160 | 2,832 | 2012 |
| 450,000 t/a | PP | Coperion ZSK 380 | Φ1223 × 112.5 | 2,950–3,375 | 2021–2025 |
| 450,000 t/a | PE | Kobe LCM 500 / LCM 560 | Φ1430 × 165 | 4,652–4,850 | 2018–2024 |
| 450,000 t/a | PE | Coperion ZSK 350 | Φ1223 × 112 | 6,125 | 2016 |
| 400,000 t/a | PE | JSW CIM 460 | Φ1570 × 135 | 6,064–6,820 | 2021–2023 |
| 350,000 t/a | PP | DLRPM SJSHL-Z350 | Φ1150 × 130 | 2,400 | 2019–2020 |
Die-hole diameters on these plates are typically 2.5–2.8 mm for PP and 3.2–3.5 mm for PE. Suitability for a specific line is confirmed from the drawing, the existing plate or sample, and the interface data.
Polymer Application Experience
Our application experience includes PP, PE (HDPE, LDPE, LLDPE and full-density PE), EVA, POE, and EVOH. Customers can send an existing drawing, dimensional information, photographs, or a sample for technical evaluation.
JINFENG has supplied pelletizing die plates for applications involving:
- PP
- PE
- HDPE
- LDPE
- LLDPE
- EVA
- POE (polyolefin elastomer)
- EVOH
PP and PE die plates typically run in process water at 40–70 °C, while EVA and POE die plates run in chilled water at 7–15 °C. The plate must carry the melt pressure and also the thermal stress between the water-cooled face and the hot melt and heating medium inside it, so the hard face material and heating layout are selected for the polymer. Reference EVA, POE and EVOH die plates include 200,000 t/a EVA lines (Φ912–Φ1000 mm, 2,080–2,160 holes), 30,000–50,000 t/a POE lines, and 8,000 t/a EVOH lines.
Polymer grade, additives, processing conditions, and equipment configuration can affect the required die plate. Providing this information with the inquiry helps our team assess the request in the correct operating context.
Customized to Drawings, Samples, and Equipment Interfaces
Die plates are evaluated around the actual component and installation. The technical assessment may include:
- Overall dimensions and mounting interfaces
- Die-hole arrangement
- Melt-passage layout
- Heating-channel layout
- Die face and cutting-side features
- The condition and geometry of an existing sample
- Polymer and operating information relevant to the request
This approach supports both drawing-based manufacturing and evaluation of an existing sample when complete documentation is unavailable. Final dimensions and technical requirements are agreed for the individual order.
Die Plate Hard Face
The die plate hard face is the wear-resistant working area on the cutting side of the die plate. Its configuration is considered together with the die face, die-hole area, and operating requirements.
The hard face must resist wear from the knives, cavitation from the process water, and heat. JINFENG developed its own TiC-NiCr cermet, with a TiC hard phase and a nickel-chromium binder, which keeps its hardness up to about 800 °C and bonds well to a stainless steel die plate body. Hard faces are vacuum brazed in 1.5 m and 1.7 m vacuum furnaces.
Material selection and hardness requirements are defined for the specific component. Customers with an existing specification should include the material callout and any required inspection information in the inquiry.
| Hard face material | Hardness | Bending strength | Wear resistance | Corrosion resistance | Weldability to stainless body |
|---|---|---|---|---|---|
| WC-Co cemented carbide | 66–68 HRC | 2,000–2,500 MPa | Excellent | Limited | Difficult; higher cracking tendency |
| TiC-Fe steel-bonded carbide | 61–63 HRC | 1,400–1,500 MPa | Good | Moderate | Good; machinable |
| TiC-NiCr cermet (JINFENG-developed) | 60–62 HRC | 1,500–1,800 MPa | Excellent | Excellent | Good; low cracking tendency |
Manufacturing Capabilities
JINFENG's in-house manufacturing capabilities include:
- CNC machining, including a 2.5 m CNC gantry milling machine (0.01 mm)
- Die-hole drilling on five CNC double-head drilling machines (hole roundness 0.01 mm)
- Grinding on 1.2 m and 1.8 m circular-table grinders (parallelism 0.005 mm) and CNC fine grinding (0.002 mm)
- Ten wire-cutting (EDM) machines
- Vacuum brazing in 1.5 m and 1.7 m furnaces (3 × 10⁻⁴ Pa, ±2 °C uniformity)
- Vacuum sintering of JINFENG cermet materials, and heat treatment
These processes support the manufacture and finishing of pelletizing components based on customer drawings and agreed requirements. The process route is selected according to the component design and the agreed manufacturing scope.
Quality Inspection
Inspection requirements are established from the component drawing and order requirements. JINFENG's in-house inspection capabilities include:
- Dimensional inspection
- Hardness testing
- Die-hole inspection
- Surface inspection
- Heating-channel pressure and leak testing
- Flaw detection of the hard face and brazed joints
- Hard face temperature-uniformity testing
Ultrasonic testing (UT) can be arranged through a qualified third-party inspection provider when required for a specific project. Customers should identify any inspection or documentation requirement when requesting a quotation.
Related Pelletizer Knives and Cutter Hubs
JINFENG also supplies complete pelletizing knives ready for installation, together with customized pelletizer cutter hubs. A cutter hub is the circular hub or disc that mounts multiple knives, connects to the pelletizer shaft, and positions the knives relative to the die plate.
Cutter hubs can be supplied separately or together with pelletizing knives after the drawing, dimensions, interfaces, and operating conditions have been evaluated. JINFENG supplies complete pelletizing knives rather than individual blades. Pelletizer shafts and complete rotor assemblies are outside the current supply scope.
Die Plate Repair Assessment
Repair work begins with inspection and technical evaluation of the existing die plate. Depending on its condition, available operations may include cleaning, grinding or regrinding, hard face replacement, heating-channel repair, and pressure testing. Third-party UT can also be arranged when needed.
The repair scope is determined after reviewing wear, damage, remaining thickness, structural condition, and the condition of the heating channels.
Urgent damage can sometimes be handled on site. At a 200,000 t/a PP line, knife-to-plate contact after an overhaul left 50 high spots on the hard face; JINFENG technicians restored the surface on site in about five hours so the line could restart.
Information to Include with Your Inquiry
For an efficient initial assessment, send as much of the following information as is available:
- Existing drawing and revision
- Clear dimensions and interface details
- Photos of the complete die plate and relevant working areas
- Equipment manufacturer and model for component identification
- Polymer type and grade
- Operating conditions related to the request
- Required quantity
- Inspection or documentation requirements
- A description of wear or damage for a repair inquiry
If a drawing is unavailable, photographs and sample information can help establish the next steps.
Frequently Asked Questions
Can JINFENG manufacture a die plate from an existing drawing?
Yes. Send the drawing, revision, required quantity, polymer information, and relevant operating conditions for evaluation.
Can you evaluate an existing sample?
Yes. A sample can be evaluated together with available dimensions, photographs, equipment information, and operating data.
Which polymer applications do you have experience with?
Our supply experience includes PP, PE (HDPE, LDPE, LLDPE and full-density PE), EVA, POE, and EVOH applications. The requirements for a specific grade and process are discussed with the inquiry.
Can an existing die plate be inspected for repair?
Yes. Repair options are considered after inspection and technical evaluation of the component's condition.
What size die plates can JINFENG manufacture?
Reference die plates range from small plates of about Φ250 mm to Φ1570 mm plates with more than 7,500 die holes for 500,000 t/a PE lines. Send the drawing or sample so the specific size can be evaluated.
Which extruder platforms have you supplied die plates for?
Reference die plates have been supplied for lines built on Coperion ZSK, JSW CMP and CIM, Kobe LCM, Dalian Rubber & Plastics Machinery (DLRPM), and Basell-licensed platforms. Fit is confirmed from the drawing, sample, and interface data for each order.
Discuss Your Die Plate Requirement
Send your drawing, sample details, dimensions, and operating information for evaluation by JINFENG.
Contact: sales@dieplates.com WhatsApp: +86 133 0983 7263