Glass Defect Complete
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Transcript of Glass Defect Complete
GLASS CONTAINER
DEFECT
Causes and Remedies
COPYRIGHT EMHEART GLASS
HERTFORD DIVISION
All Rights Reserved
TW0738/1191
INDEX
page
I. The examination of a Container i
II. The various Parts of a Container ii
III. Main Types of Sealing Systems iii
IV. Suggestions for Remedying Container Defects iv
V. Definition of Terms Used v
1. Defects Requiring immediate Action vi
Freaks 1
Split Finish 2
Checked Finsh 4
Crizzled Finish 6
Unfilledfinish 10
Choked Neck or Bore 12
Bottom Check 14
Thin Ware 16
Spike 18
Stuck Glass Particles 19
2. Finish Defects 20
Offset Finish 20
Bulged Finish 21
Chipped Finish 22
page
Broken Finish 24
Overpress 26
Corkage Check 27
Neck Ring Seam 28
Out-of-Round and Off-Gauge Finishes 30
Dirty of Rough Finish 31
Tear Under Finish 32
Bent or Crooked Finish 33
3. Neck Defects 35
Seam on Neck Ring Parting Line 35
Bent Necks 36
Long Necks 38
Hollow Finish or Neck 39
Dirty Neck 40
Pinched Neck 41
Danny Neck or Tear on Neck 42
4. Shoulder Defects 43
Shoulder Checks 43
Thin Shoulders 45
page
Sunken Shoulders 46
5. Body Defects 47
Stringy Glass 47
Hot or Panel Checks 48
Pressure Checks 49
Blank and Blow Mold Seam 50
Bird Cage (Bird Swing) 52
Brulse Checks 54
Letter Checks 56
Sunken Sides 57
Bulged Sides 59
Wash Boards 60
Cold Molds 62
6. Bottom Defects 64
Flanged Bottom 64
Thin Bottom 65
Thick or Heavy Bottom 67
Rocker Bottom 69
Baffle Marks 70
Swung Baffle 71
page
Wedge Bottom – Heel Top 72
7 General Defects 73
Brush Marks 73
Black Spots 74
Shear Marks 75
Oil Marks 76
Broken Ware 77
Loading Marks 79
Drag Marks 80
Lap Marks Or Wrinkles 81
Out Of Shape Ware 82
Uneven Or Bad Distribution 83
Dirty Ware 84
Stuck Ware 85
Blisters 86
Seeds 87
Cords 89
Stones 90
The Examination of a Container
A good container is a container that will go through the
customer’s filling line without causing any difficulty will carry
his product to the customer.
It is therefore essential that before a container is released for
scale from the glass plant . It successfully passes an insection
with standards set to meet the customer ‘s needs.
There are approximately one hundred defects which can
develop in the container during the production process, some
beyond the control of the operator , for example stones; but by
far the largest number occur either in the feeder or machine
operation.
It is important that all production personnel learn to recognize
the defects and understand what remedies to use in order to
eliminate them.
When a glass container fails on the customer’s filling line
because of a manufacturing defect, the reputation of glass
suffers, which results in a loss of customer good-will Always
remember; “The Price of a Quality Container is Eternal
Vigilance”.
Remedies offered hopefully give you a basic understanding of
defects and their causes. In some instances , several
remedies may be needed to correct the causes.
The Various Parts of a Container
In order to identify in a container. It is most useful to know all the
various types and parts of the container.
Types of containers
Narrow Neck Type Wide Mouth Type
Parts of a Container
The Finish
This is the top of the container above the neck ring parting line. It
includes:
The Sealing Surface
Bore
Bead or Color
The sealing device is in the finish (see next section), also the
bore or mouth for filling and emptying.
The bead or color is used to assist in transferring the parison
into the blow mold.
The Neck
The part which extends from the parting line to the curve at
the base of the neck.
The Shoulder
This extends from the base of the neck to the straight part of
the body.
The Body
The main part of the container which holds the product.
The Bottom
The part of the container on which it stands when upright.
Insweep
The curve between body and bottom which helps to improve
glass distribution and thus strength.
Push-Up
The center of the bottom which is raised up to provide a flat
surface on the outer edge of the bottom and thus provide a
firm seating.
Main Types of Sealing Systems
The finish is one of the most vital parts of the container. It
must be free of all serious defects to guarantee complete
sealing on the filling line. Some defects, such as crizzles on
the top sealing surface. May cause a container to leak slowly ;
which will only be discovered when opened and the container
to leak slowly; which will only be discovered when opened and
the contents found to be stole or to have spolled.
1. Top Sealing
Crown Cork – The sealing surface is on the
top the finish and used for narrow neck
containers being filled under pressure.
Thread or Lug – The sealing surface on the top
of the finish is closed by a screw type ca. Used
for wide mouth jars and narrow neck bottles.
2. Side Sealing
The sealing surface is on the side of the finish
and the cap is pressed on to seal the contents. It
is used for wide mouth jars in the food industry.
3. Cork Sealing
The seal is made on the inside of the
finish. It is used with narrow neck bottles.
Suggestions for Remedying
Container Defect
It is essential the the machine operator be able to isdentify
defects quickly and accurately ,and to know how to
remedy them. In this handbook all the major defects have
been listed , with an accurate description and a sketch
indicating the appearance of the defect and the position in
the container where it is most commonly found.
On the left page, the causes of the defect have been
listed, and in a corresponding position on the right hand
page are the remedies.
The operator should frequently examine the containers
passing along the conveyor from machine to stacker.
Approximately once every twenty minutes, but depending
on production speed, one container from each mold
should be set out and allowed to cool so that it can be
handled and thus examined more closely for defects. Don’t
waste these containers if they are not faulty and have not
been damaged – put them into the lehr.
Before correcting a defect , always remember the
following;
1. How many of the particular defects are rejects?
2. If corrected, what other types of defects may be
produced as a result of the adjustment made?
3. Only make adjustments when certain it will produce a
better container.
For Example:
If a few checks were appearing in the finish, do not
immediately reduce settle blow pressure or time .if it is
known that the finish r bore will then be outside
specification.
THINK BEFORE YOU ACT
Definition of Terms Used
Incorrect Too High or Too Low
Too Much or Too Little
Too long or Too Short
Blank Blank Mold
Mold Blow Mold
Parison The shape of the hot glass as it comes from
the blank mold.
Alphabetical List of Sections – Causes and Remedies
A. Feeder
B. Machine setup and Operation
C. Mold Equipment
D. Conveyor
E. Stacking Equipment
F. Inspection Equipment
G. Lehr Operation
SECTION 1
Defects Requiring IMMEDITE ACTION
Standards are set by the Quality Control Department
for most types of defects, but certain ones require
immediate action;
FREAKS
SPLIT FINISH CRIZZLED FINISH
CHECKS UNDER FINISH
UNFILLED FINISH
CHOKED NECK OR BORE
BOTTOM CHECK
THIN WARE
STUCK GLASS PARTICLES
SPIKES
If the operator is fully in control of the production on the
machine, containers with any of the eleven faults listed above should
never reach the annealing lehr.
Section 7 General Defects 90
Definition : Small pleces of refractory or unmelted batch materials.
Note : The production personnel cannot cure this defect, but it must be reported
immediately , as it is symptomatic of more serious trouble.
Some Possible Causes
1. Refractories from the furnace or foreheart are falling into the molten glass.
2. Batch materials are contaminated or incorrectly melted.
3. Furnace pull may be too high.
4. Flames impinging on furnace refractories.
5. Contaminated cullet.
STONES