Fiberglass Variable Diameter Product Production Equipment

The production of fiberglass reducing products (such as reducing pipes, tapered covers, flared mouths, etc.) is a highly specialized field. These products cannot be produced using standard pultrusion processes, but instead rely on several specialized equipment and processes.

Core production equipment and processes

1. Turning/winding machine

This is the most commonly used and efficient equipment for producing fixed-length and rotary reducing products (such as pipe reducers).

Equipment principle : The machine integrates turning and winding functions. A contour arm (or CNC axis) drives resin and fiberglass guide wheels to reciprocate along a rotating variable-diameter mandrel .

Work style :

prefabricated variable diameter mandrel onto the main shaft of the equipment.

The spindle drives the core mold to rotate.

The contour arm precisely controls the distance between the guide wire head and the mandrel surface according to the diameter change of the mandrel, so as to achieve circling and spiral winding .

By adjusting the fiber angle and winding pattern, the strength and stiffness requirements of the product at different diameters can be met.

Advantages : High degree of automation, stable product quality, uniform fiber tension, and strong designability of strength.

Applicable products : reducing pipes/fittings of various specifications , rocket engine covers, conical towers, etc.

2. Centrifugal casting machine

It is mainly used to produce reducing pipes with extremely smooth inner surfaces .

Equipment principle : A mixture of resin and chopped glass fiber is sprayed into a rotating variable diameter mold . Under the action of centrifugal force, the material is pressed tightly against the inner wall of the mold and air bubbles are expelled, thereby forming a dense and smooth inner surface.

Advantages : The inner surface is smooth as a mirror, with excellent hydraulic performance; the product has good density and strong anti-leakage properties.

Disadvantages : High equipment investment and high mold costs, generally more suitable for mass production.

Applicable products : Drainage pipes and ventilation pipes with high requirements for smooth inner wall.

3. Continuous winding machine (special design)

This is the most advanced technology for producing infinitely long reducers ; the equipment is extremely complex and expensive.

Equipment principle : By dynamically adjusting the radial position of multiple winding units on the winding ring, the winding diameter is changed in real time on the continuously advancing tube blank, thereby realizing the continuous change of tube diameter.

Advantages : It can continuously produce reducing pipes just like producing equal-diameter pipes, with extremely high efficiency.

Disadvantages : The technology threshold is extremely high, the equipment is extremely expensive, and it is only mastered by a few top companies.

Applicable products : Large-diameter variable diameter pipes for ultra-long-distance transportation.

Auxiliary production equipment and manual crafts

For small-batch, large-size, or very uniquely shaped variable-diameter products, the following semi-mechanized or manual processes are still indispensable:

4. Manual/Jet Vacuum Guide System

This is a very flexible approach that is suitable for large, non- standard variable diameter products.

Required equipment :

Vacuum pump : The core component, which generates negative pressure.

Resin drainage tube, vacuum bag film : sealing system.

Guide net and release cloth : auxiliary materials.

Process :

on the variable diameter mold .

It is completely sealed with a vacuum bag film.

Start the vacuum pump to draw in the resin under negative pressure and completely impregnate the fiber.

Advantages : Relatively low mold cost, smooth product on both sides, high fiber content, and environmentally friendly.

Applicable products : large variable diameter covers (such as fan covers), ship hulls, and irregularly shaped variable diameter parts.

5. Traditional hand lay-up tools

The most basic and flexible method, suitable for samples, small batches or giant products .

Required equipment : Very simple, mainly rollers, brushes, resin mixing containers , etc.

Process : Workers manually lay fiber cloth on the reducing mold and apply resin with a roller, layer by layer.

Advantages : Almost unrestricted by product shape and size, with extremely low initial investment.

Disadvantages : Quality is highly dependent on worker skills, resulting in low efficiency, high labor intensity, harmful health effects from resin volatilization, and poor product quality consistency.

Core common equipment: molds

Regardless of the process used, the variable diameter mold is one of the most crucial pieces of "equipment".

Fiberglass molds : the most commonly used type, with moderate cost, suitable for small to medium batch production and large-scale products. High precision is required in their manufacture.

Metal molds (steel/aluminum) : used for centrifugal casting, molding or high-performance winding, with high precision and long service life, but also high cost.

Wooden molds/plaster molds : These are usually used as transitional master molds for making fiberglass molds , for single-piece or prototype production.