Summerschool2011 - plastic shaping part II

CCCLEMCLEM

VACUUM FORMINGVACUUM FORMINGVACUUM FORMING VACUUM FORMING

dHr. Verheust V.

CLEM N.V. Spinnerijkaai 39, B-8500 Kortrijk

Overview• Vacuum forming ?

• Commonly used techniques

• Design: opportunities restrictions

• Finishing g

• Projectsj


Vacuum forming ?Thermoplastic, semimanufactured product in plate form p

3-D product


Vacuum forming - process

3 stages in the process

Heating up Forming Cooling

(plate thickness sort of material)(plate thickness, sort of material)(form place dependent)


Forming

Heated plateMould

Clamp systemp y

Temp. control channels

Vacuum channel

channels


Forming machines 2 basic concepts 2 basic concepts

• Single-station (discontinuous)

• Multi-station(quasi-continuous)(q )


Forming machines

Single-station Multi-station (carrousel)

3 different treatment stations(loading/unloading, heating, forming)

1 treatment station


(loading/unloading, heating, forming)

Commonly used techniques • Positive forming

– Usual positive forming – Forming using pre-blowing – Forming a vacuum

• Negative forming – Usual negative forming – Forming with stamp – Forming using pre-blowing, stamp and vacuum

Hi h f i (HPF)• High pressure forming (HPF)• Twin sheet forming g


Usual positive forming

Heating

Elastic

iForming


Usual positive forming

V i bl ll hi k improvement via• Variable wall thickness improvement viapre-blowing or

vacuum• Inside – correct dimensions

vacuum


Application


Positive forming + pre-blowing

• Better division of wall thickness via pre-blowing

1. Pre-blowing

2. Vacuum


Positive forming + pre-blowing


Applications


Application


Positive forming + vacuum

• Better division of wall thickness via vacuum

Vacuum


Application

Lighting hood (base: 500 x 350)

(h i ht 600)(height: 600)


Negative forming

Variable wall thickness

Vacuum


Negative forming

Improvement via• Variable wall thickness Improvement via stamp

• Outside – correct dimensions


Application


Negative with stamp • Better division of wall thickness via stamp

1. Stamp1. Stamp stretching

2 V2. Vacuum


Applications


Negative forming with pre-Negative forming with preblowing, stamp and vacuum

• Better division of wall thickness Better division of wall thickness

1. Pre-blowing

2 St2. Stamp stretching

3. Vacuum


Applications


High pressure forming (HPF)

At atmosphere High pressure

A t l ?Acute angles? •Almost always negative

•Acute angles no problem

•Adding texture to the surface is possible


Negative HPF

• Variable wall thickness • Adding texture to the surface is possible


Negative HPF with stamp

• Better division of wall thickness via stamp• Adding texture to the surface is possible


Twin sheet forming

• 2 sheets are heated up simultaneously + formed + welded


Design:Design:opportunities restrictionsopportunities restrictions

• Variable wall thickness

Positive Negative

• 1 side with correct dimensions as a result of contact with mould


Design:Design:opportunities restrictions

• Ideal angle

opportunities restrictions g

135 °, ideal 90°, good 60°, to be avoided

to be avoided better best



• Conics

opportunities restrictions

A id d t th h th ibl• Avoid undercuts, though they are possible



• Depth of draw

opportunities restrictions p

Stamp necessary ?necessary ?

S d d• Secondary draw Strong thinning of wall thickness

Stamp from above i h ll d


with controlled temperature


• Draw ratio

opportunities restrictions

initial thickness average final thickness

Draw ratio = sum of all surfaces initial surface

=


FinishingFrom plate to final product

Vacuum forming with automatic loader


automatic loader

FinishingFrom plate to final product

5-axis milling 3D measurement bench


bench

Projects

• Realised projects in very diverse domains – Medical sector

Automotive sector / transport– Automotive sector / transport– Industry– Design & display– Art – ...


Projects

• Medical sector

Part of radiology device Communication aid


Projects

• Automotive sector / transport

Bodywork Roof part


Projects

• Industry

Housing of a loom Internal door


Projects

• Design & display


Projects

• Art

Pieces of scenery


Summerschool2011 - plastic shaping part II

Self Improvement

Transcript of Summerschool2011 - plastic shaping part II