Carbon and Autoclave Temperatures

Contents

Introduction
Overview
CFRP Molding Temperatures
Molding Temperature and Pressure Controls
Summary

Introduction

In this issue, we will examine CFRP, a term and type of Fiber Reinforced Plastic (FRP) that has become synonymous with lightweight robust materials.

Overview

This issue covers molding temperatures in autoclaves, which are indispensable for producing high-quality CFRP products (dry carbon).

CFRP Molding Temperatures

Molding temperatures for CFRP and other polymer-based composites will depend on the properties of the resin employed as the matrix. Thermosetting CFRP (CFRTS) typically use an epoxy resin, with molding temperatures ranging from 120°C to 180°C, while other resins such as vinyl ester, bismaleimide, cyanate, and polyimide resins are cured at temperatures ranging from 200°C to 400°C based on the resin curing reaction temperature. Thermoplastic CFRP (CFRTP), on the other hand, requires temperatures up to about 400°C to melt advanced polymers, referred to as Super Engineering Plastics, such as PEI, PEKK, and PEEK.

Molding Temperature and Pressure Controls

Molding pressure is a key feature when it comes to autoclave molding high-quality and stable products. The inside of the chamber is pressurized with compressed air to ensure an evenly applied pressure while minimizing the formation of any voids or bubbles in the product. Typically, molding pressure is controlled at around 0.3MPa to 1.5MPa, or 2.0MPa depending on the product.

Autoclave operation is automated based on parameters such as molding temperatures (curing rate), holding times, pressurization timing, pressure rise/hold times, and cooling times, which we program according to the characteristics of the resin used, product structure, type of mold materials used, and so forth.

If the autoclave can handle 400℃ and 2.0MPa, then we can mold polymer-based CFRPs.

CFRP fabricated with autoclaves or other equipment capable of molding high-quality CFRP is sometimes called “dry carbon.”

Summary

This article delves into the autoclave method used for high-quality molding of carbon, CFRP, and other composites. The lack of available information makes it difficult to fully understand the ins and outs of these advanced materials. For starters, high-quality CFRP production in one stop is impossible without autoclave molding and specialized facilities and equipment for material storage, cutting processes, clean room processes, inspection, and machining. We hope this provides insight into the manufacturing processes and needs of CFRP and other polymer-based composites.

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We leverage a wealth of technical expertise as a CFRP molding and processing manufacturer using FRP, GFRP, and CFRP materials. We offer a one-stop solution, encompassing design, analysis, manufacturing, secondary processing, assembly, painting, quality assurance, and testing.

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UCHIDA's equipment

We have cutting-edge equipment to ensure that we can address even the most advanced challenges of our customers.

DMG森精機 - VS1000/40/2050
X軸：2,050mm（ストローク）／ Y軸：1,000mm ／ Z軸：600mm ／テーブル作業面：2,250×1,000mm

ASHIDA MFG Co., Ltd.
Autoclave Oven 2
Size : Ø1,150x1,000mm / Operating temperature : at normal temperature - 400℃ / Design pressure : 2.0Mpa (maximum working pressure) / Vacuum system : back suction system / Vacuum units : 5

ASHIDA MFG Co., Ltd.
Autoclave Oven 3
Size : Ø3,000x6,000mm / Operating temperature : at normal temperature - 200℃ / Distribution accuracy : ±2.5℃less / Heating rate : 4.0℃/min. (empty furnace) / Cooling rate : 4.0℃/min. (empty furnace) / Design pressure : 0.99Mpa (maximum working pressure) / Working pressure : 0.7Mpa less (if no specification from the manufacuturer 0.3Mpa around) / Pressure accuracy : ±0.02Mpa（for pressure setting of ０ - 0.99Mpa/cm²） / Boost pressure accuracy : 0 - 0.03Mpa/min / Pressure source : compressed air (regular use) / Vacuum system : back suction system / Vacuum units : 10

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Oven
Size : W1,000xH1,000xD1,000mm / Temperature range : Environmental Temperature +20 - 300℃ / Temperature elevation capability : Environmental Temperature (20 - 40℃) - 300℃ / 45min less / Vacuum system : back suction system / Vacuum units : 10

ESPEC CORP.
Temperature & Humidity Chamber

INSTRON
Static Universal Testing Machine 5985

Oven
Size : W7,000xH3,000xD2,000mm / Temperature range : Environmental Temperature +20 - 300℃ (Max) / Temperature elevation capability : Environmental Temperature (20 - 40℃) - 300℃ / 60min less / Vacuum system : back suction system / Vacuum units : 10

NEO
X axis : 4,000mm (stroke) / Y axis : 2,000mm / Z axis : 1,200mm / C axis : 0° - ±270° / B axis : 0° - ±110° / Table working place : 4,000x2,000mm

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3Dプリンター | Markforged

Painting booth
Various painting, and clear finish is done in dedicated painting booth

Adhesion, Finishing, Coating Room
Finishing process, such as trimming, drilling, and bonding, surface treatment of the molded product type and is done in a private booth

Toshiba Matrixeye EX (Ultrasonic flaw detector)
Matrix-Arrey : 32

AMETEK CREAFORM Metra
SCAN750 Elite (3D scan)

Olympus Corp.
Inverted Microscopes

Oven
Size : W450xH450xD450mm / Temperature range : Environmental Temperature +20 - 650℃ / Temperature elevation capability : Environmental Temperature+50 - 650℃/120min less

Cutting Plotter Table working place : W1,500xL3,500mm

SHIMA SEIKI MFG., LTD
Cutting Plotter

KUKA
Robot

Krauss Maffei
Epoxy resin injection machine Resin 60L ／ Hardener 25L

Krauss Maffei
630t Press machine Height total 5,200mm ／ Length max 1,500mm ／ Width max 1,200mm ／ Whole cycle time per component part 240sec

DMG森精機 - NV5000B/40
X軸：1,020mm（ストローク）／ Y軸：510mm ／ Z軸：510mm ／テーブル作業面：1,320×600mm

Big sized clean room
JIS B 9920 cleanliness class maximum concentration (Pcs/m³） / Class 5 : 100,000m³ / Capacity : m² (16,000x16,000mm) 760m² (16,000x16,000x3,000mm) / Temperature and humidity condition : Temperature : 23℃±3℃, Humidity 65% less / Ambient conditions : Temperature 35℃ during summer, Humidity 70% less / Ambient conditions : Temperature 35℃ during summer, Humidity 70% less / Temperature -5℃ during winter, Humidity 40% less