Professional Analysis of Daqing 18D0 LDPE: Ideal Resin for Coating and Foaming Processing
Many factory workers cannot tell the difference between high-pressure LDPE and linear LLDPE in actual use. They often use Daqing 7042 blown film resin to replace professional coating and foaming materials. This wrong matching causes many production problems, such as coating pinholes, collapsed foam holes, paper-plastic separation and large-area defective products. Daqing Petrochemical 18D0 is a special high-pressure kettle-process LDPE. Its product positioning is completely different from Daqing 7042 for blown film and Daqing 8320 for high-flow injection. This resin has rich long-chain branched structures. It provides high melt elasticity, uniform ductility and stable low-temperature toughness, and meets food-grade safety standards. It is the core raw material for three mainstream processes: paper-plastic extrusion coating, buffer foam molding and light composite film production.
Core Drawbacks of Improper LLDPE Application
LLDPE is dominated by short branched chains with very few long branched chains. Its high-temperature melt elasticity is much weaker than traditional high-pressure LDPE. When used for high-speed coating production, insufficient melt tension cannot form continuous and uniform coating layers on 300 m/min high-speed machines. It leaves a lot of pinholes and uneven coating thickness, which directly damages the waterproof performance of finished products. During foaming production, LLDPE has no effective strain hardening ability. Foam bubbles are easy to break and merge, forming many open holes. The finished foam has poor compression resilience and cannot be used for precision product buffer packaging. Its low-temperature performance is also unstable. Composite products are easy to delaminate during cold chain transportation and outdoor storage in northern areas. Besides, LLDPE has poor adhesion with paper. Factories need to add a large amount of tackifier, which keeps raising long-term formula costs.
Unique Core Advantages of Daqing Petrochemical 18D0
Daqing 18D0 is produced through high-pressure free radical polymerization. The resin contains a large number of long-chain branched structures. Its low-flow characteristic keeps melt strength stable under high-temperature shearing. It fully adapts to high-speed extrusion coating and foaming processes. The material remains flexible in low-temperature environments and will not harden or crack easily. The original virgin pellets have extremely few fish eyes and impurities. The product is non-toxic and odorless, and meets food contact standards. It can be safely used for bakery and dairy waterproof coating paper bags. During foaming processing, stable melt tension locks tiny and uniform bubble holes. It forms high closed-cell foam with strong compression resistance and no permanent deformation. Complete physical data and national standard test reports are available on the official Daqing Petrochemical 18D0 product details page.
Three Applicable Processes & Application Limitations
High-speed paper-plastic coating is its main application. It is suitable for single-sided coating on kraft paper and non-woven fabrics, widely used in food paper bags, waterproof express bags and fertilizer lining paper. It matches 300 m/min high-speed production equipment. The recommended barrel temperature is 160–180℃, and the die head temperature is 170–190℃. It can form smooth and pinhole-free coating with strong heat sealing performance, and effectively reduce tackifier usage.
For EPE buffer foam production, it can be used as single raw material with stable processing temperature at 160–180℃ to produce fine and high-elasticity foam. Factories can also mix it with a small amount of LLDPE for formula modification.
For light composite shrink film, it can be blended with HDPE and LLDPE to improve film surface smoothness and heat sealing performance.
Due to its low MFR and high melt strength characteristics, Daqing 18D0 is not suitable for thin-wall injection molding. It cannot independently produce high-rigidity heavy-duty film. If higher hardness is required, users can mix it with HDPE for production.
Procurement & On-Site Production Guidelines
Store the three Daqing resin grades separately. Do not replace each other arbitrarily. Daqing 7042 is for ordinary blown film production. Daqing 8320 is for thin-wall injection molding and masterbatch carrier. Daqing 18D0 is specially used for coating and foaming processes.
Keep the proportion of Daqing 18D0 above 70% in foam formulas. Excessive addition of high-flow resin will destroy the foam pore structure and reduce product elasticity.
Do not keep die head temperature above 200℃ for a long time during coating production. High temperature will precipitate low-molecular substances and fail food contact safety standards.
Choose original virgin pellets for formal production. Recycled LDPE has unstable melt strength and easily causes large-scale defective products.
Summary
Daqing 7042 focuses on large-scale blown film production. Daqing 8320 is mainly used for injection molding and material modification. As a mature high-pressure LDPE grade for coating and foaming, Daqing 18D0 solves two major industry problems: paper-plastic delamination and foam bubble collapse. It has high melt elasticity, low fish eye content and excellent low-temperature resistance. It is the ideal raw material for extrusion coating, buffer foam and food-grade paper-plastic packaging. It ensures stable mass production and controls comprehensive material costs. You can contact our technical team for segmented processing temperature parameters, foam blending formulas and sample quotations.
