INTRODUCTION

Soric is a bulker material that is designed to be placed in a sandwich with fibre reinforced skins. In this capacity, Soric allows impact behavior of a sandwich close to that of a full glass laminate.

Soric TF is typically used to improve the surface of a composite laminate.
The other Soric grades build thickness and act as a flow medium in infusion and RTM. Historical impact tests have proven that a laminate with Soric has comparable resistance to impact as a full fibre laminate. In order to assess whether the failure mechanism is also comparable, a series of comparative impact tests is performed. For impact testing a drop weight tower is used.
In order to assess the total damage in the laminate, ultrasonic C-scan is used.

From each considered laminate a panel will be selected which will be cut along a damaged area in order to compare the failure mode. Main mode of failure is breaking (fracturing) of the resin. No inter-laminar failures occur. In light of the test results it is recommendable to add a layer of CSM between the barrier coat and the Soric.

ADOPTING LANTOR SORIC
This document is originally a part of the campaign to adopt Lantor Soric into a yacht infusion process.
In particular, the Soric TF is assessed as a surface enhancer. Soric TF is a bulker material that is designed to be placed in a sandwich with fibre reinforced skins. In this capacity, Soric TF allows impact behavior of a sandwich close to that of a full glass laminate.

GOAL
To analyze the failure mode after impact in a laminate with Soric

RESULTS

FAILURE MODE
Below the cross sections of a selected hole (impacted with 27 Joule) for each laminate is given.
The cross-section in panel 1A location 3, which is impacted at 61 Joule, is presented first.
This location is the one with the clearest damage and will be used to analyze the failure mechanics involved.
breakline
Possible fibre
No fibre between Soric and barrier coat
Perpendicular
Fibre bundle

The first layer of CSM seems to be interrupted next to the centre of the impacted area.
The absence of any dark spots between the fibre layers and the Soric
indicates the absence of interlaminar (delamination) failures.
A break line can be seen running through the Soric XF, indicating a break in the core.
The laminate cross-section becomes ‘whiter’ to the center below the impacted area.
This is because of the damage to the resin, or the breaking of the resin,
making the otherwise transparent polyester resin opaque.
Because the opacity of the damaged resin ‘masks’ the fibres of the top EQX layer, fibre breaking cannot be established.

The absence of indicators for delamination and the shift in resin opacity nearer to the impacted area, shows that the observed damage areas from the c-scan indicate the area where the resin in the core is broken and does not indicate delamination as it would do for full fibre laminates. The darker areas in the fibre layers are the fibre bundles perpendicular to the cross-section surface.
Of the failure symptoms only the impact location and matrix cracks can be observed.

CONCLUSIONS
Under impact, a laminate without any CSM between the barrier coat and the Soric TF will suffer a damaged area almost two times as large as a laminate with CSM 600gsm between the barriercoat and Soric TF.
Applying CSM 450gsm results in a 30% larger damaged area.
Main mode of failure is breaking (fracturing) of the resin, which can be observed visually as the resin becoming less transparent (opaque, whiter) near the impact area.
No delamination, separation of fibre layer and core, is observed. Fibre breaking of the EQX cannot be seen. Impact deformation is fully absorbed by the Soric TF and XF.

RECOMMENDATIONS
Consider using Soric as a bulker material when delamination after impact is a design concern.
In light of the test results it is recommendable to add a layer of CSM between the barriercoat and the Soric TF. This will significantly reduce the damaged area after impact and therefore the area that should be repaired.
Applying a greater mass of CSM reduces the damaged area even further. Because the TF is applied mainly for cosmetic purposes it is recommended to apply a fine fibre CSM (200-450gsm). The fibres in CSM of 450 gsm and below have fibres with a smaller diameter, leading to better surface finish and less obvious print-through. To obtain the impact behavior of adding a CSM 600gsm, two layers of CSM 300gsm may be considered.

Introduction
SC 110 is a new cosmetic grade prepare that utilises a high clarity, versatile, hot-melt epoxy resin formulation.

The unique formulation ensures that no dicey white-wash or spots are evident in the cured resin, reducing scrap rate by up to 20%. It is ideal for manufacturing high visual quality components using autoclave and press moulding. It can be cured at temperatures as low as 80°C, or it can be used for faster moulding of components at 120°C. Even faster cures are achievable using press moulding technologies at temperatures up to 150″C. This is achieved whilst maintaining good out-life of up to 3 weeks at 21″C. It is a toughened system, and offers excellent mechanical properties on a wide variety of reinforcing

Features :
Ultra high clarity- ideal for cosmetic components with no white-wash or spots
High-strength prepreg system
Versatile process window with autoclave, and press moulding
Curable at temperatures as low as 80°C
Fast 1 hour cure at 120°C
Rapid 10min cure at 150°C in a press
Excellent tack allowing easy in-mould repositioning

            ROBUST DEVELOPMENT VALIDATION

During the development of SC 110, extensive beta testing has been conducted to manufacture the most challenging cosmetic components in order to demonstrate the robustness of the unique dicey-free resin formulation. Light curvature, resin rich seams and numerous components have been produced through autoclave and press moulding processes without any sign of white wash or spots.

IMPROVED WEATHERING PERFORMANCE
In order to measure the weathering performance, SC 110 was benchmarked using a OUV SE Accelerated Weathering Tester with the following cycle: 4hrs condensation at 50°C I 4hrs UV exposure at 60°C I 28 days of exposure.

The subsequent loss in gloss measurement after 28 days was found to be significantly lower than competitor materials.

Other products from Gurit
Other products in Gurits new automotive prepreg materials include:

SE200-STRUCTURALPREPREG
Toughened structural epoxy prepreg with excellent hot/wet performance.
Achieves a Tg > 200°C after press curing in 15 minutes at 195°C
Suitable for compression moulding, autoclave or vacuum bag processing

PN 901 -HIGH TG PREPREG
Cyanate Ester prepreg with good mechanical performance at high temperatures.
Can achieve a Tg > 300°C after a post-cure temperature of 180 to 300°C
Ideal for components exposed to high temperatures for short durations

The need for Fire Retardant resins.

During fire, the most hazardous ingredient is smoke, rather than heat/temperature. A fire occurs when fuel, heat and oxygen come in contact. If one of them is removed, the fire can be stopped.

Fuel: Resin, Catalyst, Rags, Wood, Paper, Plastic Sheeting, Composites. An unsaturated polyester resin basically acts as fuel.

Heat: Smoking, Hot Work, Electrical Equipment, Pilot Lights, Floor Scrubbers, Sparks from Tool Strikes, Static Electricity, Chemical Reaction, Curing, etc.

Oxygen: Found in air. Good ventilation is mandatory in composite operations so there will be lots of oxygen and it will be hard to stop. Lots of surface area (e.g. rags, sprayed resin) affords more contact for oxygen to get into the mix.

Chain Reaction: The Fire Process (sustained burning).The burning process is quite complex and described by the Fire Triangle.
If one angle is missing, the fire is over!

Flammability Properties of un-cured Resins (Liquid form)
Flammability of resin when in liquid form is usually related to the styrene monomer content
Flash Point Range74 –84°F, Class 1C
Flammable Limits (in air)Lower Explosive Limit (LEL) = 0.9%, Upper Explosive Limit (UEL)
= 6.8%This would be intolerable in the breathing zone (NOTE: 1% = 10,000 ppm) Styrene vapors are heavier than air and can collect in low areas
Vapors may also travel great distances to ignition sources

Atomization of liquids effects ignitability. Atomized combustible liquids can easily ignite when used in spray applications.

Fire Retardants, an Indian Perspective
• IS 6746-1994 / UL 94 V0 Compliance (Flammability)
• Filled System Primarily comprise of Halogen additives and Synergistic Flame Retardants like ATH / Antimony trioxide
• If FR Application is for Outside exposure conditions an UV absorber is added in the resin system.
• Applications to which these systems would be used are HLU/RTM/Pultrusion
• Resin System would be designed to have an Ortho/ ISO / Vinyl ester base polymer

Note: Other standards like ASTM E-84, NFF 16 101, EN 45545, etc. are getting more importance in India Specified by Leading OEM especially in Railways and Building & Construction.

A quick look at FR standards :

A. Test compliance IS 6746-1994
Very Low Flammability resins extinguishes in less than 10 Sec and low Flammability less than 25 sec.

Other Compliances to be Met on specific needs of customer are :
ASTM D 635 – Flame Spread
BS 476 part 7 : Surface Spread of Flame
IS 15061/2002 : Burning Characteristic Vertical/Horizontal
ASTM D 2863 – LOI / ASTM D 149 – Electrical

Ashland India’s Product Range
Resins Orthopthalic Base – Aropol IN 2645F, 7102F Resins Isopthalic Base
Aropol IN 5225F

B. Test compliance ASTM E 84 –
Tunnel Test Mainly for CR applications Derakane Resins 510 Series comply to this requirement

C. Test compliance Flame Smoke Toxicity (Non Halogenated System) UIC 564 / NCD 1409/ IS 13501
• Flame : Class B
• Smoke : Class B
• Toxicity : 1

Ashland India’s product Range
Aropol IN 2645 F/ Enguard SO 90202 A IN V3 ( Ortho UPR) Aropol IN 5225 F / Maxguard FRN 10001 A IN V3 ( ISO UPR)

Applications include: Railway coaches/window frames/Cable trays/ Pultruded Platforms CR/FR- Electrical Fuse gear/ Switching and Insulated Rods and profiles,Halogenated – Non Filled System Automotive Vehicles

D. Test compliance Horizontal/Vertical Burning rate IS 15061-2002 Cl 3.2 Annexe A/ Cl 3.3 Annexe B
• Horizontal : Less Than 100mm/Min
• Vertical : Less than 100mm/min

Ashland India’s product Range
Aropol / Hetron resins HLU/RTM/Infusion System Automotive Vehicles
Flammability requirement
Aropol IN 2016 TF / GelCoat Enguard SO 90201 A IN V3 Ortho UPR)

A quick glance – Ashland Products Vs. FR Test results*

* The results obtained at third party laboratories

UV versions of AROPOL IN 5225F and 5335F meets the requirement of ASTM G 154

We all know that our readers are aware about the safety norms & precautions to be taken for safe working. But we thought, that reminding our readers of what they know is important With this in mind we have tried to prepare a wall – chart for you.

We expect you can print & paste this in your work area. To bring home the point,
we have taken help of some images & slogans.

INDUSTRIAL SAFETY WALL CHART 

IS YOUR COMPANY RISK-READY?

Industrial Safety is of prime concern in our workshops and shopfloors. Are companies today doing enough to ensure the safety of their premises and employees? There are two ways to protect and preserve your assets both human and material:

1. Ensure that adequate fire precautions are in place, and employees and materials are protected in an untoward situation A fire safety plan, regular drills, and the proper storage and handling of combustible material will go a long way in protecting your employees and premises in case of a fire. Ensure that electrical earthing is done properly, and machine safety procedures are in place.

2. Material insurance for safety
In case of a fire, material loss is huge. To avoide losses, ensure that you have adequate material insurance in place. Industrial al risk policies are the norm today.

Gurit has developed a broad range of tried, tested and qualified performance prepreg systems and structural core materials that are ideally suited to manufacture weight-optimised laminate structures, sandwich or crushed-core components that exceed the customers’ performance criteria and the most stringent safety requirements of the global rail market. Gurit is already known as a trusted supplier of composite materials for interior and structural aerospace applications.

Gurit prepregs are used in a growing range of rail projects from High-Speed to Subway trains across the globe. From concept to product development and into production, Gurit’s experience and understanding ensure products are delivered on time and to specification.

MAXIMUM PASSENGER COMFORT

Sandwich constructions are an ideal way to achieve optimal results and meet passenger requirements. In a sandwich panel, two outer material layers provide a stable and smooth surface, while a lightweight core section adds stiffness and insulation, both ideal for rail applications. Modern rail tracks are designed for speed – the straighter the tracks, the smoother and faster the ride. The topography or cityscape between two destinations is a given and the availability of land is often scarce. Therefore, fast, high-speed, urban train lines feature ever-longer tunnels and bridges, consequently travellers and train crew must be even better protected to get a maximum chance of safely escaping during the unlikely event of an emergency. This is a true call for phenolic prepregs!

MEETING THE MOST STRINGENT SAFETY STANDARDS

Favourable mechanical profiles are important, but chemical features of the material are equally vital, especially in terms of passenger safety requirments. The fire, smoke and toxicity performance (FST) is a top priority when selecting new materials. Gurit’s experience in the development of tailored, long-term solutions for the complex aerospace industry has allowed the development and market introduction of Gurit’s range of Phenolic and Epoxy prepregs to the rail market. The outstanding behaviours of Gurit’s prepregs include short burn lengths, lowest smoke densities and smoke toxicities and very low heat release values. The range of epoxy and phenolic prepregs and structural core materials now balance high performance, with the most stringent safety requirements for maximum passenger safety, including fire and fumes regulation EN45545.

PH 840
Phenolic Prepreg

Recyclable     High temp processing  Excellent FST properties 

• Tested to EN45545- HL3 Rating in R1 Category (highest rating)
• Excellent mechanical behaviour
• Good surface finish
• Autoclave-free processes possible
• Short curing t ime 15 min at 160⁰C/320⁰F
• long shelf and shop life                                                                                                                                           

INTRODUCTION

PH 840 is a haloge free modified phenolic system. designed for laminate with bright colour and good surface quality.

This prepreg material has been developed for industrial and rail applications with high specific mechanical properties and excellent
FST (low heat-release and smoke-density) behaviour.

PH 840 can be cured between 120⁰C and 160⁰C (248⁰F and 320⁰F) Monolithic and sandwich structures can be easily manufactured
with this prepreg. The curing can be performed by press. vacuum and autoclave moulding with a pressure of at least 0.7 bar / 10 psi.
Suitable for composite structures experiencing in-service temperatures of -55⁰C up to + 80⁰C.

TYPICAL APPLICATIONS

PH 840 is ideally suited to rail / industrial / commercial marine craft and automotive applications.

ST 70FR
Fire Retardant SPRINT^TM

Excellent FST properties70⁰C cure temperature SPRINT ^TMTechnology

INTRODUCTION

• Award winning SPRINT^TM Matrix
• Self extinguishing
• Suitable for Lioyds and MCA Compliant Structures
• Suitable for monolithic and sandwich structures
• Excellent laminate quality, from vaccum-only Processing
• Low smoke toxicity
• Halogen-free

ST 70FR is a fire retardant hot melt. Diuron free epoxy SPRINT^TM. This is ideally suited to the manufacture of thik requiring fire protection.It can be cured at temperatures as low as 70⁰C, but can also be used for the rapid manufacture of components through its 25-minute cure at 120⁰C. All of this can be achieved together with an outlife of 14 days at 20⁰C.

TYPICAL APPLICATIONS

Industrial / commercial manna craft and civil applications where thick tea retardant laminates are required.

G-PET^TM FR
Fire Retardant Structuctural Core

Excellent FST properties Recyclable High tem processing

INTRODUCTION

• Excellent FST performance (Evaluated against DIN 5510, ASTM E1354, ASTM E662 & BSS7239)
• Withstands high process temperatures
• Good adhesion & mechanical properties
• Compatible with all composite processes
• Excellent chemical resistance
• Recyclable
• Available with G-PET^TM lite technology

G-PET ^TM 75FR and G-PET ^TM 100FR have been developed in order to meet the growing need for structural core materials with good Fire,Smoke and Toxicity (FST) properties used in Marine, Civil and Transportation markets. It offers a much lower cost FST materia compared to high cost/ high performance materials such as PMI, PEl, PES foams. addressing lower requirements and needs.

TYPICAL APPLICATIONS

G-PET ^TM can be Processed at high temperatures. withstanding exotherms up to 150⁰C / 300⁰F and offers outstanding fatigue properties. chemical resistance, good adhesion. is a highly consistent extruded foam. it is ideal
for wind energy, marine. Industnal, and transportation applications. Applicable processing toctniques include vacuum infusion. bonding,prepreg. and thermoforming. Available in a wide range of thickness and finishes.

PRODUCT INFORMATION

Pre-Pigmented Gelcoats from Scott Bader are now Made in India using Scott Bader’s proprietary Gelcoat-making technology. Satyen Scott Bader has announced the launch of their Crystic Pre-Pigmented Gel Coats in India.

Satyen Scott Bader’s Gel Coats are designed using individually selected base resins depending on the requirements of the application. Crystic pre-pigmented gelcoats are manufactured using Crystic base pigments which have been thoroughly tested for long-term performance. The best quality pigments are selected to offer the lowest colour change and highest gloss retention. The company offers colour matching-service for customer-specific colours in addition to offering the products in standard RAL range. The gel coats have excellent resistance to osmosis (blistering) and have a low porosity finish. Crystic Gel Coats are tested and passed for 12 months Florida test for UV stability. These products find applications in various markets viz. marine, automotive, buildings, swimming pools, recreation, architecture etc. All Gelcoats are available in Brush and Spray versions.

