Something you may not know about Wood plastic composite
Wood plastic composite (WPC) can be formed from many different base resins, but mainly there are 2 main groups: PVC based WPC and PE based WPC.
Primary criteria to differentiate the two group is their based composition:
- PVC based WPC is formed by: PVC + wood powder + additives.
- PE based WPC is formed by: PE/HDPE + wood powder + additives.
Differences between PVC and PE lead to many differences between the two WPC as bellowed:
|PVC based WPC
|PE based WPC
|MIXING – PROFILE EXTRUDING – SURFACE TREATMENT
In most case, raw material after mixed can go directly to Profile Extruder to form profiles with just a single melted at the extruder.
Production can be Foaming or Non – Foaming process
|MIXING – PALEETIZING – PROFILE EXTRUDING – SURFACE TREATMENT
Raw material after mixed need to go through Palletizer machine to form WPC pallets, then the pallets go through Profile Extruder to form profiles.
Production is often Non – Foaming process.
|PVC based WPC products with FOAMING process have low specific density, inside look spongy, surface look more like wood than PE based.
|PE based WPC products mainly with NON – FOAMING process has higher specific density, surface is less like natural wood but inside is solid and product is homogeneous and hard.
|In general, PVC based WPC (with foam process) is cheaper than PE based WPC, the virgin resin itself is lower in price and also many PVC based WPC are foamed, so unit weight of finished product uses relatively less material.
|With Non – foaming process, products have higher density so same amount of raw material will produce less volume of final products. Also more steps on production so in general price of PE based WPC is higher than PVC based.
|Mainly use for indoor decoration or semi-outdoor that do not directly expose to sun light and rain, such as ceiling in porch.
|Use for all outdoor application, where expose to direct sun, rain and hard weather conditions
- What will happen when PVC based WPC use for Outdoor application?
WPC was first manufactured in the 80s of last Century with main applications in car interiors or indoor decorations. At that time, there only Indoor PVC based WPC. When people bring this WPC use for outdoor application, in a short time, product change color, crack and wear off, etc. due the fact that the product cannot stand in weathered conditions. Since then PE based WPC was developed to fill the need for outdoor applications, such as decking in swimming pool, walk way paths in parks, fences, pergola, wall cladding etc.
Bellowed are comparison of some special features between the two WPC
|PVC based WPC
|PE based WPC
|Water resistant and stand in hard weather conditions
|Durable under sun light
|Anti- Scratch and wear off.
|Fire resistance level 2
- How to differentiate Indoor and Outdoor WPC?
These days, in Vietnam market, there are both PVC based and PE based WPC suppliers. However, some suppliers do not have enough PE based WPC in their product range. In this condition, they normally do not explain clearly the differences between the two kind of WPC and suggest customers to use their PVC based WPC (with foaming process) products for outdoor applications.
In order to avoid wrong use of WPC products for certain applications like decking/ rails/ wall cladding etc. that can lead to shorten life time of outdoor projects people involved can easily differentiate the two kind of WPC by some visual feature show in some pictures bellowed: