Question 1

What is a multilayer coextrusion blow molding machine?

Accepted Answer

A multilayer coextrusion blow molding machine simultaneously extrudes 2–6 layers of different resins through a single multi-layer die head, forming containers with layered wall structures. Each layer serves a specific function — structural HDPE, oxygen-barrier EVOH, chemical-resistant PA, or recycled regrind core.

Sailwin machines use a FIFO die head that keeps each resin in strict flow sequence, eliminating dead zones.

Question 2

What is the difference between 2-layer, 3-layer and 6-layer coextrusion?

Accepted Answer

2-layer coextrusion (DT) typically uses HDPE outer + regrind or HDPE inner, reducing material cost by using recycled material in the core. 3-layer coextrusion (TH) adds an EVOH or PA barrier layer between two HDPE layers — this provides oxygen and chemical permeation resistance for food, pharma and agrochemical applications. 6-layer coextrusion adds tie layers to bond incompatible resins (e.g. HDPE / tie / EVOH / tie / HDPE / regrind) — used in automotive fuel tanks and high-performance barrier containers. Sailwin supplies machines for all configurations.

Question 3

What is a FIFO die head and why is it important?

Accepted Answer

FIFO (First-In-First-Out) die head design keeps resin flowing in a strict first-in-first-out sequence through the die channels, eliminating dead zones where resin stagnates and degrades. The key benefit is that color or material changes require 60–70% less purging material and time compared to conventional die heads. For production lines that switch container colors or resin grades frequently, a FIFO die head significantly reduces waste and downtime.

Question 4

What is EVOH and why is it used as a barrier layer?

Accepted Answer

EVOH (Ethylene Vinyl Alcohol) is a copolymer with exceptionally low oxygen and hydrocarbon permeability — up to 10,000 times lower than standard HDPE. In a multilayer container, a thin EVOH layer (typically 3–8% of total wall thickness) acts as a molecular barrier, preventing oxygen ingress (extending shelf life for food and pharma) and preventing hydrocarbon emissions (required for automotive fuel tanks by ECE R34 and EPA regulations). EVOH is sandwiched between HDPE layers using tie-layer resins that bond the incompatible materials.

Question 5

Can multilayer coextrusion blow molding machines produce UN-certified containers?

Accepted Answer

Yes. Multilayer coextrusion blow molding machines can produce UN 3H1 and UN 3H2 certified containers when configured with appropriate mold design and material specification. The 100-point parison wall thickness controller on Sailwin machines ensures the consistent wall distribution required for hazardous goods certification. Please specify UN certification requirements when requesting a quotation.

Question 6

What container sizes can multilayer coextrusion blow molding machines produce?

Accepted Answer

Sailwin multilayer coextrusion blow molding machines produce containers from small cosmetic bottles (under 500ml) to large industrial jerrycans and drums (up to 30L+). The SW-2S5L-DT and SW-2S5L-TH double-station models handle containers up to 5L; the SC-PD12L large-capacity model handles containers up to 12L and above. Custom configurations are available for specific size and layer requirements.

Question 7

How much does a multilayer coextrusion blow molding machine cost?

Accepted Answer

Multilayer coextrusion blow molding machine price depends on the number of layers, container size, station configuration (single or double) and automation level. Machines with more layers and larger die heads are priced higher than standard single-layer machines. Contact Sailwin with your specific requirements — layer count, container volume, daily output and barrier material — to receive a factory-direct quotation within 24 hours.

Question 8

What parameters do I need to provide to get a multilayer coextrusion blow molding machine quote?

Accepted Answer

Please provide: (1) Number of layers required — 2, 3 or 6; (2) Barrier material — EVOH, PA, or regrind core; (3) Container volume and shape; (4) Required daily output; (5) Application — food, pharma, agrochemical, automotive or chemical; (6) UN certification requirement if applicable. With these parameters, Sailwin will recommend the correct model and issue a detailed quotation within 24 hours.

Parameter	Unit	SW-2S5L-DT 2-Layer	SW-2S5L-TH 3-Layer EVOH	SC-PD12L Up to 6-Layer
Number of Layers	—	2	3 (HDPE/EVOH/HDPE)	2 / 3 / 6 (configurable)
Barrier Material	—	Regrind / Virgin HDPE	EVOH / PA	EVOH / PA / Tie Layer
Max Container Volume	L	5	5	12+
Station Configuration	—	Double Station	Double Station	Single / Double
Die Head Type	—	FIFO (First-In-First-Out) — Standard on all models
Color Change Time	—	60–70% faster than standard die head
Parison Control	pts	100-point (standard)
Control System	—	Siemens PLC + touchscreen HMI
Oxygen Barrier (EVOH)	—	N/A	<0.01 cc/pkg/day	<0.01 cc/pkg/day

Multilayer Coextrusion Blow Molding Machine —
2 to 6 Layer, EVOH / PA Barrier

Multilayer Coextrusion Blow Molding Machine — Full Specifications

FIFO Multi-Layer Die Head — The Core of Coextrusion Performance

EVOH Oxygen Barrier Layer — How It Works Inside a Multilayer Container

Sailwin Multilayer Coextrusion Blow Molding Machines —
Installed in Customer Factories Across 60+ Countries

Multilayer Coextrusion Blow Molding Machine — Applications

Cosmetic & Personal Care Barrier Bottles

Fuel Tank & Industrial Multilayer Parts

Pesticide & Pharmaceutical EVOH Barrier Bottles

Multilayer Chemical Jerrycan & Drum

Multilayer Coextrusion Blow Molding Machine — FAQ

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Multilayer Coextrusion Blow Molding Machine

Multilayer Coextrusion Blow Molding Machine — 2 to 6 Layer, EVOH / PA Barrier

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