Standard Gelcoats include :

Crystic 65E PA – Isophthalic Brush Gel Coat with excellent water resistance.
Crystic LS97PA – Low Styrene Content Isophthalic superior weathering gel coat with excellent water resistance and improved spray characteristics.
Crystic 69PA – Chemical and water resistant Isophthalic-NPG Brush Gel Coat.
Crystic 92PA – Chemical and water resistant Isophthalic-NPG Spray Gel Coat.

Isophthalic Brush Gelcoat  with Excellent Water Resistance.

Introduction

Crystic Gelcoat 65PA is a pre-accelerated, isophthalic gelcoat. It has been formulated for brush application, but spray versions are available. Crystic Gelcoat 65PA is available in a wide range of colours and the information contained in this technical data sheet also applies to these pigmented versions. A non-accelerated version, Crystic Gelcoat 65, can also be supplied.

Applications

Crystic Gelcoat 65PA is designed for use in the marine, building and transport industries. It is also suitable for general moulding requirements.

Features and Benefits

Crystic Gelcoat 65PA has excellent water and weather resistance.

Approvals

Crystic Gelcoat 65PA is approved by Lloyd’s Register of Shipping for use in the construction of craft under their survey.
When backed with Crystic 356PA, it is capable of obtaining a Class 1 certificate to BS476 Part 7 and of satisfying the requirements of the Building Regulations for a Class O structure. The same laminate can also achieve an M1 rating to the French Epiradiateur NFP 92-501 test.

Formulation

Crystic Gelcoat 65PA should be allowed to attain workshop temperature (18 ⁰C-20⁰C) before use. Stir well by hand, or with a low shear mixer to avoid aeration, and then allow to stand to regain thixotropy. Crystic Gelcoat 65PA requires only the addition of catalyst to start the curing reaction. The recommended catalyst is Butanox M50 (or other equivalent catalyst), which should be added at 2% into the gelcoat. (Please consult our Technical Service Department if other catalysts are to be used). The catalyst should be thoroughly incorporated into the gelcoat, with

The gelcoat, mould and workshop should all be at, or above 15⁰C before curing is carried out.

Application

For normal moulding, the application of Crystic Gelcoat 65PA should be controlled to 0.4-0.5 mm (0.015-0.020 inch) wet film thickness. As a guide, approximately 450-600 g/m2 of gelcoat mixture (depending on pigment) will give the required thickness when evenly applied.Application

Additives

Crystic Gelcoat 65PA is supplied in a wide range of colours. This eliminates the potential for mixing errors with small quantities of pigment paste. The addition of fillers or pigments can adversely affect the water and weather resistance of the cured gelcoat. Crystic Gelcoat 65PA can be used as a topcoat provided that 2% Crystic Solution MW is added to overcome the normal tackiness.

Recommended Testing

It is recommended that customers test all pigmented gelcoats before use under their own conditions of application to ensure the required surface finish is achieved.

Typical Properties

The following tables give typical properties of Crystic Gelcoat 65PA when tested in accordance with SB, BS, EN or BS EN ISO test methods.

I* Curing schedule – 24 hrs @ 20⁰C, 3 hrs @ 80⁰C
† Curing schedule – 24 hrs @ 20⁰C, 5 hrs @ 80⁰C, 3 hrs @ 120⁰C

Post-Curing

Satisfactory laminates for many applications can be made with Crystic Gelcoat 65PA by curing at workshop temperature (20⁰C). However, for optimum properties, laminates must be post-cured before being put into service. The moulding should be allowed to cure for 24 hours at 20⁰C, and then be oven-cured for 3 hours at 80⁰C.

Storage

Crystic Gelcoat 65PA should be stored in its original container and out of direct sunlight. It is recommended that the storage temperature should be less than 20⁰C where practical, but should not exceed 30⁰C. Ideally, containers should be opened only immediately prior to use.

Packaging

Crystic Gelcoat 65PA is supplied in 25kg and 225kg containers.Information courtesy: Satyen Scott Bader