Raw materials preparation
The process starts with PEX and EVOH resin pellets. Additives and stabilizers are mixed in. The materials are dried to remove moisture. PEX EVOH pipes begin with high-quality raw materials.
PEX extrusion
The PEX resin is melted in an extruder. The molten PEX is pushed through a die. This forms the inner and outer layers. PEX EVOH pipes have PEX layers formed by extrusion.
EVOH extrusion
EVOH resin is melted in a separate extruder. It is fed into a co-extrusion die. This creates the middle barrier layer. PEX EVOH pipes have the EVOH layer formed by extrusion.
Adhesive application
Adhesive layers are extruded between the PEX and EVOH. They bond the layers together. The adhesive ensures layer adhesion. PEX EVOH pipes have strong layer bonding.
Co-extrusion process
All layers are extruded simultaneously. A specialized die forms the multi-layer pipe. The layers bond together in the die. PEX EVOH pipes are formed in one co-extrusion step.
Crosslinking (PEX formation)
PEX crosslinking occurs during or after extrusion. This creates the durable PEX structure. Methods include peroxide or moisture cure. PEX EVOH pipes are crosslinked for strength.
Cooling and sizing
The extruded pipe is cooled in a water bath. It passes through sizing dies to set dimensions. The pipe is pulled through the line. PEX EVOH pipes are cooled and sized precisely.
Marking and printing
The pipe is marked with product information. This includes size, pressure rating, and standards. Markings are applied during production. PEX EVOH pipes have clear markings.
Cutting and packaging
The continuous pipe is cut into lengths. Standard lengths are 4-6 meters. The pipe is packaged for shipment. PEX EVOH pipes are cut and packaged.
Quality control testing
Samples are tested for strength and dimensions. Oxygen permeability is measured. Pressure testing ensures quality. PEX EVOH pipes undergo rigorous testing.
Example: co-extrusion line
A factory operates a co-extrusion line. PEX and EVOH are fed into the extruders. A 5-layer pipe is produced continuously. PEX EVOH pipes are manufactured efficiently.
Final manufacturing summary
PEX EVOH pipes are manufactured by co-extrusion. PEX and EVOH resins are melted separately. Adhesive layers bond the materials together. All layers are formed simultaneously in a die. The pipe is cooled, sized, and marked. Quality control ensures product standards. PEX EVOH pipes are produced in a continuous, efficient process. Example: a modern, high-quality manufacturing process.