Manufactured Sheet and Panel Products Flashcards
plywood has an even number of layers. true or false
false
what type of plywood is used for construction applications
structural exterior plywood
describe the process of making custom millwork/cabinet plywood
custome millwork/cabinet plywood is plywood made in house by bonding high-quality matched veneers to cores. full sheets of manufactured sheet product may be pressed or smaller pieces of core can be cut and then bonded with veneer
list two benefits of alternating the grain when manufacturing plywood
a) minimize the amount of shrinkage or swelling
b) add strength
how is a sheet of plywood designed in order to minimize dimensional movement?
typically the grain direction and thickness of the veneers is balanced across the thickness of the plywood
what are the core types use in plywood
composites, veneers or a combination of both
describe the outside piles used in plywood
the face and back plies are the outside faces of a sheet. it is best that they are the same thickness and species but the may not be of the same quality depending on whether the sheet is visible on both sides. face plies are of higher quality veneer than back plies
how are softwood veneers typicall cut for the production of construction plywood
veneers for construction plywood are tupicall rotary-cut softwood
what are the advantages and disadvantages of using an engineered wood core in plywood construction?
engineered wood core tupically costs less and is flatter but weights more than a softwood veneer core
how do the expansion characteristics of plywood (along the face grain and across the face grain) compare to the expansion characteristics of solid wood?
expansion in plywood of balanced construction is slightly agreater along the grain but much less across the grain thanfor solid wood`
what is the mimimum number of layers found in lumber core plywood
5
describe combination core plywood
this type of plywood useses a combination of composites and veneers for plies
describe the combination core plywood
american markes are not applicable and shoudl be ignored only canadian markings apply
can plywood displaying only an american grading stamp be used in canada
no, american markes are not applicable and should be ignmored only canadian markings apply
does plywood bend more sharply perpendicular or parallel to the face grain
plywood can be bent more sharply when the bend is perpendicular to the direction of the face grain
list three benefits that vcomposite panels have over solid wood
a) composite panels produce uniform density with a smooth surface
b) panels produce thickness tolerances with a smooth surface
c) panels provide a solid base that is free of knots, voids and grain
three benefits that composite panels have over solid wood
bendable sheets are designed for structures that require curves. the two most common types are kerfed core and flexible plywood.
what advantages does flexible plywood have over kerf core?
tigher radius is possible with thin sheets of flexible plylaminated together than with kerfed material. flexible plywood also has the ability to be formed in two directions, such as compond S shapes. flexible plywood is more suitable for areas of high use or impact and no substructure is required
describe overlays and common types available
overlays are materials that are bonded over a core of material. overlays include plastic laminates, veneers, vinyl films, medium-density overlays and thin metal sheets
describe overlays and the common types available
peel coat
for what is post-forming laminate designed?
it is designed for thermoforming to irregular shapes
why are backer and regrind laminate used?
as inexpensive back faces of panels that are not visible
what is the overlay called that is very thin melamine-impregnated paper fused to a substrate?
low-pressure laminate (melamine)
list common uses of solid plastics
A) waterproof insulation
b) protyping
c) furniture parts
d) shelves
e) counter and table tops
f) shatterproof glass for doors, windows, cabinet glass and security partititions
what advantages does lexan have over plexiblas
lexan has more impact resistance and does not yellow with UV exposure
what type of core materials is used when lightweight construction is required such as in the recreational vehicle aeronautical and marine industries
honeycomb sheets
four things to consider in the use of manufactured sheet products
a) dimensional stability from changes in moisture content
b) balanced construction to minimize warping
c) application ofor which the panel will be used
d) handling and storage
how does moisture content in sheet goods change as compared to the humidity of the ambient air?
change in moisture content is much slower than changes in relative humidity in the ambient air
how do overlays contribute to dimensional stability?
overlays like veneer and plastic and coatings vary in their ability to reduce moisture transfusion when applied properly all increase panel stabiltty and reduce warping
what is meant by the term balanced construction?
both sides of the panel are treated identically in order to maintain balance and minimize warping. whatever is done to one side of the panel is done to the other.
what is used to keep material flat and act as a barrier to moisture movement?
a cover sheet
when applying overlays with adhesive what must you remember in order to maintain panel balance?
apply an equal quantity and type of adhesive to both faces in order to balance the humidity absorbed from the glue is important for the overlays to have the same moisutre content
what role does concurrent timing have when coatings or overlays are applied to manufactured sheet goods?
simultaneous treatment of both faces of a panel minimizes warping., warping is minimized when a panel is overlaid sanded or coated as concurrently as possible.
what product alternatives do you have if you have clients with environment sensitivity?
composites plywood anbd overlays that minimize off gassing and improve air quality.
what can be done to reduce the formaldehyde emissions from a composite panel?
properly applied laminates or coatings can reduce emission levels by 95% or more. barriers are most effective when all surfaces are treated
how should sheet goods be handled in order to minimize damage to finished surfaces?
sheets should not be slid off a stack. it is best to lift sheets to avoid scratching.
why should sheet products not be stored directly on concrete?
sheets stored on concrete are susceptible to moisure absorption.
what types of panels are made with cellulose based fibre and adhesive?
what are the two primary types of material used?
composite cores for panels are made from cellulose based fibre and adhesive.
these materials are by-products of swamills (wood fibre) and agriculture (agrifibre)
two methods used to produce particle board products?
a) mat pressing
b) extruding
how can sheets of particle board be produced with different layers?
made up of layers of mats that are consolidated and hot pressed into a finished sheet. mats allow manufactures to choose the particle size and the amount of adhesive used in each layer of a sheet.
three common grades of particleboard used in cabinetmaking?
a) high density
b) medium density
c) low density
fireboard is consolidated into sheets by what process
interfelting (interlocking) of fibres and the use of pressure rather than resins conslidate and hold the panels together.
what type of kibreboard is cold pressed and for what is it used?
low-density fibreboard is cold pressed and is used for projects requiring a light weight and sound deadening.
two main attributes of medium-density particleboard.
suitable for painted projects sharp clean surfaces are produced when cutting and shaping.
what three grades of hardboard is availalbe?
a) standard
b) service
c) tempered
five special use products are hardboard manufactured?
a) underlayment
b) perforated
c) acoustical
d) embossed patterns
e) speciality etched patterns
two main applications of OSB.
a) inexpensive substitute for plywood
b) core material in composite plywood
what characteristic does OSB have that is the same as plywood?
OSB has a strength axis along its length as does plywood.
minimum number of layers in plywood? describe the layers.
plywood consists of three or more layers which are called plies.
minimum plywood has two outside face plies of hardood or softwood veneer and at least one core ply consisting of a sheet of veneer or a layer of composite panel.
