CAD CAM

Question 1

What does CAD stand for?

Answer 1

Computer Assisted Design

Question 2

What does PDS stand for?

Answer 2

Pattern Design Systems

Question 3

What is PDS used for?

Answer 3

Digital pattern drafting, a form of CAD.
• Once patterns have been drafted using traditional skills they can be digitised to enable them to be shared globally.
• Enables ‘grading’ to be carried out digitally (see next slide).
• Errors can also be rectified quickly
• Patterns stored easily in catalogues and can be reused
• ‘Markers’ can also be produced in this way (see next slide).
• Customised fit for individual needs

Question 4

What are some advantages of PDS

Answer 4

• Time saving
  • Less human error
  • Better accuracy
  • Makes grading and marking easier
  • Makes storage of pattern easier
  • Can be shared globally

Question 5

What are some disadvantages of PDS?

Answer 5

It reduces jobs available and reduces the skill market.

Question 6

What are Markers?

Answer 6

Markers are a guide used in the cutting process. It is a long sheet of paper with all of the pattern pieces used to make a garment.
• The different pieces are laid out in a configuration intended to reduce fabric waste as much as possible, including all of the sizes needed.
• Markers are often made by computer and printed out with a plotter. The marker is laid on top of the fabric layers, which cutters then use to cut out all of the pieces at once.

Question 7

What is grading?

Answer 7

• Pattern grading, most simply put, is the proportional increase, or decrease in the size of a pattern.
• The purpose of grading is to fit a range of body types and sizes from one base pattern style.

Question 8

How is fabric design used in CAD?

Answer 8

Now standard practice for fabrics to be designed using CAD packages: woven, knitted, printed and embroidered.
• Repeat patterns can be altered, colourways can be experimented with, elements changed and resized quickly.
• Standard colour references applied using systems such as Pantone colour guides (a worldwide colour known agency) to ensure accuracy.
• Can create databases of designs easy to modify for new trends
• Patterns can be applied to ‘virtual models’ to provide an insight as to how they might appear when applied to a garment.

Question 9

What is CAM?

Answer 9

Computer Assisted Manufacturing

Question 10

How is CAM used in fabric manufacturing and printing?

Answer 10

• Computers control automated machines
• Quality more consistent
• 24/7 production
• Less repetitive strain injuries for workers
• Automated looms (water and air jet looms) for woven fabrics.
• Weft and warp knitting machines, circular knitting machines for knitted fabrics.
• Seamless knitted garments produced with latest computerised design package.

Question 11

What is computer controlled cutting?

Answer 11

1. Rolls of fabric are scanned for flaws by automated machines
2. A barcode is used for each roll of fabric to identify it and record any flaw.
3. Computer systems can spread the fabric neatly in layers, which can all be cut at the same time
4. A lay plan to cut out the pattern pieces is produced for minimum material wastage

Question 12

What is lay planning?

Answer 12

A lay plan is a diagram showing how pattern pieces should be placed ready for cutting
• Computers take into account grainlines and direction of patterns when laying the pattern pieces, patterns can be placed in the wrong places which is why it is important to follow the connection of the patterns
• Machines cut the fabric using knives, laser beams and water jets

Question 13

What are other CAM processes?

Answer 13

• Automated buttonholing: pre-programmed processes for making buttonholes and stitch buttons enable efficiency and accuracy
• Making and sewing of pockets: laser technologies enable perfect placement of components
• Seam stitching: can be done on automated machines
• Pressing: more even finish with temperature and pressure control (e.g. interfacing)
• Decorations: embroideries in particular are produced more cheaply and efficiently (less labour-intensive and more
accuracy and colours)
• Laser cutting/etching: as well as cutting or etching, laser cutting prevents fabric from fraying by sealing cut edges.
• jacquard fabric:

Question 14

What does EDI stand for?

Answer 14

Electronic Data Interchange

Question 15

What does EDI do?

Answer 15

• Often used in the form of barcodes which contains data about a garment.
Allows computer-to-computer exchange of information between business partners with instant effect.
• No need for traditional documents .
Often used in conjunction with a EPOS (Electronic Point of Sale System).

Loyalty store cards can inform retailers of consumers shopping preference and habits to help target individuals.
• Very helpful in predicting trends for current and future seasons. Leads to demand activated manufacture (dam).
• Efficient stock control in larger retailers allows garments less popular in one area to be moved to other stores.

Question 16

What is EPOS?

Answer 16

Electronic Point of Sale
• EPOS is a self contained electronic checkout that accepts all forms of payment and updates stock level. Paper reciets are not needed, they can be emailed or text message. Can also go back and identify where the product started and where (if any) problems happened within the EDI system.
This helps control stock, inform retailers/manufacturers of popular styles to enable further manufacture or redesign.

Question 17

What is Virtual Modelling?

Answer 17

Virtual prototypes can be developed on screen, using computer software and Pattern Design Systems (PDS).

The client can see a simulated product, which can be shown on screen, on a storyboard, or in a virtual reality catwalk show, produced using multimedia.
• The client selects a design from the storyboard and a sample of material. Once the ‘first fit’ sample has been approved by the client, production can begin.
◦ 3D Body scanners can be used to create a more accurate representation of a specific client, easy way to make sure the product fits without having in person fittings etc, time and money saving, much more efficient.

Question 18

What does PDS do?

Answer 18

• It uses CAD software to design and texture map, or lay a fabric design onto a textile product.
◦ Designing virtual products can save a manufacturer time and money, because it reduces the need to produce actual samples.
◦ However it relies a lot on the internet, and the workers need to be trained in order to use this software, relies on energy and having engineers in case the programmes dont work etc, can be very reliant on the internet etc.

Question 19

What is PPC?

Answer 19

Production planning and control

Question 20

What is PPC responsible for?

Answer 20

• Allocating work in the most profitable and efficient way
• Providing information to other departments and clients about the progress of orders
• Adjusting production schedules to meet changing situations, e.g. transport or supply issues

Question 21

What does successful manufacturing entail?

Answer 21

Successful manufacturing depends on carefully planning so that materials, machines and workers are available when needed
• The system should be adaptive and allow for changes in the market or the supply chain so the manufacturer remains competitive in an ever-changing environment.
• Each operation will be timed to make a production plan
This is why PPC is used.

Question 22

What is scheduling?

Answer 22

• The progress of orders, timing, capacity are also monitored throughout production.
• If delays occur, action is taken to balance production.

Scheduling is part of planning and control and its key feature are to specify:
1. The size of the work content- i.e. the scope or detail of the job
2. The first start date
3. The latest completion date
4. The availability of specialist materials, machinery and skills

Question 23

What are the charts used for scheduling?

Answer 23

Scheduling allocates work to the production capacity of the company, based on available machinery and labour capacity. Detailed production schedules are drafted.
◦ We sometimes refer to them as GANTT charts: