Have you ever encountered this frustrating problem?

You bought the best machines, used top-secret formulas, but the extruded films are riddled with fisheyes, uneven in thickness, or inexplicably deteriorate and discolor? Waste piles up, and your profits are practically wasted!

Hey, stop blaming the raw materials, and stop firing your technicians.

Today, I’m going to uncover the “hidden killer” inside the extruder—the cooling system. Choosing the right cooling method will unlock your machine’s full potential, allowing it to perform at its best. Choosing the wrong one will only turn it into a money-guzzling monster.

If you want to survive and succeed in this highly competitive industry, you must master the art of “cooling and heating.”

Step 1: Understanding the Two Mainstream Cooling Methods—Avoid Being Misled

When it comes to cooling methods, there are only two main types on the market: “air cooling” and “water cooling.” There is no absolutely “best” solution, only the “solution best suited to your business.”

“Air-cooled”: An economical and easy-to-maintain “old-school” solution

Think of it as “air drying.” It uses a fan to blow heat away from the tank.

Key advantages: Low price, robust and durable, low maintenance costs.

No need to build cooling towers or lay piping; even water treatment equipment is unnecessary.
Maintenance is extremely simple—just wipe off the dust. No need to worry about freezing in winter, rusting in summer, or leaks.

Suitable scenarios:

Laboratory/sampling equipment: For low-volume applications such as R&D and testing, air cooling is perfectly adequate.
Heat-sensitive materials (e.g., PVC): These materials are delicate and easily damaged, sensitive to both cold and heat. Air cooling is gentle and won’t cause them to “cold out” and decompose.
Small businesses/startups: Every penny invested in the equipment is crucial. Recouping costs is key.

“Water-cooled”: The high-yield, stable “dominant force”

It can be understood as “ice-cooled.” It achieves forced heat dissipation through a “jacket” that circulates water around the cylinder.

Key Advantages: Rapid cooling, precise control, high-end performance.

Water has a very high specific heat capacity. Its heat dissipation efficiency is far higher than that of air.
You can precisely control the temperature, achieving extremely high accuracy and minimal fluctuations.

Case Studies:

Large factories/24/7 operation: Large machines generate enormous amounts of heat. Air cooling simply cannot suppress the heat; you need water cooling to “physically suppress” the heat.
High-difficulty materials (e.g., nylon PA, PET): These materials have very high processing temperatures and shear heat. If the temperature is not strictly controlled, the product will definitely be scrapped.
Pursuing ultimate quality: If you are producing high-end aseptic packaging or optical films, where even a single fisheye is unacceptable, then the precise control of water cooling will significantly improve your product yield.

Step Two: Little-Known Facts

If you think cooling is merely cooling the “cylinder,” then you are only seeing the surface.

True industry leaders always focus on a more hidden aspect when choosing configurations—internal screw cooling (core cooling).

The logic is simple: if the human body’s internal temperature is very high (shear heat), then blowing a fan on the outside (surface cooling) is useless.

Pain Point: Plastic generates extremely high “shear heat” when squeezed and rubbed inside the screw. If this heat isn’t dissipated from the screw’s interior, the surface temperature may appear normal, but the internal material is on the verge of combustion.
Winning Strategy: If you’re processing high-viscosity materials or pursuing maximum output, an internal screw cooling configuration is a must. This is the “nuclear button” for increasing productivity. It allows your machine to operate at high speeds without damaging the material.

Final Advice:

Stop making decisions impulsively in the meeting room! Take out your books and consider these two paths:

If you are a “conservative and profit-driven” company: You mainly produce ordinary shopping bags, PVC pipes, or have limited funds.

Preferred Choice: Air-cooled system. You save not only on equipment costs, but also on decades of maintenance hassles, water bills, and stress. If you are an industry leader or a tech whiz: You focus on high-end films and barrier materials, or are setting up a fully automated 24/7 production line.

Preferred option: Water cooling system (or even oil cooling). This is not an expense, but an investment. Precise temperature control is your profit protector. Every 1% reduction in scrap rate means pure profit!