2016年5月26日星期四

CHOOSING THE RIGHT WEIGHT OF CSM (CHOPPED STRAND MAT) FIBREGLASS MATTING

(Article from Fixmyroof)

You may find all sorts of suggestions from fibreglass suppliers of what weight of fibreglass CSM (CHOPPED STRAND MAT) mat to use on your roof. Some don’t say, some say 450g, some 600g or others say double laminate 300g or 450g. In the end it turns into a “mines bigger then yours” contest devoid of all logic and reason. The simple truth is there are guessing because they want the best for you but they haven’t seen your roof, it’s size, it’s shape or how well it’s constructed. Some fibreglass suppliers are just suppliers and only that, and some have a history of fibreglassing roofs and can speak from real experience. Here are my suggestions, feel free to use them, ignore them, or improve on them.

  Small roofs – small garages, porches and bays 450g ( 1.5oz)
  Small garage sized roof’s – with foot traffic or medium to large roof 600g ( 2oz )
  Large roofs – i.e. > 50m2 single 600g or possible 450g double laminate for walkways.

  Large roofs – i.e. > 100m2 double 450g laminate

If you want to find fiberglass CSM with good quality and better price, please go to our website, http://www.zccyfiberglass.com, or email me: fred@chinaweibo.com.cn

2015年12月4日星期五

How to Choose the Resin

Resin selection can vary from fabric compatibility, service conditions, and desired characteristics of the finished part. There are generally three types of thermosetting resin to consider when approaching your project: Epoxy, Vinyl Ester, and Polyester. Let’s take a look at each of the choices, their characteristics, and what they should be used for.

1. Epoxy Resin

For composite parts that demand the ultimate strength, fabricators will use an Epoxy Resin. In addition to increased strength properties, epoxies also generally outperform polyester and vinyl ester for dimensional stability and increased bonding with other materials.

Pros: 
Epoxy Resin, High Strength Properties, Can be used in vacuum infusion applications, Easy to handle, Medium viscosity

Cons: 
Cannot be used with chopped strand mat
Not UV stable. This must be paired with a top coat when exposed to UV rays

2. Polyester Resins

Polyester Resins are the most widely used resins in the composites industry. Polyester Resins are less expensive, offer some corrosion resistance, and are more forgiving than epoxies. The majority of all fiberglass parts are constructed using Polyester Resins because they are easy to use, fast curing, and tolerant of temperature and catalyst extremes. Fibre Glast carries two different types of Polyester Resins, each with their own strengths and uses.

POLYESTER MOLDING RESIN
Pros:
Inexpensive, Easy to handle, Rapid wet-out, High thixotropic index (product won’t run on vertical surfaces)

Cons:
lower physical properties compared to more expensive resins

ISOPHTHALIC POLYESTER RESIN
Pros:
Dimensionally stable (minimal shrinkage), resists post cure problems, can be used in food contact applications

Cons:
Slightly more expensive than general purpose polyester resins

3. Vinyl Ester Resin

Vinyl Ester Resin is considered a hybrid of polyester and epoxy—meaning its handling characteristics, properties, and price generally fall just between the other two. It is important to note that, Of the three, vinyl ester resin will provide the highest corrosion resistance, temperature resistance and elongation (toughness.) Because of this, they are typically used when high durability, thermal stability, and corrosion resistance is needed.

Pros:
Vinyl Ester Resin, Extremely tough, corrosion resistant, heat resistant

Cons:
Short shelf life (3 months)

2015年12月2日星期三

A Simple Female Mold Construction with Fiberglass

Composite materials offer ability to be molded to complex shapes is perhaps the most popular. When a shape needs to be reproduced numerous times, it is most efficient to build a tool or mold within which the part can be fabricated. Molded parts emerge perfectly shaped every time and require little post-finishing work.

