Hot-Cold Plastic Mixing Machine

Vertical type mixer unit

Horizontal type mixer unit

Product Overview

The hot mixing and cold mixing unit is a dual-tank integrated system designed for pre-processing plastic materials (e.g., PVC, PE, WPC composites) in extrusion and injection molding production. It combines high-temperature hot mixing (to homogenize raw materials, melt additives, and remove moisture) and low-temperature cold mixing (to quickly cool the mixture and prevent agglomeration)—addressing the problem of uneven material mixing and moisture-related defects (e.g., bubbles, surface pits) in traditional single-tank mixing. Equipped with a automatic material transfer system (between hot and cold tanks) and precise temperature control, this unit ensures consistent material quality across batches, making it a key pre-processing equipment in plastic processing industries.

Product Features

Hot Mixing Tank: Constructed with stainless steel 304 (corrosion-resistant and easy to clean) with capacity ranging from 50-500L (to match production scale). Heating is achieved via electric heating tubes (power 15-50kW) with temperature control up to 120-180℃—suitable for different plastic types (e.g., 120-140℃ for PVC, 160-180℃ for PE). The tank’s inner wall is polished to Ra ≤0.8μm to prevent material adhesion, and a high-speed impeller (1000-1500rpm) creates strong turbulence for efficient mixing.

Mixing Efficiency: The high-speed impeller’s optimized design (with inclined blades) promotes radial and axial material flow, ensuring complete homogenization of raw materials and additives in 5-10 minutes (30% faster than standard mixers). The hot mixing process also removes moisture from the material (reducing moisture content to ≤0.2%), eliminating bubbles in subsequent extrusion or molding.

Cold Mixing Tank: Jacketed cooling tank (with water or refrigerant circulation) offering cooling capacity 5-20m³/h. It quickly reduces the temperature of the hot mixture (from 180℃ to 40-60℃) to prevent material agglomeration (a common issue when hot materials are stored) and ensure easy handling. The cold tank is also equipped with a low-speed agitator (200-300rpm) to maintain material uniformity during cooling.

Control System: Adopts PLC control with a 5-inch touchscreen, enabling automatic transfer of materials from the hot tank to the cold tank (triggered by preset temperature or time). It supports storage of 10+ mixing recipes (including temperature, time, and speed parameters), allowing quick recall for different material formulas. The system also features fault alarm functions (e.g., over-temperature, low water pressure) to ensure safe operation.

Applications

PVC Material Preparation: Used for mixing PVC resin, plasticizers, stabilizers, and fillers (e.g., calcium carbonate) in the production of PVC pipes, profiles, and sheets. The hot mixing process ensures complete dissolution of plasticizers (reducing plasticizer migration in finished products) and uniform dispersion of stabilizers (extending the product’s heat resistance). The cooled mixture (at 50℃) can be directly fed into extruders without additional cooling time.

Masterbatch Mixing: Ideal for uniformly blending pigments, functional additives (e.g., anti-UV agents, flame retardants), and carrier resins (e.g., PE, PP) in masterbatch production. The high-speed hot mixing ensures that pigments are fully dispersed (dispersion degree ≥98%), preventing color streaks in downstream products (e.g., colored plastic films, injection molded parts). The cold mixing step stabilizes the masterbatch’s color and performance by preventing additive volatilization.

WPC Material Processing: Mixes wood flour, PVC resin, coupling agents, and foaming agents for the production of PVC WPC foam boards. The hot mixing process activates the coupling agent (improving the bonding between wood flour and PVC) and removes moisture from wood flour (reducing foam defects caused by moisture vapor). The cooled mixture (at 45℃) has good flowability, ensuring smooth extrusion of WPC boards.

FAQ

Q: What is the temperature control accuracy of the hot mixing tank?

A: The temperature control accuracy is ±2℃, achieved via PID temperature control technology—ensuring stable material properties (e.g., plasticizer content, moisture level) across different batches. For high-precision applications (e.g., medical-grade PVC), an optional temperature calibration function (using a standard thermometer) is available to further improve accuracy to ±1℃.

Q: How often does the mixing unit need cleaning?

A: It is recommended to clean both the hot and cold tanks every 3-5 batches when changing material types (e.g., from white PVC to black PVC) to avoid cross-contamination. Cleaning involves wiping the tank inner walls with a clean cloth (after cooling) and, for stubborn residues, using a mild solvent (e.g., ethanol) compatible with the tank material. For continuous production of the same material, cleaning can be extended to every 10 batches.