In the civil engineering, landscaping and construction worlds, geotextiles are used for soil stabilisation, aiding the drainage and occultation of water, and protecting soil and other structures, and more. Two of the myriad of choice available are heat bonded geotextile and needle punched geotextile, and knowing the difference between the two will help engineers, contractors and project planners to choose the right geotextile for their specifications.
What is Heat bonded geotextile?
Heat bonded geotextile is a non woven geotextile made by delivering high-pressure heat to thermoplastic fibres in order to bond them. This creates a smooth surface fabric with;surface, consistent density and uniform thickness.
Some features:
High Dimensional Stability: Because the fibres are bonded with fibre, this process of heat bonding prevents a strain when under pressure.
Smooth Surface: This results in more being able to improve the flow of water/improve filtration performance.
Light Weight: Much lighter than a needle punched geotextile and was very much easier to move/install.
Chemical Resistance: These resist acid/alkalis and some other chemicals found in earth.
Applicability: Used for a drainage layer, roads subgrade, erosion control and separation purposes
What is Needle punched geotextile?
This is non woven geotextile that is made by mechanically entangling fibres together via barbed needles. The resulting fabric is highly durable and puncture resistant.Notable features:
High Tensile Strength: Repeated mechanical bonding renders the fabric durable and of superior strength for heavy duty applications.
Highly Puncture Resistant: The ability of this material to resist damage from sharp grades is unrivaled.
Permeability: Performance of geotextile of moderate permeability, for drainage and seepage use.
Durability: Long life in difficult conditions.
Applications: In road making, lining of landfill and other rubbish deposits, stabilising the track bed where the line runs on made up ground, control of erosion, etc.
Making A Comparison Between Heat-bonded Geotextiles and Needle-punched Products
There are as many things to consider when thinking of heat-bonded vs needle-punched geotextiles as there are turning of raggedy black pants that come from weaving plastic fibers together.
- Strength and Durability
Usually the needle-punched geotextile will have greater tensile and puncture strength, capable of carrying more load and resisting soil movement. Heat-bond will be of moderate strength but great in maintaining its shapelessness and stability under a uniform load. - Permeability and Filtration
Depending on the filament size, heat-products could have a higher impermeability rating and filtering of finer particles. Needle-punched will have more permeability allowing water-blown through to carry its sediment to the exfiltration side and not to erode soil. - Installation and Handling
More easily rolled out on large areas to be laid. Heat-bonded will be lighter. Time will be saved in installation, as the duration of spreading it and rolling out is shorter.
Needle-punched might be heavier, more time-consuming in its attachment in large areas. - Cost
Generally, needle punched will be slightly more.
Heat-bonded might be less in jobs that do not require great resistance to load.
Which Ones Should You Choose?
If medium loads and general lightweight requirements, erosion control, drainage, and separation of soil are the primary consideration, heat in sheet will be all the geotechnical company would want to install.
On the other hand if heavy California and New England winter loads in construction, road subgrades, beds of land-fills, etc., of extreme density, etc., and danger of puncture, so on and so forth, then a good needle-punched product would be needed. But again, many modern jobs allow for both in tandem whereby heat bond is utilized for exfiltration and drainage on its own contour, with a product of needle-punchs for protection and reinforcement, etc. This makes for greater efficiency and economy.
Both types can have great lengths of service in use as suggested in both points above. To the engineer and contractor that permits; whether one or the other.