How Are Silicone Hoses Made

How Are Silicone Hoses Made

Preparing the Silicone Rubber:

The first step is obtaining the raw silicone material, which typically arrives as a thick, dough‑like compound. Manufacturers then mix in several components to achieve the desired properties:

  • Pigments – to create specific colour options
  • Curing agents – either peroxide‑based or platinum‑based, depending on the required curing method
  • Additives – to enhance heat resistance, oil resistance, and chemical stability

These ingredients are thoroughly kneaded together in large industrial mixers until the silicone becomes completely uniform.

Cutting & Preparing Fabric Reinforcement:

The next stage involves preparing the reinforcing fabric, which provides the hose with its structural strength. Common reinforcement materials include polyester, aramid, or fiberglass, chosen based on the hose’s required performance level.

The fabric is typically:

  • Cut into strips to match the required hose diameter
  • Sometimes pre‑treated with a primer, allowing the silicone to bond more effectively
  • Sized according to the hose’s intended pressure rating, ensuring the correct strength and flexibility

Adding additional layers of reinforcement increases the hose’s pressure-handling capability—the more layers applied, the higher the potential operating pressure.

Building The Hose On A Mandrel

The hose construction process takes place on a metal bar called a mandrel. The mandrel acts as the internal mould, defining the hose’s inside diameter, shape, and overall geometry. This ensures the finished hose has the correct form based on its specific design requirements.

Manufacturers build the hose by applying alternating layers in a precise sequence:

  1. Silicone rubber sheet
  2. Reinforcing fabric layer
  3. Silicone rubber sheet
  4. (Repeat as required for strength, pressure rating, and flexibility)

Each layer is carefully wrapped to prevent air bubbles, wrinkles, or misalignment—any of these defects could lead to weak points or failures during later quality testing.

For more complex hose shapes such as elbows, reducers, or multi‑angle bends manufacturers use flexible mandrels or multi‑part mandrel systems. These specialised mandrels allow silicone to be built up in complex geometries while still maintaining accurate internal dimensions.

Consolidation (Removing Air & Smoothing)

After the builder completes the final silicone and fabric layer, the hose moves on to the tape‑wrapping stage. At this point, the entire hose—still on the mandrel—is tightly wrapped with cellophane or nylon pressure tape. This step is essential for both structural integrity and appearance.

The tape serves several important functions:

  • Compresses the layers to ensure the silicone and reinforcement bond properly
  • Forces out trapped air, preventing voids or weak spots inside the hose wall
  • Creates a smooth exterior finish, improving both aesthetics and performance

This compression process is crucial for strength, durability, and the professional finish expected from a high‑quality silicone hose.

Curing (Vulcanisation)

Once the hose is fully wrapped and smoothed, it is placed into a curing oven, typically set between 150–200°C depending on the silicone formulation and the curing system used (peroxide‑cure or platinum‑cure).

During curing, the heat:

  • Cross‑links the silicone polymer chains, transforming the soft, uncured material into a strong elastic structure
  • Gives the hose its final flexibility, heat resistance, and mechanical strength
  • Permanently bonds all layers together, locking the silicone and reinforcement fabric into a single unified wall

This step is essential—without proper curing, the hose would not hold its shape, pressure rating, or durability.

Removing the Tape & Mandrel

Once the curing process is complete, the builder removes the outer tape wrapping and carefully extracts the hose from the mandrel. For straight hoses, this is typically done by simply sliding the hose off the mandrel. However, for more complex geometries—such as elbows, reducers, or multi‑angle designs—the mandrel may need to be disassembled, collapsed, or flexed to allow for safe removal without distorting or damaging the finished hose.

Cutting & Finishing

Once the hose has been removed from the mandrel, it undergoes the final finishing stages. The excess silicone at the ends is trimmed cleanly to ensure accurate dimensions and a neat appearance. Each hose is then carefully inspected for any flaws, defects, or irregularities that may have occurred during building or curing.

After inspection, the hose is subjected to a pressure test, verifying that it can safely withstand its intended operating pressures without leaking, blistering, or deforming. Only hoses that successfully pass this test are approved for use and deemed safe for sale.

 

We also have a video from a our parent company on youtube that goes through the process : Click Here

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