Molding or “stamping” has been used for years to shape metal products like car bodies, home appliances, and industrial fixtures. Metal stamping dies are cumbersome and cost thousands of dollars to produce. Only large companies can afford to build, operate, store, or even move these tools. Composite materials offer a cost effective way for anyone to make even large production runs of identical plastic parts in molds they can produce themselves.

Female molds or cavity molds offer numerous advantages for medium to large production runs. Finishing time is significantly reduced because every part emerges with a smooth outer surface.
PRODUCTS FOR MOLD CONSTRUCTION 
Duratec Gray Surfacing Primer
Modeling Clay
Parting Wax
PVA Release Film
Tooling Gel Coat
Tooling Fabric
Woven Roving
10 oz Fabric
Polyester Molding Resin

2015年11月19日星期四

Comparison between Fiberglass and Carbon Fiber

Fiber fabric and the resin are the general two parts of composite materials, with the physical properties of the material being fiber dominant. What that means is, when the resin and fiber are combined, their performance will primarily depend upon the fiber used. Test data shows that the fiber reinforcement is the component that will carry the majority of the load within the composite. So what does that mean? Well. Simply put, what fabric you choose is going to matter.

The two most common types of fabric in the industry are fiberglass, and carbon fiber. Both have a wide assortment of usages, and are extremely versatile. How do the two weigh up against each other? While comparing the two, Keep in mind, both fiberglass and carbon fiber will vary depending on the fabric you choose. A lightweight 2 oz Fiberglass Fabric will not have the durability of the more structural 10 oz Fiberglass Fabric. Additionally, the weave of the fabric and the resin used will have a large impact on the strength and properties of your composite product. 

Fiberglass
Fiberglass is the most widely used fiber in the industry, and with good reason. Fiberglass is versatile, easy to handle and relatively inexpensive compared to its counterparts. Fiberglass is perfect for every day projects that are not expected to need the added strength and durability of higher priced fabrics. Fiberglass is compatible with most resins, and comes in a multitude of patterns and weaves.
Carbon Fiber

Carbon Fiber is far and away the premium end for composite materials. With excellent ultimate tensile strength, along with the greatest compressive, flexural, and bend strength in the industry, carbon fiber is the go to on projects that need to be built tough. Carbon Fiber is ideal for projects that need that added “umph” of strength, so long as you can handle the corresponding “umph” to your wallet. With its distinctive design look, carbon fiber is a popular choice in a multitude of industries, including the automotive and aerospace sectors.

More information regarding fiberglass, please visit chopped strand mat manufacturer-wbcomposites.com

2015年11月17日星期二

Glass Fiber VS Carbon Fiber

Glass Fiber and carbon fiber are widely used in composites these years. So what’s the difference between them?

WEIGHT
Glass Fiber Carbon Fiber Comparison So how do the two match up, against each other? For one,  Glass Fiber fabric is much less efficient in it’s density, when compared to it’s composite counterparts. While Glass Fiber is still significantly lighter than conventional materials (wood, steel, etc) for it’s given strength, on weight critical projects carbon fiber will preform much better as a reinforcement.

STRENGTH AND DURABILITY
Similarly, carbon fiber will outperform Glass Fiber in it’s tensile strength (the amount of force that needs to be placed on a fiber in order to pull it apart) and compressive strength (the amount of force that presses down on a fiber). However, Glass Fiber is more “durable” in that you can bring Glass Fiber near to it’s breaking point repeatedly without much cause for concern, unlike carbon fiber.

MODE OF FAILURE
Additionally, once carbon fiber reaches it’s breaking point, the mode of failure is catastrophic (it will fracture/shatter the piece.) Glass Fiber on the other hand, will develop cracks or deform before it breaks.

COST
Unfortunately, due to the nature of carbon fibers, it is much more expensive compared to its counterparts. So if your project isn’t weight dependent, and won’t need the excellent strength that comes from carbon fiber, Glass Fiber is a great choice to go with. 

This article is from fiberglass chopped strand mat manufacturer wbcomposites.com .