Vectorply’s Technical Service comprises a comprehensive suite of technical services for customers
who are developing new laminates, optimizing existing laminates or who are looking for ways to improve productivity and performance through innovative solutions. Services include:
Laminate Analysis & Comparison
Comparison of laminates begins with customers providing either parameter of design criteria for new laminates, existing laminates, or in the case of marine, hull geometry and propulsion requirements. In return the customer receives a comprehensive report including:
- Comparison of laminates on the basis of stiffness, strength, weight, and cost
- Construction tips on optimizing material application
- Marine – Design reports including DNV, ISO, and/or ABS
New laminates can also be fabricated and analyzed in Vectorply’s onsite lab. Sample panels are fabricated using hand lamination or vacuum infusion processes to help determine wet-out rates and basic physical properties such as thickness, weight, fiber content, and general cosmetics.
VectorLam™ Technical Support
Enrolled users of VectorLam receive no charge technical support for one of the most popular laminate design software programs. Users also automatically receive program updates when new versions are released.
For specific applications there can be a need for custom designed reinforcements. The Vectorply team will walk you through the process and help you design a reinforcement to fit your requirements.
Reinforcement Application and Processing Optimization
A feature of non-crimp multiaxial reinforcements is the ability to engineer the strength and stiffness requirements into the fabric at the point of manufacture. This includes considerations for fiber angle, fiber weight, fiber type, stitch type, handling characteristics, and most important, the process. Matching reinforcements to the process is a critical step to achieving the optimal laminate and, above all, saving money. A poorly engineered reinforcement will eat up valuable labor hours if the shop crew has to spend extra time working with the reinforcement to conform or match property requirements. Typical composite fabrication processes are given below along with the Vectorply reinforcements suited for each process.
Composite Fabrication Processes
Hand lamination is the oldest and still most widely used fabrication process in the industrial composites industry. Dry reinforcement fabrics are placed in a one-sided mold (typically female), resin is applied either by hand or spray gun, and the laminate is compacted via hand held FRP serrated rollers.
Virtually all of Vectorply’s reinforcement fabrics are compatible with this process. However, ultra-heavy weight reinforcements designed specifically for other processes such as vacuum infusion may be difficult to properly impregnate with resin which can lead to dry areas or voids within the laminate. Typically, reinforcements under 70 oz/yd² (2370 gsm) are used in this process, not only for lower dry spot/void content, but also for ease in moving and manipulating it in and to the mold.
For hand laminated structures using standard DCPD, orthophthalic, or isophthalic based polyester resins, it is recommended to use Vectorply reinforcements containing chopped mat layers (BXM, LTM, TTXM, TLXM, and QXM) for better bonding between the layers.
Vacuum infusion processing (VIP), or the various other acronyms the process is known under (VARTM, SCRIMP, etc.) has become the most widely used closed mold process for large, complicated, low volume structures. Dry reinforcements are applied to a one-sided mold (typically female), resin and vacuum manifolds (made of tubing and barbed tees) are constructed on top of the stack, and a flexible polymer bag is sealed around the perimeter. The air within the cavity is then evacuated via a vacuum pump until a full atmosphere of pressure (-14.7psi / -29.95”Hg) is applied. The liquid resin is then fed through the resin manifold(s) and uses the atmospheric pressure as the driving force to impregnate the dry reinforcements.
Under vacuum pressure reinforcements can compress, choking resin flow all thereby stalling infusion, and compromising laminate integrity. Vectorply’s VectorFusion™ line of multiplane infusion specific reinforcements has been designed to maximize permeability and minimize infusion time.
Vectorply’s proven non-crimp multiaxial technology provided the DNA for reinforcements like E-2LTi 7200 and E-3LTi 10800, the thickest reinforcement of its kind. It starts with a unique multiplane architecture and precision-guided fibers bonded together by proprietary stitch mechanisms. The roving bundles sustain loft ensuring the laminate will achieve the greatest thickness, and more importantly will not be resin starved.
