How it's made

There are two distinctly ways to manufacture TPU lay flat hose. Hose produced more traditional way referred to as 3-ply PU, or laminated PU. Hose produced with more technique referred to as \"extruded-through-the-weave\".

3-Ply or called  Laminated PU

3-Ply hose is actually comprised of five layers; an inner PU tube, an adhesive tube, a reinforcement jacket, an adhesive tube, and an outer PU tube. Since the adhesive tubes melt during the manufacturing process, only three layers can be seen in the finished product; hence, the name \"3-Ply.\" The manufacturing process of 3-Ply starts by pulling a polyurethane (PU) tube though the inside an adhesive tube; then, pulling these two tubes through the inside a woven reinforcement jacket. Steam is blown through the PU tube to melt the adhesive and bond the PU tube to the reinforcement jacket. The tube inside the jacket is then turned inside-out (\"turning the inside tube out\") and the process is repeated with a second PU tube and a second adhesive tube. During this procedure, moisture builds up on the reinforcement jacket and numerous pin holes are made in the outer PU tube to permit this moisture to escape.

ETW - Extruded through the weae

The manufacturing process for extruded-through-the-weave (ETW) hose uses two polyurethane tubes separated by a reinforcement jacket. The PU tubes are extruded through the weave of the reinforcement jacket, melding all components into a single piece of reinforced TPU lay flat hose.

3-Ply hose could use less TPU material, the manufacturing process can keep the hose tubes as thin as they like, this results from the necessary procedure of turning the inside tube out, which becomes very difficult if the tubes are too thick. While ETW hose normally use more TPU material, and has to test hose after made, to make sure whole woven jack coved tight.

Advantage of ETW vs 3-Ply

Some advantages of through-the-weave TPU lay flat hose are:

1. No adhesive is used; hence, there is no potential for the hose to delaminate.
2. At working pressure, through-the-weave TPU hose has an elongation rate of 1%, as compared to up to 10% for 3-Ply. An elongation rate of this magnitude results in \"snaking\" which causes the hose to move in an - unpredictable manner and may lead to damage to the hose and the environment, as well as a reduced flow rate.
3. The pin holes made in the outer layer of 3-Ply hose during the manufacturing process could allow moisture to come back through the pin holes while the hose is in use in the field, compromising the integrity of the adhesive. The slightest loss in adhesion could cause the hose to delaminate and, in the worst case, result in a major spill.
4. Peel tests of lay flat hose (a procedure that pulls the TPU old the ranNrcernent rack.) have quantified that the strength required to separate TPU from the reinforcement tacket is twice as great for extruded through-the-weave as that required for 3-Ply.
5. The interior of through-the-weave hose is much smoother than 3-Ply hose, thus a/MA.9 a higher flow rate for through-the-weave hose than for 3-Ply.
6. In the process of \'turning the inside tube out\" manufacturers have to use a sorter polyurethane material than ETW hose As a consequence. ETW hose IS more resistant to abrasion and less puncture than 3-Ply hose
7. Fabricators and field people probably preffer 3-Ply because it isn\'t as stiff as ETW and is eamer to cut.