Table of Contents
BASIC TECHNOLOGY ………………………………………………………………………………………………11
General Remarks…………………………………………………………………………………………………………….. 11
Classification of Knitting Machines…………………………………………………………………………………… 13
The Three Main Types of Needle …………………………………………………………………………………….. 14
The Latch Needle……………………………………………………………………………………………………………. 15
Needle Specifications ……………………………………………………………………………………………………… 18
The Stitch Formation Cycles with the Three Types of Needles……………………………………………… 19
Stitch Formation with a Latch Needle (picture 13)………………………………………………………………. 19
Stitch Formation with a Spring Beard Needle (picture 14)……………………………………………………. 20
Stitch Formation with a Compound Needle (picture 15). ……………………………………………………… 20
The Needle-bed………………………………………………………………………………………………………………. 21
FLAT KNITTING MACHINES …………………………………………………………………………………..23
The Manual Flat Knitting Machine …………………………………………………………………………………… 24
The Needle-bed ……………………………………………………………………………………………………………… 25
The Carriage ………………………………………………………………………………………………………………….. 26
The Cam-locks ………………………………………………………………………………………………………………. 27
High-butt Needles and Low-butt Needles ………………………………………………………………………….. 29
Knit Stitch Formation …………………………………………………………………………………………………….. 30
Tuck Stitch Formation …………………………………………………………………………………………………….. 31
Miss Stitch Formation …………………………………………………………………………………………………….. 32
Fabric Take-down …………………………………………………………………………………………………………… 34
Needle-bed Racking ……………………………………………………………………………………………………….. 35
Stitch Transfer………………………………………………………………………………………………………………… 36
Automatic Flat Knitting Machines…………………………………………………………………………………….. 37
Fabric Take-down Motion ………………………………………………………………………………………………. 38
Program Reading System ………………………………………………………………………………………………… 39
The Thread Guide ………………………………………………………………………………………………………….. 41
Lateral Control System……………………………………………………………………………………………………. 41
The Needle-beds ……………………………………………………………………………………………………………. 42
Carriage and Cam Plates …………………………………………………………………………………………………. 42
The Exchange Technique…………………………………………………………………………………………………. 44
Selection with Sliders or Sinkers ………………………………………………………………………………………. 45
The Stitch Transfer Process ……………………………………………………………………………………………… 47
The Integrated Cam-lock …………………………………………………………………………………………………. 49
Electronic Flat-bed Machines …………………………………………………………………………………………… 50
The Technical Evolution of Flat-bed Machines ………………………………………………………………….. 51
Links-links Machines………………………………………………………………………………………………………. 58
CIRCULAR KNITTING MACHINES ………………………………………………………………………….60
Introduction…………………………………………………………………………………………………………………….60
Classification Criteria……………………………………………………………………………………………………….60
Classification by Diameter ……………………………………………………………………………………………….60
Classification by Number of Needle-beds……………………………………………………………………………60
Basic Structure of a Large-diameter Circular Knitting Machine……………………………………………..61
The Yarn Feeding System…………………………………………………………………………………………………63
The Spool Holder …………………………………………………………………………………………………………….63
Yarn Feeders ………………………………………………………………………………………………………………….64
The Thread Guide ……………………………………………………………………………………………………………66
Stitch Formation Motions………………………………………………………………………………………………….68
The Main Components of a Single-bed Machine …………………………………………………………………68
The Main Components of a Double-bed Machine ……………………………………………………………….69
The Technical Evolution …………………………………………………………………………………………………..71
Selection Systems ……………………………………………………………………………………………………………72
Selection by means of Needles with Multilevel Butts……………………………………………………………72
Jacquard Selection……………………………………………………………………………………………………………73
Mechanical Jacquard Selection System……………………………………………………………………………….73
Electronic Jacquard Selection System ………………………………………………………………………………..75
Take-down and Winding Motions ……………………………………………………………………………………..76
Take-down Motion ………………………………………………………………………………………………………….76
Winding Motion………………………………………………………………………………………………………………77
Drives, Control and Monitoring Systems ……………………………………………………………………………79
Drives ……………………………………………………………………………………………………………………………79
Control and Monitoring System ………………………………………………………………………………………..79
Ancillary Systems ……………………………………………………………………………………………………………80
Lubrication System ………………………………………………………………………………………………………….80
Suction and Blowing Systems……………………………………………………………………………………………81
Safety Systems ………………………………………………………………………………………………………………..81
Large-diameter Circular Knitting Machines ……………………………………………………………………….82
Single-bed Circular Knitting Machines ………………………………………………………………………………82
Stitch Formation Cycle on Single-bed Knitting Machines …………………………………………………….82
Jersey Knitting Machines …………………………………………………………………………………………………84
Terry Knitting Machines ………………………………………………………………………………………………….84
Fleece Knitting Machines …………………………………………………………………………………………………86
Double-bed Circular Knitting Machines ……………………………………………………………………………..87
Dial-cylinder Knitting Machines………………………………………………………………………………………..87
Stitch Formation on Dial-cylinder Knitting Machines …………………………………………………………..88
Rib-stitch Machines …………………………………………………………………………………………………………89
Interlock Machines ………………………………………………………………………………………………………….89
Variable Needle-bed Machines ………………………………………………………………………………………….90
Double-cylinder Machines ……………………………………………………………………………………………….92
Stitch Formation and Needle Transfer ………………………………………………………………………………..93
Medium-diameter Knitting Machines …………………………………………………………………………………95
Medium-diameter Cloth-manufacturing Machines ………………………………………………………………95
Bodysize / Seamlesswear Machines……………………………………………………………………………………95
Small-diameter Circular Knitting Machines ……………………………………………………………………….96
Single-cylinder Machines ……………………………………………………………………………………………….. 98
Single-cylinder Machines with Needles in the Dial (Rib Stitch) ……………………………………………. 99
Double-cylinder Machines …………………………………………………………………………………………….. 100
FULL-FASHIONED KNITTING MACHINES……………………………………………………………101
LOOP-WHEEL CIRCULAR KNITTING MACHINES ………………………………………………102
WARPING …………………………………………………………………………………………………………………103
WARP KNITTING MACHINES ……………………………………………………………………………….104
The Guide Bar ……………………………………………………………………………………………………………… 105
The Guide Bar Chain ……………………………………………………………………………………………………. 106
Classification of Warp Knitting Machines ……………………………………………………………………….. 107
Stitch Formation on Flat Warp Knitting Machines…………………………………………………………….. 108
Flat Single-bed Warp Knitting Machines with Spring Beard Needles…………………………………… 108
Single-bed Raschel Machines with Latch Needles ……………………………………………………………. 110
Flat Single-bed Warp Knitting Machines and Single-bed Raschel Machines
with Compound Needles ……………………………………………………………………………………………….. 111
Flat Double-bed Warp Knitting Machines and Double-bed Raschel machines ………………………. 113
CROCHET MACHINES ……………………………………………………………………………………………114
Stitch Formation with Latch Needles……………………………………………………………………………….. 116
Foreword
I am pleased to present the second in a series of four textile machinery technology handbooks that the ACIMIT Foundation is producing for use in Italy’s institutes of textile technology.
This particular book looks at machinery, accessories, auxiliary equipment and technologies relating to knitwear, a segment in which Italy boasts companies of international prominence and advanced “knowhow”.
This knitwear handbook follows the one on weaving, published in October 2000. A thousand copies of the weaving handbook have already been distributed and it has been translated into English for distribution overseas.
The third handbook in the series, on textile finishing, is due to be published in Italian by the end of 2001, while the one on spinning will be ready in spring 2002.
The need to produce these books emerged in the course of a series of meetings that ACIMIT, in the context of various initiatives designed to promote relations between the industry and schools, had with heads and teachers.
We were told that the textbooks currently in use do not reflect the continued and rapid technological evolution the sector has seen in recent years.
With the precise aim of producing handbooks that respond, as far as possible, to students’ learning needs, the ACIMIT Foundation decided, in agreement with the heads, to entrust a group of teachers from the schools themselves with the task of realising the series of books. The teachers involved accepted this challenge enthusiastically.
Thanks therefore go, on behalf of Italy’s textile machinery manufacturers, to the heads and teachers whose schools are source of valuable human resources, essential for the development of their industrial concerns.
Since no job is ever done to perfection the first time round, we will be grateful to anyone (students, teachers, company technicians, etc.) who sends us suggestions and corrections that might enable us to improve this publication and increase the value of the whole enterprise.