The multi-0° / multi-90° architecture creates a stacking geometry that keeps channels open for both air to escape and for resin to flow quickly and simultaneously across the surface and through the thickness. The stitch-bonded construction provides a smoother finished surface with less print-through compared to other high crimp and “z” axis type reinforcements.
Our stitching process also means that reinforcements can be cut without unraveling prior to installation, reducing waste and saving time. VectorFusion™ reinforcements are designed for the infusion process, without the need for aids such as plastic flow mediums and meshes that add weight and cost.
Successful infusion is in the details; material choices have been fine-tuned, procedures routinely reviewed for efficiency, and a dedicated workforce have been trained for the job. Vectorply’s Technical Service team is an integral part to this process starting with a thorough analysis of the current laminates.
Pultrusion, a process mostly known for producing composite ladder rails and tubes, now utilizes multiaxial reinforcements to produce a wide variety of structural parts. In the pultrusion process reinforcements are “pulled” through a resin bath and then through a heated die to set the cross sectional shape. When pultruding only single end fiber rovings, large warp creels holding several hundreds (if not thousands) of roving packages must be set up to produce the optimum fiber content, plus all of the fiber is oriented in only one direction. Using multiaxial reinforcement fabrics with heavy 0° fiber layers replaces the large warp creels, while off-axis layers allow for more optimized structures.
Advancements in pultrusion have lead to direct resin injection into the die, which allows for tighter control of fiber weight/volume fraction, lower volatile emissions, and a cleaner work environment. With these direct resin injection dies, the reinforcements must be permeable enough to allow thorough resin impregnation. Vectorply reinforcements designed specifically for the pultrusion process allow for quick resin infiltration and low void content producing stronger, more optimal composite products.
The stitch bonding process also allows for combinations of multiaxial reinforcements with surfacing veils or continuous fiber mats. The stitching fiber keeps the veils/mats from necking down or folding over, allowing for faster line speeds and greater productivity.
The filament winding process is used to make many cylindrical composite products such from CNG and O2 high pressure tanks to large tank trailers. Filament winding typically takes individual fiber rovings or tows which are run through a resin bath and wound onto a rotating mandrel (or wound dry if towpreg – preimpregnated tow/roving). This process is excellent for orienting fiber in the “hoop” or cross sectional direction of the part, but does not allow for fibers to be placed directly in the longitudinal orientation. Vectorply’s stitch bonded weft unidirectional fabrics (T) can be used to provide longitudinal reinforcement while utilizing the same hoop winding process. Filament wound sections are also commonly joined together using Vectorply’s weft unidirectional reinforcements. If torsional stiffness and strength are of concern, double bias (BX, BXM) reinforcements may be applied, and weft triaxials (TTX and TTXM) provide both longitudinal and bias fibers in one fabric.
Other Closed Molding Processes:
RTM, Compression Molding, Light RTM, and Prepreg
Closed molding processes such as RTM (Resin Transfer Molding), Light RTM (RTM with a more cost effective counter mold), and compression molding are used to make mid to high volume parts with a high level of cosmetics and low thickness tolerances. These processes typically use metal or high end composite matched tooling (molds) which allow for long tool life and fast cycle times. Typical reinforcements used are chopped or continuous mat in either roll goods or in preforms, which produce moderately structural composite parts. Vectorply reinforcements are used in combination with these mats to provide localized strength and/or stiffness in critical part areas.
Prepreg (short for “preimpregnated”) reinforcement applications tend to produce the highest mechanical properties out of all the composite fabrication processes. Dry reinforcement fabric is fed through a prepreg machine where it is coated on either side by a thin resin film, B-staged cured (partial cure), and then stored in refrigeration until needed. The prepreg process produces highly consistent fiber volume fractions and low void contents (especially when used with an autoclave) that are typically called for in high end aerospace and sporting good applications. Vectorply reinforcements are used in prepreg materials to provide higher mechanical properties over the more traditional woven versions. Off-axis fibers (BX, TLX, and TTX) are also easily prepregged and provide high in-plane shear and torsional properties over wovens.